The present invention concerns the field of wireless communication systems, such as a mobile communication network. Embodiments of the present invention relate to the access control of network slices implemented in a wireless communication system.

Conventionally, different services use a corresponding number of dedicated communication networks, each tailored to the respective service to be implemented. Instead of using a plurality of specifically designed networks, another approach, known as network slicing, may use a single network architecture, like a wireless communication network, on the basis of which a plurality of different services is implemented.

Fig. 1 is a schematic representation of a system for implementing different services using the concept of network slices. The system includes physical resources, like a radio access network (RAN) 100. The RAN 100 may include one or more base stations for communicating with respective users. Further, the physical resources may include a core network 02 having, e.g., respective gateways for connections to other networks, a mobile management entity (MME), and a home subscriber server (HSS). A plurality of logical networks #1 to #n, also referred to as network slices, logical networks or subsystems, are implemented using the physical resources depicted in Fig. 1. For example, a first logical network #1 may provide a specific service to one or more users. A second logical network #2 may provide for an ultra-low reliable low latency communication (URLLC) with users or equipment. A third service #3 may provide general mobile broadband (MBB) services for mobile users. A fourth service #4 may provide for a massive machine type communication (mMTC). A fifth service #5 may provide health services. Yet further services #n, to be determined, may be implemented using additional logical networks. The logical networks #1 to #n may be implemented at the network side by respective entities of the core network 102, and access of one or more users of the wireless communication system to a service involves the radio access network 100.

Fig. 2 is a schematic representation of an example of the wireless network 100 or wireless network infrastructure of the wireless communication system of Fig. 1. The wireless

network 100 may include a plurality of base stations eNBt to eNB5, each serving a specific area surrounding the base station schematically represented by the respective cells 106! to 1065. The base stations are provided to serve users within a cell. A user may be a stationary device or a mobile device. Further, the wireless communication system may be accessed by loT devices which connect to a base station or to a user. loT devices may include physical devices, vehicles, buildings and other items having embedded therein electronics, software, sensors, actuators, or the like as well as network connectivity that enable these devices to collect and exchange data across an existing network infrastructure. Fig. 2 shows an exemplary view of only five cells, however, the wireless communication system may include more such cells. Fig. 2 shows two users UE1 and UE2, also referred to as user equipment (UE), that are in cell 1062 and that are served by base station eNB2. Another user UE3 is shown in cell 1064 which is served by base station eNB4. The arrows 1081 t 1082 and 1083 schematically represent uplink/downlink connections for transmitting data from a user UE-i, UE2 and UE3 to the base stations eNB2, eNB4 or for transmitting data from the base stations eNB2, eNB4 to the users UE1 f UE2, UE3. Further, Fig. 2 shows two loT devices 110! and 1102 in cell 1064, which may be stationary or mobile devices. The loT device 110i accesses the wireless communication system via the base station eNB4 to receive and transmit data as schematically represented by arrow 1121 = The loT device 1102 accesses the wireless communication system via the user UE3 as is schematically represented by arrow 1122.

The wireless communication system may be any single-tone or multicarrier system based on frequency-division multiplexing, like the orthogonal frequency-division multiplexing (OFDM) system, the orthogonal frequency-division multiple access (OFDMA) system defined by the LTE standard, or any other IFFT-based signal with or without CP, e.g. DFT-s-OFDM. Other waveforms, like non-orthogonal waveforms for multiple access, e.g. filter-bank multicarrier (FBMC), generalized frequency division multiplexing (GFDM) or universal filtered multi carrier (UFMC), may be used.

For data transmission, a physical resource grid may be used. The physical resource grid may comprise a set of resource elements to which various physical channels and physical signals are mapped. For example, the physical channels may include the physical downlink and uplink shared channels (PDSCH, PUSCH) carrying user specific data, also referred to as downlink and uplink payload data, the physical broadcast channel (PBCH) carrying for example a master information block (MIB) and a system information block (SIB), the physical downlink control channel (PDCCH) carrying for example the downlink control information (DCI), etc. For the uplink, the physical channels may further include the physical random access channel (PRACH or RACH) used by UEs for accessing the network once a UE synchronized and obtained the IB and SIB. The physical signals may comprise reference signals (RS), synchronization signals and the like. The resource grid may comprise a frame having a certain duration, e.g. a frame length of 10 milliseconds, in the time domain and having a given bandwidth in the frequency domain. The frame may have a certain number subframes of predefined length, e.g., 2 subframes with a length of 1 millisecond. Each subframe may include two slots of 6 or 7 OFDM symbols depending on the cyclic prefix (CP) length. The PDCCH may be defined by a pre-defined number of OFDM symbols per slot. For example, the resource elements of the first three symbols may be mapped to the PDCCH.

The above described wireless communication system may be a 5G wireless communication system which may allow network slicing. As mentioned above, the logical networks or slices are implemented at the network side 102, but there is also an effect on the radio access network 100. The resources provided by the radio access network 100 are shared between the respective slices, for example, they are assigned dynamically by a scheduler of a base station. At the radio access network 100, for one or more of the slices #1 to #n, which may use a different numerology, respective logical radio access networks 114! to 114n are defined. A logical radio access network defines for a certain slice the resources of the radio access network 100 to be used. For example, for one or more different services, in the frequency domain, a certain subband or a certain number of carriers of the radio access network 100 may be used. In accordance with other examples, the physical separation may be in time, code or spatial domains. In spatial domain, separation may be performed using special beamforming techniques. Such a separation may be used for services using different numerologies, e.g., different physical layer parameters such as subcarrier distance, cyclic prefix length, modulation or access scheme. For services using the same numerology different predefined physical resource blocks may be used.

Fig. 3 is a schematic representation of a plurality of logical radio access networks or logical RANs 114, to 114 , also referred to in the following as RAN subsystems, for a wireless communication system implementing the logical networks or subsystems #1 to #4. Fig. 3 assumes services implemented by respective subsystems #1 to #4 using different numerologies which are physically separated in the frequency domain. Fig. 3 schematically represents a part of physical resource grid to be used. Each of the logical RANs 11 ! to 1142 to be used for a specific subsystem #1 to #4 has assigned a certain bandwidth or a number of continuous carriers in the frequency domain. In accordance with other examples, a service may have assigned multiple subbands or different carriers. Fig. 3 schematically represents the transmission of downlink control information 116 for the respective subsystems #1 to #4. The control information 116 for all of the subsystems #1 to #4 is transmitted only on the resources for the subsystem #3. The control information 116 may include the control channels and control signals, e.g., the synchronization signals, the common reference symbols, the physical broadcast channel, the system information, paging information and the like. Instead of transmitting control information for each of the subsystems #1 to #4, the control information 116 is only transmitted once on the resources of the subsystem #3. The subsystems #1 , #2 and #4 also listen to these resources to see whether any control information form them is transmitted. In the example of Fig. 3, the logical RANs 114-1 to 1144 are provided for specific subsystems #1 to #4, namely for subsystems providing an enhanced mobile broadband (e BB) service, an ultra-low reliable low latency communication (URLLC), an enhanced massive machine type communication (eMTC), or another service not yet specified. Providing the control information 116 in a way as depicted in Fig. 3 is resource efficient as only one transmission is needed for ail subsystems #1 to #4, instead of transmitting separate control information for each of the subsystems #1 to #4 via the respective the logical RAN 114i to 1 44.

Fig. 3 refers to the resource sharing during the downlink. However, the resources may also be shared during the uplink. For example, during a connection setup, the resources for the random access channel (RACH) may be shared, e.g., like in the downlink also in the uplink the RACH information is only transmitted on the resources of the subsystem #3. For example, the control information 116 may indicate the common uplink random access resources to be used for the random access procedure. The RACH may be operated at relatively low load to avoid collisions and thus multiple transmissions and added latency. For example, a four-step RACH procedure may be used, as it is illustrated in Fig. 4. In a radio access network, such as the one depicted in Fig. 2, a UE, after sending an uplink random access preamble © in the uplink, monitors for a random access response message © from the base station generated by the MAC layer and transmitted on the shared channel. Dependent on the cause of the RACH message, for example, an initial connection set-up using a radio resource control (RRC) connection request or a request for re-establishing a connection, different RRC messages may be sent in the uplink. Following the access, respective scheduled transmissions ® are performed. There may

be a further response message ® from the base station to resolve collisions with other UEs that may happen during the access procedure.

Mobile communication systems may also provide for an access control so as to control the access of UEs to the system, e.g., to the entire system or only to one or more cells of the system to avoid congestion and overflow. One mechanism is the so-called access class barring (ACB), in accordance with which certain cells limit access to certain classes of UEs. ACB is broadcast by the base station of the cell to control the random access procedure. Other congestion control mechanisms, such as an RRC reject or a Non-access stratum (NAS) reject, may require additional signaling at the RRC layer, the NAS layer or a higher layer. In such a case, the fully overloaded system may not even be capable transmitted successfully such a control signaling, despite its usually high priority. For example, in accordance with the LTE standard, ACB provides means to control access of regular devices with access classes 0 to 9, and to limit access to only special access classes, for example to:

special AC 11 Reserved for Network Operator

special AC 12 Security Services (police, surveillance, etc.)

special AC 13 Public Utilities (water, gas, electricity, etc.)

special AC 14 Emergency Services

special AC 15 Network Operator Staff (maintenance, etc.)

AC 10 may control as to whether any emergency calls are allowed for regular devices or not.

There may be another congestion and overload control mechanisms defined at the radio and network levels. For example, the following admission and overload control mechanisms are defined by the LTE standard:

Radio Rel.8 eNB Access Class Barring (idle UEs)

Radio Rel.8 RRC Reject Message (connected UEs)

NW Rel.8 NAS reject message or data throttling

Radio/NW Rel.9 Service Specific Access Control (SSAC)

Radio/NW Rel.12 Skip Access Class Barring for MMTel

Radio/NW Rel.13 Application specific congestion control

In other wireless communication network systems, such as the 5G wireless communication system, a single or common access control scheme may be used. As long as a wireless communication system operates under standard circumstances, it is beneficial to share the resources among the respective logical RANs, as explained above, however, sharing resources among the network slices may not be efficient in each and every situation in which a network is operated.

It is an object of the present invention to provide for an improved concept for accessing logical radio access networks of a wireless communication system.

This object is achieved by the subject matter as defined in the independent claims.

Embodiments are defined in the dependent claims.

Embodiments of the present invention are now described in further detail with reference to the accompanying drawings, in which:

Fig. 1 is a schematic representation of a system for implementing different services using the concept of network slices;

Fig. 2 shows a schematic representation of an example of the wireless network or wireless network infrastructure of the wireless communication system of Fig. 1 ;

Fig. 3 is a schematic representation of a plurality of logical radio access networks for a wireless communication system implementing logical networks;

Fig. 4 illustrates a conventional four-step RACH procedure;

Fig. 5 shows an embodiment for prioritizing eMBB operations over mMTC operations during the daytime;

Fig. 6 shows on the left the situation of Fig. 3 assuming a regular operation of the system, i.e., working in a first operation mode, and on the right the

configuration of the system when operating in a second operation mode, for example, in case of an emergency;

shows an embodiment for implementing control access on the basis of additional access control information;

Fig. 7(a) and Fig. 7(b) show another embodiment for implementing control access using a first operational mode executed during an initial attach of the UE, and a second operational mode once the UE is configured with additional access control information by the network;

Fig. 8 shows an embodiment in which the system information blocks are split into general control information for all UEs, and additional control information for the different subsystems;

Fig. 9 shows a location specific group access in accordance with an embodiment of the present invention;

Fig. 10 schematically shows an access control hierarchy using a basic access control and a detailed access control in accordance with embodiments of the present invention;

schematically shows an access control hierarchy with detailed access control information provided by the subsystems in accordance with embodiments of the present invention;

Fig. 12 shows a block diagram for the acquisition of system information in accordance with an embodiment of the present invention;

Fig. 13 is a schematic representation for the isolation of control signals and channels for certain subsystems, such as a PPDR (public protection and disaster relief) subsystem;

Fig. 14 is a schematic representation of a plurality of logical radio access networks for a wireless communication system implementing logical networks in the downlink and in the uplink;

Fig. 15 schematically shows the acquisition of system information for the use of RACH resources;

Fig. 16 is a schematic view of a two-step RACH procedure in accordance with an embodiment of the present invention;

Fig. 17 schematically represents an RRC state model for a wireless communication system, such as a 5G system;

Fig. 18 is a schematic representation of a wireless communication system for communicating information between a transmitter and a receiver; and

illustrates an example of a computer system on which units or modules as well as the steps of the methods described in accordance with the inventive approach may execute.

In the following, preferred embodiments of the present invention are described in further detail with reference to the enclosed drawings in which elements having the same or similar function are referenced by the same reference signs.

As mentioned above, when a wireless system operates regularly, the above described sharing of the resources is beneficial. However, there may be situations in which such sharing needs tighter control, for example, in response to specific events or at specific times. In accordance with the present invention the physical resources of the wireless communication network assigned to the logical radio access networks are selectively controlled, and/or access of the users or user groups to one or more of the logical radio access networks is controlled. More specifically, embodiments of the present invention introduce a more flexible handling of resources for an access control (first and second aspects) and for the configuration of the RACH resources (third aspect).

In accordance with the first aspect, a subsystem specific access control is described, and in accordance with the second aspect, the system information is split into a first part, which is referred to as basic access control (BAC) and defines general access control parameters, and into a second part, which is referred to as detailed access control (DAC) and defines subsystem specific access control parameters. In accordance with the third aspect a dynamic RACH resource sharing/isolation is described. It is noted that all aspects and embodiments may be combined and used together, except they are mutually exclusive.

First Aspect

In accordance with embodiments of the first aspect of the present invention, the common downlink system information, for example, the broadcast channel may be used to adaptively control access to the respective subsystems, via the associated logical radio access networks.

When the wireless communication system operates in a first operation mode, access to all of the subsystems may be allowed. When the wireless communication system operates in a second operation mode, in accordance with the inventive approach, the number of subsystems to which access is allowed and/or the number of users allowed to access the system may be limited. The access control may be performed by a base station of a cell, when the wireless communication system is in the second operation mode in which access control is desired. For example, this may be the case in an emergency or when specific events occur or at specific days or times. Further, the wireless communication system may cover a large geographical area, and the access control may not be required in the overall area covered but only in one or more subareas or cells in which the event occurred. In such a case, only the base stations serving the cells or defining a subarea may perform the inventive access control. Base stations in other areas may operate without the inventive access control, i.e., the resources are shared among all subsystems implemented. In the other areas, the system operates in the first operation mode, which may be a regular mode. In specific cases, such as nation-wide emergency cases, the entire wireless subsystem may operate on the basis of the inventive access control approach. When not all of the base stations or cells are operated in accordance with the inventive access control approach, users at the edge of a cell or a subarea for which the limited access control is performed, may try to access the desired subsystem in neighboring cells, provided this is allowed and sufficient connectivity is given.

As mentioned above, in accordance with embodiments, the switching from the first operation mode to the second operation mode may occur responsive to predefined events, such as

emergency situations,

overload situations,

special events,

specific minimum requirements of one or more of the subsystems operated, or a certain day or time.

Fig. 5 shows an embodiment for prioritizing eMBB operations over m TC operations during the daytime. On the left, Fig. 5 schematically represents the access control during the nighttime, during which access is allowed to all of the subsystems #1 to #4. During the daytime, however, control is restricted to subsystems #1 to #3. The physical resources, which are assigned to the logical RAN 1144 for the subsystem #4 during the night time, are assigned to the logical RAN 1143 for the subsystem #3 during the daytime, i.e., the mMTC subsystem is no longer accessible. In accordance with embodiments, access control is achieved by no longer scheduling any resources for the radio access to the subsystem #4, i.e., the logical RAN 1144 is no longer present. The embodiment of Fig. 5 is advantageous as it allows a delay un-critical service, as provided by the mMTC subsystem #4, to be temporarily barred so as to limit this service to a specific time, like the nighttime, during which the massive machine type communications may be performed. For example, sensors or machines which provide data that is not time critical may be read out via the wireless communication system once a day. During the daytime, this allows for an increase in the available resources that may be used for the other subsystems. In the embodiment of Fig. 5, while the resources associated with the subsystems #1 and #2 remain the same, the resources associated with the eMBB subsystem #3 are increased.

In accordance with further embodiments, one or more of the respective subsystems may be further differentiated, for example, in terms of different service qualities of a service provided by the respective subsystem. For example, when considering the eMBB subsystem, some services provided by this subsystem may include the transmission of specific data, such as video data, in different service qualities. Services may provide video content to users with a high quality so as to fulfill the user experience when downloading video information, whereas other services, such as security services, provide video information with a quality that depends, for example, on whether a specific event requires more details of the scene currently recorded or as to whether only a surveillance to monitor an area for moving objects is performed. Dependent on such services, the subsystem may be further differentiated into bandwidth classes, and for different service qualities respective bandwidth may be assigned so that the different service qualities may be prioritized. The specific access control class (AC class) may be signaled to the UEs

together with additional information about the video qualities available, which may be different for different users. In other words, according to embodiments, to limit or suspend one or more services using the logical radio access network the base station may select for one or more users or user groups of a service a certain service quality from different service qualities, like video quality, and/or bandwidth, and/or latency, e.g., in terms of number of resources grants in a given time interval.

The embodiment as described with reference to Fig. 5 allows for gradually evacuating the wireless communication system such that specific services on existing connections may be scaled-down or even terminated. This may be achieved by using specific signaling protocols. For example, in order to offload video users in case of emergency events, a signaling is provided to regular users to "stop streaming/requesting new data" for example, by using a DASH SAND message. Further, if one or more of the subsystems demands a higher capacity, for example, in case a PPDR (PPDR = public protection and disaster relief) UE requests high data rates without terminating other subsystems, the DASH SAND message may be used in an existing DASH session so as to scale down the video service. A similar mechanism may be applied for other services, for example, to terminate or limit software updates, e.g., sessions with online stores. The particular DASH SAND message may be triggered by a network entity, such as the HSS (home subscriber register) the MME or the DANE (Dash Aware Network Element), or it may directly be triggered by the base station. In case scaling down is not sufficient, the inventive approach for controlling access may completely shut down subsystems by admission control on other layers.

In the embodiments described above, it has been described that one specific subsystem, like the mMTC subsystem #4, may be temporarily barred. The invention is not limited to such embodiments. Other subsystems may be barred dependent on other events, such as other times or dates, on the basis of reoccurring events or in case of an emergency. In the latter case, an example for a subsystem that may be prioritized over other subsystems is the PPDR subsystem. Such a subsystem may be prioritized over the other subsystems in case of an emergency, such as a terrorist attack or a disaster, so as to avoid overload situations in the entire wireless communication system or in affected cells of the system. For example, all or most of the other subsystems may be shut down so that access is only possible to the wireless communication system by PPDR UEs, i.e., regular UEs may not be able to access the system anymore. In accordance with further embodiments, one or more of the subsystems, besides the PPDR subsystem, may remain operative; however,

with a lower priority than the PPDR subsystem. For example, the subsystem allowing emergency calls may remain operative; however, to avoid an overflow of the network and the blocking of RACH resources, emergency calls may only be allowed with a priority lower than any communication in the PPDR subsystem.

In the embodiments described so far, access control included the barring of one or more subsystems from access; however, in accordance with further embodiments, access control may also be achieved by gradually reducing the number of UEs that are allowed to access one or more of the subsystems via the respective logical RANs 11 i to 1144. The control information 116 may signal to a UE a time period during which the subsystem is not accessible, also referred to as a barring time, so as to inform the UE about the next time at which an access is possible. The related access barring back-off parameters may be subsystem-specific parameters. Further, the control information may indicate that a specific subsystem, like the above described mMTC subsystem, is generally supported and that the UE requesting access to such a system stays connected to the network; however, that access is temporarily barred. Once the access is allowed again, the UE can immediately connect to the service provided by the respective subsystem. In accordance with other embodiments, in case the control information signals that the service provided by a specific subsystem is generally supported but temporarily not available, the UE may start a scan for other subsystems providing the same or similar services.

In accordance with the embodiments described so far, a specific event, such as a specific time, date was assumed to trigger the access control; however, in accordance with further embodiments, such events may be reoccurring events. For such reoccurring events an access schedule may be provided as a part of the system information that is, for example, transmitted upon connection set-up via the system information to the UE. The access schedule may indicate, when considering the embodiment of Fig. 5, that during nighttime the mMTC subsystem #4 is available, but not during the daytime. Another reoccurring event is, for example, that people commute during the day and are in the office so that during this time high-speed mobile broadband services as provided by the eMBB subsystem #3 are required, while during nighttime the required eMBB capacity may be decreased significantly, thereby freeing resources which may be used for another subsystem, e.g., for a URLLC communication in subsystem #2. In accordance with yet further embodiments, rather than providing the access schedule as a part of the system information, it may also be signaled as part of the control information, for example, a daily schedule about which subsystem is served at what time of the day, may be submitted.

Different schedules may be transmitted for different days, for example, weekdays may use a first schedule and weekend days may use a second, different schedule.

In the embodiments described above, access to one of the subsystems has been barred; however, in accordance with further embodiments, the inventive access control may limit access to only one subsystem. In accordance with an embodiment, the subsystem #1 accessed via logical radio access network 1 14† may be a PPDR subsystem. The inventive access control may limit access only to the PPDR subsystem #1 while barring all other subsystems #2 to #4. This is schematically depicted in Fig. 6, which shows on the left the situation of Fig. 3 assuming a regular operation of the system, and on the right the configuration of the system in the second operation mode, for example, in case an emergency occurred. In Fig. 6, responsive to switching the wireless communication system or a part thereof into the second operation mode, access to the subsystems #2 to #4 via the logical RANs 114i to 1 144 is no longer possible. All resources are scheduled to the logical RAN 1 14: for accessing the PPDR subsystem #1. Limiting access to one of the subsystems is advantageous as, for example, in the PPDR subsystem #1 mission-critical operations may require a higher bandwidth. For example, HD (high definition) videos may be transmitted permanently from a disaster area or during a mission-critical operation. However, it is not efficient to reserve such a huge amount of resources permanently, while such events may happen only rarely. Further, it is not necessary to reserve the amount of resources for the entire system permanently as, even in case such an event occurs, it is likely that it is only occurring in a limited region of the area covered by the wireless communication system. Thus, in such exceptional cases, the approach, as explained with reference to Fig. 6, allows providing the PPDR subsystem #1 with a sufficiently large transmission capacity, in case the exceptional situations occur. The outage of the general services to other UEs, in such exceptional cases, may be acceptable.

In the above described embodiments, when specific services are disabled so as to free resources for high priority services, the base station may redirect UEs from the currently used subsystem, which no longer provides the service or provides the service with a reduced quality, to other subsystems still providing the service. In accordance with embodiments, an inter-subsystem handover or redirection signaling to all UEs connected to the subsystem is provided. For example, the UEs of a subsystem may form a group having a specific group or subsystem identity. By signaling the group identity, all of the UEs currently connected or making use of the specific subsystem may be identified and addressed. The signaling may be sent via a paging channel or a common control channel, and part of the signaling may be information about the new or target subsystem to which the UEs are redirected, such as the carrier frequencies, cell identity, access technology type (like FDD or TDD), and/or subframe configuration details of the new subsystem now providing the service.

Now, further embodiments are described for realizing the inventive subsystem based admission control in case of shared resources so as to allow providing resource sharing during a first mode of operation of the system or parts of the system, like a regular operation, and a second mode of operation, like resource isolation, in exceptional cases. The inventive access control may also be referred to as a basic access control (BAC) which may be realized in accordance with the subsequently described embodiments.

In accordance with a first embodiment of the BAC, the control information 116 may include one or more bits, preferably a single bit. The control information provided by a base station to the UEs is to inform the UEs whether a certain subsystem is supported or not. For example, when considering Fig. 5 and Fig. 6, the control information may include information as represented in the following table:

In accordance with a second embodiment of the BAC, the control information 116 may include access control information, like a single bit or multiple bits, which indicates that only certain devices, such as UEs or loT devices, have access to one or more of the subsystems. For example, in case of one of the above mentioned events the wireless communication system, at least in part, operates in the second operation mode. The following table shows an embodiment for a single bit access control information indicating that for specific subsystems only specific UE types are allowed to access or not access, i.e., are barred or not barred.

Indicator Meanin

Access Control for eMBB devices UE type barred / not barred

Access Control for URLLC devices UE type barred / not barred

Access Control for mMTC devices UE type barred / not barred

Access Control for PPDR devices UE type barred / not barred

For example, in Fig. 6 a single bit may limit access to the system only to PPDR devices.

In accordance with other embodiments, the access control information given in the table above may be used to block specific UE hardware or software. In such a case, additional information may be signaled for the access control purpose, for example, the equipment type, such as the IMEI (international mobile equipment identity) or a software version (SV), for example, IMEI-SV. The access control in accordance with this embodiment provides additional functionality included into the radio layers at the UE and at the base station. Conventionally, the UE type is known to the higher layers in the UE, for example, it may be stored on the SIM (scriber identity module) card. In the network, UE type is also known at the higher layer and may be stored in the HSS or the MME. However, conventionally, the UE type is not known at the radio layer of the UE, for example, at the radio resource control (RRC) layer. In accordance with embodiments, for implementing the access control on the basis of the UE type during the connection set-up phase, the RRC layer may consider the UE terminal type during the access control procedure, and the UE RRC layer is informed about the parameter describing the UE type. More specifically, the higher layer (e.g. NAS protocol) of the UE informs the lower layer of the UE either during the connection/call/session set-up phase, or the lower layer (e.g. RRC protocol) may have stored this information from previous procedures, for example, from an initial connection set-up.

In accordance with a third embodiment of the BAC, the control information 116 may include access control information per subsystem. For example, a single bit or multiple bits may made be used to bar a complete subsystem, as indicated in the table below. For example for each subsystem of Fig. 5 and Fig.6 a single bit indictor may be provided in the controi information 116 indicating that the respective subsystem is barred or not barred.

In accordance with this embodiment, for implementing the inventive access control scheme, the UE radio functions, such as the RRC layer, are made aware of the

subsystem that is to be accessed, which may be performed in a way as described above with regard to the second embodiment.

in accordance with a fourth embodiment of the BAC, the control information 116 includes information, like one or more bits, to indicate that additional access control information must be obtained. The system information that is broadcast to all UEs may be limited, however, when using only a limited number of bits, preferably a single bit, the additional information that needs to be signaled is reduced. On the basis of this additional information the UEs are requested to obtain additional system information with additional control parameters before actually accessing the subsystem, e.g., via an associated logical RAN. The additional information, as is shown in the table below, indicates, e.g. in the system information, that prior to actually starting the access procedure, additional access class barring information is to be obtained and considered. The additional information to be obtained may be the information described with regard to the first, second and third embodiments of the BAC.

Fig. 7 shows an embodiment for implementing the control access on the basis of additional access control information. In Fig. 7, a wireless communication system is assumed which is similar to the one in Fig. 5 and Fig. 6; however, only three subsystems #1 to #3 are implemented. In this embodiment, the PPDR subsystem #1 , the URLLC subsystem #2 and the eMBB subsystem #3 are provided, which are accessed via the respective logical RANs 114i to 1143. When compared to Fig. 5 and Fig. 6, the control information now includes first control information 116a and second control information 116b. For example, when system information transmitted, for example, via the SIB, the control information 116a may include a bit which, when being set, indicates that the wireless communication system or at least part thereof operates in accordance with the second operation mode. When the bit is set, a UE is not allowed to access the system right away, but needs to obtain additional access class barring information provided by the additional control information 116b. Like in the embodiments described so far, the additional control information 116 for all of the subsystems may be transmitted only on the resources for one of the subsystems, in the depicted embodiment the resources of the subsystems #3.

in accordance with another embodiment a first operational mode, using, e.g., the access control based on BAC, is only executed during an initial attach of the UE, see for example Fig. 7(a), while a second operational mode is used once the UE is configured with additional access control information by the network, see for example Fig. 7(b). The additional access control information may be mapping information to map a group identity, a subsystem identity, a certain device type or specific services to a newly defined access category to be used in a second operational mode of access control. This allows a flexible mapping of various parameters to a single parameter that can be used for access control.

During the initial step, after receiving the basic system information from the gNB (see message "0" in Fig. 7(a)), the UE may access the system on a first logical access network or default access network using a first set of access parameters, e.g., a first or default access category (see messages "1 " and "2" in Fig. 7(a)). In this initial access attempt the UE does not have a detailed network configuration such as an access category for access control. It may thus use a preconfigured access category, a default access category or a configuration based on the service type but not on the network slice. Once the access category is decided the UE reads the RRC System Information (see messages "3" and "4" in Fig. 7(a)), e.g., which access category is barred and which is not barred, to get to know if it is allowed to access the base station or not (see message "4" in Fig. 7(a)).

Once the UE is connected to the network, the network configures the UE with additional control information 1 16b (see message "5" in Fig. 7(b)). The additional control information may include slice specific configurations as well as additional access control information such as the mapping information to map a group identity, a subsystem identity, a device type or a service type to an access category. As is shown in Fig. 7(b), such control and mapping information may be provided by a higher layer protocol such as the Non-Access Stratum protocol (NAS). By means of NAS messages are exchanged between the UE and the next generation network via the 5G base station.

After the UE is configured with the mapping information, the UE operates in a second mode. In this mode the UE considers its newly assigned access category in the access control process (see for example Fig. 7(b)). Before accessing the base station, e.g., due to a mobile originating call or session, once again the UE needs to identify the access category that is applicable for this specific access attempt (see messages "0" to "5" in Fig. 7(b)). Due to the flexible configuration, there may be various criteria such as access to a specific network slice, a specific service type, e.g., an emergency call, a specific terminal type etc. Once the access category is known the UE checks the RRC System Information whether this respective access category is barred or not. In accordance with embodiments, the Access Control may be always executed.

As is depicted in Fig. 7(a) and in Fig. 7(b), one implementation of this embodiment may use the NAS protocol at the UE to define an access category for the access attempt, while the UEs RRC protocol at the access stratum performs the final barring check. This is done by comparing the access category to the RRC System Information received from the base station indicating the access categories that are barred or are not barred. The barring check therefore involves interactions between the UE NAS and RRC layer that are exchanged via primitives. In case the system is barred temporarily the RRC may check a barring timing during this process. In case the network slices are mapped to access categories, the network may control access to specific slices by changing respective RRC system information in the base station.

In accordance with a fifth embodiment of the BAC, an access is only allowed if access control information of the subsystem has been obtained. A subsystem is considered to be barred until the access control information has been obtained. The access control information may be provided using the one or more control information as described above in the first to fourth embodiments. In accordance with further embodiments, the access control information may be obtained via dedicated RRC control signaling. Fig. 8 shows an embodiment in which the access control information is split into general control information 1 16 for all UEs and additional control information 1 16! to 1 163 for the respective subsystems #1 to #3. Like in the embodiments described so far, the general control information 1 16 for all of the subsystems may be transmitted only on the resources for one of the subsystems, in the depicted embodiment the resources of the subsystems #3. The additional control information 16τ to 1 163 for the respective subsystems #1 to #3 may be transmitted on the resources for the respective subsystem. For example, for each subsystem supported the general information 1 16 may inform a UE about the resources, like the frequency band or the carrier(s), to listen to for obtaining the additional control information for the subsystem to which the UE wishes to connect.

This embodiment is advantageous as the additional access barring information 116i to 1163 for the respective subsystem provides more detailed information. For example, besides limiting access to the subsystem, further limits with regard to accessible services, for example, conversational services, or further limits with regard to allowed UE types, such as devices of security services, public utilities or staff of the network operator, may be provided. Also, when operating the system or parts thereof in the second operation mode, it may be beneficial not to bar all other subsystems or all other services; rather, some services may still be allowed, for example, emergency calls for public users.

In accordance with a sixth embodiment of the BAC, the control information 116 may include an indicator that a public warning message exists. The existence of such a public warning message may trigger a UE to read additional barring information, such as those described above with reference to the fifth embodiment. Public warning messages are basically known in the 2G/3G/4G systems, for example, for issuing earthquake warnings or tsunami warnings. In the system block information, for example, a bit may be provided that indicates that further system information relating to the public warning message are available and may be read. In the table below, an example for the indicator is given. When activated or set, before granting access the UE needs to read the additional access barring information, and on the basis of this information access is finally granted or not.

It is noted that the access control in the warning or error indicator messages may be combined so that, for example, in case an access is blocked, the user may get a message that indicates the cause for the blocking. The broadcast message content may include a message referring to an emergency situation, or an overload situation, or a certain event at a certain date and for a certain duration, or changes in a service using the logical radio access network, or a certain day and/or night time.

In accordance with a seventh embodiment of the BAC, the inventive control access approach includes a system load indicator query for UEs of a specific subsystem. For example, when considering a PPDR subsystem, PPDR UEs may query the system load during the access phase so as to indicate the number of UEs/the percentage of cell load of PPDR UEs in the cell. Based on this information, the PPDR UEs within the same zone

may connect to a master PPDR UE which is itself connected to the wireless communication system, for example, to a base station such as a macro base station or a micro base station. The master PPDR UE is also connected to one or more slave PPDR UEs within the same coverage zone and may communicate with these slave devices in a device-to-device manner, for example, over the PC5 interface. This approach is advantageous as it allows multiple UEs of a specific type qualifying for the specific subsystem to connect to the system via the master UE.

In accordance with an eighth embodiment of the BAC, the inventive access control approach may allow for a location specific access. For example, in public safety situations, ubiquitous access to the network may be crucial. Access to the network may be achieved via a direct connection to the base station or via device-to-device (D2D) connections over a directly connected UE, as indicated, for example, in the seventh embodiment described above. Even in the case of the seventh embodiment or in other situations, direct access to a base station may be limited, and access control information in the UE may force the UE to first check if the connection via D2D with neighboring UEs may be achieved. Fig. 9 shows an example for a location specific group access in accordance with the eighth embodiment. Fig. 9 shows a cell including a base station eNB and a plurality of users UE that are directly connected to the base station, as is indicated by the arrow "Uu ". In case one of the users within the cell recognizes that it is not possible to directly access the base station, in accordance with the inventive access control scheme of the eighth embodiment, the UE may include access control information forcing the UE try to make a D2D connection, for example, via the PC5 interface, to a neighboring UE. In Fig. 9, such connections are indicated by the arrow "PC5". This approach may be beneficial, for example, when specific areas of the cell are crowded so that access to the base station from this area of the cell is limited by the base station to a reduced number of UEs. In such a case, to allow other UEs to also access the network, the UEs may connect to the base station via the master UE. The information regarding the access control to be stored in the UE may indicate that an indirect connection is possible so that when the respective information is enabled or a bit is set in the information block, the UE not in a position to make a connection to the base station, tries to connect via D2D to directly connect to UEs, as indicated in the table below.

Indicator Meaning

Indirect connection enforced Try connecting via D2D to directly

connected UEs.

The master user equipment may relay certain information from the logical radio access network to one or more blocked slave users. The relayed information may include:

(1 ) relay control and/or data channels in the downlink direction, or

(2) relay control and/or data channels in the uplink direction, or

(3) both (1) and (2).

Second Aspect

In the embodiments described thus far, the new access control parameters described above have been provided or introduced on a per-subsystem basis. However, the invention is not limited to such an approach; rather, in accordance with a second aspect of the inventive approach, the access control may be split into a first part, which is referred to as the basic access control (BAC), and a second part, which is referred to as the detailed access control (DAC). The BAC and the DAC may both be part of the system information, e.g. in the SIB, provided to a UE when connecting to the system.

The BAC defines a first set of access control parameters, for example, those described above with reference to Fig. 4 to Fig. 9. The BAC may be part of the control information 1 16 described in the embodiments above, and may be delivered on the resources for one of the subsystems, also referred to as an anchor subsystem. The DAC defines a second set of access control parameters. The DAC includes additional access control parameters for one or all of the subsystems. In accordance with embodiments, the DAC for the different subsystems may be provided using the resources of the anchor subsystem. In accordance with other embodiments, the DAC for a subsystem may be provided using resources assigned to the corresponding subsystem.

Fig. 10 schematically shows the access control hierarchy using a BAC and a DAC in accordance with a first embodiment of the second aspect of the present invention. The BAC and the DACs may be provided as part of the control message 116 described above. The BAC 1 18 and a plurality of DACs 120i to 1203 for the subsystems is provided by using anchor subsystem.

Alternatively the Basic Radio Access Control (BAC 118) is part of the Radio Resource Control system information that is broadcasted, while the detailed access control (DAC 120) is part of dedicated RRC signaling or part of the Non-Access Stratum protocol. During the initial attach procedure (see for example Fig. 7(a)) the BAC with a pre-configured or default DAC is used. This initial attach procedure may be performed based

on cell wide BAC system information without any dedicated signaling. Once the UE access is authorized, the UE will connect to the base station and the network, which will provide additional detailed access control parameters (see for example Fig. 7(b)). Any following access attempt may consider the BAC information together with the network configured DAC information. This procedure allows for a fast initial access with minimum signaling overhead based on a basic access control, while any other access in the future also allows for more detailed configurations of the access control.

In accordance with a second embodiment, the DAC information may be provided within each subsystem using resources assigned to the corresponding subsystem. Fig. 1 1 shows the access control hierarchy in accordance with the second embodiment with DAC information provided by the respective subsystems. Other than in Fig. 10, the BAC is provided using resources allocated to the logical RAN for the anchor subsystem, while the DAC 102x, 120y for the respective subsystems x and y are signaled using resources allocated to the logical RANs of the respective subsystems x and y.

CLAIMS

A base station for a wireless communication network having a plurality of logical radio access networks, wherein:

the base station is configured to communicate with a plurality of users to be served by the base station for accessing one or more of the logical radio access networks, and

the base station is configured to selectively control the physical resources of the wireless communication network assigned to the logical radio access networks and/or to control access of the users or user groups to one or more of the logical radio access networks.

The base station of claim 1 , wherein a logical radio access network comprises one or more network slices, and wherein information controlling the access of the users or user groups comprises an access class or an access category for the users or user groups.

The base station of claim 1 or 2, wherein

during a first operation mode of the wireless communication network, the base station is configured to allow access of users or user groups of one or more of the logical radio access networks (e.g. eMBB, URLLC, eMTC), and

during a second operation mode of the wireless communication network, the base station is configured to

adaptively limit access of users or user groups to one or more of the logical radio access network, and/or

adaptively control the distribution of the physical resources among the plurality of logical radio access network, and/or

adaptively control the physical resources to be used dependent on one or more service characteristics of a service using the logical radio access network, and/or

adaptively reduce a number of enabled logical radio access network.

The base station of claim 3, wherein to adaptiveiy limit access of users or user groups to one or more of the logical radio access network(s) the base station is configured to

gradually reduce the number of users or user groups allowed to access the logical radio access network, and/or

at least temporarily bar one or more users or user groups from the logical radio access network, and/or

at least temporarily bar one or more of the logical radio access networks from being accessed.

The base station of claim 4, wherein to at least temporarily bar one or more users or user groups from the logical radio access network the base station is configured to signal to the user a barring time indicating when the user should try the next time to access the logical radio access network.

The base station of one of claims 3 to 5, wherein to adaptiveiy reduce the number of enabled logical radio access networks the base station is configured to

at least temporarily bar the enabled logical radio access network so as to increase the available physical resources for one or more of the non-barred logical radio access networks, or

allow access only to a single one of the enabled logical radio access networks or to a subset of the enabled logical radio access networks so as to increase the available physical resources for the single one or the subset of enabled logical radio access networks.

The base station of claim 6, wherein to temporarily bar the enabled logical radio access network the base station is configured to control the user to stay on the logical radio access network and to signal to the user that access to the logical radio access network is temporarily barred.

The base station of one of claims 3 to 7, wherein, to adaptiveiy control the distribution of the physical resources among the plurality of enabled logical radio access networks, the base station is configured to

modify a number of physical resources allocated to the enabled logical radio access network, and/or

limit or suspend one or more services using the logical radio access network, and/or

increase a scheduling priority of one or more of the enabled logical radio access networks relative to one or more disabled logical radio access networks, or decrease the scheduling priority of one or more disabled logical radio access networks relative to the scheduling priority of the one or more enabled logical radio access networks.

9. The base station of claim 8, wherein to limit or suspend one or more services using the logical radio access network the base station is configured to

select for one or more users or user groups of a service using the logical radio access network a service quality for the service from different service qualities (e.g., video quality, bandwidth, latency e.g. in terms of number of resources grants in a given time interval), or

- prioritize for one or more users or user groups of the logical radio access network one of the services using the logical radio access network.

10. The base station of one of claims 3 to 9, wherein the second operation mode is determined responsive to a certain event.

1 1. The base station of claim 10, wherein the certain event includes one or more of:

a certain emergency situation,

an overload situation of at least a part of the wireless communication network, a need to balance the load between the logical radio access networks, - a need to provide highest resilience to one of the logical radio access networks,

a certain event at a certain date and for a certain duration,

changes in a service using the logical radio access network,

a certain day and/or night time, and/or

- a schedule of certain reoccurring events.

12. The base station of one of claims 1 to 1 1 , wherein

the wireless communication network is configured to enable a plurality of instances for a logical radio access network, the plurality of instances using different carriers (carrier frequency, cell identity, access technology type like FDD or TDD, subframe configuration details), and

when an instance of the logical radio access network is barred, the base station is configured to redirect one or more of the users or user groups to the carriers of another instance of the logical radio access network.

13. The base station of one of claims 1 to 12, wherein the base station configured to perform the control using common downlink system information provided by the wireless communication network for the users or user groups (e.g. RRC - Broadcast Channel).

14. The base station of one of claims 1 to 13, wherein the base station is configured to perform the control using signaling of a certain communication protocol used by a iogical radio access network.

15. The base station of claim 14, wherein the base station is configured to signal to a user of the Iogical radio access network to stop or reduce a certain action via a control message (e.g. "stop streaming/requesting new data" via a DASH SAND message).

16. The base station of one of claims 13 to 15, wherein the base station is configured to signal control information to inform the users or user groups whether a certain Iogical radio access network is supported or is not supported by the wireless communication network.

17. The base station of one of claims 13 to 16, wherein the base station is configured to signal control information to limit access to a iogical radio access network to specific users or user groups only.

18. The base station of claim 17, wherein the control information to limit access includes an equipment type of the user (e.g. !MEI) or a software version (e.g. I EI-SV) of the user.

19. The base station of one of claims 13 to 18, wherein the base station is configured to signal control information to at least temporarily bar one or more logical radio access networks.

20. The base station of one of claims 13 to 19, wherein the base station is configured to signal control information to at least temporarily limited access to specific service types of a service using the logical radio access network.

The base station of one of claims 13 to 20, wherein the base station is configured to broadcast to the users or user groups control information to indicate that additional access control information is to be obtained before access, the additional access control information controlling access of the users or user groups to one or more of the logical radio access networks.

The base station of claim 21 , wherein the base station is configured to broadcast the control information that additional access control information for the logical radio access network is to be obtained during the second operation mode so that one or more users or user groups are not allowed to access the logical radio access network, but need to obtain the additional access control information.

The base station of claims 21 or 22, wherein the base station is configured to broadcast to the users or user groups the access control information using the RRC protocol and the additional access control information using the NAS protocol.

The base station of one of claims 21 to 23, wherein the logical radio access network is barred until the additional access control information is obtained.

25. The base station of one of claims 21 to 24, wherein the additional access control information includes one or more of:

- information limiting access to the logical radio access network, and/or

information limiting access to certain services using the logical radio access networks (e.g. conversational services), and/or

information limiting access to certain user and/or device types (e.g. devices of security services, public utilities or the staff of network operators).

26. The base station of one of claims 13 to 25, wherein, when access to a logical radio access network is blocked or limited, the base station is configured to broadcast to the users or user groups a message that indicates the cause of the limitation or blocking.

27. The base station of claim 26, wherein the broadcast message content includes a message referring to

an emergency situation, or

an overload situation, or

- a certain event at a certain date and for a certain duration, or

changes in a service using the logical radio access network, or

a certain day and/or night time.

28. The base station of one of claims 13 to 27, wherein, when access to a logical radio access network is blocked for some of the users or user groups, the base station is configured to signal to a master user, which is connected to the wireless communication network (Macro, Micro, Pico), to connect to slave users within the same coverage zone for a communication over a device-to-device interface, wherein the slave users including at least some of the blocked users.

29. The base station of one of claims 1 to 28, wherein the control signal comprises a first set of access control parameters and a second set of access control parameters.

30. The base station of claim 29, wherein the base station is configured to broadcast to first set of access control parameters using the RRC protocol and the second set of access control parameters using the NAS protocol

31. The base station of one of claims 1 to 30, wherein the base station is configured to signal basic access control (BAC) information including a first set of access control parameters, and detailed access control (DAC) information including a second set of access control parameters for one or more of the logical radio access networks.

32. The base station of claim 31 , wherein the base station is configured to signal the BAC information more frequently than the DAC information.

33. The base station of claim 31 or 32, wherein the base station is configured to signal the BAC information and the DAC information using different physical resources in frequency and/or time and/or space.

34. The base station of claim 33, wherein the base station is configured to signal the DAC information for a certain logical radio access network using physical resources allocated to the certain logical radio access network.

35. The base station of one of claims 1 to 34, wherein to selectively control the logical radio access network the base station is configured to isolate the physical resources for one or more of the logical radio access network from the physical resources of the other logical radio access network.

36. The base station of claim 35, wherein the decision to isolate a certain logical radio access network is based on system load per logical radio access network over the air (e.g. number of certain UEs or service types connected to a logical radio access network, overall or per user throughput per logical radio access network etc.) and/or on the load of certain processing (e.g. processing power, buffer) and/or transport resources (e.g. fronthaul, backhaul capacity).

37. The base station of claim 35 or 36, wherein the decision to isolate a certain logical network is provided by a core network via an interface to the base station.

38. The base station of one of claims 35 to 37, wherein, before the support of shared physical resources is stopped, the base station is configured to handover or redirect some or all active users or user groups to the isolated physical resources.

39. The base station of one of claims 1 to 38, wherein, during the first operation mode, the base station is configured to allocate common RACH resources to be used for all users or user groups to access the logical radio access networks (signaled via

Battles).

40. The base station of claim 39, wherein the base station is configured to define logical radio access network specific RACH transmission parameters for the users or user groups of one or more of the logical radio access networks.

The base station of claim 40, wherein the logical radio access network specific RACH transmission parameters include

a narrow-band RACH transmission with several retransmissions, and/or a wide-band RACH transmission, and/or

radio parameters, and/or

RACH transmit power, and/or

RACH power increase parameters and repetition, and/or

backoff parameters.

The base station of one of claims 39 to 41 , wherein, during the second operation mode, the base station is configured to increase the resources assigned for the common RACH, or to bar the cell from new access attempts.

The base station of one of claims 39 to 42, wherein the base station is configured to switch from providing the common RACH resources for all logical radio access networks to dedicated RACH resources to be used for users or user groups to access one or more of the logical radio access networks, wherein the dedicated RACH resources are used in addition to or instead of the common RACH resources.

The base station of claim 43, wherein the base station is configured to switch from providing the common RACH resources to the dedicated RACH resources during the second operation mode.

The base station of claim 43 or 44, wherein the common RACH resources are used for an initial access only (e.g. connection setup, handover), and wherein the dedicated RACH resources are used for users or user groups already connected (e.g. connection reestablishment, tracking area update).

The base station of one of claims 43 to 45, wherein the base station is configured to signal a resource indication of the dedicated RACH resources at a later point of time and/or at a different frequency than a resource indication of the common RACH resources.

47. The base station of one of claims 43 to 46, wherein the base station is configured to signal the resource indication of the common RACH resources more frequently than the resource indication of the dedicated RACH resources.

48. The base station of one of claims 43 to 47, wherein a user is configured to use the common RACH resources to connect to the base station, and to request via control signaling a dedicated RACH resource configuration or a configuration of another logical radio access network containing dedicated RACH resources.

49. The base station of one of claims 43 to 48, wherein a RACH preamble sequence space is split among the common RACH resources not using all preambles and the dedicated RACH resources using certain preambles.

50. The base station of one of claims 43 to 49, wherein the base station is configured to signal the common RACH resources together with an indication that dedicated RACH resources for other logical radio access networks exist.

The base station of claim 50, wherein a user is configured to not use the common RACH resources when the existence of dedicated RACH resources is indicated.

52. The base station of claim 51 , wherein a user is configured to decide to not use the common RACH resources dependent on a user type.

53. The base station of one of claims 43 to 52, wherein the base station is configured to continuously provide dedicated RACH resources for one or more certain logical radio access networks.

The base station of one of claims 43 to 53, wherein the common RACH resources and the dedicated RACH resources support not all and/or different RACH formats.

The base station of one of claims 43 to 54, wherein, during the second operation mode, certain RACH resources are assigned only to one or more logical radio access networks.

The base station of one of claims 43 to 55, wherein the base station is configured to notify all users or user groups in the cell about a change in the dedicated RACH resources.

57. The base station of one of claims 39 to 56, wherein the base station is configured to select different RACH procedures for different ones or for different groups of logical radio access networks, and/or for different users or user groups of a logical radio access network.

58. The base station of claim 57, wherein RACH procedures are selected from the group comprising:

a four-step RACH procedure as used in accordance with LTE, and a two-step RACH procedure.

59. The base station of claim 58, wherein the base station is configured to select the four-step RACH procedure for a user to initially connect to a logical radio access network, and to select the two-step RACH procedure for a user redirected to another logical radio access network.

60. The base station of one of claims 1 to 59, wherein the base station is configured to limit a number of available RRC states for one or more of the logical radio access networks, and/or for different users or user groups of a logical radio access network.

61. A user equipment to be served by a base station of a wireless communication network having a plurality of logical radio access networks, wherein:

the user equipment is configured to access at least one of the logical radio access networks,

the user equipment is configured to receive and process a control signal from the base station, and

wherein the control signal indicates the physical resources of the wireless communication network assigned to the logical radio access network and/or includes access control information for the user equipment for accessing the logical radio access network.

62. The user equipment of claim 61 , wherein a logical radio access network comprises one or more network slices, and wherein information controlling the access of the users or user groups comprises an access class or an access category for the users or user groups.

63. The user equipment of claim 61 or 62, wherein the control signal indicates that additional access control information is to be obtained before access, the additional access control information controlling access of the user equipment to one or more of the logical radio access networks.

64. The user equipment of claim 63, wherein the access control information is received using the RRC protocol and the additional access control information is received using the MAS protocol.

65. The user equipment of claim 63 or 64, wherein the user equipment is configured to access the logical radio access network only after obtaining the additional access control information.

66. The user equipment of one of claims 63 to 65, wherein the additional access control information includes one or more of:

information limiting access to the logical radio access network, and/or - information limiting access to certain services using the logical radio access networks (e.g. conversational services), and/or

information limiting access to certain user and/or device types (e.g. devices of security services, public utilities or the staff of network operators).

67. The user equipment of one of claims 61 to 66, wherein, when access to a logical radio access network is blocked or limited, the user equipment is configured to indicate the cause of the limitation or blocking.

68. The user equipment of one of claims 61 to 67, wherein, when access to a logical radio access network is blocked, the user equipment is configured to operate as to a master user equipment, which is connected to the wireless communication network (Macro, Micro, Pico), and to connect to slave user equipments within the same coverage zone for a communication over a device-to-device interface.

69. The user equipment of claim 68, wherein the master user equipment is configured to relay certain information from the logical radio access network to blocked a slave user equipment, wherein the relayed information may include (1 ) relay control and/or data channels in the downlink direction, or (2) relay control and/or data channels in the uplink direction, or (3) both (1 ) and (2).

70. The user equipment of one of claims 61 to 67, wherein, when access to a logical radio access network is blocked, the user equipment is configured to operate as to a slave user equipment, and to connect to a master user equipment within the same coverage zone for a communication over a device-to-device interface, the master user equipment connected to the wireless communication network (Macro, Micro, Pico).

71. The user equipment of one of claims 61 to 70, wherein the control signal comprises a first set of access control parameters and a second set of access control parameters.

72. The user equipment of one of claims 61 to 70, wherein the control signal comprises basic access control (BAC) information including a first set of access control parameters, and detailed access control (DAC) information including a second set of access control parameters for one or more of the logical radio access networks.

73. The user equipment of claim 71 or 72, wherein the first set of access control parameters is received using the RRC protocol and the second set of access control parameters is received using the NAS protocol.

74. The user equipment of claim 72 or 73, wherein

during the first operation mode, the user equipment is configured to access and connect to the base station once the user reads the BAC information, and

during the second operation mode, the user equipment is configured to access and connect to the base station only once the user reads both the BAC information and the DAC information.

75. The user equipment of one of claims 72 to 74, wherein

the user equipment is configured to decode the BAC information to obtain the first set of access control parameters,

when a first access control according to the first set of access control parameters is successful, the user equipment is configured to access the logical radio access network, and

when the first access control fails, the user equipment is forbidden to access the logical radio access network immediately, and the user equipment is configured to decode the DAC information to obtain the second set of access control parameters (e.g. with details of the specific subsystems) before the user equipment accesses the logical radio access network.

76. The user equipment of one of claims 72 to 75, wherein responsive to the receipt of the BAC information, the user equipment is configured to request via control signaling the DAC information for a logical radio access network the user equipment wants to connect to.

77. The user equipment of one of claims 61 to 76, wherein, during the first operation mode, the user equipment is configured to use common RACH resources to access the logical radio access networks (signaled via SIB).

78. The user equipment of one claim 77, wherein the user equipment is configured to switch from using the common RACH resources for all logical radio access networks to the use of dedicated RACH resources to access one or more of the logical radio access networks, wherein the dedicated RACH resources are used in addition to or instead of the common RACH resources.

79. The user equipment of claim 78, wherein the common RACH resources are used for an initial access only (e.g. connection setup, handover), and wherein the dedicated RACH resources are used once the user equipment is connected (e.g. connection reestablishment, tracking area update).

80. The user equipment of claim 78 or 79, wherein the user equipment is configured to receive a resource indication of the dedicated RACH resources at a later point of time and/or at a different frequency than a resource indication of the common RACH resources.

81. The user equipment of one of claims 78 to 80, wherein the user equipment is configured to use the common RACH resources to connect to the base station, and to request via control signaling a dedicated RACH resource configuration or a configuration of another logical radio access network containing dedicated RACH resources.

82. The user equipment of one of claims 78 to 81 , wherein

the common RACH resources are signaled together with an indication that dedicated RACH resources for other logical radio access networks exist, and

wherein the user equipment is configured to not use the common RACH resources when the existence of dedicated RACH resources is indicated.

83. The user equipment of claim 82, wherein the user equipment is configured to decide to not use the common RACH resources dependent on a type of the user equipment.

84. The user equipment of one of claims 77 to 83, wherein the user equipment is configured to select different RACH procedures for different ones or for different groups of logical radio access networks.

85. The user equipment of one of claims 61 to 84, wherein the user equipment is configured operate in a limited number of available RRC states for one or more of the logical radio access networks.

86. The user equipment of one of claims 61 to 85, wherein the user equipment is configured to receive and process a control signal from the base station of one of claims 1 to 60.

87. A wireless communication network, comprising:

one or more base stations of one of claims 1 to 60;

a plurality of user equipments of one of claims 61 to 86;

wherein the wireless communication network is configured to enable a plurality of logical radio access networks, and to provide a plurality of physical resources for a wireless communication among a base station and a plurality of users to be served by the base station.

88. The wireless communication network of claim 87, wherein a logical radio access network comprises one or more logical network slices.

89. The wireless communication network of claim 87 or 88, wherein the wireless communication network comprises a cellular network, a wireless local area network or a wireless sensor system.

90. The wireless communication network of one of claims 87 to 89, wherein the user equipment is a mobile terminal, or an loT device, or a device implemented inside a moving vehicle, like a moving vehicle, e.g., a car or a robot, or inside a flying device, e.g., an unmanned aerial vehicle (UAV) or a plane.

91. The wireless communication network of one of claims 87 to 90, using an IFFT (Inverse Fast Fourier Transform) based signal, wherein the IFFT based signal includes OFDM with CP, DFT-s-OFDM with CP, IFFT-based waveforms without CP, f-OFDM, FBMC, GFDM or UFMC.

92. A method in a wireless communication network having a plurality of logical radio access networks, wherein a base station communicates with a plurality of users to be served by the base station for accessing one or more of the logical radio access networks, the method comprising:

selectively controlling, by the base station, the physical resources of the wireless communication network assigned to the logical radio access networks and/or controlling, by the base station, access of the users or user groups to one or more of the logical radio access networks.

93. A method in a wireless communication network having a plurality of logical radio access networks, wherein a base station communicates with a user equipment to be served by the base station for accessing one or more of the logical radio access networks, the method comprising:

receiving and processing, by the user equipment, a control signal from the base station, wherein the control signal indicates the physical resources of the wireless communication network assigned to the logical radio access network and/or includes access control information for the user equipment for accessing the logical radio access network.

94. A method in a wireless communication network having a plurality of logical radio access networks, wherein a base station communicates with a plurality of user equipments to be served by the base station for accessing one or more of the logical radio access networks, the method comprising:

selectively controlling, by the base station, the physical resources of the wireless communication network assigned to the logical radio access networks and/or controlling, by the base station, access of the users or user groups to one or more of the logical radio access networks; and

receiving and processing, by the user equipment, a control signal from the base station, wherein the control signal indicates the physical resources of the wireless communication network assigned to the logical radio access network and/or includes access control information for the user equipment for accessing the logical radio access network.

95. A non-transitory computer program product comprising a computer readable medium storing instructions which, when executed on a computer, carry out the method of one of claims 92 to 94.