Technical field
[0001]
The present disclosure relates to wireless communication system, a handover of a wireless terminal between particular different Radio Access Technologies (RATs).
BACKGROUND
[0002]
3rd Generation Partnership Project (3GPP) has (see Non-Patent Document 1) fifth standardization work generation mobile communication system (5G) as 3GPP Release 14 have started in 2016 towards the introduction of 2020 migration. 5G is realized by a combination of innovative improvement and development through the introduction of continuous improvement and development of the LTE and LTE-Advanced (enhancement / evolution) and new 5G air interface (new Radio Access Technology (RAT)) It is assumed to be. New RAT, for example, LTE / LTE-Advanced continuous development frequency band of interest (eg, 6 GHz or less) frequencies higher than, for example 10 GHz or more super high frequency band and 30 GHz or more mm to support the sideband.
[0003]
　In this specification, the fifth-generation mobile communication systems, also called Next Generation (NextGen) System (NG System). New RAT for NG System may, New Radio (NR), called 5G RAT, or NG RAT. New radio access network (Radio Access Network (RAN)) and a core network for NG System are called respectively NextGen RAN (NG RAN) and NextGen Core (NG Core). Wireless terminal connected to a NG System (User Equipment (UE)) is called NextGen UE (NG UE). RAT for NG System, UE, radio access network, core network, the network entity (node), and the official name, such as protocol layer will be future decisions in the process of standardization work progresses.
[0004]
　Also, the term "LTE" as used herein, unless otherwise indicated, includes an improvement and development of the LTE and LTE-Advanced for enabling interworking with NG System. Improvement and development of LTE and LTE-Advanced for the interworking of the NG System is, LTE-Advanced Pro, LTE +, or also referred to as enhanced LTE (eLTE). Furthermore, "Evolved Packet Core (EPC)" as used herein, "Mobility Management Entity (MME)", "Serving Gateway (S-GW)", and "Packet Data Network (PDN) Gateway (P-GW terminology LTE network or logical entities) "or the like, unless otherwise indicated, includes these improvements and development for enabling interworking with NG System. Improved EPC, MME, S-GW, and P-GW, for example, enhanced EPC (eEPC), enhanced MME (eMME), enhanced S-GW (eS-GW), and enhanced P-GW (eP-GW ) also called.
[0005]
　In LTE and LTE-Advanced, in order of Quality of Service (QoS) and packet routing, bearer RAN (ie, Evolved Universal Terrestrial RAN) of each and PDN connection for each QoS class and a core network (ie, Evolved Packet core (EPC used by both)). That is, in the Bearer-based QoS (or per-bearer QoS) concept is one or more Evolved Packet System (EPS) bearers are set up between the P-GW of the UE and EPC, the plurality that have the same QoS class service data flow (service data flows (SDFs)) is transferred through one EPS bearer satisfying these QoS. SDF is, Policy and Charging Control (PCC) rule-based SDF template (ie, packet filters) is one or more packet flows that match. Further, for packet routing, each packet to be sent through the EPS bearer can discern whether associated with this packet which bearer (ie, General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel) (The identify ) contains information for.
[0006]
　In contrast, in the NG System, might radio bearer is used in the NG RAN, in the interface between the NG Core and NG Core and NG RAN bearer has been considered to not be used (Non-patent Document see 1). Specifically, PDU Flows are defined instead of the EPS bearer, one or more SDFs are mapped to one or more PDU Flows. PDU flow between the NG UE user plane termination entity in NG Core (ie, the entity corresponding to the P-GW in the EPC) corresponds to the EPS bearer in EPS Bearer-based QoS concepts. In other words, NG System is, Bearer-based QoS concept of place in Flow-based QoS (or per-flow QoS) to adopt the concept. In the Flow-based QoS concept, QoS is handled in the PDU flow unit (handled). Note that association between the UE and the data network (association) is referred to as PDU session (PDU session). PDU session is a term corresponding to LTE and LTE-Advanced PDN connection (PDN connection). Can be more than one PDU Flows are set in one PDU session.
[0007]
　In this specification, such as the LTE and LTE-Advanced system, set the end-to-end bearer (eg, EPS bearer) between the edge nodes in the UE and the core network (eg, P-GW), a system that employs the Bearer-based QoS concept, referred to as the "bearer-based system" or "bearer-based network". On the other hand, as the NG System, without the bearer in interface of the core network and the core network and the RAN, a system employing a Flow-based QoS concept referred to as "bearer-less system" or "bearer-less network". As NG System described above, the bearer-less network of the RAN radio bearers may be used. The term "bearer-less", for example, GTP-less, and (PDN) connection-less, tunnel-less, (IP) flow-based, SDF-based, stream-based, or (PDU) session-based It can be rephrased. However, in this specification, NG System may function as bearer-based system, may support both flow-based forwarding and bearer-based transfer of user data.
[0008]
　Furthermore, the NG System supports network slicing also been studied (see Non-Patent Document 1). Network slicing uses Network Function Virtualization (NFV) technology and software-defined networking (SDN) technology makes it possible to create a logical network having a plurality of virtualization on a physical network. Each of virtualized logical networks, called network slice (network slice) or network slice instance (network slice instance), comprising a logical node (nodes) and functions (functions), certain traffic and it is used for signaling. NG RAN or NG Core or both have the Slice Selection Function (SSF). SSF, based on information provided by at least one of NG UE and NG Core, selects one or more network slices suitable for the NG UE.
[0009]
　Incidentally, Patent Document 1, bearer-less network (eg, 5G) handover from bearer-based network (eg, LTE) to, and bearer-based network (eg, LTE) from bearer-less network (eg, 5G) including the disclosure relating to handover to. The handover from 5G shown in Patent Document 1 to the LTE, source control node 5G core (NG Core) (ie, Access Control Server (ACS) / eMME) is, bearer-less network of service Flows of (5G) to map the QoS parameters to the EPS-bearer-level QoS of the bearer-based network (LTE). QoS parameters of 5G of service Flows, for example, a DiffServ code point (DSCP) values. LTE of EPS-bearer-level QoS is, for example, a QoS class identifier (QCI) and allocation and retention priority (ARP). Mapping to EPS bearers of the DSCP values ​​may be performed in one-to-one or n-to-one. Source ACS / eMME sends the APN information, including the information of the EPS-bearer-level QoS to the target MME. Target MME according APN information received, to set up a GTP tunnels for the UE.
[0010]
　Further, the handover to 5G from LTE shown in Patent Document 1, target ACS of source MME is, 5G core encompassing forward relocation request the bearer context information necessary for LTE core (ie, EPC) (NG Core) / send to eMME. target ACS / eMME is, LTE (ie, source MME) the QCI values ​​obtained from the 5G QoS parameters (ie, DSCP values) maps to, transfer node (ie of which the 5G core (NG Core), Mobility Gateway Access Router (M-GW / AR) or supplied to the Mobility Gateway Edge Router (M-GW / ER)). Thereby, Target ACS / emme sets up at least one Generic Routing Encapsulation (GRE) tunnel for sending UE of service flows (ie, IP packets).
CITATION
Patent Document
[0011]
Patent Document 1: International Publication No. WO 2015/160329
Non-patent literature
[0012]
非特許文献1 : 3GPP TR 23.799 V0.6.0 (2016-07) “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on Architecture for Next Generation System (Release 14)”, July 2016
Summary of the Invention
Problems that the Invention is to Solve
[0013]
　Present inventors have conducted studies with respect to handover between NG System and (5G) and LTE System, we found several problems. For example, while Patent Document 1 from LTE System handover procedure to the NG System, Access Stratum (AS) layer settings or Non-Access Stratum of network slice is target RAT the UE after the handover is connected (NG RAT) (NAS ) not described to be considered for setting.
[0014]
　Therefore, one of the objective to be achieved is the embodiment disclosed herein, the AS layer settings or NAS layer setting the target RAT in the handover from the network that does not support network slicing to a network that supports network slicing It contributes to appropriately perform that device is to provide a method, and a program. Incidentally, this objective should more embodiments disclosed herein is noted that only one of several objects of it and to achieve. Other objects or problems and novel features will become apparent from the description, or the accompanying drawings of this specification.
Means for Solving the Problems
[0015]
　In one embodiment, the target radio access network (RAN) node associated with the second network includes at least one memory, and at least one processor coupled to the at least one memory. Wherein the at least one processor is in the handover of the radio terminal to the second network from a first network, receiving the slice information about the network slice of the wireless terminal in said second network connected from a core network , in response to receiving the slice information, the wireless terminal generates a radio resource configuration information used by the second network after the handover, the first of said wireless terminal said radio resource configuration information over the network configured to transmit to.
[0016]
　In one embodiment, the source radio access network (RAN) node associated with the first network includes at least one memory, and at least one processor coupled to the at least one memory. Wherein the at least one processor, said at handover of a wireless terminal from a first network to a second network, the wireless terminal is the second slice information about the network slices in a network and said second network connected a message regarding handover including at least one radio resource configuration information based on network slice of the inner, received from the second network, configured to send a message about the handover to said radio terminal.
[0017]
　In one embodiment, the wireless terminal includes at least one memory, and at least one processor coupled to the at least one memory. Wherein the at least one processor, said at handover from a first network to which the wireless terminal is connected to the second network, the network slice of the second slice information and in said second network about the network slices in the network configured to receive a message regarding handover including at least one of the radio resource configuration information from the radio access network (RAN) node of the first network-based.
[0018]
　In one aspect, the core network node includes at least one memory, and at least one processor coupled to the at least one memory. Wherein the at least one processor is in the handover of a wireless terminal from a first network to a second network, the slice information about the network slice of the wireless terminal in said second network connected to the second network configured to send the target associated with a radio access network (RAN) node.
[0019]
　In one aspect, a method in the target radio access network (RAN) node associated with the second network,
　in the handover of the radio terminal to the from the first network second network,
　the said radio terminal is connected receiving the slice information about the network slices in the second network from the core network,
　in response to receipt of said slice information to generate radio resource configuration information the wireless terminal uses in the second network after the handover it, and
　it, to be transmitted to the wireless terminal the radio resource configuration information via said first network
including.
[0020]
　In one aspect, a method in the source radio access network (RAN) node associated with the first network,
　in the handover of the radio terminal from the first network to a second network,
　the said radio terminal is connected a message regarding handover including at least one radio resource configuration information based on network slice of the second slice information and in said second network about the network slices in a network, receiving from the second network, and
　wherein sending a message regarding handover to the wireless terminal,
including.
[0021]
　In one aspect, a method in a wireless terminal, wherein the handover from the first network to which the wireless terminal is connected to a second network, the second slice information and in said second network about the network slices in the network It includes receiving a message about the handover comprises at least one radio resource configuration information based on network-slice from the radio access network (RAN) node of the first network.
[0022]
　In one aspect, a method in a core network node, in the handover of a wireless terminal from a first network to a second network, the slice information about the network slices in the second network to which the wireless terminal is connected first It includes sending to the target radio access network (RAN) node associated with the second network.
[0023]
　In one embodiment, the program, when loaded into a computer, including instructions for performing the method according to the manner described above to a computer (software code).
Effect of the invention
[0024]
　According to the embodiments described above, provides the AS layer set or contribute apparatus appropriately perform that the NAS layer setting of target RAT in the handover from the network that does not support network slicing to a network that supports network slicing method, and program it can.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025]
It is a diagram illustrating a configuration example of a wireless communication network according to FIG. 1 with some embodiments.
It is a diagram illustrating a configuration example of a wireless communication network according to FIG. 2 some embodiments.
[Figure 3A] according to the first embodiment, it is a sequence diagram showing an example of inter-RAT handover procedure from the LTE System to NG System.
[Figure 3B] according to the first embodiment, is a sequence diagram showing an example of inter-RAT handover procedure from the LTE System to NG System.
[Figure 4A] of the first embodiment, is a sequence diagram showing another example of the inter-RAT handover procedure from the LTE System to NG System.
[Figure 4B] according to the first embodiment, it is a sequence diagram showing another example of the inter-RAT handover procedure from the LTE System to NG System.
5 is a flowchart showing an example of a method performed by the core network according to the first embodiment.
6 is a flowchart showing an example of a method performed by the target NR NodeB according to the first embodiment (NR NB).
7 is a flowchart showing an example of a method performed by a source LTE eNB according to the first embodiment.
8 is a flowchart showing an example of a method performed by a wireless terminal according to the first embodiment.
[9] according to the second embodiment is a sequence diagram showing an example of inter-RAT handover procedure from the LTE System to NG System.
[10] according to the second embodiment is a sequence diagram showing an example of inter-RAT handover procedure from the LTE System to NG System.
[11] according to the third embodiment is a sequence diagram showing an example of inter-RAT handover procedure from the LTE System to NG System.
[12] according to the third embodiment is a sequence diagram showing an example of inter-RAT handover procedure from the LTE System to NG System.
[Figure 13A] according to the fourth embodiment is a sequence diagram showing an example of inter-RAT handover procedure from the NG System to LTE System.
[Figure 13B] according to the fourth embodiment is a sequence diagram showing an example of inter-RAT handover procedure from the NG System to LTE System.
[Figure 14A] according to the fourth embodiment is a sequence diagram showing another example of the inter-RAT handover procedure to LTE System from NG System.
[Figure 14B] according to the fourth embodiment is a sequence diagram showing another example of the inter-RAT handover procedure to LTE System from NG System.
15 is a block diagram showing a configuration example of a radio terminal according to some embodiments.
16 is a block diagram showing an exemplary configuration of a base station in accordance with some embodiments.
17 is a block diagram showing an exemplary configuration of a base station in accordance with some embodiments.
18 is a block diagram showing an example of the configuration of a core network node according to some embodiments.
Is a diagram illustrating an example of the format of FIG. 19A] Mobility from EUTRA command message.
Is a diagram illustrating an example of the format of FIG. 19B] Mobility from EUTRA command message.
Is a diagram illustrating an example of the format of FIG. 20] Handover Required message.
21 is a diagram showing an example of the format of the Source NR NB to Target NR NB Transparent Container.
22 is a diagram showing an example of the format of the Source NR NB to Target NR NB Transparent Container.
23 is a diagram showing an example of the format of the Source NR NB to Target NR NB Transparent Container.
Is a diagram illustrating an example of FIG. 24 format Source NR NB to Target NR NB Transparent Container.
It is a diagram illustrating an example of the format of FIG. 25] (NR) Handover Request message.
It is a diagram illustrating an example of the format of FIG. 26] (NR) Handover Request message.
It is a diagram illustrating an example of the format of FIG. 27] (NR) Handover Request message.
It is a diagram illustrating an example of the format of FIG. 28] Slice Information.
FIG. 29 is a diagram showing an example of the format of Session Endpoint ID.
Is a diagram illustrating an example of the format of FIG. 30] (NR) Handover Request Acknowledge message.
[FIG. 31] is a diagram showing an example of the format of the Target to Source Transparent Container.
Is a diagram illustrating an example of FIG. 32] (NR) Handover Request Acknowledge format.
Is a diagram illustrating an example of FIG. 33] (NR) Handover Request Acknowledge format.
FIG. 34 is a diagram showing an example of a Forwarding Address format.
Is a diagram illustrating an example of the format of FIG. 35] S1AP Handover Command message.
Is a diagram illustrating an example of the format of FIG. 36] NG2AP Handover Command message.
DESCRIPTION OF THE INVENTION
[0026]
　Hereinafter, specific embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, for clarity of description, repeated explanation of these is omitted as appropriate.
[0027]
　A plurality of embodiments described below can can either be carried out independently, also be implemented in appropriate combination. These several embodiments have different novel features together. Accordingly, the plurality of embodiments, contribute to solving the different purpose or task to each other, which contributes to achieve different effects from each other.
[0028]

　FIG 1 shows a configuration example of a wireless communication network according to some embodiments including the present embodiment. In the example of FIG. 1, a wireless communication network, the wireless terminal (UE) 1, LTE base station (ie, eNB) 2, New Radio (NR) base station (ie, NR NodeB (NR NB )) 3, EPC4 and, NextGen (NG), including the Core5. UE1 has the ability to connect to the LTE system including the LTE eNB2 and EPC4, and has the ability to connect to the NextGen (NG) systems including NR NB3 and NG Core5.
[0029]
　In the example of FIG. 1, EPC4 is connected to the NG Core5. Specifically, one or more nodes in EPC4 through the control plane interface is connected to one or more nodes in the NG Core5. In some implementations, MME in EPC4 can be connected to a control node having at least a portion of the function of MME in NG Core5 via a control plane interface (ie, Control Plane Function (CPF) node) good. Additionally, one or more nodes in EPC4 may include one or more data nodes in the NG Core5 via the user plane interface may be connected to (ie, User Plane Function (UPF) node). Wherein said data node (UPF node) may be a node having at least a portion of the functionality of the S-GW. That, EPC4 is been improved (enhanced) to perform the interworking between the NG System including NG Core5, may be referred to as eEPC.
[0030]
　Similarly, NR NB3 may be connected to one or more of CPF nodes in NG Core5 via a control plane interface (eg, NG2 interface). Furthermore, NR NB3 may be connected to one or more of UPF nodes in NG Core5 via a user plane interface (eg, NG3 interface). Furthermore, UE1 may be connected to one or more of CPF nodes in NG Core5 via a control plane interface (eg, NG1 interface). Here, NG1 interface is defined as a logical interface for transferring information of the NAS layer, the transmission of information of the NAS layer, through the NG2 interface, and NR NB3 and UE1 radio interface between the (NG Uu) it may be performed Te.
[0031]
　Figure 2 shows another example of a configuration of a radio communication network in accordance with some embodiments including the present embodiment. In the example of FIG. 2, LTE eNB2 are connected to the NG Core5. That, LTE eNB2 are connected to the control node having at least a portion of the function of MME or MME in NG Core5 via a control plane interface (eg, NG2 interface) (ie, CPF node), the user plane interface (eg, NG3 interface) Serving Gateway (S-GW) via the inside NG Core5 or data node having at least a part of the functions of the S-GW (ie, UPF nodes) are connected to. Thus LTE eNB2 is been improved (enhanced) to be connected with the NG Core5, may be referred to as ELTE eNB. In some implementations, NG Core5 may set up the network slices virtualized to provide logical EPC nodes (nodes) and EPC function (functions). In some implementations, NG RAN including E-UTRAN and NR NB3 including LTE eNB2 may be connected to the same network slice. Alternatively, NG RAN including E-UTRAN and NR NB3 including LTE eNB2 may be connected to different networks slices from each other.
[0032]
　In the example of FIGS. 1 and 2, LTE eNB2 may be connected to the NR NB3 by direct inter-base station interface (eg, X3 interface). Between direct base station interface may be used for signaling or user packet forwarding or both between the LTE eNB2 and NR NB3. However, direct inter-base station interface between the LTE eNB2 and NR NB3 may not be present.
[0033]
　NG System is described above NG1, NG2, NG3 addition to the interface, it may further comprise other interfaces. Interface, also referred to as the reference point (reference point). Between NG RAN (different NR NB) may be connected via the NX2 interface. Mobility management functions (Mobility Management Function: MMF) and session management functions: CPF node having either or both of (Session Management Function SMF) is connected via a control plane interface (eg, NG4 interface) to UPF node it may be. Different UPF nodes may be connected via a user plane interface (eg, NG9 interface). Between CPF nodes having different functions may be connected via a control plane interface. For example, CPF node with MMF and SMF, the policy control function (Policy Control Function: PCF) and CPF node having a may be connected via a control plane interface (eg, NG7 interface). CPF node with MMF and SMF, the subscriber data management function (Subscriber Data Management: SDM) and a node having a may be connected via a control plane interface (eg, NG8 interface). CPF node, application function (Application Function: AF) may be connected via a node and a control plane interface having a (eg, NG5 interface). UPF node, external or local data network (Data Network: DN) and user plane interface (eg, NG6 interface) may be connected via a. Incidentally, SMF may include the functionality of the authentication of the user or terminal (Authentication), approval of the service or network slicing (Authorization). Note that points to each of the above network node, or collectively network function thereof also referred to as a (Network Function (s) NF (s)).
[0034]
　In some implementations, NG System comprising NR NB3 and NG Core5 supports data transfer based on Flow-based QoS (or per-flow QoS) concept described above. NG System comprising NR NB3 and NG Core5 may be further configured to support Bearabesudo transfer using a bearer for each QoS class for each and PDU session. Bearer NG System during the pairs network function (Network Functions (NFs)), for example, is set between the user plane functions in the NR NB3 and NG Core5, or between two user plane functionality in NG Core5 it may be. Alternatively, the bearer of the NG System may be set via the NR NB3 during user plane functions in the UE1 and NG Core5. NG System bearer may be referred to as NG-EPS-bearer, the radio access bearer NG System may be referred to as NG-RAB. Bearer NG System can be utilized for the transfer of a plurality of packet flows (PDU flows).
[0035]
　NG-RAB is set between the UE1 (NG UE) and user plane functions within a radio bearer, NR NB3 and NG Core5 set between the NR NB3 (eg, Edge Gateway (Edge GW)) that the bearer (eg, NG3 bearers) may be configured from a. NG-EPS-bearer is a NG-RAB, between the user plane functions in the NG Core5 core network bearer (eg, NG9 bearer is set to (eg, Edge GW and Data Network Gateway (between DN GW)) ) may be configured from a. Edge GW is the gateway between the radio access network corresponds to the user plane functions of the LTE S-GW. However, unlike the LTE S-GW, the NG System UE1 may be connected to a plurality of Edge GW. DN GW is the gateway to an external network (ie, Data Network), which corresponds to the user plane functions of the LTE P-GW. Similarly to the LTE of P-GW, the NG System UE1 may be connected to a plurality of DN GW.
[0036]
　More specifically, NG-EPS-bearer may be established between the UE1 (NG UE) and a slice-specific user plane functionality in NG Core5 (Slice specific User plane NF (SUNF)). NG-RAB may be set between the UE1 (NG UE) and a common user plane functionality in NG Core5 (Common User plane NF (CUNF)). In this case, CUNF provides the functionality of Edge GW, SUNF provides the function of DN GW. CUNF may associate between the NG-RAB and the core network bearer (eg, NG9 bearer). That, NG-EPS-bearer is, UE1 and NG-RAB between (NG UE) and CUNF, may be constituted from a core network bearer between the CUNF and SUNF (eg, NG9 bearer).
[0037]
　NG System to support Bearabesudo transfer, further, QoS handling (eg, packet discard) the data flow (PDU flow) each may be configured to identify the data flow in the bearer (PDU flow) for. For example, NR NB3 associates the set bearer between the user plane functions in the NR NB3 and NG Core5 (eg, NG3 bearer) to the radio bearer, the bearer (eg, NG3 bearer) and between the radio bearers perform packet forwarding, further data flow within the bearer (PDU flow) for each of the QoS handling (eg, packet drops) may be performed.
[0038]
　Incidentally, (e) if the LTE eNB2 are connected by NG2 interface NG Core5, radio access bearer corresponding to the LTE of EPS Radio Access Bearer (E-RAB) is defined as NG EPS Radio Access Bearer (NE-RAB) it is, bearer corresponding to the LTE of EPS bearer may be defined as NG EPS bearer (NEPS bearer). NE-RAB includes a radio bearer is set between the UE1 and the LTE eNB2, LTE eNB2 and user plane functions of the NG Core5, bearer (eg set between the (eg, Edge GW or CUNF) NG3 it may be configured from a bearer). NEPS bearer is, NE-RAB and, between the user plane functions in the NG Core5 (eg, between the Edge GW and DN GW, or between the CUNF and SUNF) core network bearer (eg, NG9 bearer is set to ) may be configured from a.
[0039]
　LTE eNB2 connected to NG System, the data flow (PDU flow) for each of the QoS handling (eg, packet drops) may be configured to identify the data flow in the NE-RAB (PDU flow) for. For example, LTE eNB2 associates the set bearer between the user plane functions in the LTE eNB2 and NG Core5 (eg, NG3 bearer) to the radio bearer, the bearer (eg, NG3 bearer) and between the radio bearers perform packet forwarding, further data flow within the bearer (PDU flow) for each of the QoS handling (eg, packet drops) may be performed.
[0040]
　This embodiment provides a UE1 handover method from LTE System that does not support network slicing into NG System to support network slicing. 3A and 3B show an example of UE1 handover procedure from LTE System to NG System in the configuration example of the illustrated radio communication network in FIG. Figure 3A is a preparation for the handover indicates (preparation) phase, Figure 3B shows an embodiment of a handover (execution) phase.
[0041]
　In the illustrated procedure in Figure 3A and 3B, the source base station (ie, LTE eNB2), the source base station (ie, LTE eNB2) an interface (or a reference point between the core network (ie, EPC4) ( by sending a handover Required message on at reference point)), it starts the handover. Therefore, the procedure shown in FIGS. 3A and 3B, may be improved and development of the LTE "E-UTRAN to UTRAN Iu mode Inter RAT handover". Alternatively, the procedure shown in FIGS. 3A and 3B, may be improved and development with an LTE MME relocation "S1-based handover".
[0042]
　In step 301, UE1 is connected to the LTE eNB2, a Connected state (ie, RRC_Connected). UE1 is measured sets the (Measurement Configuration) received from LTE eNB2, E-UTRAN (LTE) cells and neighbor cell measurements comprising NG-RAN cells in accordance with the measurement configuration (neighbor cell measurements) and heterogeneous radio access technology (Radio Access run Technology) measuring the (inter-RAT measurements), send measurement reports (measurement report) to the LTE eNB2. Measurement settings include, for example, from E-UTRAN to the RRC Connection Reconfiguration message sent to the UE.
[0043]
　In step 302, LTE eNB2 determines the inter-RAT handover to a cell of NR NB3, sends the Handover Required message source control node in EPC4 (ie, the source MME) to. The Handover Required message includes the identifier of the target NR NB3. Furthermore, the Handover Required message may include a handover type information element indicating (Handover Type Information Element (IE)) it is a handover from the LTE to the NR. Handover Type IE is, for example, "LTEtoNR" is set. Additionally or alternatively, the Handover Required message, may include a target NR-NB identifier information element (Target NR-NB Identifier IE). The Handover Required message may include a Source to Target Transparent Container IE. Source to Target Transparent Container IE may include a RRC layer information (RRC container), further bearers (eg, E-RAB) may include information. The RRC layer information (RRC container), for example, is required to set the radio resources NR NB3, comprising at least part of the radio resource configuration (Radio Resource Configuration) in UE1 in serving cell LTE eNB2 is managed.
[0044]
　In step 303, the source MME in EPC4, from Handover Type IE or Target NR-NB Identifier IE in Handover Required message received, the type of the handover is Inter-RAT handover to NR (or NG System) the judges. The source MME in EPC4 selects the target control nodes in the NG Core5. Target control node is a node having at least a portion of the function of MME in EPC4. The source MME in EPC4 by sending a Forward Relocation Request message to the target control node, initiating a handover resource allocation procedure (Handover resource allocation procedure). The Forward Relocation Request message includes, Mobility Management (MM) Context, and the source system to the UE1 (ie, LTE system) all PDN connection is active in. Each PDN connection, including a list of associated APN and EPS Bearer Contexts. MM Context contains information about the EPS bearer context (s), and security-related information (security related information). Furthermore, the Forward Relocation Request message, information for identifying one or more service data flows associated with each EPS bearer context (eg, SDF templates, or Traffic Flow Templates (TFTs)) may include.
[0045]
　In step 304, the target control nodes in the NG Core5 performs generation of Beararesu session (creation) procedure. Specifically, the target control node determines that it needs a packet forwarding node for the UE1 (gateway) are rearranged (relocated), select a target forwarding node in NG Core5 (gateway). Target transfer node (gateway) is a node having at least a portion of the functionality of the S-GW in EPC4. Target control node sends a the Create Session Request message to the target transfer node (gateway). The the Create Session Request message, information for identifying one or more service data flows associated with each EPS bearer context (eg, SDF templates, or Traffic Flow Templates (TFTs)) may include. Information for identifying the one or more service data flows are derived from the Forward Relocation Request message sent from the source MME in EPC4 the target control nodes in the NG Core5. Target transfer node (gateway), assigns the local resources, and returns the Create Session Response message to the target control nodes.
[0046]
　Incidentally, NG System will support Bearabesudo transfer using a bearer for each and PDU session every QoS class, and if relocation forwarding node (relocation) is not required, the target control nodes in the NG Core5, in step 304, modify bearer instead of session generation procedure may be performed (bearer modification) procedure.
[0047]
　Further, in step 304, the target control nodes in the NG Core5 (eg, CPF) is determined network slice to be connected to the UE1 after the handover (selected) to. In one example, the target control nodes in the NG Core5 (CPF) may select a network slice for UE1 based on the required QoS for the UE1 the EPS bearer (s) or SDF (s). Additionally or alternatively, Forward Relocation Request message sent by the source MME in EPC4 (step 303) may further include a network slice support information (network slice assistance information). Network slice support information, the selection of the network Slice target control nodes, assist setting, or an approval. The source MME in EPC4 receives at least a portion of the network slice support information from the UE1, may send it to the target control nodes in the NG Core5. Target control nodes in the NG Core5 may perform the generation of the selected network slice instances (creation).
[0048]
　Network slice support information, for example, UE1 in the type (eg, Device Type, UE Category), UE1 access applications (eg, UE Usage Type), service type UE1 wishes (eg, Requested / Preferred Service Type, Multi- Dimensional Descriptor (MDD)), the slice information UE1 selects (eg, selected slice Type, selected slice Identity (ID), selected Network Function (NF) ID), the slice information (eg the UE1 is previously approved, authorized slice Type , Authorized Slice ID, Authorized NF ID), and UE1 allowable latency (eg, allowed latency, may indicate any or any combination of tolerable latency). Service Type, for example, the type of the Use Case (eg, a broadband communications (enhanced Mobile Broad Band: eMBB), reliable, low-latency communication (Ultra Reliable and Low Latency Communication: URLLC), or multi-connection M2M communication (massive Machine Type Communication: MMTC) or equivalent thereto) may indicate. Slice ID, for example, a slice instance information (Network Slice Instance (NSI) ID), the individual network information (Dedicated Core Network (DCN) ID), and a network domain name information (Domain Network Name (DNN) ID) it may indicate any or any combination. NF ID, for example, a common network function (Common NF (CNF)), a common control plane functions (Common Control plane NF (CCNF)), a common user plane functionality (Common User plane NF (CUNF)), and data gateway ( data Network Gateway (DN GW) one or any combination identification information) (ID) may indicate.
[0049]
　In step 305, the target control nodes in the NG Core5 sends NR Handover Request message to the target NR NB3. The NR Handover Request message includes a slice information (Slice Information). Slice information includes, for example, after the handover UE1 is connected (connected) information about network slices NG Core5, information about the network slices NG Core5 connection to UE1 is allowed, and UE1 network of NG Core5 connectable comprising at least one of information about the slice.
[0050]
　Specifically, the slice information is determined (selected) slices (Network Slice: NS) identification information may include identification information of the network node (NF), or the type information, or any combination of these slices . Identification information of the slice, for example, Slice ID, NSI ID, MDD, DCN ID, and may be any or any combination of DNN. Identification information of the network node, for example, NF ID, CNF ID, CCNF ID, Slice specific Control plane NF (SCNF) ID, CUNF ID, Slice specific User plane NF (SUNF) ID, UPF ID, and any DN GW ID or any combination or may contain. Type information of a slice is, for example, Service Type, Service the Category, and may include a Slice Type indicating any or any combination of the Use Case. Additionally or alternatively, type information of a slice, the Use Case or contract (Subscription Group, eg home UE or roaming UE) may include Tenant ID indicating the. Type information of the slice may include MDD containing Slice Type and Tenant ID to the element. The content of the above-described slice information may be specified for each network slice. Accordingly, if the UE1 is connected to a plurality of network slices simultaneously, the slice information may include information of a plurality of sets corresponding to the number of network slices UE1 is connected.
[0051]
　Slice information further mobility class (Mobility Class) or Session class (Session Class) or may include both. Mobility Class is predefined mobility level (eg, high mobility, low mobility, no mobility) may indicate one of the. For example, high mobility, the network slice (allow mobility to UE1) to support mobility for UE1 geographic range (Geographical area) is wider than that of the low mobility, at the time of handover services (PDU session) means that high demands on continuity (continuity). No mobility, the network slice support mobility only within a very limited geographic range for UE1 (to allow mobility to UE1) means that. Mobility Class may be specified for each UE, it may be specified for each network slice. Session Class is, pre-defined session type (eg, Session pre-setup, Session post-setup, No it may indicate one of PDU session). For example, Session pre-setup, in order to maintain the service (PDU Session) according to a mobility as the existing handover, UE is the target (cells, beams, other areas) the earlier PDU session from complete movement to the it may indicate that the establishment is required. In contrast, Session post-setup may indicate that the PDU session need be established after the UE moves to the target. Session Class may be specified for each PDU session. Mobility Class and Session Class may be included in the Slice Type. In other words, Slice Type may include a plurality of attributes including Mobility Class and Session Class.
[0052]
　Slice information may include at least a portion of the network slice support information. That is, the transfer in step 305, the target control nodes in the NG Core5 at least part of the network slice support information is received from the source MME in EPC4, included in the slice information in the NR Handover Request message to the target NR NB3 ( Forwarding) may be.
[0053]
　Furthermore, NR Handover Request message of step 305 may include flow information (Flow Information). Flow information, UE1 of the at least one packet flow (ie, PDU flow (s)) bearer-less network (ie, NG system) to transfer at least one session is established in (ie, PDU session ( s)) on. UE1 of each packet flow (ie, PDU flow) with respect to the flow information, flow identifier (eg, PDU flow ID), session end address of the transfer node in the NG Core5 (Transport Layer Address) and uplink (UL) point identifier (Session Endpoint identifier (SEID)), as well as flow QoS parameters. The session endpoint identifier (SEID), for example Tunnel Endpoint Identifier (TEID), or may be network function (node) identifier (NF ID). TEID may be, for example, a GTP-TEID or GRE-TEID.
[0054]
　The flow information may further indicate the mapping between EPS bearers and the PDU Flows for UE1. For example, the flow information may one or a plurality of SDFs mapped to the EPS bearer of the UE1, also exhibit these one or more SDFs each assigned flow identifiers of (eg, PDU flow ID). Furthermore, flow information, priority information (priority indicator), flow type information (flow type indicator), or may include a flow class (Flow Class). Priority information, for example, may indicate the relative priority of the plurality flow may indicate an absolute priority of each flow. Flow type information may indicate, for example, whether the flow corresponding to which Use Case or service. Furthermore, flow classes, for example, pre-defined flow type (eg, loss-less, delay tolerant, delay sensitive, mission critical) may indicate one of the. Flow information, above Mobility Class, it may include Session Class, or both.
[0055]
　As already explained, NG System, including the NR NB3 and NG Core5, may be configured to support Bearabesudo transfer using a bearer for each QoS class for each and PDU session, QoS handling each data flow (PDU flow) (eg, packet drops) may be configured to identify the data flow in the bearer (PDU flow) for. For example, NR NB3 associates the set bearer between the user plane functions in the NR NB3 and NG Core5 (eg, NG3 bearer) to the radio bearer, the bearer (eg, NG3 bearer) and between the radio bearers perform packet forwarding, further data flow within the bearer (PDU flow) for each of the QoS handling (eg, packet drops) may be performed.
[0056]
　In this case, the flow information described above, a bearer for UE1 (eg, NG-RAB or NG3 bearer) and UE1 of one or more packet flows are transferred through the bearer (ie, PDU flow (s)) it may indicate the association between. In other words, the control node in the NG Core5 (eg, CPF) is bearer (eg, NG-RAB or NG3 bearer) for UE1 and UE1 of one or more packet flows are transferred through the bearer (ie in order to inform the association with the PDU flow (s)) in NR NB3, it may send flow information to NR NB3. NR NB3 receives flow information from a control node in the NG Core5, in accordance with the flow information, NR NB3 and set bearer between the user plane functions in the NG Core5 (eg, NG3 bearer) data in the flow ( PDU flow) for each of the QoS handling (eg, packet drops) may be performed.
[0057]
　Target NR NB3, based on NR Handover Request message including slice information, may perform the admission control. For example, the target NR NB3, for each bearer or for each flow may be determined whether or not to accept the bearer or flow. Additionally or alternatively, the target NR NB3, based on the slice information may perform admission control for each network slice UE1 is connected. At this time, NR NB3 is whether it is possible to accept the network slice may be determined, NR NB3 is not possible to accept if there is (or accept no) network slice, the network slice the specific network slice (eg, default network slices) may be mapped to, the network slice specific NF (eg, CuPF) may be connected to. Alternatively, NR NB3 may determine the failure of acceptance of the network slice.
[0058]
　In step 306, the target NR NB3, in response to receiving the NR Handover Request message including slice information, generates a UE context (the create), allocate resources. Further, the target NR NB3 a wireless connection associated with the NG System to Support Network slicing (eg, RRC connection, radio bearer) radio resource configuration information necessary for the UE1 to establish (eg, radio parameters) the It is generated based on the slice information (or is derived from slice information). Radio resource configuration information may include at least one parameter included in the slice information.
[0059]
　Radio resource configuration information derived from the slice information may include a wireless (or RAN) parameters for each network slice (or each use case). Use cases include, for example, enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and Ultra-reliable and low-latency communications with (URLLC). Radio parameters for each network slice (or each use case) may be the basic physical channel parameters, or basic Layer 2 / Layer 3 (L2 / L3) configuration. The basic physical channel parameters, for example, frame / subframe structure, Transmission Time. Interval (TTI) length, subcarrier spacing, and may include a Physical Random Access Channel (PRACH) resource. PRACH resource may be both preamble index or time / frequency resources or them. Basic L2 / L3 configuration, for example, frame / subframe pattern, and L2 protocol sublayer settings (L2 configuration. Eg, PDCP config, RLC config, or MAC config) may contain.
[0060]
　Additionally, or alternatively, show the radio resource specifying configuration information (indicating) the RRC layer signaling derived from the slice information, message structure, format of information element (IE), the parameter values, as well as the structure definition information ASN.1 (Abstract Syntax Notation one) encoding and decoding of the target, at least one of, may be different for each slice.
[0061]
　Then, the target NR NB3 sends NR Handover Request Acknowledge message includes a Target to Source Transparent Container targeted control node. The Target to Source Transparent Container includes a radio resource configuration information generated by the target NR NB3 (eg, radio parameters). As described later, Target to Source Transparent Container is forwarded to the source LTE eNB2 via the core network (ie, EPC4 and NG Core5).
[0062]
　Further, in step 306, the target NR NB3 is the flow information that is included in the NR Handover Request message, it may be considered for the production of UE context and radio resource configuration information. Specifically, the target NR NB3 is generate UE context including based on NR Handover Request message including flow information, packet flow information and security context for (ie, PDU flow (s)) (create) it may be. Further, the target NR NB3 is, bearer-less network (ie, NG System) wireless connections associated with (eg, RRC connection, radio bearer) a radio resource configuration information necessary for the UE1 to establish, flow information it may be generated based on (or may be derived from flow information). Radio resource configuration information may include at least one parameter included in the flow information. Radio resource configuration information, cell of the target NR NB3 (or mobility area, the beam coverage area) system information in (System Information Block: SIB), UE between common radio resource configuration (Common Resource Configuration), or, UE individually radio resource configuration of (Dedicated resource Configuration) may contain. Furthermore, radio resource configuration information indicates bearer in cell source LTE eNB2 (eg, EPS bearer, Data Radio Bearer (DRB)) and flow is established in the cell of the target NR NB3 (eg, PDU flow) the mapping between information may also include.
[0063]
　In step 307, the target control nodes in the NG Core5 sends a Target to Source Transparent Container encompassing Forward Relocation Response message to the source MME in EPC4. Further, Forward Relocation Response message may include the address (Addresses) and TEID which allocated for downlink data forwarding. If indirect downlink forwarding is used, the address and TEID may be an address and TEID of the S-GW in EPC4. If the direct downlink forwarding is used, the address and TEID may be an address and TEID to the target NR NB3.
[0064]
　In step 308, the source MME sends a Handover Command message including a Target to Source Transparent Container in a source LTE eNB2. Handover Command message may further include a list of bearers that are subject to downlink data forwarding (bearers subject to data forwarding list). "Bearers Subject to Data forwarding list" IE includes, for example, address identifier of (es) and TEID (s) for user traffic data forwarding, and the flow is subject to data forwarding (PDU flow (s)). Source LTE eNB2 is, "Bearers Subject to Data forwarding list" starts data forwarding for the specified bearer or flow (PDU flow (s)) by IE.
[0065]
　In step 309, the source LTE eNB2 sends a Radio Resource Control (RRC) message including the Handover Command message to the UE1. The Handover Command message includes including transparent container the radio resource configuration information targeted NR NB3 are set up in preparation (preparation) phase. The RRC message, for example, may be a Mobility from EUTRA COMMAND message may be a RRC Connection Reconfiguration message.
[0066]
　In step 310, UE1 in response to receiving the encompassing RRC message Handover Command message, moves the target RAN (ie, NG RAN), the source eNB performs a handover according to the wireless resource configuration information supplied in Handover Command message . That, UE1 establishes a wireless connection with the target NR NB3 associated with NG System. In step 311, UE1, after successfully (successfully) synchronization with the target cell, and sends a Handover Confirm The for NR message to the target NR NB3. Message of step 311 may be NR RRC Connection Reconfiguration Complete message.
[0067]
　In step 312, if the UE1 has successfully (successfully) to access the target NR NB3, target NR NB3 by sending an NR Handover Notify message informs the target control nodes in the NG Core5.
[0068]
　In step 313, the target control nodes in the NG Core5 knows that UE1 arrives at the target side, by sending a Forward Relocation Complete Notification message, informs the source MME in EPC4. The source MME sends a Forward Relocation Complete Acknowledge message to the target control nodes.
[0069]
　In step 314, the target control nodes in the NG Core5 by implementing the flow modifiers (modification) procedure, completing the Inter-RAT handover procedure. For example, the target control node, the forwarding node in NG Core5, session (ie, PDU session) may be transmitted every Modify Flow Request message. Modify Flow Request message, flow identifier (eg, PDU flow ID), and may include a session endpoint identifier address of the target NR NB3 and downlink (DL) (SEID). The session endpoint identifier (SEID) can be, for example, Tunnel Endpoint Identifier (TEID). Forwarding node in NG Core5 is, inter-RAT HO relocation by the transfer node (relocation) or edge node in EPC4 changes RAT classification (ie, (e) P-GW) to inform the, in EPC4 edge node (ie, eP-GW) may communicate with. Specifically, the transfer nodes in the NG Core5 a session (ie, PDN connection) may be transmitted every Modify Bearer Request message to the edge node in EPC4. Edge nodes in EPC4 may transmit Modify Bearer Response message to the forwarding nodes in the NG Core5. Forwarding node in NG Core5 may return the Modify Flow Response message to the target control nodes.
[0070]
　After the handover is completed in accordance with the procedure shown in FIGS. 3A and 3B, the following route may be used for the UE1 data transfer. If NG System comprising NR NB3 and NG Core5 has support Bearabesudo transfer within NG Core5, bearer (eg, NG-EPS-bearer) are used for UE1 after the handover, for example, the uplink path and downlink link path may include (source or old) S / P-GW in the NG Core5 the (target or New) User plane Function (eg, CUNF) a path between (eg, GTP tunnel or GRE tunnel) . That, S / P-GW forwards the downlink data to the User plane Function (eg, CUNF) in NG Core5, in NG Core5 User plane Function (eg, CUNF) uplink to S / P-GW data may be transferred to.
[0071]
　On the other hand, if the bearer for UE1 after the handover (eg, NG-EPS-bearer) is not used, for example, (source or old) S / P-GW and (target or New) User plane Function (eg, NW Slicing between SUNF) having a function may be mediated CUNF a. That, S / P-GW forwards the downlink data to CUNF in NG Core5, CUNF may forward the downlink data to another UNF having a flow unit control function. Alternatively, without using the CUNF, it may be made directly transfer data to and from the S / P-GW and SUNF. In other handover procedure described below, the data transfer paths after handover described here may be used.
[0072]
　4A and 4B illustrate an example of UE1 handover procedure from LTE System to NG System in the configuration example of the illustrated radio communication network in FIG. Figure 4A is preparing for a handover indicates (preparation) phase, FIG. 4B shows an embodiment of a handover (execution) phase.
[0073]
　Similar to the procedure shown in FIGS. 3A and 3B, in the procedure shown in FIGS. 4A and 4B, the source base station (ie, LTE eNB2), the source base station (ie, LTE eNB2) and a core network ( ie, by sending a handover Required message on the interface between the NG Core5), starts the handover. Therefore, similarly to the procedure shown in FIGS. 3A and 3B, the procedure shown in FIGS. 4A and 4B, improvement and development of the LTE "E-UTRAN to UTRAN Iu mode Inter RAT handover", or MME relocation it may be the improvement and development of the associated "S1-based handover".
[0074]
　Processing in steps 401 and 402 in FIG. 4A is the same as the processing in steps 301 and 302 in Figure 3A. However, in step 402, LTE eNB2 sends a Handover Required message to NG Core5. Incidentally, as already described, in the network configuration example of FIG. 2, NG RAN including E-UTRAN and NR NB3 including LTE eNB2 may be connected to the same network slice. In this implementation, UE1 handover from LTE eNB2 to NR NB3 is one 1 produced in the network slice or a plurality of logical control node (ie, control plane function) and one or more logical transfer node (ie, user plane function) is achieved by signaling between the. In this implementation, Handover Required message in step 402 may be sent to a new or improved control node corresponding to MME.
[0075]
　Alternatively, NG RAN including E-UTRAN and NR NB3 including LTE eNB2 may be connected to different networks slices from each other. In this implementation, the LTE eNB2 UE1 handover to NR NB3 is the network slice instance corresponding to pure NG Core network slice instance and NR NB3 corresponding to the EPC LTE eNB2 is connected is connected It is implemented by the inter-slice communication between. In this implementation, Handover Required message in step 402 may be sent to the MME network slice instance the LTE eNB2 are connected.
[0076]
　Processing of steps 403-405 in FIG. 4A is the same as the processing in steps 303 to 307 in FIG. 3A. The steps in Figure 4A, shown in steps 303 and 307 shown in FIG. 3A has been omitted. Processing corresponding to step 303 and 307, performed in the NG Core5.
[0077]
　Processing in steps 406 to 411 in FIG. 4B is the same as the processing in steps 308-314 in Figure 3B. In the procedure of FIG. 4B, illustration of the step 313 shown in FIG. 3B is omitted. Processing corresponding to step 313 is performed in the NG Core5.
[0078]
　Figure 5 is a flow chart showing an example of a method performed by the core network (process 500). Core network, EPC4 and NG Core5 in FIG. 1, or NG Core5 in FIG. In step 501, the core network receives the Handover Required message to initiate the UE1 handover to NG System from LTE System from the source LTE eNB2. Step 501 corresponds to step 402 of step 302 or FIG. 4A in Figure 3A.
[0079]
　In step 502, the core network sends encompasses slice information about the network slices NG Core5 the UE1 after the handover connects a (NR) Handover Request message to the target NR NB3. Step 502 corresponds to step 404 of step 305 or FIG. 4A in Figure 3A.
[0080]
　In step 503, the core network receives encompasses Target to Source Transparent Container The (NR) Handover Request Acknowledge message from the target NR NB3. The Target to Source Transparent Container includes in order to establish a wireless connection associated with the NG System radio resource configuration information necessary for the UE1 (eg, radio parameters) and. Step 503 corresponds to step 405 of step 306 or FIG. 4A in Figure 3A.
[0081]
　In step 504, the core network sends the encompassing Handover Command message Target to Source Transparent Container in a source LTE eNB2. Step 504 corresponds to step 406 of step 308 or FIG. 4B in Figure 3B.
[0082]
　Figure 6 is a flowchart illustrating an example (process 600) of the method performed by the target NR NB3. In step 601, the target NR NB3 receives encompasses slice information about the network slices NG Core5 the UE1 after the handover connects a (NR) Handover Request message from the core network (ie, NG Core5). Step 601 corresponds to step 404 of step 305 or FIG. 4A in Figure 3A.
[0083]
　In step 602, the target NR NB3 is, Target sends encompasses-to Source Transparent Container The (NR) Handover Request Acknowledge message to the core network. The Target to Source Transparent Container includes in order to establish a wireless connection associated with the NG System radio resource configuration information necessary for the UE1 (eg, radio parameters) and. Step 602 corresponds to step 405 of step 306 or FIG. 4A in Figure 3A.
[0084]
　In step 603, the target NR NB3, based on the radio resource configuration information to establish a wireless connection associated with the NG System for UE1. Step 603 corresponds to step 408 of step 310 or FIG. 4B in Figure 3B.
[0085]
　Figure 7 is a flowchart illustrating an example (process 700) of the process performed by the source LTE eNB2. In step 701, the source LTE eNB2 sends a Handover Required message to initiate the UE1 handover to NG System from LTE System to the core network (ie, EPC4 or NG Core5). Step 701 corresponds to step 402 of step 302 or FIG. 4A in Figure 3A.
[0086]
　In step 702, the source LTE eNB2 receives encompassing Handover Command message from the core network the Target to Source Transparent Container. The Target to Source Transparent Container includes a radio resource configuration information necessary for the UE1 to establish a wireless connection associated with the NG System to Support Network slicing. Step 702 corresponds to step 406 of step 308 or FIG. 4B in Figure 3B.
[0087]
　In step 703, the source LTE eNB2 sends mobility COMMAND message (eg, Handover Command message) indicating the handover to and Beararesu network includes a radio resource configuration information to the UE1. Step 703 corresponds to step 407 of step 309 or FIG. 4B in Figure 3B.
[0088]
　Figure 8 is a flow chart illustrating an example (the process 800) of the method performed by UE1. In step 801, UE1 receives mobility COMMAND message (eg, Handover Command message) from a source LTE eNB2. The mobility COMMAND message includes the radio resource configuration information necessary for the UE1 to establish a wireless connection associated with the NG System. Step 801 corresponds to step 407 of step 309 or FIG. 4B in Figure 3B.
[0089]
　In step 802, UE1 uses the radio resource configuration information, establishing a wireless connection with the target NR NB3 associated with NG System. Step 802 corresponds to step 408 of step 310 or FIG. 4B in Figure 3B.
[0090]
　In this embodiment, the network, whether the handover target cell (NR cell) supports network slicing may be UE1 can be grasped in advance. For example, NR NB3 is that the network slicing is supported in NR cell (Alternatively, it is possible to connect a network slicing into possible NG Core) explicitly or implicitly indicate network slicing support information system information (eg, System information Block Type-x:. SIBx eg, x = 1) may be notified as. Network slicing support information transmitted explicitly to indicate the network slices are supported, the service type supported (eg, Supported Service Type), or slice is supported types (eg, the Supported Slice Type) may further comprise a. On the other hand, network slicing support information transmitted implicitly may include information about the different radio resource configuration for each network slice. UE1, by recognizing that at least a portion of the radio resource configuration received is specified for each network slice, may be understood that the network slicing is supported in the cell. Information regarding the radio resource configuration may include setting information or the system configuration information, or both of these physical resources. Setting information of physical resources, code, time, frequency, may include at least one of the RACH preamble sequence (group). System configuration information, subcarrier spacing, sampling rate, TTI, subframe / frame format may include at least one of the type. Network slicing support information may be transmitted as the information of the NAS layer, it may be transmitted as the information of the AS layer. In the former case, UE1 forwards the information received in the AS layer (RRC) to the NAS layer.
[0091]
　Detailed handover procedure from LTE System according to the present embodiment to NG System may be, for example, implementations described above, but is not limited thereto. For example, the message names shown in several handover procedure example described above are merely illustrative. Some handover procedure example described above may be different ordering of messages, to some messages may be omitted, may include additional message.
[0092]
　As understood from the above description, a handover procedure from LTE System that does not support network slicing described in the present embodiment to NG System to Support Network slicing includes the following. That is, the target NR NB3 receives slice information about the network slices UE1 is connected from NG Core5, in response to receiving the slice information, radio resource configuration information UE1 uses in NG System (NR NB3) after the handover generate, via the LTE System (LTE eNB2) transmits the radio resource configuration information to the UE1. Therefore, UE1, by using the radio resource configuration information generated based on the slice information by the target NR NB3, the AS layer settings or NAS layer setting or both target RAT associated with the NG System to Support Network slicing it can be properly carried out.
[0093]

　The present embodiment provides a modification of the UE1 of the handover process from LTE System according to the first embodiment to the NG System. Figure 9 shows an example of a UE1 handover procedure from LTE System to NG System in the configuration example of a wireless communication network shown in Figure 1. Incidentally, the handover procedure shown in FIG. 9 is a refinement and modification of the handover procedure shown in FIGS. 3A and 3B, the configuration of the NG Core5, specifically described for network slice selection by NG Core5 ing.
[0094]
　NG Core5 shown in Figure 9, network functions for common network functions (Common Network Functions (NFs)) 51, a network function for network slice A (NFs for slice A) 52, network slice B (NFs for including slice B) 53 and Home Subscriber Server (HSS) 54,.
[0095]
　Each network element (NF) is a component of a network slices. Each network slice consists needed (required) communication services (telecommunication services) and network functions needed to provide the network capacity (network capabilities) (NFs). Each network element (NF) is a processing function in the network (Processing function), defines the functional behavior (functional Behavior) and interfaces (interfaces). Each network element may be implemented as a network element on an individual hardware (dedicated hardware), may be a software instance running (the run) on separate hardware (dedicated hardware), appropriate generated on a platform (instantiated) may be virtualized capabilities are.
[0096]
　Each network slice, may be identified by the Network Slice specific Instance ID (NSI-ID). Each network function (NF) may be identified by the Network Function ID (NF ID). If the common control plane network functions that (Common CP NFs) (used), NSI-ID is, Common CP NF IDs and Slice specific IDs (ie, NF IDs for selected slice) or in combination with.
[0097]
　Common shown in FIG. 9 NFs51 includes control plane network function (CP NFs). Common NFs51 may further include a user plane network function (UP NFs). NFs for slice A52 includes the UP NFs, it may include the CP NFs. Similarly, NFs for slice B53 includes a UP NFs, it may include a CP NFs.
[0098]
　Figure 9 is a slice selection function (Slice Selection Function (SSF)) is an example to be located with Common NFs51 (co-located). However, SSF may be located remotely from the Common NFs51. In this case, Common NFs51 is to replace the SSF and the message. SSF selects a network slice associated with UE1. For example, SSF may be associated with and may be associated with UE1 to the default network slice, further or network slice designated by UE1 Alternatively (slice type). SSF may further perform NAS Node Selection Function (NNSF) to select the CP NFs corresponding to the selected slice (or CP NFIDs). Here, the default network slice, Public Land each Mobile Network (PLMN), each RAT, each UE usage type, each Service type, or may be set for each Slice type.
[0099]
　Assignment to UE1 of one or more packet flows of network slices may be performed according to any of the three examples below. In the first example, NG System comprising NR NB3 and NG Core5 supports Bearabesudo transfer using a bearer for each QoS class for each and PDU session. As already explained, the bearer of the NG System may also be referred to as NG-EPS-bearer, the radio access bearer NG System may be referred to as NG-RAB. In a first example, each bearer is assigned to one of the network slices. In some implementations, Common NFs51 communicates with Slice specific User plane NF network slice selected for UE1 (s) (SUNF (s)), sets the UE1 bearer to the SUNF (s) .
[0100]
　In a second example, as in the first example, NG System, including the NR NB3 and NG Core5, supports Bearabesudo transfer using a bearer for each QoS class for each and PDU session. Bearer NG System can be utilized for the transfer of a plurality of packet flows (PDU flows). In a second example, NG System is, QoS handling (eg, packet discard) the data flow (PDU flow) each arranged to identify the data flow in the bearer (PDU flow) for. In a second example, the packet flow UE1 (eg, PDU flow) is assigned to one of the network slice flow (PDU flow) units.
[0101]
　In a third example, NG System comprising NR NB3 and NG Core5 supports flow-based de transfer of user data. In a third example, the network slicing is set for each of UE1 PDU session. In other words, a set of a plurality of packet flows that are included in one PDU session (PDU Flows) is assigned to one of the networks slices.
[0102]
　In step 901, UE1 is connected to the LTE eNB2, a Connected state (ie, RRC_Connected). UE1 sends a network slice support information (network slice assistance information) to the LTE eNB2. LTE eNB2 sends the received network slice support information to EPC4. As already explained, the network slice support information, for example, UE1 in type, service UE1 wishes, or UE1 allowable latency, or may exhibit any combination thereof. The network slice support information may be NAS information (NAS information), it may be included in the measurement report sent from UE1 to LTE eNB2 (measurement report). The transmission network slice support information by the UE1 may be omitted.
[0103]
　Step 902 corresponds to step 303 of FIG. 3A. That is, the source MME of EPC4 is, Forward target control nodes in the NG Core5 (here, Common NFs51) Relocation Request message sent to. The Forward Relocation Request message includes the EPS Radio Access Bearer (E-RAB) QoS information element (IE). E-RAB QoS IE is, UE1 of E-RAB of QoS show the (eg, QoS class identifier (QCI), Allocation and retention priority (ARP)). The Forward Relocation Request message may further include a network slice support information sent from the UE1 of NAS layer (step 901).
[0104]
　In step 903, Common NFs51, if necessary, to perform the UE1 authentication (authentication). The authentication includes granted to UE1 (authorized) confirmation of the slice (slice authorization). In slice authorization, Common NFs51 may be determined / determined for each slice whether UE1 is allowed.
[0105]
　Figure 9 shows the case A (steps 904-906) and Case B (steps 907 and 908). Any one of case A and case B are executed. Case A, if at least one network slices are allowed to UE1, or at least one network slices are to have (ongoing) or a request made by the UE1 (requested) services (services (s)) It corresponds to the case where applicable (applicable Accept). In contrast, Case B, either when the network slice is also not allowed to UE1, or any network slice is also to have (ongoing) or a request made by the UE1 (requested) services (services (s )) corresponding to the case can not be applied (not applicable) to.
[0106]
　In Case A, Common NFs51 executes slice selection (step 904). That, Common NFs51 selects a network slice associated with UE1. In the example of FIG. 9, Common NFs51 selects a slice A for UE1. Slice selection step 904 is to have (ongoing) or a request made by the UE1 (requested) for each service (eg, EPS bearer / E-RAB, IP flow) may be performed. As already mentioned, the slice selection in step 904 may be performed by SSF located remotely from the Common NFs51.
[0107]
　Step 905 corresponds to step 304 of FIG. 3A. Common NFs51 (here, slice A) a selected slice for UE1 to generate Beararesu session in (creation), communicates with UP NFs of the selected slice (NFs for slice A52). Incidentally, support NG System is Bearabesudo transfer of user data, and if relocation forwarding node (relocation) is not required, Common NFs51 is instead bearer modification to the session generation procedure be performed (bearer modification) procedure good.
[0108]
　Step 906 corresponds to step 305 of FIG. 3A. That, Common NFs51 sends NR Handover Request message to the target NR NB3. The NR Handover Request message contains information about the network the selected slice by Common NFs51 (or SSF) (ie, slice information information element (IE)). Slice information IE, for example, NSI-ID indicating a network the selected slice, encompasses NF and IDs indicating the network function selected (NFs), or multi-dimensional descriptor (MDD), or any combination thereof it may be. MDD can be provided by the UE in the RRC signaling layer and NAS signaling layer. MDD represents tenant ID (Tenant ID), and service descriptor (Service Descriptor) / slice type (slice type). Service Descriptor / slice type indicates UE1 or selected service or use cases associated with the network slice (eg, eMBB, mMTC, URLLC, critical communications (CriC)) a.
[0109]
　In Case B, Common NFs51 does not execute the slice selection. Step 907 corresponds to step 304 of FIG. 3A. Common NFs51 in order to generate a Beararesu session in a network slice predetermined (creation), communicates with UP NFs of this slice. Predetermined network slice may be a network slice Common NFs51 belongs. Incidentally, support NG System is Bearabesudo transfer of user data, and if relocation forwarding node (relocation) is not required, Common NFs51 is instead bearer modification to the session generation procedure be performed (bearer modification) procedure good.
[0110]
　Step 908 corresponds to step 305 of FIG. 3A. Common NFs51 sends the NR Handover Request message to the target NR NB3. The NR Handover Request message does not include information about the network slice (ie, slice information IE). Alternatively, the NR Handover Request message may include a slice information IE related predefined network slices (eg, network slice Common NFs51 belongs).
[0111]
　Figure 10 shows an example of a UE1 handover procedure from LTE System to NG System in the configuration example of a wireless communication network shown in FIG. Incidentally, the handover procedure shown in FIG. 10 is a refinement and modification of the handover procedure shown in FIGS. 4A and 4B, the configuration of the NG Core5, specifically described for network slice selection by NG Core5 ing.
[0112]
　In step 1001, UE1 is connected to the LTE eNB2, a Connected state (ie, RRC_Connected). UE1 sends a network slice support information (network slice assistance information) to the LTE eNB2. The network slice support information may be NAS information (NAS information), it may be included in the measurement report sent from UE1 to LTE eNB2 (measurement report). The transmission network slice support information by the UE1 may be omitted.
[0113]
　Step 1002 corresponds to step 402 of Figure 4A. That, LTE eNB2 sends a Handover Required message to the Common NFs51 in NG Core5. The Handover Required message includes E-RAB QoS IE. The Handover Required message may further include a network slice support information sent from the UE1 of NAS layer (step 1001).
[0114]
　Processing of steps 1003 to 1008 are the same as steps 903-908 in FIG.
[0115]
　According to the handover procedure from LTE System according to the present embodiment to NG System, supplying network slice selected by Common NFs51 for UE1 information (ie, slice information IE) from NG Core5 targeting NR NB3 can. Therefore, the target NR NB3, for example, Handover Command (ie, transparent container (RRCConnectionReconfiguration)) to generate or derive information or parameters are sent to the UE1 is included in the network the selected slice by Common NFs51 for UE1 it is possible to use the information. The information of the network the selected slice by Common NFs51 (ie, slice information IE) may be sent to the UE1.
[0116]

　The present embodiment provides a modification of the UE1 of the handover process from LTE System according to the first embodiment to the NG System. Figure 11 shows an example of a UE1 handover procedure from LTE System to NG System in the configuration example of a wireless communication network shown in Figure 1. Incidentally, the handover procedure shown in FIG. 11 is a refinement and modification of the handover procedure shown in FIGS. 3A and 3B, the configuration of the NG Core5, specifically described for network slice selection by NG Core5 ing.
[0117]
　In the procedure of FIG. 9 described in the second embodiment, the slice selection by Common NFs51 (step 904) is performed in the handover preparation phase. In contrast, in the procedure of FIG. 11, the slice selection by Common NFs51 (step 1109) is performed in a handover completion phase. In the following, mainly described this difference.
[0118]
　Step 1101 corresponds to step 303 of FIG. 3A. That is, the source MME of EPC4 is, Forward target control nodes in the NG Core5 (here, Common NFs51) Relocation Request message sent to. The Forward Relocation Request message includes the E-RAB QoS IE.
[0119]
　Step 1102 corresponds to step 304 of FIG. 3A. Common NFs51 in order to generate a Beararesu session in a network slice predetermined (creation), communicates with UP NFs of this slice. Predetermined network slice may be a network slice Common NFs51 belongs. Incidentally, support NG System is Bearabesudo transfer of user data, and if relocation forwarding node (relocation) is not required, Common NFs51 is instead bearer modification to the session generation procedure be performed (bearer modification) procedure good.
[0120]
　Step 1103 corresponds to step 305 and 306 in Figure 3A. Common NFs51 sends the NR Handover Request message to the target NR NB3. The NR Handover Request message does not include information about the network slice (ie, slice information IE). Alternatively, the NR Handover Request message may include a slice information IE related predefined network slices (eg, network slice Common NFs51 belongs).
[0121]
　Step 1104 corresponds to step 307 of FIG. 3A. Common NFs51 sends a Forward Relocation Response message to the source MME in the EPC4.
[0122]
　Step 1105 is a handover execution phase, corresponding to steps 308-311 in FIG. 3B. Handover execution phase (step 1105) includes sending the Handover Confirm The for NR message from UE1 to the target NR NB3 (NR RRC Connection Reconfiguration Complete message) to (Step 1106). The, Handover Confirm The for NR message may include a network slice support information. The network slice support information may be NAS information (NAS information), it may be a RRC information (RRC information).
[0123]
　Step 1106 corresponds to step 312 of Figure 3B. That is, the target NR NB3 is a target control nodes in the NG Core5 (here, Common NFs51) NR Handover Notify message sent to. The NR Handover Notify message may include a network slice support information.
[0124]
　Processing in step 1108 is the same as the processing in step 903 of FIG. That, Common NFs51, if necessary, to perform the UE1 authentication (authentication). The authentication includes granted to UE1 (authorized) confirmation of the slice (slice authorization). In slice authorization, Common NFs51 may be determined / determined for each slice whether UE1 is allowed.
[0125]
　11, of the case A and case B described with reference to FIG. 9 shows only cases A. Case A, if at least one network slices are allowed to UE1, or at least one network slices are to have (ongoing) or a request made by the UE1 (requested) services (services (s)) It corresponds to the case where applicable (applicable Accept). In step 1109, Common NFs51 performs slice selection for UE1. Processing in step 1109 is the same as the processing in step 904 of FIG.
[0126]
　Step 1110 corresponds to step 314 of Figure 3B. That, Common NFs51 performs a flow modifiers (modification) procedure. Specifically, Common NFs51 may select a forwarding node involved in Beararesu session generated in step 1102, the UP NFs predetermined network slices (eg, network slice Common NFs51 belongs) for the UE1 to change to UP NFs of slice a. For example, Common NFs51 may send the Create Session Request message UP NFs of selected slice A for UE1 (NFs for slice A52). Meanwhile, Common NFs51 may send a Delete Session Request message UP NFs predetermined network slices (eg, network slice Common NFs51 belongs).
[0127]
　Further, in step 1110, transfer node slice A (ie, UP NFs of NFs for slice A52) is relocated (relocation) or edge node in EPC4 changes RAT type of the transfer node according to inter-RAT HO (ie , to inform the (e) P-GW), the edge node in EPC4 (ie, may communicate eP-GW) and. Specifically, the transfer node slice A (ie, UP NFs of NFs for slice A52), the session (ie, PDN connection) may be transmitted every Modify Bearer Request message to the edge node in EPC4. Edge nodes in EPC4 may transmit Modify Bearer Response message transfer node (ie, UP NFs of NFs for slice A52) of the slice A in.
[0128]
　In step 1111, Common NFs51 sends information about the network the selected slice for UE1 (ie, slice information IE) to UE1. If NFs for slice A52 has a CP NFs, transmission of step 1111 may be performed by NFs for slice A52. Slice information IE may be a NAS information, RRC: a DL Information Transfer messages may be sent from the target NR NB3 to UE1 using. Alternatively, Slice information IE can be a RRC information, RRC: may be transmitted from the target NR NB3 to UE1 using RRC Connection Reconfiguration message.
[0129]
　Figure 12 shows an example of a UE1 handover procedure from LTE System to NG System in the configuration example of a wireless communication network shown in FIG. Incidentally, the handover procedure shown in FIG. 12 is a refinement and modification of the handover procedure shown in FIGS. 4A and 4B, the configuration of the NG Core5, specifically described for network slice selection by NG Core5 ing.
[0130]
　Step 1201 corresponds to step 402 of Figure 4A. That, LTE eNB2 sends a Handover Required message to the Common NFs51 in NG Core5. The Handover Required message includes E-RAB QoS IE.
[0131]
　Step 1202 corresponds to step 403 of Figure 4A. Processing in step 1202 is the same as the processing in step 1102 of FIG. 11. Step 1203 corresponds to step 404 and 405 in Figure 4A. Processing in step 1203 is the same as the processing in step 1103 of FIG. 11.
[0132]
　Step 1204 corresponds to step 406 of Figure 4B. Common NFs51 sends a Handover Command message to the source LTE eNB2.
[0133]
　Step 1205 is a handover execution phase, corresponding to steps 407-409 in Figure 4B. Handover execution phase (step 1205) includes sending the Handover Confirm The for NR message from UE1 to the target NR NB3 (NR RRC Connection Reconfiguration Complete message) to (Step 1206). The, Handover Confirm The for NR message may include a network slice support information. The network slice support information may be NAS information (NAS information), it may be a RRC information (RRC information).
[0134]
　Processing of steps 1207-1211 are the same as steps 1107-1111 of Figure 11.
[0135]
　By handover procedure from LTE System according to the present embodiment to NG System, network slice selected by Common NFs51 for UE1 information (eg, NSI-ID, MDD, NFIDs) from NG Core5 targeting NR NB3 it can be supplied. Therefore, the target NR NB3, for example, Handover Command (ie, transparent container (RRCConnectionReconfiguration)) to generate or derive information or parameters are sent to the UE1 is included in the network the selected slice by Common NFs51 for UE1 it is possible to use the information. The information of the network the selected slice by Common NFs51 (ie, slice information IE) may be sent to the UE1.
[0136]

　The present embodiment provides a UE1 handover method from NG System to Support Network slicing to LTE System that does not support network slicing. 13A and 13B illustrate an example of UE1 handover procedure to LTE System from NG System in the configuration example of a wireless communication network shown in Figure 1. Figure 13A is a preparation for the handover indicates (preparation) phase, FIG. 13B shows an implementation of the handover (execution) phase.
[0137]
　In the illustrated procedure in Figure 13A and 13B, the source base station (ie, NR NB3), the interface (or reference point between a source base station (ie, NR NB3) and core network (ie, NG Core5) (reference point)) by sending a handover Required message on to start the handover. Therefore, the procedure shown in FIGS. 13A and 13B may be improved and development of the LTE "UTRAN Iu mode to E-UTRAN Inter RAT handover". Alternatively, the procedure shown in FIGS. 13A and 13B may be improved and development with an LTE MME relocation "S1-based handover".
[0138]
　In step 1301, UE1 is connected to NR NB3, a Connected state (eg, RRC_Connected). UE1 is measured sets the (Measurement Configuration) received from NR NB3, NG-RAN cells and E-UTRAN (LTE) adjacent cells including cells measured according to the measurement set (neighbor cell measurements) and a heterologous RAT measurements (inter-RAT measurements) is executed, and send measurement reports (measurement report) to the NR NB3.
[0139]
　In step 1302, NR NB3 determines the inter-RAT handover to the cell of the LTE eNB2, sends a Handover Required message to the source control node in NG Core5. The Handover Required message includes the identifier of the target LTE eNB2. Furthermore, the Handover Required message may include a handover type information element indicating (Handover Type Information Element (IE)) it is a handover to LTE from NR. Handover Type IE is, for example, "NRtoLTE" is set. Alternatively, the Handover Required message, may include a target LTE eNB identifier information element (Target LTE eNB Identifier IE). The Handover Required message may include a Source to Target Transparent Container IE.
[0140]
　In step 1303, the source control node in NG Core5 from Handover Type IE or Target LTE eNB Identifier IE in Handover Required message received, determines that type of the handover is Inter-RAT handover to the LTE system . Source control node in the NG Core5 selects a target MME in EPC4. Source control node in the NG Core5 by sending a Forward Relocation Request message to the target MME, initiates the handover resource allocation procedure (Handover resource allocation procedure). The Forward Relocation Request message includes, Mobility Management (MM) Context, and the source system to the UE1 (ie, NG System) all PDU session is active in. Each PDN session includes a list of the Associated APN and PDU flow Contexts. MM Context contains information about the PDU flow (s), and security-related information (security related information). Furthermore, the Forward Relocation Request message includes information for identifying the one or more service data flows associated with each PDU flow context (eg, SDF templates, or Traffic Flow Templates (TFTs)).
[0141]
　In step 1304, the target MME in EPC4 performs generation of Bearabesudo session (creation) procedure. Specifically, the target MME determines that it needs a packet forwarding node for the UE1 (gateway) are rearranged (relocated), select a target forwarding node in EPC4 (ie, S-GW) to. Target MME sends a Create Session Request message to the target S-GW. The the Create Session Request message includes information for identifying the one or more service data flows associated with each PDU flow context (eg, SDF templates, or Traffic Flow Templates (TFTs)). Information for identifying the one or more service data flows are derived from the Forward Relocation Request message sent from the source control node in NG Core5 the target MME in EPC4. Target S-GW allocates its local resources, and returns the Create Session Response message to the target MME.
[0142]
　In step 1305, the target MME in EPC4 sends a Handover Request message to the target LTE eNB2.
[0143]
　In step 1306, the target LTE eNB2 in response to receiving the Handover Request message, the UE context including information and security context for EPS bearer (s) to produce (the create), allocate resources. Then, the target LTE eNB2 sends a Target to Source Transparent Container encompassing Handover Request Acknowledge message to the target MME.
[0144]
　In step 1307, the target MME in EPC4 sends a Forward Relocation Response message including the Target to Source Transparent Container in a source control node in NG Core5. Further, Forward Relocation Response message may include the address (Addresses) and TEID which allocated for downlink data forwarding. If indirect downlink forwarding is used, the address and TEID may be an address and TEID to the transfer node in the NG Core5. If the direct downlink forwarding is used, the address and TEID may be an address and TEID to the target LTE eNB2.
[0145]
　In step 1308, the source control node sends a Handover Command message including a Target to Source Transparent Container source NR NB3. Furthermore, Handover Command message may include a flow that is subject to the downlink data forwarding list (PDU flow (s)) (flows subject to data forwarding list). "Flows Subject to Data forwarding list" IE includes, for example, address identifier of (es) and TEID (s) for user traffic data forwarding, and the flow is subject to data forwarding (PDU flow (s)). Source NR NB3 is, "flows Subject to Data forwarding list" starts data forwarding for the specified flow (PDU flow (s)) by IE.
[0146]
　In step 1309, the source NR NB3 sends Handover Command message includes RRC message to UE1. The Handover Command message includes including transparent container the radio resource configuration information target LTE eNB2 has set up in preparation (preparation) phase. The RRC message, for example, may be a Mobility from NR COMMAND message may be a RRC Connection Reconfiguration message.
[0147]
　In step 1310, the UE1, in response to receiving the encompassing RRC message Handover Command message, UE1 moves to the target RAN (ie, E-UTRAN), according to the wireless resource configuration information supplied in Handover Command message to implement the handover. That, UE1 establishes bearer-based network (ie, LTE System) wireless connection with the target LTE eNB2 associated with. In step 1311, UE1, after successfully (successfully) synchronization with the target cell, and sends a Handover Confirm The for EUTRA message to the target LTE eNB2. Step 1311 of the message may be a RRC Connection Reconfiguration Complete message.
[0148]
　In step 1312, if the UE1 has successfully (successfully) to access the target LTE eNB2, the target LTE eNB2 by sending a Handover Notify message informs the target MME in EPC4.
[0149]
　In step 1313, the target MME in EPC4 knows that UE1 arrives at the target side, by sending a Forward Relocation Complete Notification message informs the source control node in NG Core5. Source control node sends a Forward Relocation Complete Acknowledge message to the target MME.
[0150]
　In step 1314, the target MME in EPC4 by implementing a bearer modification (modification) procedure, completing the Inter-RAT handover procedure. For example, target MME, in (e) S-GW in EPC4, session (ie, PDN connection) may be transmitted every Modify Bearer Request message. Modify Bearer Request message, the bearer identifier (eg, EPS Bearer ID), and may include an address and a downlink (DL) TEID of the target LTE eNB2. (E) S-GW in EPC4 is to inform the change of the relocation (relocation) or RAT type of the transfer node according to inter-RAT HO edge node in NG Core5, it communicates with the edge node in the NG Core5 it may be. Specifically, S-GW in EPC4 may transmit Beararesu session (ie, PDU session) to every Modify Flow Request message to the edge node in the NG Core5. Edge nodes in NG Core5 may send a Modify Flow Response message to the S-GW in EPC4. S-GW in the EPC4 may reply the Modify Bearer Response message to the target MME.
[0151]
　14A and 14B show an example of UE1 handover procedure to LTE System from NG System in the configuration example of a wireless communication network shown in FIG. 14A is ready for handover indicates (preparation) phase, FIG. 14B shows an implementation of the handover (execution) phase.
[0152]
　Similar to the procedure shown in FIGS. 13A and 13B, in the procedure shown in FIGS. 14A and 14B, the source base station (ie, NR NB3), a source base station (ie, NR NB3) and a core network ( ie, by sending a handover Required message on the interface between the NG Core5), starts the handover. Therefore, similarly to the procedure shown in FIGS. 13A and 13B, the procedure shown in FIGS. 14A and 14B, improvement and development of the LTE "UTRAN Iu mode to E-UTRAN Inter RAT handover", or MME relocation it may be the improvement and development of the associated "S1-based handover".
[0153]
　Processing of steps 1401 to 1405 in FIG. 14A is the same as the processing in steps 1301 to 1307 of FIG. 13A. In the procedure of FIG. 14A, shown in steps 1303 and 1307 shown in FIG. 13A is omitted. Processing corresponding to step 1303 and 1307 are performed in the NG Core5.
[0154]
　Processing of steps 1406 to 1411 of FIG. 14B is the same as the processing in steps 1308-1314 of FIG. 13B. The steps in FIG. 14B, shown in step 1313 shown in FIG. 13B is omitted. Processing corresponding to step 1313, performed in the NG Core5.
[0155]
　Detailed handover procedure from NG System according to the present embodiment to LTE System may be, for example, implementations described above, but is not limited thereto. For example, the message names shown in several handover procedure example described above are merely illustrative. Some handover procedure example described above may be different ordering of messages, to some messages may be omitted, may include additional message.
[0156]
　Then, in the following, UE1 according to embodiments described above, LTE eNB2, NR NB3, and a configuration example of a core network node will be described. Figure 15 is a block diagram showing a configuration example of UE1. LTE transceiver 1501 to communicate with the LTE eNB2, performs analog RF signal processing relating LTE RAT PHY layer. Analog RF signal processing performed by the LTE transceiver 1501 includes a frequency up-conversion, the frequency down-conversion, and amplification. LTE transceiver 1501 is coupled to an antenna 1502, and a baseband processor 1505. That, LTE transceiver 1501 receives the modulated symbol data (or OFDM symbol data) from the baseband processor 1505, generates a transmission RF signal and provides a transmit RF signal to the antenna 1502. Also, LTE transceiver 1501 generates a baseband received signal based on the reception RF signal received by an antenna 1502, and supplies it to the baseband processor 1505.
[0157]
　New Radio (NR) transceiver 1503 to communicate with NR NB3, performs analog RF signal processing relating PHY layer of NG RAT. New 5G transceiver 1503 is coupled to an antenna 1504, and a baseband processor 1505.
[0158]
　Baseband processor 1505 performs control plane processing and digital baseband signal processing for wireless communication (data plane processing). Digital baseband signal processing, (a) data compression / decompression, (b) segmentation / concatenation of data, generation / decomposition of (c) transmission format (transmission frame), (d) transmission channel coding / decoding , including generation of (e) modulation (symbol mapping) / demodulation, and OFDM symbol data by (f) Inverse Fast Fourier Transform (IFFT) (baseband OFDM signal). On the other hand, the control plane processing, layer 1 (eg, transmission power control), Layer 2 (eg, a radio link control, and hybrid automatic repeat request (HARQ) process), and layer 3 (eg, attach, mobility, and packet communication including communication management signaling) related.
[0159]
　For example, in the case of LTE and LTE-Advanced, a digital baseband signal processing by a baseband processor 1505, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, includes a signal processing of the MAC layer, and a PHY layer But good. Further, the control plane processing by baseband processor 1505, Non-Access Stratum (NAS) protocol, RRC protocol, and may include a process of MAC CE.
[0160]
　Baseband processor 1505, a modem processor that performs digital baseband signal processing (eg, Digital Signal Processor (DSP)) and protocol stack processor for performing control plane processing (eg, Central Processing Unit (CPU), or Micro Processing Unit it may include (MPU)). In this case, the protocol stack processor for performing control plane processing may be shared with an application processor 1506 which will be described later.
[0161]
　The application processor 1506, CPU, MPU, also referred to as a microprocessor or processor cores. The application processor 1506 may include a plurality of processors (multiple processor cores). The application processor 1506 executes the memory 1508 or illustrated which do not result system read from the memory a software program (Operating System (OS)) and various application programs (e.g., the communication application for acquiring metering data or sensing data) by realizes UE1 various functions.
[0162]
　In some implementations, as indicated by the dashed line (1507) in FIG. 15, the baseband processor 1505 and an application processor 1506 may be integrated on a single chip. In other words, the baseband processor 1505 and an application processor 1506 may be implemented as a single System on Chip (SoC) device 1507. SoC devices, sometimes referred to as system Large Scale Integration (LSI) or chipset.
[0163]
　Memory 1508 is a volatile memory or nonvolatile memory, or a combination thereof. Memory 1508 may include a physically independent plurality of memory devices. Volatile memory may be, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM) or a combination thereof. The non-volatile memory, a mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or hard disk drive, or any combination thereof. For example, memory 1508, a baseband processor 1505, an application processor 1506, and may contain accessible external memory device from SoC1507. Memory 1508, within baseband processor 1505, within the application processor 1506, or may include an integrated chip memory device within SoC1507. Furthermore, memory 1508 may include a memory in the Universal Integrated Circuit Card (UICC).
[0164]
　Memory 1508 may store one or more software modules (computer program) 1509 containing instructions and data for processing by the UE1 described in several embodiments described above. In some implementations, the baseband processor 1505 or the application processor 1506, the software module 1509 that reads out and executes from the memory 1508 may be configured to perform processing of UE1 described in the above embodiments .
[0165]
　Figure 16 is a block diagram showing a configuration example of a LTE eNB2 according to the embodiment described above. Referring to FIG. 16, LTE eNB2 is, LTE transceiver 1601, a network interface 1603, a processor 1604, and memory 1605. LTE transceiver 1601 performs an analog RF signal processing in order to communicate with the UEs that support LTE RAT including UE1. LTE transceiver 1601 may include a plurality of transceivers. LTE transceiver 1601 is coupled to antenna 1602 and the processor 1604. LTE transceiver 1601 receives the modulated symbol data (or OFDM symbol data) from the processor 1604, generates a transmission RF signal and provides a transmit RF signal to the antenna 1602. Also, LTE transceiver 1601 to generate a baseband received signal based on the reception RF signal received by an antenna 1602, and supplies it to the processor 1604.
[0166]
　Network interface 1603 is used to communicate with a network node (eg, MME and S-GW in EPC4). Network interface 1603 may include, for example, a network interface card that complies with the IEEE 802.3 series (NIC).
[0167]
　The processor 1604 performs control plane processing and digital baseband signal processing for wireless communication (data plane processing). For example, in the case of LTE and LTE-Advanced, a digital baseband signal processing by the processor 1604, PDCP layer, RLC layer may include a signal processing of the MAC layer, and the PHY layer. The control plane processing by the processor 1604, S1 protocol, RRC protocol, and may include a process of MAC CE.
[0168]
　Processor 1604 may include multiple processors. For example, the processor 1604 may include a modem processor that performs digital baseband signal processing (eg, DSP) and a protocol stack processor for performing control plane processing (eg, CPU or MPU).
[0169]
　Memory 1605 is constituted by a combination of volatile and nonvolatile memory. Volatile memory is, for example, a SRAM or DRAM, or a combination thereof. The non-volatile memory, for example, MROM, PROM, flash memory, or hard disk drive, or a combination thereof. Memory 1605 may include a storage that is remotely located from the processor 1604. In this case, the processor 1604 may access the memory 1605 via the I / O interfaces that are not network interface 1603 or illustrated.
[0170]
　Memory 1605 may store one or more software modules (computer program) 1606 containing instructions and data for processing by the LTE eNB2 described in several embodiments described above. In some implementations, the processor 1604, the one or more software modules 1606 that run from the memory 1605 may be configured to perform processing of LTE eNB2 described in the above embodiments.
[0171]
　Figure 17 is a block diagram showing a configuration example of a NR NB3 according to the embodiment described above. Referring to FIG. 17, NR NB3 is, New Radio (NR) transceiver 1701, a network interface 1703, a processor 1704, and memory 1705. NR transceivers 1701 performs analog RF signal processing for communication with UEs supporting NG RAT including UE1. NR transceivers 1701 may include a plurality of transceivers. NR transceivers 1701 is coupled to antenna 1702 and the processor 1704. NR transceivers 1701 receives the modulated symbol data from the processor 1704, it generates a transmission RF signal and provides a transmit RF signal to the antenna 1702. Furthermore, NR transceivers 1701 generates a baseband received signal based on the reception RF signal received by an antenna 1702, and supplies it to the processor 1704.
[0172]
　Network interface 1703 is used to communicate with a network node (eg, the control node and forwarding node in the NG Core5). Network interface 1703 may include, for example, a network interface card that complies with the IEEE 802.3 series (NIC).
[0173]
　The processor 1704 performs control plane processing and digital baseband signal processing for wireless communication (data plane processing). Processor 1704 may include multiple processors. For example, the processor 1704 may include a modem processor that performs digital baseband signal processing (eg, DSP) and a protocol stack processor for performing control plane processing (eg, CPU or MPU).
[0174]
　Memory 1705 is constituted by a combination of volatile and nonvolatile memory. Volatile memory is, for example, a SRAM or DRAM, or a combination thereof. The non-volatile memory, for example, MROM, PROM, flash memory, or hard disk drive, or a combination thereof. Memory 1705 may include a storage that is remotely located from the processor 1704. In this case, the processor 1704 may access the memory 1705 via the I / O interfaces that are not network interface 1703 or illustrated.
[0175]
　Memory 1705 may store one or more software modules (computer program) 1706 containing instructions and data for processing by the NR NB3 described in several embodiments described above. In some implementations, the processor 1704, the one or more software modules 1706 that run from the memory 1705 may be configured to perform processing of NR NB3 described in the above embodiments.
[0176]
　Figure 18 is a block diagram showing a configuration example of a core network node 1800 according to the embodiment described above. Core network node 1800, e.g., a control node MME, or NG in Core5 in EPC4. Referring to FIG. 18, the core network node 1800 includes network interface 1801, a processor 1802, and memory 1803. Network interface 1801, network node (eg, RAN nodes, other core network nodes) are used to communicate with. Network interface 1801 may include, for example, a network interface card that complies with the IEEE 802.3 series (NIC).
[0177]
　The processor 1802, e.g., a microprocessor, MPU, or a CPU. Processor 1802 may include multiple processors.
[0178]
　Memory 1803 is constituted by a combination of volatile and nonvolatile memory. Volatile memory is, for example, a SRAM or DRAM, or a combination thereof. The non-volatile memory, for example, MROM, PROM, flash memory, or hard disk drive, or a combination thereof. Memory 1803 may include a storage that is remotely located from the processor 1802. In this case, the processor 1802 may access the memory 1803 via the I / O interfaces that are not network interface 1801 or illustrated.
[0179]
　Memory 1803, a core network node that is described by a plurality of the above-described embodiments (eg, MME in EPC4, or control nodes in NG Core5) 1 including instructions and data for processing by or more software modules may be stored (computer program) 1804. In some implementations, the processor 1802, by executing the one or more software modules 1804 from the memory 1803 may be configured to perform processing of the core network node described in the above embodiments .
[0180]
　As described with reference to FIGS. 15 to 18, each of the processors UE1 according to the embodiment described above, LTE eNB2, NR NB3, and a core network node has the performed algorithm described with reference to the drawings in the computer executing one or more programs including instructions for causing. This program is stored using a non-transitory computer readable media of various types (non-transitory computer readable medium), it can be supplied to the computer. Non-transitory computer readable media include with various types of entities (tangible storage medium). Examples of non-transitory computer readable media include magnetic storage media (such as floppy disks, magnetic tape, hard disk drive), magneto-optical recording medium (e.g., magneto-optical disk), Compact Disc Read Only Memory (CD-ROM), CD- R, including CD-R / W, a semiconductor memory (e.g., a mask ROM, Programmable ROM (PROM), Erasable PROM (EPROM), flash ROM, Random Access memory (RAM)). The program may be provided to a computer using a temporary computer readable media of various types (transitory computer readable medium). Examples of transitory computer readable media include electric signals, optical signals, and electromagnetic waves. Transitory computer readable media, wired communication path such as electrical wires and optical fibers, or via a wireless communication path can provide the program to a computer.
[0181]

　In the present embodiment, specific examples of the control messages (ie, S1 and NG2 messages) between the RRC message and RAN and a core network that is described in the above embodiment will be described.
[0182]
　19A and 19B show an example of the format of a Mobility from EUTRA COMMAND message. From LTE System handover to NG System, MobilityFromEUTRACommand message includes "handover" and purpose, which is set with, and targetRAT-Type that is the corresponding set with "ngutra" in NG RAN. Furthermore, MobilityFromEUTRACommand message includes a targetRAT-MessageContainer. targetRAT-MessageContainer includes RRCConnectionReconfigurationNR messages generated by the target NR NB3. Furthermore, targetRAT-Type is "OTHERRAN", when a clogging "utra", "geran", or "ngutra", MobilityFromEUTRACommand message includes a nas-SecurityParamFromEUTRA.
[0183]
　Figure 20 shows an example of the format of Handover Required message sent on the MME S1 interface in the LTE eNB2 EPC4 (eg, step 302 of FIG. 3A). This Handover Required message, including "LTEtoNR" and the set has been Handover Type, and Source to Target Transparent Container.
[0184]
　Figure 21 shows an example of the format of the control nodes in the NG Core5 from LTE eNB2 Handover Required message sent on NG2 interface (eg, Common Control plane NF (CCNF)) (eg, step 402 in FIG. 4A) there. This Handover Required message, including "LTEtoNR" and the set has been Handover Type, and Source to Target Transparent Container. Furthermore, Handover Required message contains CCNF UE NG2AP ID and eNB UE NG2AP ID. CCNF UE NG2AP ID is to identify the UE1 on NG2 interface, which is an identifier assigned by the control nodes in the NG Core5 (CCNF). eNB UE NG2AP ID is to identify the UE1 on NG2 interface, which is an identifier assigned by the LTE eNB2.
[0185]
　22 to 24 show some examples of the format of the Source NR NB to Target NR NB Transparent Container in Handover Required message. In the example shown in FIG. 22, Source NR NB to Target NR NB Transparent Container includes a RRC container and NextGen (NG) -RABs Information List. RRC container includes a RRC Handover Preparation Information message. NG-RABs Information List is a list of radio access bearers to be handed over from the LTE eNB2 to NR NB3 (NG-RABs). Format shown in Figure 22, NG System may be used when configured to support Bearabesudo transfer using a bearer for each and PDU per session QoS classes including NR NB3 and NG Core5. As already described, bearer between between pairs of network functions (Network Functions (NFs)), for example, NR NB3 and between the user plane functions in the NG Core5, or two user plane functions in the NG Core5 It is set to. NG System bearer may be referred to as NG-EPS-bearer, the radio access bearer NG System may be referred to as NG-RAB.
[0186]
　Source NR NB to Target NR NB Transparent Container shown in FIG. 23, similarly to that of Figure 22, including RRC container and NG-RABs Information List. However, NG-RABs Information List shown in FIG. 23 includes Flows Information the List indicating a list of packet flows that are mapped to each NG-RAB (PDU flows). Format shown in Figure 23, NR NB3 and NG System including NG Core5 is, supports Bearabesudo transfer using a bearer for each QoS class for each and PDU session, and the packet flow (PDU flow) for each of the QoS handling (eg it may be used when configured to identify a packet flow in the bearer (PDU flow) for packet discard).
[0187]
　Shown in FIG. 24 Source NR NB to Target NR NB Transparent Container may include either or both Sessions Information the List and NG-RABs Information List. Format shown in Figure 24, NG System comprising NR NB3 and NG Core5 may be used to support both Bearabesudo transfer and flow-based read transfer. Furthermore, the format shown in Figure 24, NG System comprising NR NB3 and NG Core5 may be used to support flow-based read transfer only.
[0188]
　Figure 25 shows an example of the format of sent from NG Core5 the NR NB3 on NG2 interface (NR) Handover Request message (eg, step 404 of step 305, and 4A of FIG. 3A). The (NR) Handover Request message includes CCNF UE NG2AP ID. CCNF UE NG2AP ID is to identify the UE1 on NG2 interface, which is an identifier assigned by the control nodes in the NG Core5 (CCNF). Incidentally, CCNF is an example, other control plane network function or node names (eg, CNF, CPF, SMF, MMF) may be used instead of CCNF. Furthermore, the (NR) Handover Request message includes a Security Context and NAS Security Parameters to NG-UTRAN. Security Context, for example, shows the Next Hop parameter (NH) and Next Hop Chaining Counter parameter (NCC). NAS Security Parameters to NG-UTRAN is included in the (NR) Handover Request message in case of a handover from E-UTRAN to NG RAN (NG-UTRAN). Security Context and NAS Security Parameters to NG-UTRAN may be set for each network slice.
[0189]
　Further, in the example of FIG. 25, (NR) Handover Request message includes an NG-RABs To Be Setup List. NG-RABs To Be Setup List is a list of radio access bearers should be set up in the target NR NB3 (NG-RABs). Format shown in Figure 25, NG System may be used when configured to support Bearabesudo transfer using a bearer for each and PDU per session QoS classes including NR NB3 and NG Core5.
[0190]
　Figure 26 shows a modification of the (NR) Handover Request message. In the example of FIG. 26, (NR) Handover Request message, as similar to that of FIG. 25, including NG-RABs To Be Setup List. However, NG-RABs To Be Setup List, shown in Figure 26 includes Flows Information the List indicating a list of packet flows that are mapped to each NG-RAB (PDU flows). Format shown in Figure 26, NR NB3 and NG System including NG Core5 is, supports Bearabesudo transfer using a bearer for each QoS class for each and PDU session, and the packet flow (PDU flow) for each of the QoS handling (eg it may be used when configured to identify a packet flow in the bearer (PDU flow) for packet discard).
[0191]
　Figure 27 shows a further modification of the (NR) Handover Request message. Shown in FIG. 27 (NR) Handover Request message may include either or both of the Session To Be Setup List, and NG-RABs To Be Setup List. Session To Be Setup List includes information about the UE1 of one or more sessions to be handed over. For example, Session To Be Setup List includes slice information for each session (Slice Information). Slice Information shown in FIG. 27 corresponds to the slice information described in the above embodiments. In addition, Session To Be Setup List includes a session endpoint identifier of each session (Session Endpoint Identifier (SEID)). Format shown in Figure 27, NG System comprising NR NB3 and NG Core5 may be used to support both Bearabesudo transfer and flow-based read transfer. Furthermore, the format shown in Figure 27, NG System comprising NR NB3 and NG Core5 may be used to support flow-based read transfer only.
[0192]
　Figure 28 shows an example of the format of the Slice Information. As explained in detail in the first embodiment, Slice Information is determined for the UE1 (selected) network slice identifier (ie, Network Slice Instance ID), and network functions associated with the network slice or node identifier (ie, Network Function ID) including. Slice Information is type information of the network slice (ie, Multi-Dimensional Descriptor) may contain. Furthermore, Slice Information may include a mobility class (Mobility Class) or Session class (Session Class) or both.
[0193]
　Figure 29 shows an example of the format of Session Endpoint ID. As explained in detail in the first embodiment, Session Endpoint ID is, GTP-TEID, or may be a GRE-TEID, or network functions or node identifier (NF ID).
[0194]
　Figure 30 shows an example of the format of sent on NG2 interface NG Core5 from NR NB3 (NR) Handover Request Acknowledge message (eg, step 405 of step 306, and 4A of FIG. 3A). The (NR) Handover Request Acknowledge message, including the Target to Source Transparent Container. Target to Source Transparent Container includes a radio resource configuration information generated by the target NR NB3 (eg, radio parameters). As shown in FIG. 31, Target to Source Transparent Container may include RRC Container encompasses RRC NG-UTRA Handover Command message.
[0195]
　Further, in the example of FIG. 30, (NR) Handover Request Acknowledge message includes a NG-RABs Admitted List. NG-RABs Admitted List is a list of radio access bearer resources have been prepared in the target cell (NG-RABs). Format shown in Figure 30, NG System may be used when configured to support Bearabesudo transfer using a bearer for each and PDU per session QoS classes including NR NB3 and NG Core5.
[0196]
　Figure 32 shows a modification of the (NR) Handover Request Acknowledge message. In the example of FIG. 32, (NR) Handover Request Acknowledge message, similarly to that of Figure 30, including NG-RABs Admitted List. However, NG-RABs Admitted List shown in FIG. 32 includes Flows Information the List indicating a list of packet flows that are mapped to each NG-RAB (PDU flows). Format shown in Figure 32, NG System comprising NR NB3 and NG Core5 are supports Bearabesudo transfer using a bearer for each QoS class for each and PDU session, and the packet flow (PDU flow) for each of the QoS handling (eg it may be used when configured to identify a packet flow in the bearer (PDU flow) for packet discard).
[0197]
　Figure 33 shows a further modification of the (NR) Handover Request Acknowledge message. Shown in FIG. 33 (NR) Handover Request Acknowledge message may include either or both of the Session Admitted the List and NG-RABs Admitted List. Session Admitted the List, the resource contains information about one or more sessions of UE1 that has been prepared in the target cell. Format shown in Figure 33, NG System comprising NR NB3 and NG Core5 may be used to support both Bearabesudo transfer and flow-based read transfer. Furthermore, the format shown in Figure 33, NG System comprising NR NB3 and NG Core5 may be used to support flow-based read transfer only.
[0198]
　Figure 34 shows an example of a Forwarding Address format shown in Figure 33. Forwarding Address is for downlink data forwarding information (ie, DL Transport Layer Address and DL Session Endpoint ID) and information for uplink data forwarding (ie, UL Transport Layer Address and UL Session Endpoint ID) including either or both.
[0199]
　Figure 35 shows an example of the format of S1AP Handover Command message sent on the S1 interface to the LTE eNB2 from the MME in EPC4 (eg, step 308 in FIG. 3B). This Handover Command message, including the E-RABs Subject to Forwarding List. E-RABs Subject to Forwarding List shows E-RABs that are subject to data forwarding.
[0200]
　Further, when a handover to "OTHER RAN" from E-UTRAN, in other words Handover Type IE is "LTEtoNR (or LTEtoNGUTRAN)", "LTEtoUTRAN" time, or "LTEtoGERAN", S1AP Handover Command message, NAS including the Security Parameters from E-UTRAN. NAS Security Parameters from E-UTRAN includes a security-related information for the Inter-RAT handover from E-UTRAN (security related information).
[0201]
　Figure 36 is a control node in the NG Core5 (eg, CCNF) NG2AP Handover Command message sent from the LTE eNB2 on NG2 interface shows an example of the format of (eg, step 406 of FIG. 4B). This Handover Command message includes a NE-RABs Subject to Forwarding List. NE-RABs Subject to Forwarding List shows the NextGen E-RABs to be subject to data forwarding. Setup Here, NextGen E-RAB (NE-RAB) via the extended ELTE eNB to support interface with NG Core User plane Function (eg, CUNF) in the UE and NG Core5 between is an E-RAB to be.
[0202]

　The above-described embodiments, each may be implemented independently embodiment all or a portion thereof may be implemented in appropriate combination.
[0203]
　E-URAN and NG RAN described in the above embodiments may be implemented based on the Cloud Radio Access Network (C-RAN) concept. C-RAN may also be referred to as the Centralized RAN. Thus, processing and operations performed by each of the LTE eNB2 and NR NB3 described in the above embodiment is provided by a combination of Digital Unit contained in C-RAN architecture (DU) or DU and Radio Unit (RU) it may be. DU is called the Baseband Unit (BBU) or Central Unit (CU). The RU, Remote Radio Head (RRH), Remote Radio Equipment (RRE), or also called Distributed Unit (DU). DU and RU are a function of the AS layer provided throughout RAN may be provided separated in the DU and RU. For example, in a configuration arranged part of the AS layer (the Layer 2 / Layer 3 or their sublayers, or some functions of the layers) in DU, placing the remaining layers (or part functions of Layer) to RU, DU and the RU may be provided. That is, the processes and operations performed by each of the LTE eNB2 and NR NB3 described in the above embodiments may be provided by any one or more wireless stations (or RAN node).
[0204]
　NR NB 3 may be configured to dynamically change the allocation (allocation) to the DU and RU in the AS layer (Layers) or function. In other words, NR NB 3 may be configured to dynamically change the separation point of the AS layer (Layers) or function between the DU and RU. For example, NR NB 3 may be configured so that one of a plurality of different functions separation options (different functional split options) can be selected dynamically. In this case, in the HO procedure for LTE-to NR in some of the embodiments described above, NG Core5 is, Forward Relocation in response to receiving the Request message or Handover Required message, the NR NB3 of the AS layer or functional DU and RU the distribution may be determined to. Alternatively, NR NB3 may determine the distribution to DU and RU of NR NB3 of AS sublayer or function. NG Core5 or NR NB 3 may be selected from a plurality of functional separation option which is predetermined one functional separation options that apply to NR NB 3.
[0205]
　In one example, function separation options that apply to NR NB 3 is, Forward Relocation Request message or Handover Required message to the E-RAB QoS information IE included, eg QCI, determined on the basis of such an ARP or flow information (selection) is by it may be. Additionally or alternatively, functional separation options that apply to NR NB 3 may be determined based on information about the slice or slices produced by NG Core5 or NR NB3 (slice information). Additionally or alternatively, functional separation options that apply to NR NB 3 may be determined based on the network slice support information included in the NAS information transmitted from the UE1.
[0206]
　Further, in some embodiments described above may include UE identifier in a message transmitted and received between the nodes. The UE identifier is used to identify the UE1 to be handed over in a handover procedure.
[0207]
　More specifically, the UE identifier, a the UE identifier interface between the control nodes corresponding to the MME of the NR NB3 and NG Core5 (eg, Sn interface or NG2 interface, n represents an integer) is used on it may be. The UE identifier, NR NB UE SnAP ID (NR NB UE Sn Application Protocol Identifier) ​​or NR NB UE NG2AP ID may be expressed as.
[0208]
　Alternatively, the UE identifier, the interface between the NR NB3 and LTE eNB2 (eg, Xn interfaces, n represents an integer) may be a UE identifier used on. The UE identifier may be expressed as NR NB UE XnAP ID.
[0209]
　Alternatively, the corresponding UE identifier, the interface between the MME of the control nodes and the EPC4 corresponding to MME of NG Core5 (eg, Sm interface, m is an integer) be the UE identifiers used on good. The UE identifier, for example emme UE SMAP ID and may be expressed.
[0210]
　Alternatively, UE is the UE identifier, the interface between the control node and the LTE eNB2 corresponding to MME of NG Core5 (eg, Sl interface, l is an integer) is used on, assigned and by that control node it may be an identifier. Identifier of this UE may for example emme UE SLAP ID and may be expressed.
[0211]
　Furthermore, these UE ID may be transferred between the nodes in the handover procedure. Incidentally, Sn for identifying each interface described above, NG2, Sm, Sl, and Xn are exemplary, and may be another representation.
[0212]
　Furthermore, the above-described embodiments are only examples for the application of technical ideas obtained by the present inventor. In other words, the technical idea is not limited to the embodiments described above, it is needless to say various modifications are possible.
[0213]
　For example, some or all of the above embodiments, can be described as the following notes, not limited to the following.
[0214]
(Supplementary Note 1)
　A target wireless access network (RAN) node associated with the second network,
　and at least one memory,
　and at least one processor coupled to the at least one memory,
comprising a
　at least one processor is
　in the handover of the radio terminal to the second network from a first network,
　receiving the slice information about the network slice of the wireless terminal in said second network connected from a core network,
　wherein in response to receiving the slice information, the wireless terminal generates a radio resource configuration information used by the second network after the handover,
　transmitting the radio resource configuration information via said first network to said wireless terminal configured to, target R AN node.
[0215]
(Supplementary Note 2)
　the at least one processor is
　configured to receive a handover request message requesting a handover of the wireless terminal to the second network from the first network from the core network, wherein the handover request message , the wireless terminal includes a slice information about the network slices in the second network connected;
　in response to the handover request message, the handover request acknowledge message including a Target to Source Transparent Container in the core network configured to transmit,
　the Target to source Transparent Container encompasses radio resource configuration information derived from said slice information, which and forwarded to the source RAN node associated with the first network via the core network ,
The target RAN node according to Appendix 1.
[0216]
(Supplementary Note 3)
　The slice information, (a) the identity of the network the selected slice for wireless terminals, (b) the type information of the selected network slices for the wireless terminal, or (c) the network node or identification information of the network function associated with the selected network slices for wireless terminals, or any combination thereof,
the target RAN node according to Supplementary note 1 or 2.
[0217]
(Supplementary Note 4)
　The slice information, the includes both mobility class or session classes or network slice supports selected for the wireless terminal,
the target RAN node according to any one of Appendices 1 to 3 .
[0218]
(Supplementary Note 5)
　the at least one processor, based on the slice information, the each bearer or each flow of the wireless terminal, and is configured to determine whether to accept the bearer or flow,
Appendix 1-4 target RAN node according to any one of.
[0219]
(Supplementary Note 6)
　the at least one processor, based on the slice information, and is configured to determine whether it is possible to accept the network slice,
according to any one of Appendices 1 to 5 target RAN node.
[0220]
(Supplementary Note 7)
　A source radio access network (RAN) node associated with the first network,
　and at least one memory,
　and at least one processor coupled to the at least one memory,
comprising a
　at least one processor is
　in the handover of the radio terminal from the first network to a second network,
　the wireless terminal is the second slice information and in said second network about the network slices in the network to be connected a message regarding handover including at least one radio resource configuration information based on network slice, received from the second network,
　configured to send a message about the handover to said radio terminal,
the source RAN node.
[0221]
(Supplementary Note 8)
　the at least one processor is
　configured to send a handover required message to initiate handover of the wireless terminal to the second network from the first network to the core network;
　Target-to the handover COMMAND message including Source Transparent Container is configured to receive from the core network, the target to Source Transparent Container is generated by the target RAN node associated with the second network, the wireless terminal is connected that the second of said encompass radio resource configuration information necessary for the wireless terminal to establish a wireless connection associated with the network slices in the network;
　includes the radio resource configuration information and the second network handover to The is configured to send a mobility COMMAND message to the wireless terminal shown;
source RAN node according to Appendix 7.
[0222]
(Supplementary Note 9)
　A wireless terminal,
　and at least one memory,
　the at least one processor coupled to at least one memory,
comprising a
　at least one processor, a first of said wireless terminal is connected in handover from the network to a second network, the messages relating to the handover comprises at least one of the second radio resource configuration information based on network slices in a network slice slice information and the second about the network in the network configured to receive from the radio access network (RAN) nodes of the first network, the wireless terminal.
[0223]
(Supplementary Note 10)
　the at least one processor,
　the first is the mobility COMMAND message indicating handover to the second network from a network configured to receive from the RAN node, the mobility COMMAND message, the second is generated by the target RAN node associated with a network, radio resource settings required for the wireless terminal to the wireless terminal establishes a wireless connection associated with the network slices in the second network connected It encompasses information;
　by using the radio resource configuration information, wherein with the target RAN node associated with a second network is configured to establish a wireless connection,
the wireless terminal according to supplementary note 8.
[0224]
(Supplementary Note 11)
　A core network node,
　at least one memory,
　the at least one processor coupled to at least one memory,
comprising a
　at least one processor from a first network second in the handover of the radio terminal to the network, configured to send the the target radio access network (RAN) nodes to the slice information about the network slice associated with the second network in the second network to which the wireless terminal is connected It is the,
core network node.
[0225]
(Supplementary Note 12)
　the at least one processor,
　wherein the first source RAN node a handover required message to initiate a handover of the wireless terminal associated with the first network from the network to the second network is configured to receive from;
　in response to the handover required message, is configured to send a handover request message requesting a handover of the wireless terminal from the first network to the second network to the target RAN node the handover request message includes the slice information;
core network node according to Appendix 11.
[0226]
(Supplementary Note 13)
　the at least one processor is further
　configured to receive encompasses handover request acknowledge message from the target RAN node Target to Source Transparent Container, the Target to Source Transparent Container is electrically from the slice information Karel include radio resource configuration information;
　the Target to source Transparent Container which encompassing Handover Command message is constructed to send to the source RAN node;
core network node according to Appendix 12.
[0227]
(Supplementary Note 14)
　The slice information, (a) the identity of the network the selected slice for wireless terminals, (b) the type information of the selected network slices for the wireless terminal, or (c) the identification information of the network node or network capabilities associated with the selected network slices for wireless terminals, or any combination thereof,
the target RAN node according to any one of appendices 11-13.
[0228]
(Supplementary Note 15)
　The slice information, the includes both mobility class or session classes or network slice supports selected for the wireless terminal,
the target RAN node according to any one of Appendices 11-14 .
[0229]
(Supplementary Note 16)
　A method in a target radio access network (RAN) node associated with the second network,
　in the handover of the radio terminal to the second network from the first network,
　the wireless terminal is connected that the second to the slice information about the network slices in the network receives from the core network,
　in response to receipt of said slice information, the radio resource configuration information the wireless terminal uses in the second network after the handover resulting that, and
　it, to be transmitted to the wireless terminal the radio resource configuration information via said first network
comprises a method.
[0230]
(Supplementary Note 17)
　A method in a source radio access network (RAN) node associated with the first network,
　in the handover of the radio terminal from the first network to a second network,
　the wireless terminal is connected said second message related to handover comprises at least one radio resource configuration information based on network slice of slice information and in said second network about the network slices in the network, received from the second network that that, and
　that, to send a message about the handover to said radio terminal
comprises a method.
[0231]
(Supplementary Note 18)
　A method in a wireless terminal,
　the first in the handover from the network to a second network, the second slice information and the second network regarding network slices in a network that the wireless terminal is connected a message regarding handover including at least one radio resource configuration information based on network slices inner comprises receiving from the radio access network (RAN) node of the first network,
the method.
[0232]
(Supplementary Note 19)
　A method in a core network node,
　in the handover of a wireless terminal from a first network to a second network, the slice information about the network slices in the second network to which the wireless terminal is connected comprising sending to the target radio access network (RAN) node associated with the second network,
the method.
[0233]
(Supplementary Note 20)
　A program for causing a process in a computer in the second target radio access network associated with the network (RAN) node,
　the method comprising
　the first network to the second network in the handover of the wireless terminal,
　receiving a slice information about the network slices in the second network to which the wireless terminal is connected from a core network,
　in response to receipt of said slice information, wherein the wireless terminal after the handover generating a radio resource configuration information used in the second network, and
　it, to be transmitted to the wireless terminal the radio resource configuration information via said first network
comprises a
program.
[0234]
(Supplementary Note 21)
　A program for causing a process in a computer in the first source radio access network associated with the network (RAN) node,
　the method
　from the first network to a second network in the handover of the radio terminal,
　a message about the handover comprises at least one of the radio resource configuration information based on network slices in the wireless terminal is the second to be connected in the slice information and the second related to network slices network network and said receiving from the second network, and
　it, to send a message about the handover to said radio terminal
comprises a
program.

The scope of the claims
[Requested item 1]
A target radio access network (RAN) node associated with the second network,
　and at least one memory,
　the at least one processor coupled to at least one memory,
comprising a
　at least one processor ,
　in the handover of the radio terminal to the second network from a first network,
　receiving the slice information about the network slice of the wireless terminal in said second network connected from a core network,
　the reception of the slice information in response to, the wireless terminal generates a radio resource configuration information used by the second network after the handover,
　is configured to transmit the radio resource configuration information via said first network to said wireless terminal that, the target RAN node.
[Requested item 2]
　Wherein the at least one processor is
　configured to receive a handover request message requesting a handover of the wireless terminal to the second network from the first network from the core network, wherein the handover request message, the radio ; terminal includes a slice information about the network slices in the second network connected
　configured to in response to the handover request message, it transmits a handover request acknowledge message including a Target to Source Transparent Container in the core network is,
　the Target to source Transparent Container, said include radio resource configuration information derived from the slice information is and forwarded to the source RAN node associated with the first network via the core network,
claim Target RAN node according to.
[Requested item 3]
　The slice information, (a) the identity of the network the selected slice for wireless terminals, (b) the type information of the network the selected slice for wireless terminals, or (c) for the wireless terminal network node or identification information of the network function associated with the selected network slices, or any combination thereof,
the target RAN node according to claim 1 or 2.
[Requested item 4]
　The slice information, the includes both mobility class or session classes or network slice supports selected for the wireless terminal,
the target RAN node according to any one of claims 1-3.
[Requested item 5]
　Wherein the at least one processor, based on the slice information, the each bearer or each flow of the wireless terminal, and is configured to determine whether to accept the bearer or flow,
any one of claims 1 to 4, target RAN node according to item 1.
[Requested item 6]
　Wherein the at least one processor, based on the slice information, and is configured to determine whether it is possible to accept the network slice,
the target RAN node according to any one of claims 1 to 5, .
[Requested item 7]
　A source radio access network (RAN) node associated with the first network,
　and at least one memory,
　the at least one processor coupled to at least one memory,
comprising a
　at least one processor ,
　in the handover of the radio terminal from the first network to a second network,
　based on network slice of the wireless terminal is the second slice information and in said second network about the network slices in the network to be connected a message regarding handover including at least one radio resource configuration information, received from the second network,
　configured to send a message about the handover to said radio terminal,
the source RAN node.
[Requested item 8]
　Wherein the at least one processor is
　the first from said network to said second network is configured to send a handover required message to initiate a handover of the wireless terminal to the core network;
　the Target to Source Transparent Container encompassing handover COMMAND message is configured to receive from the core network, the target to Source Transparent Container is generated by the target RAN node associated with the second network, the second in which the wireless terminal is connected the encompasses radio resource configuration information necessary for the wireless terminal to establish a wireless connection associated with the network slices in a network;
　a handover to the encompasses radio resource configuration information and the second network mobil shown The ity COMMAND message is configured to transmit to the wireless terminal;
source RAN node of claim 7.
[Requested item 9]
　A wireless terminal,
　and at least one memory,
　the at least one processor coupled to at least one memory,
comprising a
　at least one processor is the second from the first of the network to which the mobile station is connected in the handover to the network, the second of said first network a message regarding handover including at least one radio resource configuration information based on network slice of slice information and in said second network about the network slices in the network configured to receive from the radio access network (RAN) node, the wireless terminal.
[Requested item 10]
　Wherein the at least one processor is
　the first mobility COMMAND message from the network indicating the handover to the second network the is configured to receive from the RAN node, the mobility COMMAND message, associated with the second network is generated by the target RAN node, it includes the radio resource configuration information necessary for the wireless terminal to establish a wireless connection associated with the network slices in the second network to which the wireless terminal is connected ;
　using said radio resource configuration information, wherein with the target RAN node associated with a second network is configured to establish a wireless connection,
the wireless terminal according to claim 8.
[Requested item 11]
　A core network node,
　at least one memory,
　the at least one processor coupled to at least one memory,
comprising a
　at least one processor is a radio from a first network to a second network in the handover of the terminal, configured to send the the target radio access network (RAN) nodes to the slice information about the network slice associated with the second network in the second network to which the wireless terminal is connected,
the core network node.
[Requested item 12]
　Wherein the at least one processor is
　to receive the handover required message for initiating a handover of the wireless terminal to the second network from the first network from a source RAN node associated with the first network is constructed;
　in response to the handover required message, is configured to send a handover request message requesting a handover of the wireless terminal from the first network to the second network to the target RAN node, the handover request message includes the slice information;
core network node according to claim 11.
[Requested item 13]
　Wherein the at least one processor is further
　configured to receive encompasses handover request acknowledge message from the target RAN node Target to Source Transparent Container, the Target to Source Transparent Container is radio resource configuration derived from the slice information It encompasses information;
　the Target-to source Transparent encompassing Handover Command message Container is configured to send to the source RAN node;
core network node according to claim 12.
[Requested item 14]
　The slice information, (a) the identity of the network the selected slice for wireless terminals, (b) the type information of the network the selected slice for wireless terminals, or (c) for the wireless terminal network node or identification information of the network function associated with the selected network slices, or any combination thereof,
the target RAN node according to any one of claims 11 to 13.
[Requested item 15]
　The slice information, the includes both mobility class or session classes or network slice supports selected for the wireless terminal,
the target RAN node according to any one of claims 11 to 14.
[Requested item 16]
　A method in a target radio access network (RAN) node associated with the second network,
　in the handover of the radio terminal to the second network from the first network,
　the second in which the wireless terminal is connected of the slice information about the network slices in the network receives from the core network,
　in response to receipt of said slice information, that the wireless terminal generates a radio resource configuration information used by the second network after the handover, and
　that, to be transmitted to the wireless terminal the radio resource configuration information via said first network
comprises a method.
[Requested item 17]
　A method in a source radio access network (RAN) node associated with the first network,
　in the handover of the radio terminal from the first network to a second network,
　the second in which the wireless terminal is connected of messages about handover including at least one radio resource configuration information based on network slice of slice information and in said second network about the network slices in a network, receiving from the second network, and
　relates to the handover sending a message to the wireless terminal,
comprising the method.
[Requested item 18]
　A method in a wireless terminal,
　network slice of the in the handover from the first network to which the wireless terminal is connected to a second network, the second slice information and in said second network about the network slices in the network at least messages about encompassing handover one comprises receiving from the radio access network (RAN) node of the first network, the radio resource configuration information based on the
method.
[Requested item 19]
　A method in a core network node,
　the first network in the handover of the radio terminal to the second network, the wireless terminal connected to the second in the slice information the second about network slice network comprising sending to the target radio access network (RAN) node associated with the network,
the method.
[Requested item 20]
　The non-transitory computer readable medium storing a program for causing a process in a target radio access network (RAN) node associated with the second network to the computer,
　the method comprising
　the the first network in the handover of the radio terminal to the second network,
　receiving a slice information about the network slices in the second network to which the wireless terminal is connected from a core network,
　in response to receipt of said slice information; the wireless terminal generates a radio resource configuration information used by the second network after the handover, and
　that, to be transmitted to the wireless terminal the radio resource configuration information via said first network
comprises a
non-transitory computer-readable media.
[Requested item 21]
　The non-transitory computer readable medium storing a program for causing a process in the source radio access network (RAN) node associated with the first network to a computer,
　the method
　from the first network in the handover of the radio terminal to the second network,
　at least one of the radio terminal radio resource configuration information based on network slices in the second slice information and the second related to network slices in a network of network connected a message regarding handover includes the receiving from the second network, and
　it, to send a message about the handover to said radio terminal
comprising a
non-transitory computer readable media.
[Requested item 22]
　The non-transitory computer readable medium storing a program for causing a method in a wireless terminal to a computer,
　the method includes, in a handover from a first network to which said wireless terminal connects to the second network, the second radio resource configuration the first messages about handover including at least one of information based on the slice information about the network slices and network slices in the second network in a network of networks of a radio access network (RAN) It comprises receiving from the node,
a non-transitory computer readable media.
[Requested item 23]
　The non-transitory computer readable medium storing a program for causing a process in the core network node to the computer,
　the method includes, in the handover of a wireless terminal from a first network to a second network, the wireless terminal comprises sending to the target radio access network (RAN) nodes to the slice information about the network slice associated with the second network in the second network connected,
non-transitory computer readable media.