阅读说明：本技术 确定是否传送网络切片选择辅助信息的方法和装置 (Method and apparatus for determining whether to transmit network slice selection assistance information ) 是由 哥纳季·韦列夫 拉维·库奇波特拉 约阿希姆·勒尔 普拉泰克·巴苏马利克 于 2019-10-01 设计创作，主要内容包括：提供了一种方法和装置,其用于确定是否将网络切片选择辅助信息作为无线电连接建立信令的一部分传送给网络。从网络接收关于是否需要网络切片选择辅助信息的指示(402)。当确定需要该信息时,激活网络切片选择辅助信息的传输,或者当确定为不需要该信息时,停用其传输(404)。当用户设备处于连接管理空闲状态时,在服务请求过程的发起期间,非接入层层面向接入层层面通知网络切片选择辅助信息(406),并且当信息的传输被激活时,在无线电连接建立信令中向网络传送网络切片选择辅助信息(408)。(A method and apparatus are provided for determining whether to communicate network slice selection assistance information to a network as part of radio connection setup signaling. An indication is received from a network as to whether network slice selection assistance information is required (402). The transmission of network slice selection assistance information is activated when the information is determined to be needed or deactivated when the information is determined not to be needed (404). The non-access layer notifies the access stratum layer plane of network slice selection assistance information during initiation of a service request procedure when the user equipment is in a connection management idle state (406), and transmits the network slice selection assistance information to the network in radio connection setup signaling when transmission of the information is activated (408).)

1. A method in a user equipment for determining whether to communicate network slice selection assistance information to a network as part of radio connection establishment signaling, the method comprising:

receiving, at an access stratum level in the user equipment, an indication from the network as to whether the network slice selection assistance information is required as part of the radio connection establishment signaling;

activating transmission of the network slice selection assistance information when it is determined that the network slice selection assistance information is needed, or deactivating transmission of the network slice selection assistance information when it is determined that the network slice selection assistance information is not needed;

when the user equipment is in a connection management idle state, during the initiation of a service request program, notifying the network slice selection auxiliary information to the access layer by the non-access layer; and

transmitting the network slice selection assistance information to the network in the radio connection setup signaling when transmission of the network slice selection assistance information is activated.

2. The method of claim 1, wherein the indication from the network comprises system information received from a cell of the network.

3. The method of claim 2, wherein the system information received from a cell of the network is broadcasted system information, the broadcasted system information being received while the cell of the network is operating as a serving cell.

4. The method of claim 1, wherein the indication from the network comprises radio resource control signaling from the network.

5. The method of claim 4, wherein the indication from the network included as part of radio resource control signaling from the network is included as part of a radio resource control connection setup message.

6. The method of claim 1, wherein the transmission of the network slice selection assistance information in the radio connection setup signaling is included as part of a radio resource control connection complete message.

7. The method of claim 1, wherein an access stratum layer plane in the user equipment is configured to inform the non-access stratum layer plane whether the network slice selection assistance information is needed.

8. The method of claim 1, wherein the signaling information comprises an always-on parameter that may include an associated value that selectively identifies between an indication that network slice selection assistance information for all allowed slices needs to be included in the radio connection setup signaling, an indication that network slice selection assistance information is included in the radio connection setup signaling for at least a slice where a packet data unit connection is to be activated, and an indication that network slice selection assistance information does not need to be included.

9. The method of claim 1, wherein the signaling information comprises an optionally present parameter, wherein when present, a value of the parameter may distinguish between an indication that network slice selection assistance information for all allowed slices needs to be included in the radio connection setup signaling and an indication that network slice selection assistance information is included in the radio connection setup signaling for at least a slice for which a packet data unit connection is to be activated, and wherein when not present, may be used as an indication that network slice selection assistance information does not need to be included.

10. The method of claim 1, wherein the determination as to whether network slice selection assistance information is needed should be based on system information from the cell currently serving as a serving cell operation when the radio connection setup signaling is part of an attempt to resume a connection from an inactive state.

11. The method of claim 1, wherein the transmission of network slice selection assistance information is activated when the user equipment transitions from an old cell that does not require network slice selection assistance information to a new cell that requires network slice selection assistance information, or if the system information associated with a current cell changes to include an indication that network slice selection assistance information is required.

12. The method of claim 1, wherein transmission of network slice selection assistance information is disabled when the user equipment transitions from an old cell requiring network slice selection assistance information to a new cell not requiring network slice selection assistance information or if the system information associated with a current cell changes to include an indication that network slice selection assistance information is no longer required.

13. A user equipment in a communication network, the user equipment comprising:

a transceiver that receives an indication from the network at an access stratum level of the user equipment as to whether the network slice selection assistance information is required as part of the radio connection establishment signaling; and

a controller, wherein the controller activates transmission of the network slice selection assistance information when it is determined that the network slice selection assistance information is needed, or wherein the controller deactivates transmission of the network slice selection assistance information when it is determined that the network slice selection assistance information is not needed;

wherein, when the user equipment is in a connection management idle state, during initiation of a service request procedure, the controller notifies the network slice selection assistance information to the access layer via the non-access layer level; and

wherein the network slice selection assistance information is communicated to the network by the transceiver in the radio connection setup signaling when transmission of the network slice selection assistance information is activated.

14. The user equipment of claim 13, wherein the indication from the network comprises system information received from a cell of the network.

15. The user equipment of claim 14, wherein the system information received from a cell of the network is broadcasted system information, the broadcasted system information being received while the cell of the network is operating as a serving cell.

16. The user equipment of claim 13, wherein the signaling information comprises an always-on parameter that may include an associated value that selectively identifies between an indication that network slice selection assistance information for all allowed slices needs to be included in the radio connection setup signaling, an indication that network slice selection assistance information is included in the radio connection setup signaling for at least a slice where a packet data unit connection is to be activated, and an indication that network slice selection assistance information does not need to be included.

17. The user equipment of claim 13, wherein the signaling information comprises an optionally present parameter, wherein when present, a value of the parameter may distinguish between an indication that network slice selection assistance information for all allowed slices needs to be included in the radio connection setup signaling and an indication that network slice selection assistance information is included in the radio connection setup signaling for at least a slice for which a packet data unit connection is to be activated, and wherein when absent, may be used as an indication that network slice selection assistance information does not need to be included.

18. The user equipment of claim 13, wherein the determination as to whether network slice selection assistance information is needed should be based on system information from the cell currently serving as a serving cell operation when the radio connection setup signaling is part of an attempt to resume a connection from an inactive state.

19. The user equipment of claim 13, wherein the transmission of network slice selection assistance information is activated when the user equipment transitions from an old cell that does not require network slice selection assistance information to a new cell that requires network slice selection assistance information, or if the system information associated with a current cell changes to include an indication that network slice selection assistance information is required.

20. The user equipment of claim 13, wherein transmission of network slice selection assistance information is disabled when the user equipment transitions from an old cell requiring network slice selection assistance information to a new cell not requiring network slice selection assistance information or if the system information associated with a current cell changes to include an indication that network slice selection assistance information is no longer required.

Technical Field

The present disclosure is directed to a method and apparatus for determining whether to transmit network slice selection assistance information (e.g., as part of radio connection establishment signaling).

Background

Currently, user equipment, such as wireless communication devices, communicate with other communication devices using wireless signals, such as within a network environment, which may include one or more cells within which various communication connections may be supported with the network and other devices operating within the network. A network environment typically involves one or more sets of standards, each set of standards defining aspects of any communication connections made within the network environment using a respective standard. Examples of standards being developed and/or existing include new radio access technology (NR), Long Term Evolution (LTE), Universal Mobile Telecommunications Service (UMTS), global system for mobile communications (GSM), and/or Enhanced Data GSM Environment (EDGE).

In some instances, the possibility of creating multiple virtual networks that may operate independently, but run within the same physical hardware, is considered beneficial. This may be referred to as a network slice. In some instances, different slices may be configured and maintained to support different applications, services, and/or to support other arrangements that may benefit from a form of separation from other slices, where each slice may potentially have an alternate overall purpose. In essence, each slice is analogous to a separate and distinct virtual network, where each particular network slice may have its own architecture, and has its own separate provisioning management and security, where each network slice may be customized to take support into account, which is more suitable for the corresponding purpose associated with the particular slice.

When managing communications for a particular user equipment entity, network slices may form another level of potential distinction when interacting with elements supporting the physical network environment. In some instances, the network environment will behave as if each of the slices corresponds to multiple different networks, where each of the slices may have different requirements associated with access and interaction in establishing and maintaining a communication connection. In connection with establishing and maintaining a communication connection between a particular user device and one or more potential slices of a network environment, it may be helpful for the user device to exchange and/or communicate network slice selection assistance information. In some cases, this information may be communicated as part of the initial radio resource control signaling. The present inventors have realised that it may be beneficial to more flexibly allow network slice selection assistance information to be communicated between a user equipment and a network, wherein an indication may be exchanged between the user equipment and each particular network informing the user equipment of the amount and/or type of assistance information and the way in which it should be shared, which information may change dynamically as the interaction between the user equipment and the network changes. In some instances, it may be desirable for the user equipment not to share any network slice selection assistance information with the network.

Disclosure of Invention

A method in a user equipment for determining whether to communicate network slice selection assistance information to a network as part of radio connection setup signaling is provided. The method comprises receiving, at an access stratum layer (access stratum layer) in the user equipment, an indication from the network as to whether network slice selection assistance information is required as part of radio connection establishment signaling. The transmission of the network slice selection assistance information is activated when it is determined that the network slice selection assistance information is needed, or deactivated when it is determined that the network slice selection assistance information is not needed. The method further comprises the following steps: when the user equipment is in a connection management idle state, during the initiation of a service request program, notifying the access layer of network slice selection auxiliary information through a non-access stratum layer (non-access stratum layer); and transmitting the network slice selection assistance information to the network in radio connection setup signaling when the transmission of the network slice selection assistance information is activated.

According to another possible embodiment, a user equipment in a communication network is provided. The user equipment comprises a transceiver that receives an indication from the network at an access stratum level in the user equipment as to whether network slice selection assistance information is required as part of the radio connection setup signaling. The user equipment further includes a controller, wherein the controller activates transmission of the network slice selection assistance information when it is determined that the network slice selection assistance information is required, and deactivates transmission of the network slice selection assistance information when it is determined that the network slice selection assistance information is not required. The controller also notifies the network slice selection assistance information to the access stratum level via the non-access stratum layer during initiation of a service request procedure when the user equipment is in a connection management idle state. The network slice selection assistance information is transmitted to the network in radio connection setup signaling through the transceiver when transmission of the network slice selection assistance information is activated.

According to another possible embodiment, a method in a network entity is provided. The method comprises the following steps: transmitting, to the user equipment via an access stratum in the user equipment, an indication as to whether network slice selection assistance information is required as part of radio connection establishment signaling; and exchanging radio connection setup signaling between the network entity and the user equipment. As part of exchanging radio connection setup signaling, the network entity receives the network slice selection assistance information when transmission of the network slice selection assistance information is activated, and excludes the network slice selection assistance information from the exchanged radio connection setup signaling when transmission of the network slice selection assistance information is deactivated. The selective activation and deactivation of the transmission of the network slice selection assistance information is in response to a determination in the user equipment after being informed of an indication transmitted by the network entity as to whether the network slice selection assistance information is required as part of the radio connection establishment signaling, wherein the non-access stratum layer plane has informed the network slice selection assistance information to the access stratum plane of the user equipment during initiation of the service request procedure when the user equipment is in a connection management idle state.

According to another possible embodiment, a network entity for communicating with one or more user equipments in a communication network is provided. The network entity includes a controller and a transceiver. The transceiver transmits an indication to the user equipment via an access stratum in the user equipment as to whether network slice selection assistance information is required as part of the radio connection establishment signaling, and the radio connection establishment signaling is exchanged between the network entity and the user equipment. As part of exchanging radio connection setup signaling, the network entity receives the network slice selection assistance information when transmission of the network slice selection assistance information is activated, and excludes the network slice selection assistance information from the exchanged radio connection setup signaling when transmission of the network slice selection assistance information is deactivated. The selective activation and deactivation of the transmission of the network slice selection assistance information is in response to a determination in the user equipment after being informed of an indication transmitted by the network entity as to whether the network slice selection assistance information is required as part of the radio connection establishment signaling, wherein the non-access stratum layer plane has informed the network slice selection assistance information to the access stratum plane of the user equipment during initiation of the service request procedure when the user equipment is in a connection management idle state.

These and other features and advantages of the present application will become apparent from the following description of one or more preferred embodiments, which proceeds with reference to the accompanying drawings.

Drawings

FIG. 1 is a block diagram of an exemplary network environment in which the present invention is suitable for operation.

Fig. 2 is an overview of a user equipment radio resource control state machine and state transitions for a New Radio (NR) standard;

fig. 3 is a signaling flow diagram for a user equipment determining whether to transmit network slice selection assistance information as part of radio connection establishment signaling;

fig. 4 is a flow chart in a user equipment for determining whether to transmit network slice selection assistance information;

fig. 5 is a flow diagram in a network entity for providing an indication for selectively activating and deactivating transmission and reception of slice selection assistance information in the network entity in a user equipment; and

fig. 6 is an example block diagram of an apparatus according to a possible embodiment.

Detailed Description

While the present disclosure is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.

Embodiments provide a method and apparatus for determining whether to transmit network slice selection assistance information as part of radio connection establishment signaling.

Fig. 1 is an exemplary block diagram of a system 100 according to a possible embodiment. System 100 may include a wireless communication device 110, such as a User Equipment (UE), a base station 120, such as an enhanced nodeb (enb) or next generation nodeb (gnb), and a network 130. The wireless communication device 110 may be a wireless terminal, a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a personal digital assistant, a personal computer, a selective call receiver, a tablet computer, a laptop computer, or any other device capable of sending and receiving communication signals over a wireless network.

Network 130 may include any type of network capable of sending and receiving wireless communication signals, respectively. For example, the network 130 may include a wireless communication network, a cellular telephone network, a Time Division Multiple Access (TDMA) -based network, a Code Division Multiple Access (CDMA) -based network, an Orthogonal Frequency Division Multiple Access (OFDMA) -based network, a Long Term Evolution (LTE) network, a fifth generation (5G) network, a third generation partnership project (3GPP) -based network, a satellite communication network, a high-altitude platform network, the internet, and/or other communication networks.

In 3GPP release-15, a Network Slice Selection Assistance Information (NSSAI) parameter is sent in Radio Resource Control (RRC) signaling, such as described in the CT1 LS reply in C1-182643, according to the following principle, where the following is stated:

depending on the non-access stratum (NAS) messages that need to be sent, the NAS may provide NSSAI to the lower layer plane as follows:

1. for NAS service request messages, the NAS layer does not provide NSSAI

2. For NAS registration request messages, NSSAI is provided by the NAS layer except in cases where the User Equipment (UE) is performing periodic registration updates

However, in SA2 and RAN2, extensive discussion is made regarding what NSSAI value is included in the RRC connection setup msg5 for the specific case of service request triggered connection setup. In S2-187889, the following suggestions have been discussed, but not agreed:

one issue to debate is whether it makes more sense to include all the individual network slice selection assistance information (S-NSSAI) for the allowed NSSAI in the NSSAI information for the RRC connection establishment msg5 or only in the slice that is triggering the service request. It should be noted that the service request may restart all Protocol Data Unit (PDU) sessions at once, or may restart only selected ones or only one. For example, the Scheduling Request (SR) may be related to Mobile Terminal (MT) signaling or data, so it is not clear what S-NSSAI triggered the SR. Therefore, all allowed slices S-NSSAI should in principle be potential targets for MT signaling or data.

The Radio Access Network (RAN) may use the NSSAI information received in RRC msg5 to trigger some initial access policy before contacting the Core Network (CN). The benefit of including all allowed NSSAIs or a subset thereof (set of slices that trigger SR) in the RRC connection setup msg5 is predicted in the RAN on the Public Land Mobile Network (PLMN) that has configured such a policy. The PLMN may also choose not to configure such a policy. The PLMN may also decide to configure these policies in certain areas of the network but not in others. Furthermore, some operators may simply be willing to consider the slicing of the UE directly for the initial access policy and defer any subsequent processing to the allowed NSSAI received from the CN.

Thus, the proposed PLMN may instruct the UE which behaviour to take in the registration accept message by including an indication as to whether the UE should include the access layer connection establishment caused by the service request (note that the UE is expected to include the requested nssai in the registration request.

a) NSSAI is set to UE allowed NSSAI; or

b) NSSAI comprises S-NSSAI of a network slice that triggers connection establishment; or

c) No NSSAI.

Some supporters propose to include NSSAI in the RRC connection establishment msg5 and may introduce it in later releases even if this is not indicated as agreed in Rel-15. One problem is that including NSSAI information in RRC signaling will make it possible to avoid situations associated with Core Network (CN) overload.

An additional aspect to consider is the RRC inactive state. According to 3GPP TS 38.331, when an RRC connection has been established, the UE is in either an "RRC _ CONNECTED" state or in an "RRC _ INACTIVE" state. If this is not the case, i.e. no RRC connection is established, the UE is in the "RRC _ IDLE" state. The RRC state may also be identified as follows:

-RRC_IDLE 206：

UE-specific Discontinuous Reception (DRX) may be configured by the upper layer;

-UE controlled mobility is based on network configuration;

-UE：

-monitoring a paging channel for CN paging using a fifth generation serving temporary mobile subscriber identity (5G-S-TMSI);

-performing neighbor cell measurements and cell (re) selection;

acquire system information and may send a System Information (SI) request (if configured).

-RRC_INACTIVE 204：

UE-specific DRX may be configured by the upper layer or by the RRC layer;

-UE controlled mobility is based on network configuration;

-the UE storing Access Stratum (AS) context;

-RAN-based notification area is configured by RRC level;

UE：

-monitoring a paging channel for CN paging using 5G-S-TMSI and RAN paging using inactive state radio network temporary identifier (I-RNTI);

-performing neighbor cell measurements and cell (re) selection;

-performing a RAN-based notification area update periodically and when moving out of a configured RAN-based notification area;

acquire system information and may send SI requests (if configured).

-RRC_CONNECTED 202：

-the UE storing the AS context;

-delivering unicast data to/from the UE;

at a low level, the UE may be configured with UE-specific DRX;

-for a UE supporting Carrier Aggregation (CA), using one or more secondary cells (scells) aggregated with a serving primary cell (SpCell) to increase bandwidth;

-for a UE supporting Dual Connectivity (DC), using one Secondary Cell Group (SCG) aggregated with a Master Cell Group (MCG) to increase bandwidth;

-network controlled mobility within a New Radio (NR) and a universal terrestrial radio access network (E-UTRA) evolving to and from;

-UE：

-monitoring the paging channel (if configured);

-monitoring a control channel associated with the shared data channel to determine whether data has been scheduled for it;

-providing channel quality and feedback information;

-performing neighbor cell measurements and measurement reporting;

-obtaining system information.

Fig. 2 illustrates an overview 200 of state transitions in a UE RRC state machine and NR. The UE may have only one RRC state in the NR at a time.

The general problem to be solved includes how to let the RAN know as early as possible the network slice that the UE intends to use, so that the RAN can make a decision whether to allow the UE to access the RAN and network resources in case of limited (e.g. overloaded or congested) network resources.

The UAC (unified access control) mechanism does not know the access and mobility management function (AMF) load and therefore the load of a single AMF may result in the rejection of all UEs attached to any AMF. It is specified that the UAC supports only 32 operator-defined classes, which may limit its usefulness. Furthermore, only 8 UAC access categories (including standardized categories) may be broadcast at a given time. In view of this, UAC mechanisms may not be able to solve access control challenges based on the load (or other conditions) of a particular network slice.

The previously proposed mechanisms are more or less semi-static, i.e. the configuration in the UE is valid for a specific PLMN and the UE obeys this configuration as long as the UE is camped under this PLMN.

Sending the NSSAI parameter in an RRC connection establishment msg5 (independent of whether a single S-NSSAI is included or at most 8S-NSSAIs are included) typically introduces a longer RRC msg5, which may result in a somewhat slow procedure. Given that NSSAI information can only be used in the gNB in limited situations, such as when an overload start message is sent from the core network (which is not expected to occur frequently), adding NSSAI information in the RRC for a service request may unnecessarily load all service requests from the RRC idle.

At least one problem sought to be solved by the present application is the question of how to better optimize the use of NSSAI in RRC signaling for service request procedures.

A proposal has been described in S2-187889 in which NAS signaling (NAS registration accept message) is used to configure the UE AS to whether NSSAI information is included in AS/RRC signaling for the service request procedure. At least one disadvantage of this proposal is that the procedure is generally static for the entire PLMN.

At least one possible benefit of the present disclosure is a potentially enhanced capability that provides a solution for flexible configuration of UEs, including when NSSAI is included in RRC signaling. It is proposed to allow the configuration of UEs on a per cell basis.

According to a possible embodiment, at least one aspect of the present disclosure is to utilize signaling (broadcasted system information or unicast signaling) in the current serving cell in order to determine (in the UE) whether to include NSSAI in the RRC signaling (e.g., in the RRC signaling for the service request procedure).

Various alternatives are possible as to how and which system information may be used.

In one possible alternative relating to the first possible solution, new information (parameters or indications) may be introduced in the broadcasted system information, which may explicitly indicate whether e.g. a UE camping on the serving cell when initiating the service request procedure may include NSSAI information in the RRC signaling, such as by including the service request in an RRC message to the RAN node.

This new SI indication (parameter) may be included in the system broadcast and set to one of some predefined values, e.g. including an instance as to whether the network should receive NSSAI in RRC signaling for connection establishment (such as an RRC setup complete message as defined in TS 38.331-f30, or also referred to as RRC message # 5). This new SI indication (parameter) may always be present in the system information (e.g., not an on-demand indication). In another possibility, the SI indication may be made optional and may be sent on demand. In this case, the absence of an indication would indicate that network slice information (S-NSSAI or NSSAI) need not be included in RRC signaling. Further, the SI indication may have different topological (or geographical) validity, e.g. cell-specific or registration/tracking area-specific.

The SI indication may have multiple values, which may mean, for example, that the indication may be encoded with 2 or more bits. For example, at least one of the following values is possible:

a) one value may indicate to the UE that the entire list of S-NSSAI parts of the allowed NSSAI needs to be included in RRC signaling;

b) another value may indicate that only the S-NSSAI to initiate the PDU connection is included; and

c) another value may indicate that NSSAI information need not be included (e.g., in the case where the indication is always sent in the SI).

In another alternative, when initiating the service request procedure, the UE may use existing parameters in the system information to determine whether to include NSSAI information in the RRC signaling. This may be, for example, a particular access category as part of a Unified Access Control (UAC), such as access category "5" or any reserved, special, or operator used access category. The prohibit timer for the access category need not exist.

As another possibility, an implicit indication may be made by access constraints of any of the access categories, which may be used as a new and above-discussed broadcast indication.

As a further enhancement, it may be dispensed with that certain access categories and/or access identities and/or UE types/levels/categories include any NSSAI information in RRC signaling. For example, the NAS layer plane of the UE belonging to any one of the exempt access category, the access identity and/or the UE type/level/category may not provide any NSSAI information to the access stratum. The indication may be sent in SI for different UE categories, such as enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), and/or vehicular wireless communication technology (v2x), etc.

In another or second possible alternative in relation to the other possible solution, dedicated (i.e. unicast) signaling from the RAN node (e.g. the gNB or eNB) to the UE may be used to indicate whether the UE should include NSSAI information in RRC signaling. For example, RRC message #4 ("RRCSetup" message) may contain such an explicit indication to the UE.

In another or third possible alternative to another possible solution, when the NAS layer is in (E) CM IDLE state, the NAS layer may send NSSAI information to the AS layer upon initiating the service request procedure, whereas the AS layer decides whether to include the NSSAI information in RRC message #5 (RRCSetupComplete). The AS layer may determine this based on an indication from the network in RRC message # 4. For example, if the network indicates in RRC message #4 that NSSAI information is required, the AS layer of the UE may include this information in RRC message # 5. Conversely, if the network indicates in RRC message #4 that NSSAI information is not needed, the AS layer of the UE may not include NSSAI information in RRC message # 5.

Note that in one example, the implementation of the indication from the network in RRC message #4 may be an indication having 2 values, such as "no NSSAI information required" (or "off") and "NSSAI information required" (or "on"). In another example, the implementation of the indication from the network in RRC message #4 may be a single value indication, such as "NSSAI information required".

For a UE in an RRC inactive state, when attempting to resume an RRC connection, the UE should operate according to the SI in the current cell (e.g., the cell in which the UE is attempting to perform the resume procedure). The UE behavior does not consider whether the UE includes NSSAI information the last time it established an RRC connection. The RAN node may store the UE context, but the UE may want to resume the connection in order to establish/start user plane resources in another network slice. In the case where the recovery procedure is initiated by the UE due to a trigger from the NAS level to establish a connection with a new/another network slice (e.g., start or establish a new PDU session), it may be helpful to include NSSAI information in the signaling for the recovery procedure (e.g., RRC recovery complete message).

It should be noted that for any of the above solutions, the RAN node may determine whether to transmit (or broadcast) an indication in RRC signaling requesting and/or requiring NSSAI information, as described in step zero in fig. 3.

Fig. 3 shows a signaling flow of one or more of the alternatives identified in the present disclosure, and more particularly, a signaling flow diagram 300 illustrating a user equipment determination as to whether to transmit network slice selection assistance information as part of radio connection establishment signaling.

The following is a description of the steps:

RAN 304 receives input from the core network 306 (step 0a) or from the OAM system (step 0b) to inform the UE 302 of the overload of a particular network slice.

a. By receiving 308 input from the Core Network (CN)306, such as signaling from an AMF on the N2 interface, indicating some load or congestion in the core network; or

b. By receiving 310 input from an OAM (operations, administration and maintenance/administration) system that configures the RAN node and is operated by the network manager.

The RAN node determines 312 to include NSSAI information in the system information.

This indication is described as "SR requires NSSAI", but any other suitable IE name may be used. Please refer to the description of the first solution set forth above for further details.

2. When an indication on the required NSSAI information is received in the AS signaling for establishing the connection for the service request, the UE performs 314 the internal configuration AS described in the first solution set forth above and the following UE internal configuration. This step may include activating or deactivating a mechanism for including NSSAI information in RRC connection setup signaling.

The UE initiates 316 a RACH (random access channel) procedure.

The UE sends 318 an RRC connection setup request message, which can also be described as RRC msg 3.

5. The network replies 320 with an RRCSetup message.

If the second solution applies, the message may be modified accordingly to include an additional indication to the UE as to whether NSSAI information is included in the RRC msg5 (step 6).

If the first solution is applicable (i.e., the RAN node already includes an indication in the SI that requires the UE to send NSSAI information), the RAN node may determine to assign a larger AS resource for RRC msg5, since the RAN node expects that by including NSSAI information, RRC msg5 may be a little larger.

The UE sends 322 a RRCSetupComplete message, which may also be described as RRC msg 5. As described in the first solution, the message may include NSSAI information as well as a NAS message.

The NSSAI information included in this RRC msg5 may be described as the IE "requested NSSAI", such as in the case where this information is equal to the allowed NSSAI. Another option might be to describe this Information Element (IE) as a 'service NSSAI' or similar name to indicate that the S-NSSAI included in the NSSAI information is the S-NSSAI for which a service request has been sent from the NAS layer. In other words, the UE may indicate which S-NSSAIs are included in the NSSAI information by indicating from the description for the first solution whether it meets the value a or b.

The RAN node may determine 324 whether to accept or reject the RRC connection establishment based on the NSSAI information received in step 6 and based on the network slice load/congestion condition according to step 0.

8. If one or more of the S-NSSAI portions of the NSSAI information included in step 6 are part of network slice overload/congestion control at the RAN, the RAN node may reject (or release) 326 the RRC connection establishment. The RAN node may include one or more specific S-NSSAI values within the reject/release cause value (or as a separate parameter).

Additionally, the RAN node may include a timer to indicate to the UE how long the UE is not allowed to initiate U-plane resource start up/establishment for a particular network slice (e.g., S-NSSAI).

Within the UE (mainly step 2 of fig. 3), the following processing may be applied in order to apply the UE configuration according to the proposed solution set forth above (such as the first solution):

initiate a mechanism to include NSSAI information in the RRC connection setup signaling for the service request procedure:

o premise is that the UE enters a new cell, where the broadcasted system information is used to indicate that NSSAI information is needed in the RRC connection setup signaling for the service request procedure; or

o premise that broadcasted system information is changed to include information for service request procedure

An indication in RRC connection setup signaling that NSSAI information is required,

the AS plane sends the indication to the NAS plane. If the system information indication also includes the NSSAI type to be included in the RRC signaling (e.g., all S-NSSAIs from allowed NSSAIs or S-NSSAIs triggering UP resource initiation), the AS layer will also send this information to the NAS layer. The AS plane can track the fact that the indication has been made known to the NAS plane so that the AS plane does not need to inform the NAS plane again until the broadcast indication changes, or until the UE moves to a new cell, containing the system information that requires the indication of NSSAI.

After the NAS plane has received the indication from the AS plane, when the NAS plane triggers a service request procedure from an Evolved Packet System (EPS) connection management- (E) CM IDLE state, the NAS plane should send corresponding NSSAI information to the AS plane.

Mechanism to deactivate the inclusion of NSSAI information in the RRC connection setup signaling for the service request procedure:

o if the UE enters a new cell, wherein the broadcasted system information does not indicate that NSSAI information is needed in the RRC connection setup signaling for the service request procedure; or

If the broadcasted system information changes to exclude the indication that NSSAI information is needed in the RRC connection setup signaling for the service request procedure,

the AS layer sends an indication to the NAS layer that NSSAI information is not required in RRC signaling for the service request procedure.

Within the UE, if dedicated signaling from the RAN node to the UE is used to indicate that NSSAI information is needed in the RRC connection setup signaling for the service request procedure (such AS the second solution), the NAS layer may send the NSSAI information to the AS layer, and the AS layer may decide which information to include in the RRC signaling (e.g., AS in RRC msg 5), such AS all accepted slice IDs or a specific slice ID related to the service request, AS indicated by the NAS to the access layer.

Potential benefits of the proposed solution may include the following capabilities: the UE is configured to send NSSAI information in access layer connection establishment signaling caused by a service request in a flexible manner (such as including or changing the broadcasted SI) and in a limited topological location (such as a single cell or a group of cells in a registration area). This configuration of the UE may be performed based on network operator requirements and area loading conditions.

It should be noted that the disclosed solution is primarily described using New Radio (NR) RAT terminology, but the solution is not limited to NR and may also be applied to other Radio Access Technologies (RATs) or communication systems (e.g., LTE/EPS or UTRAN/UMTS, etc.).

Fig. 4 illustrates a flow diagram 400 in a user equipment for determining whether to transmit network slice selection assistance information. The method comprises receiving 402, at an access stratum level in a user equipment, an indication from a network whether network slice selection assistance information is required as part of radio connection establishment signaling. The transmission of network slice selection assistance information is activated when it is determined that network slice selection assistance information is needed, or deactivated when it is determined that network slice selection assistance information is not needed 404. The method further comprises the following steps: when the user equipment is in a connection management idle state, during the initiation of a service request program, informing 406 network slice selection auxiliary information layer by layer of a non-access layer to an access layer; and transmitting 408 the network slice selection assistance information to the network in radio connection setup signaling when the transmission of the network slice selection assistance information is activated.

In some instances, the indication from the network may include system information received from a cell of the network. In some of these examples, the system information received from the cell of the network may be broadcast system information that may be received while the cell of the network is operating as a serving cell.

In some instances, the indication from the network may include radio resource control signaling from the network. In some of these instances, the indication from the network that is included as part of the radio resource control signaling from the network may be included as part of a radio resource control connection setup message.

In some instances, the transmission of the network slice selection assistance information may be included in the radio connection setup signaling as part of a radio resource control connection complete message.

In some examples, an access stratum layer plane in a user equipment is configured to inform a non-access stratum layer plane whether network slice selection assistance information is needed. If network slice selection assistance information is needed, the non-access stratum level may determine to send the network slice selection assistance information to the access stratum level, for example, during a service request procedure. If network slice selection assistance information is not needed, the non-access stratum level may determine to omit sending network slice selection assistance information to the access stratum level, for example, during a service request procedure.

In some instances, the signaling information may include an always-on parameter, which may include an associated value that selectively identifies between: an indication that network slice selection assistance information for all allowed slices needs to be included in the radio connection setup signaling; the network slice selection assistance information comprises an indication in radio connection setup signaling for at least a slice for which a packet data unit connection is to be initiated; and an indication that the network slice selection assistance information need not be included.

In some instances, the signaling information may include an optionally present parameter, wherein when present, the value of the parameter may distinguish between: an indication that network slice selection assistance information for all allowed slices needs to be included in the radio connection setup signaling; and the network slice selection assistance information comprises an indication in the radio connection setup signalling for at least the slice for which a packet data unit connection is to be initiated, and wherein when not present, may serve as an indication that the network slice selection assistance information does not have to be included.

In some examples, when the radio connection setup signaling is part of an attempt to recover a connection from an inactive state, the determination as to whether network slice selection assistance information is needed may be based on system information from a cell currently operating as a serving cell.

In some instances, the transmission of network slice selection assistance information may be activated when the user equipment transitions from an old cell that does not require network slice selection assistance information to a new cell that requires network slice selection assistance information, or if system information associated with the current cell changes to include an indication that network slice selection assistance information is required.

In some instances, the transmission of network slice selection assistance information may be disabled when the user equipment transitions from an old cell requiring network slice selection assistance information to a new cell not requiring network slice selection assistance information, or if system information associated with the current cell changes to include an indication that network slice selection assistance information is no longer required.

Fig. 5 illustrates a flow diagram 500 provided in a network entity for selectively enabling and disabling transmission and corresponding reception of slice selection assistance information by the network entity in a user equipment. The method comprises transmitting 502 an indication to the user equipment via an access stratum in the user equipment as to whether network slice selection assistance information is required as part of the radio connection establishment signalling, and exchanging 504 radio connection establishment signalling between the network entity and the user equipment. As part of exchanging radio connection setup signaling, the network entity receives 506 network slice selection assistance information when transmission of the network slice selection assistance information is activated, and excludes the network slice selection assistance information from the exchanged radio connection setup signaling when transmission of the network slice selection assistance information is deactivated. The selective activation and deactivation of the transmission of the network slice selection assistance information is responsive 508 to a determination in the user equipment after being informed of an indication transmitted by the network entity as to whether the network slice selection assistance information is required as part of the radio connection establishment signaling, wherein the non-access stratum layer has informed the network slice selection assistance information to the access stratum layer of the user equipment during initiation of the service request procedure when the user equipment is in a connection management idle state.

It should be understood that although specific steps are shown in the figures, a variety of additional or different steps may be performed according to embodiments, and one or more of the specific steps may be rearranged, repeated, or eliminated entirely depending on the embodiment. Further, some of the steps performed may be repeated simultaneously on a continuing or continuous basis while other steps are being performed. Moreover, different steps may be performed by different elements of the disclosed embodiments or in a single element.

Fig. 6 is an exemplary block diagram of an apparatus 600, such as a wireless communication device 110, according to a possible embodiment. The apparatus 600 may include a housing 610, a controller 620 within the housing 610, audio input and output circuitry 630 coupled to the controller 620, a display 640 coupled to the controller 620, a transceiver 650 coupled to the controller 620, an antenna 655 coupled to the transceiver 650, a user interface 660 coupled to the controller 620, a memory 670 coupled to the controller 620, and a network interface 680 coupled to the controller 620. The apparatus 600 may perform the methods described in all embodiments.

Display 640 may be a viewfinder, a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display, a plasma display, a projection display, a touch screen, or any other device that displays information. The transceiver 650 may include a transmitter and/or a receiver. The audio input and output circuitry 630 may include a microphone, a speaker, a transducer, or any other audio input and output circuitry. The user interface 660 may include a keypad, keyboard, button, touchpad, joystick, touchscreen display, another additional display, or any other device for providing an interface between a user and an electronic device. Network interface 680 may be a Universal Serial Bus (USB) port, an ethernet port, an infrared transmitter/receiver, an IEEE 1394 port, a WLAN transceiver, or any other interface that can connect an apparatus to a network, device, and/or computer and can send and receive data communication signals. The memory 670 may include random access memory, read only memory, optical memory, solid state memory, flash memory, removable memory, a hard drive, cache, or any other memory couplable to a device.

The apparatus 600 or controller 620 may implement any operating system, such as Microsoft WindowsOrAndroid^TMOr any other operating system. For example, the device operating software may be written in any programming language, such as C, C + +, Java, or Visual Basic. The device software may also run on an application framework, such asA frame,A framework or any other application framework. The software and/or operating system may be stored in memory 670 or elsewhere on device 600. The apparatus 600 or the controller 620 may also use hardware to implement the disclosed operations. For example, controller 620 may be any programmable processor. The disclosed embodiments may also be implemented on: general purpose or special purpose computers, programmed microprocessors or microprocessors, peripheral integrated circuit elements, application specific integrated circuits or other integrated circuits, hardware/electronic logic circuits (such as discrete element circuits), programmable logic devices (such as programmable logic arrays, field programmable gate arrays), or the like. In general, the controller 620 may be any controller or processor device or apparatus capable of operating an apparatus and implementing the disclosed embodiments. Some or all of the additional elements of the apparatus 600 may also perform some or all of the operations of the disclosed embodiments.

The method of the present disclosure may be implemented on a programmed processor. However, the controller, flow diagrams and modules may also be implemented on: general purpose or special purpose computers, programmed microprocessors or microcontrollers and peripheral integrated circuit elements, integrated circuits, hardware electronic or logic circuits (such as discrete element circuits), programmable logic devices, etc. In general, any device on which resides a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processor functions of this disclosure.

While the present disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in the other embodiments. In addition, all of the elements of each figure are not necessary for operation of the disclosed embodiments. For example, those of ordinary skill in the art of the disclosed embodiments will be able to derive and use the teachings of the present disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.

In this document, relational terms such as "first," "second," and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The phrase "at least one of … …", "at least one selected from the group of … …", or "at least one selected from … …" followed by a list is defined to mean one, some, or all, but not necessarily all of the elements in the list. The terms "comprises," "comprising," "includes," "including," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further restriction, the use of the elements "a", "an", etc. does not exclude the presence of additional identical elements in a process, method, article, or apparatus that comprises such elements. In addition, the term "another" is defined as at least a second or more. The terms "comprising," "having," and the like, as used herein, are defined as comprising. Furthermore, the background section is written as an understanding of the background of some embodiments by the inventors themselves at the time of filing, and includes the inventors' own recognition of any problems with the prior art and/or problems encountered in their own work.