1. A method for controlling a session in User Equipment (UE), the method comprising: receiving a Radio Resource Control (RRC) message based on information for Quality of Service (QoS) on a session for transmitting new downlink data and at least one already established data radio bearer; and activating a connection corresponding to the session.

2. A method for controlling a session in an Access Network node, the method comprising: transmitting a Radio Resource Control (RRC) message based on information for Quality of Service (QoS) on a session for transmitting new downlink data and at least one already established data radio bearer.

3. The method according to claim 2, further comprising: receiving a first request message including an Session Identifier (ID) corresponding to the session and at least one QoS profile corresponding to the information of the QoS.

4. A method for controlling a session in an access and mobility management function node, the method comprising: receiving a second request message including a session identifier (ID) indicating a session for transmitting a new downlink data; and transmitting a first request message including the Session ID and at least one Quality of Service (QoS) profile corresponding to QoS on the session.

5. User Equipment (UE), comprising: a memory storing instructions; and at least one processor configured to process the instructions to: receive a Radio Resource Control (RRC) message based on information for Quality of Service (QoS) on a session for transmitting new downlink data and at least one already established data radio bearer, and activate a connection corresponding to the session.

6. An Access Network node, comprising: a memory storing instructions; and at least one processor configured to process the instructions to: transmit a Radio Resource Control (RRC) message based on information for Quality of Service (QoS) on a session for transmitting new downlink data and at least one already established data radio bearer. 7.The Access Network node according to claim 6, wherein the at least one processor is configured to process the instructions to: receive a first request message including an Session Identifier (ID) corresponding to the session and at least one QoS profile corresponding to the information of the QoS. 8.An access and mobility management function node, comprising: a memory storing instructions; and at least one processor configured to process the instructions to: receive a second request message including a session identifier (ID) indicating a session for transmitting a new downlink data, and transmit a first request message including the Session ID and at least one Quality of Service (QoS) profile corresponding to QoS on the session.

METHOD FOR USER PLANE CONNECTION ACTIVATION OR DEACTIVATION PER
SESSION
[Technical Field]
[0001]
The present disclosure relates to a communication system. The disclosure has particular but not
exclusive relevance to wireless communication systems and devices thereof operating according to
the 3rd Generation Partnership Project (3GPP) standards or equivalents or derivatives thereof. The
disclosure has particular although not exclusive relevance to the so-called ‘Next Generation’
systems.
[Background Art]
[0002]
The disclosure includes a method for independent activation or deactivation of user plane
connection per Protocol Data Unit (PDU) session or network slice, where the session contexts in a
User Equipment (UE) and in a network (e.g. a Session Management Function (SMF), and a User
Plane Function (UPF)) are already established. The solution proposes a (Session Management
(SM)) state machine for each established PDU session, where the state machine is maintained either
in the SMF or in a Mobility Management Function (MMF) network function. The SM state
machines run independently of a Mobility Management (MM) state machine.
[0003]
General
The following terminologies are used within this document and can be applied to any generation of
mobile networks like 2G (Global System of Mobile communications (GSM)), 3G (Universal
Mobile Telecommunication System (UMTS)), 4G (Long Term Evolution (LTE)/Evolved Packet
Core (EPC)), 5G (New Radio (NR)/NextGen) or any other. For example, if the “UE” or a “serving
node” is mentioned in the below description, it can be any generation of the UE or the serving node.
[0004]
The terms ‘serving node’, ‘Mobility Management Entity (MME)/Serving General Packet Radio
Service (GPRS) Support Node (SGSN)’, ‘Mobile Switching Centre (MSC)/SGSN/MME’, or
Cellular Internet of Things (CIoT) Serving Gateway Node (C-SGN) is generally used through the
various embodiments of this document to describe a functional entity like the MSC, the SGSN, the
MME, the C-SGN, or other possible control plane functional entities in the mobile network which terminate a control plane signalling (known as a Non Access Stratum (NAS) signalling) between a
core network and a terminal. The serving node (MME/SGSN) can be also a functional entity from
future generation networks which is responsible for mobility and session management.
[0005]
The term Home Subscriber Server (HSS)/Home Location Register (HLR) means a repository where
the UE’s subscription data is stored and can be either the HSS or the HLR or a combined entity.
Instead of the HSS also the term Next Generation User Data Management (UDM), Subscriber
Database Management (SDM) or Authentication Authorization Accounting (AAA) could be used
synonymously.
[0006]
Functional entities or a network function used in this document as separate entities could be also
collocated together or even finer separated in particular deployments or as described in the
architecture figures.
[0007]
The terms ‘terminal’, ‘device’, ‘user terminal’, ‘User Equipment (UE)’, or ‘Mobile Terminal (MT)’
are used in an inter-exchangeable manner where all of the terms express similarly an equipment
used to send/receive data and signalling from the network, a mobile network, or a radio access
network.
[0008]
The term “session” is used in the same meaning as a “PDU session”, a “Packet Data Network
(PDN) connection”, an “Access Point Name (APN) connection”, or a “connection for a particular
network slice”. The existing sessions are those sessions for which already UE context exists (is
established) in the core network control plane and/or user plane and the UE itself. The “existing
sessions” has the same meaning as an “established PDU session” or an “established PDN
connection”. Each session can be identified with a “session ID”, which can be similar to an
“Evolved Packet System (EPS) bearer ID”, the “APN”, a “slice ID”, a “slice instance ID”, a
“service ID” or any other temporary or a permanent identifier of the PDN connection, the PDU
session or a service used by the UE.
[0009]
The term “connection” is mostly used for user plane connection where a kind of “path” is
established to send uplink (UL) or downlink (DL) data between the UE and a user plane Gateway
(GW) terminating the PDU session. Depending on the context, a connection can be either the
whole user plane path for the PDU session; or only a connection over a given interface, e.g. connection over a radio interface, or connection over NG3 interface (between the UPF in a next
generation core network (NG CN) and a (Radio) Access Network ((R)AN).
[0010]
The following terminology for the procedures is used:
- Session establishment: e.g. PDU session establishment where SM context exists (is
established) in the UE and in the NG CN control plane and/or user plane.
- Session release: deletion of the PDU session, which means the SM context is deleted
(released) in the UE and in the NG CN control plane and/or user plane.
- Session/connection activation: activating an UP connection path for session, for which
the SM context exist in the UE and in the NG CN.
- Session/connection deactivation: deactivating the UP connection path without deleting
the SM context in the UE and in the NG CN. With other words just releasing the UP connection.
[0011]
The mobility states of the UE are called De-Registered, Registered-Standby (“Standby” for
simplicity) and Registered-Ready (“Ready” for simplicity). These states are also called MM states.
Please note that there is a difference between the mobility states (the MM states) and session states
(SM states).
[0012]
The telecommunication industry started to work on new generation of network referred as 5th
generation (5G) networks. Activities in multiple research and standardization organizations were
initiated to develop the 5G network which shall offer services to multiple vertical service providers
and serving high variety of terminals. Especially 3GPP in activities were initiated in the RAN area
under the term “New Radio” (NR) and in the core network (CN) under the term “NextGen” (NG).
Please note that those terms will most probably change before the 5G system is introduced to the
market. Therefore terms like NG CN (or NG AN) as used in this document have the meaning of
any 5G CN or AN technology.
[0013]
3GPP studies the NG system architecture and corresponding issues and solutions are captured in
3GPP TR 23.799 [see, NPL 1]. Figure 1 describes the NG architecture for simultaneous access to
multiple PDN connections (called PDU sessions in the NG study), as agreed in [see, NPL 1] by the
time of writing. The upper part of Figure 1 shows an example for NG control plane (NG CP)
including a subscriber database management (SDM) 22, a Policy Control function (PCF) 24 and
Core Control functions (CCFs) 26. The NG CCF 26 includes among others mobility management function (MMF) and session management function (SMF). The user plane (UP) function(s) are
shows as a Core User plane function (NG UPF) 28, as there could be one or multiple UPFs per
PDU session configured. Further information about the description of the interfaces and the
network functions can be found in TR 23.799 clause 7.3 [see, NPL 1].
[0014]
One main feature of a 5G system is called network slicing. The 5G use cases demand very diverse
and sometimes extreme requirements. The current architecture utilizes a relatively monolithic
network and transport framework. Thus, it is anticipated that the current architecture is not
flexible and scalable enough to efficiently support a wider range of business needs. To meet such
needs, the 5G NG system can be “sliced” in multiple network instances which are referred as
network slice instances (NSI). The network slices can be referred as logically separated networks
where the resources (processing, storage and networking resources) for different network slices are
isolated. A network operator uses a Network Slice Template/Blueprint to create a NSI. The NSI
provides the network characteristics which are required by a Service Instance. One example of
network architecture allowing a UE to connect to multiple NSIs simultaneously is shown in Figure
2, as described in [see, NPL 1].
[0015]
Figure 2 shows a first network slice type/category (e.g. for IoT services) and a second slice type (e.g.
for broadband services). The second network slice type can have multiple NSIs for particular 3rd
party customers. This figure shows that the (R)AN is shared and network slicing is applied in the
NG CN. However, in future also network slicing the (R)AN is possible where the RAN resources
are sliced/isolated, either in baseband processing or in frequency spectrum or both.
[0016]
[NPL 1] also describes the Common Control Network Functions (CCNF) 32 and Slice-specific
Control Plane Network Functions (SCNF), as shown in detail in Figure 3. The CCNF 32 can
include fundamental control plane network functions to support basic functions operation common
among the NSIs, for example:
1. Subscriber Authenticator,
2. Mobility Management,
3. Network Slice Instance Selector (NSI Selector),
4. NAS Routing Function, etc.
[0017]
In general, the NG system design should enable the transmission of any kind of data. It is assumed that the NG system supports the following PDU session types:
- IP type (e.g. IPv4 or IPv6 or both), or
- non-IP session (any unstructured data) or
- Ethernet type.
[0018]
One further solution described in 23.799 in clause 6.4.3 is shown in Figure 4. The UE 34 may
establish multiple PDU Sessions to the same data network in order to satisfy different connectivity
requirements of different applications (e.g. session continuity) that require connectivity to the same
data network. In this solution, the MM and SM functions are separated. With this, one main
concept is that multiple SM contexts can be available per MM context. Also, different session
continuity types per PDU session are possible.
[Citation List]
[Non Patent Literature]
[0019]
[NPL 1]
3GPP TR 23.799 v0.6.0, 2016-07, “Study on Architecture for Next Generation System”
[NPL 2]
3GPP TS 23.401, v14.0.0, 2016-06, “General Packet Radio Service (GPRS) enhancements for
Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access”
[Summary of Invention]
[Technical Problem]
[0020]
The scenario considered in this document is that a UE is attached to the network and can be
associated with multiple UP-GWs (UPFs). The different UPFs can be part of the (a) same PDU
session, (b) part of different PDU sessions, or (3) part of different network slice instances (NSIs).
With other words, multiple NG3 connections (e.g. tunnels over NG3 interface) between the (R)AN
and the UP-GWs can be available. If the UE has established multiple PDU sessions, then multiple
Session Management Function (SMF) instances may exist per UE.

WE CLAIM:
1. A method for controlling a session in User Equipment (UE), the method comprising:
receiving a Radio Resource Control (RRC) message based on information for Quality of Service (QoS) on a
session for transmitting new downlink data and at least one already established data radio bearer; and
activating a connection corresponding to the session.
2. A method for controlling a session in an Access Network node, the method comprising:
transmitting a Radio Resource Control (RRC) message based on information for Quality of Service (QoS) on a
session for transmitting new downlink data and at least one already established data radio bearer.
3. The method according to claim 2, further comprising:
receiving a first request message including an Session Identifier (ID) corresponding to the session and at least
one QoS profile corresponding to the information of the QoS.
4. A method for controlling a session in an access and mobility management function node, the method
comprising:
receiving a second request message including a session identifier (ID) indicating a session for transmitting a
new downlink data; and
transmitting a first request message including the Session ID and at least one Quality of Service (QoS) profile
corresponding to QoS on the session.
5. User Equipment (UE), comprising:
a memory storing instructions; and
at least one processor configured to process the instructions to:
receive a Radio Resource Control (RRC) message based on information for Quality of Service (QoS)
on a session for transmitting new downlink data and at least one already established data radio bearer, and
activate a connection corresponding to the session.
6. An Access Network node, comprising:
a memory storing instructions; and
at least one processor configured to process the instructions to:
transmit a Radio Resource Control (RRC) message based on information for Quality of Service (QoS)
on a session for transmitting new downlink data and at least one already established data radio bearer.
7.The Access Network node according to claim 6, wherein the at least one processor is configured to
process the instructions to:
receive a first request message including an Session Identifier (ID) corresponding to the session and
at least one QoS profile corresponding to the information of the QoS.
8.An access and mobility management function node, comprising:
a memory storing instructions; and
at least one processor configured to process the instructions to:
receive a second request message including a session identifier (ID) indicating a session for
transmitting a new downlink data, and
transmit a first request message including the Session ID and at least one Quality of Service (QoS)
profile corresponding to QoS on the session.