CN117063531A

CN117063531A - Methods and mechanisms for slice-based cell reselection

Info

Publication number: CN117063531A
Application number: CN202280020464.1A
Authority: CN
Inventors: P·戈丁; H·M·古尔苏; G·沃尔费内; O·布拉克奇; M·纳希尔-厄尔-伊斯拉姆; A·卡萨蒂
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2021-03-31
Filing date: 2022-02-03
Publication date: 2023-11-14
Also published as: WO2022208176A1; EP4315997A1; JP2024512734A

Abstract

Systems, methods, apparatuses, and computer program products for cell reselection are provided. A method may include: radio mapping information is received between tracking area identifiers of tracking areas adjacent to the served cell and a list of physical cell identifiers associated with each tracking area associated with a physical cell identifier corresponding to the neighbor cell of the served cell. Slice assistance information may be received from a network entity associated with the apparatus, the slice assistance information mapping one or more network slices and at least one of: one or more tracking area identifiers of tracking areas in the user device registration area or one or more tracking area identifiers of tracking areas adjacent to the user device registration area supporting one or more network slices. The radio mapping information and the slice assistance information may be used in a cell reselection procedure.

Description

Methods and mechanisms for slice-based cell reselection

Technical Field

Some example embodiments may relate generally to mobile or wireless telecommunication systems, such as Long Term Evolution (LTE), fifth generation (5G) Radio Access Technology (RAT), new Radio (NR) access technology, and/or other communication systems. For example, certain example embodiments may relate to systems and/or methods for cell reselection.

Background

Examples of mobile or wireless telecommunications systems may include 5G RAT, universal Mobile Telecommunications System (UMTS) terrestrial radio access network (UTRAN), LTE evolved UTRAN (E-UTRAN), LTE-advanced (LTE-a), LTE-a Pro, NR access technology, and/or MulteFire alliance. The 5G wireless system refers to the Next Generation (NG) radio system and network architecture. The 5G system is typically built on 5G NR, but a 5G (or NG) network may also be built on E-UTRA radio. It is expected that NR can support service classes such as enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), and large-scale machine type communication (mctc). NR is expected to deliver extremely broadband, ultra-robust, low latency connectivity, and large-scale networking to support internet of things (IoT). The next generation radio access network (NG-RAN) represents a 5G RAN that can provide radio access for NR, LTE and LTE-a. It is noted that a node providing radio access functionality to user equipment in 5G, e.g. like a node B in UTRAN or an evolved node B (eNB) in LTE, may be referred to as next generation node B (gNB) when built on an NR radio and as next generation eNB (NG-eNB) when built on an E-UTRA radio.

Drawings

For a proper understanding of the exemplary embodiments, reference should be made to the accompanying drawings in which:

fig. 1 illustrates an example of a format of single network slice selection assistance information.

Fig. 2 illustrates an example of a signaling diagram in accordance with certain embodiments.

Fig. 3 illustrates an example of a flow chart of a method in accordance with various embodiments.

Fig. 4 illustrates an example of a flow chart of another method according to some embodiments.

Fig. 5 illustrates an example of a flow chart of another method in accordance with certain embodiments.

Fig. 6 illustrates examples of various network devices according to some embodiments.

Fig. 7 illustrates an example of a 5G network and system architecture in accordance with certain embodiments.

Detailed Description

It will be readily understood that the components of certain example embodiments, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for cell reselection is not intended to limit the scope of certain embodiments, but is representative of selected example embodiments.

An important function in the third generation partnership project (3 GPP) fifth generation (5G) is the ability to support different services using the same underlying mobile network infrastructure through network slicing. Network slicing involves grouping devices with similar performance requirements, such as latency, throughput, and transmission rate. In this way, the physical infrastructure of the network may be divided into logically isolated virtual networks, such as according to ultra-reliable low latency communications (URLLC) and enhanced mobile broadband (eMBB). Each network slice may be uniquely identified by single network slice selection assistance information (S-nsai), as illustrated in fig. 1.

Currently, 3GPP allows a UE to connect to and be served by up to eight single network slice selection assistance information (S-nsais), while a single cell may support hundreds of S-nsais, with a single Tracking Area (TA) capable of supporting up to 1024 network slices. As illustrated in fig. 1, each S-NSSAI may include a Slice Service Type (SST) and an operator-defined Slice Differentiator (SD) field (32-bits length), or may include only an SST field (8-bits length). The SST field may have standardized and non-standardized values ranging from 0 to 127. For example, an SST value of 1 may indicate that a network slice is compatible with 5G emmbb, while an SST value of 2 may indicate that a network slice is compatible with URLLC. While network slicing provides many benefits, some enterprise/industry scenarios may require service continuity when a UE moves into a neighboring cell where network slicing is not available. Thus, to provide service continuity, it would be beneficial for a UE to have uninterrupted service for ongoing Protocol Data Unit (PDU) sessions.

While in idle/inactive mode, the UE may perform periodic cell reselection and may camp on a cell when a more suitable cell is selected. During cell reselection, the UE may detect for neighbor cells, decode a Master Information Block (MIB) from the detected neighbor cells, prioritize the detected neighbor cells, and select a best cell. The UE may then decode a system information block (SIB 1) of the selected best cell to determine whether the selected best cell is a suitable cell. If not, the UE may evaluate the second prioritized cell by decoding SIB1 of the second prioritized cell until the UE finds a suitable cell.

As mentioned above, the UE currently does not consider network slices supported in neighboring cells during cell reselection. This results in the active PDU session being dropped once the UE enters the connected state, thereby interrupting service continuity. In addition, even though each cell broadcasts its supported network slices, the UE needs to decode SIB1 of each cell, thus unnecessarily consuming network resources and delaying service continuity. Current cell reselection techniques do not consider network slices supported in neighboring cells. Cell reselection in network slice deployment has been considered for service continuity, which involves reserving an established PDU session on any slice, e.g., for RRC inactive UEs. This is not supported because the UE is not aware of the slice support of any neighboring cells. Thus, after cell reselection, the UE may select a cell that does not support network slicing with PDU sessions. Thus, the UE is connected to a cell and must perform a registration area update procedure after which the PDU session of the UE may be dropped because no network slice is supported in the cell. The challenge also applies to RRC idle UEs, i.e. when the UE reselects the cell without slice support for the intended slice of the UE, e.g. a slice from the allowed nsai (or a new slice the UE has selected to connect), the unsupported network slice in the TA of the cell will not be included in the allowed nsai in the registration accept message.

Certain embodiments described herein may have various benefits and/or advantages to overcome at least the disadvantages described above, and other problems that may not be described herein. For example, some embodiments may avoid transmitting duplicate identifiers, such as group IDs. Some embodiments may also enable the broadcasting of information of limited size and enable fast cell reselection. Various example embodiments may also implement PDU session continuity by supporting slicing for cell reselection. Accordingly, certain embodiments discussed below relate to improvements in computer-related technology.

According to an embodiment, a fifth generation core (5 GC) network may transmit to a UE a list of network slices in a UE-configured nsai and/or a UE-allowed nsai that are supported by and in Tracking Areas (TAs) adjacent to a current Registration Area (RA). The network slice list may allow the UE to select the best cell if radio conditions allow, thereby maximizing service continuity or the ability to accept the requested slice.

Fig. 2 illustrates an example of a signaling diagram depicting cell reselection, in accordance with an embodiment. Note that in some embodiments, NEs 240 and 250 may be similar to NE 610 illustrated in fig. 6, and UE 230 may be similar to UE 620 illustrated in fig. 6. In addition, in some embodiments, the 5gc 260 may be similar to the network illustrated in fig. 7.

In one embodiment, in 201, NE 250 may transmit an NG setup message to 5gc 260 with similar information as described below for NE 240. In 203, for intra-frequency cell reselection information, NE 240 may transmit to UE 230 a PCI list for each TAC of TACs neighboring the current UE RA and a PCI list for the current UE RA or each TAC belonging to the current RA. In 205, for inter-frequency cell reselection information, NE 250 may transmit to UE 230 a list of frequency bands for TACs adjacent to the current RA and/or a list of PCIs per frequency band for each TAC and a list of frequency bands for the current RA or each TAC belonging to the current RA and/or a list of PCIs per frequency band. In 207, NE 240 may transmit an NG setup message to 5gc 260 that includes the supported TAC and a list of neighbor TACs of the supported TAC (such as TA1 and neighbor TA 3) and a list of nsais supported by the neighbor TACs.

In various example embodiments, the UE 230 may determine which network slices each neighboring cell supports. The prioritization of candidate cells during cell reselection may also take into account the information in any of the example embodiments described above. In some embodiments, the S-nsai list may be a priority list, and/or priority information may be assigned to a different list that UE 230 may consider during cell reselection.

Further, it is noted that in any of the example embodiments described herein, the TAC may be replaced with a CAG identifier. In addition, the exact encoding of the information may vary according to some embodiments; for example, instead of sending a list of slices for each TA or CAG, a list of TAs that allow nsais or configure each slice in nsais may be transmitted.

In yet another embodiment, in 209, the UE 230 may transmit at least one registration request to the 5gc 260. In 211, the 5gc 260 may determine that the UE Registration Area (RA) includes a plurality of TAs, such as TA1 and TA2. In 213, the 5gc 260 may transmit one or more registration accept messages, such as NAS registration accept messages, to the UE 230 during the registration update procedure. In some embodiments, the registration accept message may include slice assistance information. In one embodiment, the slice assistance information may include an indication that NSSAI is allowed, a UE RA including TA1 and TA2 with a supported slice list, and/or a third TA (TA 3) indicating a slice list. Alternatively, the 5gc 260 may transmit a list of supported slices for all TAs of the RA of each TA (such as TA1, TA 2) and a list of supported slices for all TAs adjacent to the RA (such as TA 3).

In some other embodiments, the 5gc 260 may transmit in the slice assistance information those Tracking Area Codes (TACs) and/or those network slices (also for boundary TACs) associated with the allowed nsais of the UE 230 and/or the requested nsais of the configuration nsais or UE 230. For example, if NSSAI is only allowed for service continuity, only network slices supported by tracking areas adjacent to the current RA may be sent.

In various other example embodiments, the 5gc 260 may transmit TAC boundary information (i.e., delta) in the slice assistance information for only those network slices that are not part of the nsaai enabled. As an example, the information may include delta coding instead of allowing nsaai. For example, an empty list of network slices provided for a TAC in a border TAC or RA would mean that the same network slices are supported in the border TA or TA in the current RA as in the admission nsaai. In some embodiments, a negative increment may also be used in the slice assistance information, e.g., where S-nsai sst=15 increment indicates that it is an allowed nsai for TAC supporting all slices except S-nsai sst=15 in the allowed nsai. Similar considerations may apply to configuration NSSAI delta, where only negative delta may be applied to configuration NSSAI since no additional slices that are not in configuration NSSAI need to be signaled.

In some embodiments, the 5gc 260 may transmit an indication of the trajectory of the UE 230, e.g., based on Artificial Intelligence (AI)/Machine Learning (ML) of a portion of the TAC boundary information. Further, in some embodiments, the TAC may be replaced by a Closed Access Group (CAG) identifier.

In yet another embodiment, in 215, 5gc 260 may transmit a NG context setup message, such as a Next Generation Application Protocol (NGAP) initial context setup request or a NGAP handover request, to NE 240. In various example embodiments, the above NG context setup message may include slice assistance information. In some embodiments, the slice assistance information may include a list of S-NSSAIs for the UE RA or each TA of RA with a list of S-NSSAIs and TA3 associated with the list of S-NSSAIs. In 217, NE 240 may store the information received in 215. In 219, NE 240 may transmit a Handover (HO) request to NE 250, which may include the UE RA with the S-nsai list or the S-nsai list for each TA of the RA and an indication of TA3 (TA adjacent to the RA) including the S-nsai list. In 221, NE 250 may transmit a Radio Resource Control (RRC) release message to UE 230, which may include slice assistance information. In some embodiments, this may include a list of S-NSSAIs for the UE RA or each TA of RA with a list of S-NSSAIs and an indication of TA3 (TA adjacent to RA) that includes the list of S-NSSAIs. In some embodiments, NE 250 may transmit information to UE 230 during PDU session establishment/modification of a network slice associated with the PDU session.

In some other embodiments, the 5gc 260 may transmit only those TACs and/or those network slices associated with the allowed nsais of the UE 230 and/or the configuration nsais or the request nsais of the UE 230 (also for boundary TACs) in 215. For example, if NSSAI is only allowed for service continuity, only network slices supported by tracking areas adjacent to the current RA may be sent.

In various other example embodiments, the 5gc 260 may transmit only TAC boundary information (i.e., delta) for those network slices that are not part of the nsai enabled in the slice assistance information. As an example, this information may include incremental encoding instead of allowing nsais to provide an empty list of network slices for the TACs in the border TACs or RA. This means that the network slices supported in the TACs in the borders TA and RA are the same as there are in the admission nsai. Negative increments may also be used in the slice assistance information, e.g. where the S-nsai sst=15 increment indicates that it is an allowed nsai for supporting TACs for all slices in the allowed nsai except S-nsai sst=15. Similar considerations may apply to configuration NSSAI delta, where only negative delta may be applied to configuration NSSAI since no additional slices that are not in configuration NSSAI need to be signaled.

In some other example embodiments, the 5gc 260 may transmit an indication of the trajectory of the UE 230, e.g., based on AI/ML for only a portion of the TAC boundary information. Additionally or alternatively, in the slice assistance information, the boundary TA and an indication that all boundary TAs support nsaai slices are allowed may be transmitted to the UE 230. Similarly, an indication that all network slices in the configuration nsai are supported in the TA and/or boundary TA of the RA may be transmitted in the slice assistance information. The UE 230 may receive slice support for boundary TAs around the RA or may also provide slice support for TAs in the RA of the UE 230.

Fig. 3 illustrates an example of a flowchart of a method that may be performed by a UE (such as UE 620 illustrated in fig. 6) in accordance with various example embodiments. As illustrated in the example of fig. 3, in 301, a UE may receive radio mapping information between TA identifiers of TAs neighboring a served cell and a list of physical cell identifiers associated with each TA, each TA being associated with a physical cell identifier corresponding to a neighboring cell of the served cell.

In 303, the UE may receive radio mapping information including a mapping between TA identifiers of TAs adjacent to the served cell and a list of physical cell identifiers associated with each of the tracking areas, wherein the physical cell identifiers correspond to at least one of the neighbor cells of the served cell configured for use by at least one frequency band adjacent to the served cell.

In 305, the UE may receive slice assistance information associated with the apparatus from a network entity, the slice assistance information mapping one or more network slices and at least one of: one or more TA identifiers of a tracking area in the UE RA or one or more TA identifiers of a tracking area adjacent to the UE RA supporting one or more network slices.

In 307, the UE may use the radio mapping information and the slice assistance information in a cell reselection procedure. In some embodiments, the radio mapping information and the slice assistance information may be used in the cell reselection procedure only when multiple neighboring cells are deemed appropriate. Furthermore, the radio mapping information may be received by the served cell via SIB. Further, the slice assistance information may be inversely encoded as a mapping between the tracking area identifier list and at least one network slice supported in each of the corresponding TAs, wherein the TAs may be at least one of a tracking area of the UE RA or a tracking area adjacent to the TAs of the UE RA.

In various embodiments, the slice assistance information may indicate a network slice corresponding to at least one of a list of slices requested by the UE during the registration update procedure, a list of requested slices that the network has allowed during the registration update procedure, or a list of configured network slices that the network has configured to the user equipment. In addition, the slice assistance information may include only network slices that do not belong to the set of network slices that the network reported as allowed in the registration update procedure. In another embodiment, the tracking area identifier may comprise a closed access group identifier.

Fig. 4 illustrates an example of a flowchart of a method that may be performed by a 5GC (such as the network illustrated in fig. 7) in accordance with various example embodiments. As illustrated in the example of fig. 4, in 401, the 5GC may determine at least one tracking area in the UE RA. In 403, the 5GC may transmit slice assistance information including a slice (of either the nsai enabled or the nsai configured) associated with the UE, the slice assistance information indicating a mapping between one or more network slices and at least one of: one or more TA identifiers of a tracking area in the UE RA or one or more TA identifiers in a tracking area adjacent to the UE RA supporting one or more network slices.

In some embodiments, each network slice included in the slice assistance information may indicate at least one of SST and SD for each of the one or more network slices. Additionally or alternatively, the slice assistance information may be transmitted to at least one user equipment. Further, slice assistance information may be transmitted during the registration update procedure.

In some embodiments, the slice assistance information may include at least one of: a list of network slices requested by the user device during the registration update procedure, a list of requested network slices allowed by the network during the registration update procedure, and/or a list of network slices configured by the network to the user device. Further, in an embodiment, the one or more tracking area identifiers of the slice assistance information may comprise only tracking area identifiers of tracking areas adjacent to the user equipment registration area. The list of network slices in the slice assistance information may include a plurality of network slices that the network allows during the registration update procedure.

In various example embodiments, the slice assistance information may be inversely encoded as a mapping between the tracking area identifier list and the network slices supported in each of the corresponding tracking areas. The tracking areas may include one or more tracking areas of the user device registration area and/or one or more tracking areas adjacent to the tracking areas of the user device registration area. Additionally, according to some embodiments, the slice assistance information may include only network slices that do not belong to the set of network slices that the network reported as allowed in the registration update procedure. In some embodiments, the slice assistance information may be associated with a trajectory of the user device. In some embodiments, the mapping information (both radio mapping and slice assistance information) may comprise at least one closed access group identifier instead of the tracking area identifier.

Fig. 5 illustrates an example of a flowchart of a method that may be performed by a network entity (such as NE 610 illustrated in fig. 6) according to various example embodiments. As illustrated by the example of fig. 5, in 501, a NE may receive slice assistance information associated with a user equipment indicating a mapping between one or more network slices and one or more TA identifiers of TAs in a UE RA and/or one or more tracking area identifiers of tracking areas adjacent to the UE RA supporting the one or more network slices.

In 503, the NE may store slice assistance information. In 505, the NE may transmit a radio resource control release message including slice assistance information to the UE. In 507, the NE may communicate the stored slice assistance information to the network entity in response to the at least one handover procedure.

In some embodiments, the method may further include communicating the stored slice assistance information to the network entity in response to at least one handover procedure. Further, the radio resource control release message may be configured to cause the user equipment to enter a radio resource control inactive state. Additionally or alternatively, each network slice included in the slice assistance information may indicate at least one of SST and SD.

In some embodiments, the slice assistance information may be received from the core network. Further, in some embodiments, the slice assistance information may be received in an NGAP initial context setup request message or an NGAP handover request message.

In various example embodiments, the method may further include transmitting radio mapping information including: mapping information between tracking area identifiers of tracking areas adjacent to the served cell and a list of physical cell identifiers associated with each tracking area (associated with physical cell identifiers of neighboring cells corresponding to the served cell), and/or radio mapping information of: a mapping between tracking area identifiers of tracking areas adjacent to the served cell and a list of physical cell identifiers associated with each of the tracking areas, wherein the physical cell identifiers correspond to at least one of the neighboring cells of the served cell configured for use by at least one frequency band adjacent to the served cell. Further, in some embodiments, the radio mapping information may be transmitted via system information broadcast by the serving cell.

Fig. 6 illustrates an example of a system according to some example embodiments. In an example embodiment, the system may include one or more devices, such as, for example, NE 610 and/or UE 620.

NE 610 may be one or more of the following: a base station, such as an eNB or a gNB, a serving gateway, a server, an access point, a Transmission Reception Point (TRP), a citizen broadband radio service device (CBSD), and/or any other access or radio node or combination thereof.

In embodiments where NE 610 may be a gNB, NE 610 may also include at least one gNB-CU that may be associated with at least one gNB-DU.The at least one gNB-CU and the at least one gNB-DU may be via at least one F1 interface, at least one X _n -C interface and/or communication via at least one NG interface of a 5 GC.

UE 620 may include one or more of the following: a mobile device such as a mobile phone, a smart phone, a Personal Digital Assistant (PDA), a tablet computer or portable media player, a digital camera, a pocket video camera, a video game console, a navigation unit such as a Global Positioning System (GPS) device, a desktop or laptop computer, an IoT device, a unit location device such as a sensor or smart meter, or any combination thereof.

NE 610 and/or UE 620 may include at least one processor, indicated as 611 and 621, respectively. The processors 611 and 621 may be implemented by any computing or data processing device, such as a Central Processing Unit (CPU), application Specific Integrated Circuit (ASIC), or similar device. A processor may be implemented as a single controller or as multiple controllers or processors.

At least one memory may be provided in one or more devices, as indicated at 612 and 622. The memory may be fixed or removable. The memory may include computer program instructions or computer code embodied therein. Independently, memories 612 and 622 may be any suitable storage devices, such as non-transitory computer-readable media. A Hard Disk Drive (HDD), random Access Memory (RAM), flash memory, or other suitable memory may be used. The memory may be combined into a processor on a single integrated circuit or may be separate from one or more processors. Furthermore, the computer program instructions stored in the memory and which may be processed by the processor may be in any suitable form of computer program code, such as a compiled or interpreted computer program written in any suitable programming language.

The processors 611 and 621, memories 612 and 622, and any subset thereof may be configured to provide components corresponding to the various blocks of fig. 2-5. Although not shown, the device may also include positioning hardware, such as GPS or microelectromechanical system (MEMS) hardware, which may be used to determine the location of the device. Other sensors are also allowed and may be configured to determine position, altitude, speed, orientation, etc., such as barometers, compass, etc.

As shown in fig. 6, transceivers 613 and 623 may be provided and one or more devices may also include at least one antenna, illustrated as 614 and 624, respectively. The device may have many antennas, such as an antenna array configured for multiple-input multiple-output (MIMO) communications or multiple antennas for multiple RATs. For example, other configurations of these devices may be provided. Transceivers 613 and 623 may be transmitters, receivers, both transmitters and receivers, or units or devices that may be configured for transmission and reception.

The memory and computer program instructions may be configured with a processor for a particular device to cause a hardware apparatus, such as a UE or NE, to perform any of the processes described above (i.e., fig. 2-5). Thus, in certain embodiments, the non-transitory computer readable medium may be encoded with computer instructions that, when executed in hardware, perform a process, such as one of the processes described herein. Alternatively, some embodiments may be implemented entirely in hardware.

In some embodiments, an apparatus may include circuitry configured to perform any of the processes or functions illustrated in fig. 2-5. For example, the circuitry may be a hardware-only circuit implementation, such as analog and/or digital circuitry. In another example, the circuitry may be a combination of hardware circuitry and software, such as a combination of analog and/or digital hardware circuitry and software or firmware and/or a hardware processor (including a digital signal processor) with software, and any portion of at least one memory that work together to cause the apparatus to perform various processes or functions. In yet another example, the circuitry may be hardware circuitry and/or a processor, such as a microprocessor or a portion of a microprocessor, that includes software (such as firmware) for operation. Software in the circuitry may not be present when hardware is not required to operate.

Fig. 7 illustrates an example of a 5G network and system architecture in accordance with certain embodiments. A plurality of network functions are shown which may be implemented as software operating as part of, or as virtual functions operating as, a network device itself or dedicated hardware. The NE and UE illustrated in fig. 7 may be similar to NE 610 and UE 620, respectively. User Plane Functions (UPFs) may provide services such as intra-RAT and inter-RAT mobility, routing and forwarding of data packets, inspection of packets, user plane quality of service (QoS) handling, buffering of downstream packets, and/or triggering of downstream data notifications. Application Functions (AFs) may interface primarily with the core network to facilitate application usage of traffic routing and interact with the policy framework.

The features, structures, or characteristics of the example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the use of the phrases "various embodiments," "certain embodiments," "some embodiments," or other similar language throughout this specification refers to the fact that: the particular features, structures, or characteristics described in connection with the example embodiments may be included in at least one example embodiment. Thus, appearances of the phrases "in various embodiments," "in certain embodiments," "in some embodiments," or other similar language throughout this specification do not necessarily all refer to the same group of example embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments.

Additionally, if desired, the different functions or procedures discussed above may be performed in a different order and/or concurrently with each other. Furthermore, one or more of the described functions or procedures may be optional or may be combined, if desired. Thus, the foregoing description should be considered as merely illustrative of the principles and teachings of certain exemplary embodiments, and not in limitation thereof.

Those of ordinary skill in the art will readily appreciate that the example embodiments discussed above may be practiced in a different order of programs and/or with hardware elements in a different configuration than that disclosed. Thus, while some embodiments have been described based on these example embodiments, it will be apparent to those of ordinary skill in the art that certain modifications, variations, and alternative constructions will be apparent while remaining within the spirit and scope of the example embodiments.

According to a first embodiment, a method may include: radio mapping information is received between tracking area identifiers of tracking areas adjacent to the served cell and a list of physical cell identifiers associated with each tracking area associated with a physical cell identifier corresponding to the neighbor cell of the served cell. The method may further comprise: radio mapping information is received that includes a mapping between tracking area identifiers of tracking areas adjacent to the served cell and a list of physical cell identifiers associated with each of the tracking areas, wherein the physical cell identifiers correspond to at least one of the neighboring cells of the served cell that is configured for use by at least one frequency band adjacent to the served cell. The method may further comprise: receiving slice assistance information associated with the apparatus from a network entity, the slice assistance information mapping one or more network slices with at least one of: one or more tracking area identifiers of tracking areas in the user device registration area or one or more tracking area identifiers of tracking areas adjacent to the user device registration area supporting one or more network slices. The method may further comprise: the radio mapping information and the slice assistance information are used in the cell reselection procedure.

In a variant, the radio mapping information and the slice assistance information may be used in the cell reselection procedure only when a plurality of neighboring cells are considered suitable.

In a variant, the radio mapping information may be received via system information broadcast by the serving cell.

In a variation, the slice assistance information may be inversely encoded as a mapping between a tracking area identifier list and at least one network slice supported in each of the corresponding tracking areas, wherein the tracking areas are at least one of: a tracking area of the user equipment registration area or a tracking area adjacent to the tracking area of the user equipment registration area.

In a variation, the slice assistance information may indicate a network slice corresponding to at least one of: a list of slices requested by the user device during the registration update procedure, a list of requested slices that the network has allowed during the registration update procedure, or a list of configured network slices that the network has configured to the user device.

In a variant, the slice assistance information may include only network slices that do not belong to the set of network slices that the network reported as allowed in the registration update procedure.

In a variant, the tracking area identifier may comprise a closed access group identifier.

According to a second embodiment, a method may include: at least one tracking area of the user device registration area is determined. The method may further comprise: transmitting slice assistance information associated with the user equipment, the slice assistance information indicating a mapping between one or more network slices and at least one of: one or more tracking area identifiers of tracking areas in the user device registration area or one or more tracking area identifiers of tracking areas adjacent to the user device registration area supporting one or more network slices.

In a variant, each network slice may be included in slice assistance information indicating at least one of: a slice service type and a slice differentiator for each of the one or more network slices.

In a variant, the slice assistance information may be transmitted to at least one user equipment.

In a variant, the slice assistance information may be transmitted during the registration update procedure.

In a variation, the slice assistance information may include at least one of: the list of network slices requested by the user device during the registration update procedure, the list of requested network slices allowed by the network during the registration update procedure, and the list of network slices configured by the network to the user device.

In a variant, the one or more tracking area identifiers of the slice assistance information may comprise only tracking area identifiers of tracking areas adjacent to the user equipment registration area, wherein the network slice list comprises a plurality of network slices allowed by the network during the registration update procedure.

In a variation, the slice assistance information may be inversely encoded as a mapping between a tracking area identifier list and network slices supported in each of the corresponding tracking areas, wherein the tracking areas include at least one of: one or more tracking areas of the user device registration area or one or more tracking areas adjacent to the tracking area of the user device registration area.

In a variant, the slice assistance information may be associated with a trajectory of the user device.

In a variant, the mapping information may comprise at least one closed access group identifier instead of the tracking area identifier.

According to a third embodiment, a method may include transmitting at least one of: radio mapping information to a user equipment, the radio mapping information comprising mapping information between tracking area identifiers of tracking areas adjacent to a served cell and a list of physical cell identifiers associated with each tracking area, the each tracking area being associated with a physical cell identifier of an adjacent cell corresponding to the served cell; and radio mapping information of a mapping between a tracking area identifier of a tracking area adjacent to the served cell and a list of physical cell identifiers associated with each of the tracking areas, wherein the physical cell identifiers correspond to at least one of the neighboring cells of the served cell configured for use by at least one frequency band adjacent to the served cell.

In a variant, the method may further comprise: the stored slice assistance information is communicated to the network entity in response to the at least one handover procedure.

In a variant, the radio resource control release message may be configured to cause the user equipment to enter a radio resource control inactive state.

In a variation, each network slice may be included in slice assistance information including at least one of a slice access type and a slice differentiator.

In a variant, the slice assistance information may be received from the core network.

In a variant, the slice assistance information may be received in a next generation application protocol initial context setup request message or a next generation application protocol handover request message.

In a variant, the method may further comprise: receiving slice assistance information associated with a user equipment, the slice assistance information indicating a mapping between one or more network slices and at least one of: one or more tracking area identifiers of tracking areas in the user device registration area or one or more tracking area identifiers of tracking areas adjacent to the user device registration area that support one or more network slices. The method may further comprise: slice assistance information is stored. The method may also include transmitting a radio resource control release message including the slice assistance information to the user equipment.

In a variant, the radio mapping information may be transmitted via system information broadcast by the serving cell.

According to a fourth, fifth and sixth embodiment, an apparatus may comprise at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform the method according to the first embodiment and any variations thereof.

According to a third embodiment, an apparatus may comprise means for performing the method according to the first embodiment and any variant thereof.

According to a seventh, eighth and ninth embodiment, a computer program product may be encoded with instructions for performing a process comprising the method according to the first embodiment and any variant thereof.

According to a tenth, eleventh and twelfth embodiments, a non-transitory computer readable medium may have stored thereon instructions that, when executed in hardware, perform a process comprising the method according to the first embodiment and any variant thereof.

According to a thirteenth, fourteenth and fifteenth embodiment, the computer program code may comprise instructions for performing the method according to the first embodiment and any variants thereof.

According to a sixteenth, seventeenth and eighteenth embodiment, an apparatus may comprise circuitry configured to perform a process including a method according to the first embodiment and any variations thereof.

Partial vocabulary

3GPP third Generation partnership project

Fifth generation of 5G

5GC fifth generation core

5GS fifth generation system

5QI fifth generation quality of service indicator

AI artificial intelligence

AMF access and mobility management functions

ASIC specific integrated circuit

BS base station

CAG closed access group

CBSD citizen broadband radio service equipment

CN core network

CPU central processing unit

DL downlink

DMRS demodulation reference signal

DRB data radio bearer

eMBB enhanced mobile broadband

eMTC enhanced machine type communication

eNBs evolved node B

eOLLA enhanced outer loop link adaptation

EPS evolution grouping system

gNB next generation node B

GPS global positioning system

HDD hard disk drive

HO handover

LTE long term evolution

LTE-A advanced long term evolution

MAC medium access control

MBS multicast and broadcast system

MCS modulation coding scheme

MEMS micro-electromechanical system

MIB master information block

MIMO multiple input multiple output

ML machine learning

MME mobility management entity

mMTC large-scale machine type communication

NAS non-access stratum

NB-IoT narrowband Internet of things

NE network entity

NG next generation

NGAP next generation application protocol

NG-eNB next generation evolution node B

NG-RAN next generation radio access network

NR new radio

New radio with unlicensed NR-U

OFDM orthogonal frequency division multiplexing

OLLA outer loop link adaptation

Bit rate for PBR prioritization

PCI physical cell identifier

PDA personal digital assistant

PDU protocol data unit

PRACH physical random access

RA registration area

RACH random access channel

RAM random access memory

RAN radio access network

RAT radio access technology

RRC radio resource control

SD slice differentiator

SIB system information block

S-NSSAI single network slice assistance information

SST slice service type

TAC tracking area code

TR technical report

TS technical Specification

UE user equipment

UL uplink

UMTS universal mobile telecommunications system

Ultra-reliable low latency communication of URLLC

Terrestrial radio access network for UTRAN universal mobile telecommunication system

WLAN wireless local area network

Claims

1. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to:

Receiving radio mapping information between tracking area identifiers of tracking areas adjacent to a served cell and a list of physical cell identifiers associated with each tracking area, each tracking area being associated with a physical cell identifier corresponding to an adjacent cell to the served cell;

receiving radio mapping information comprising a mapping between the tracking area identifiers of tracking areas adjacent to the served cell and the list of physical cell identifiers associated with each of the tracking areas, wherein a physical cell identifier corresponds to at least one of the adjacent cells of the served cell configured for use by at least one frequency band adjacent to the served cell;

receiving slice assistance information associated with the apparatus from a network entity, the slice assistance information mapping one or more network slices and at least one of: one or more tracking area identifiers of tracking areas in a user device registration area or one or more tracking area identifiers of tracking areas adjacent to the user device registration area supporting the one or more network slices; and

The radio mapping information and the slice assistance information are used in a cell reselection procedure.

2. The apparatus of claim 1, wherein the radio mapping information and the slice assistance information are used in the cell reselection procedure when a plurality of neighboring cells are deemed suitable.

3. The apparatus of claim 1, wherein the radio mapping information is received via system information broadcast by the served cell.

4. The apparatus of claim 1, wherein the slice assistance information is inversely encoded as the mapping between a list of tracking area identifiers and at least one network slice supported in each of the corresponding tracking areas, wherein the tracking areas are at least one of: a tracking area of the user equipment registration area or a tracking area adjacent to a tracking area of the user equipment registration area.

5. The apparatus of claim 1, wherein the slice assistance information indicates a network slice corresponding to at least one of: a list of slices requested by the user equipment during the registration update procedure, a list of requested slices that the network has allowed during the registration update procedure, or a list of configured network slices that the network has configured to the user equipment.

6. The apparatus of claim 4, wherein the slice assistance information comprises only: network slices that do not belong to the network that are reported in the registration update procedure as a set of allowed network slices.

7. The apparatus of claim 1, wherein the tracking area identifier comprises a closed access group identifier.

8. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code,

determining at least one tracking area in a user equipment registration area; and

transmitting slice assistance information associated with the user equipment, the slice assistance information indicating a mapping between one or more network slices and at least one of: one or more tracking area identifiers of tracking areas in the user device registration area or one or more tracking area identifiers of tracking areas adjacent to the user device registration area supporting the one or more network slices.

9. The apparatus of claim 8, wherein each network slice included in the slice assistance information indicates at least one of: a slice service type or a slice differentiator for each of the one or more network slices.

10. The apparatus of claim 8, wherein the slice assistance information is transmitted to at least one user equipment.

11. The apparatus of claim 8, wherein the slice assistance information is transmitted during a registration update procedure.

12. The apparatus of claim 8, wherein the slice assistance information comprises at least one of:

a list of network slices requested by the user equipment during the registration update procedure;

a list of requested network slices allowed by the network during the registration update procedure; or alternatively

The network configures a list of network slices to the user device.

13. The apparatus of claim 11, wherein the one or more tracking area identifiers of the slice assistance information comprise: a tracking area identifier of a tracking area adjacent to the user device registration area, wherein the network slice list comprises: the network allows for multiple network slices during the registration update procedure.

14. The apparatus of claim 8, wherein the slice assistance information is inversely encoded as the mapping between a list of tracking area identifiers and the network slices supported in each of the corresponding tracking areas, wherein the tracking areas comprise at least one of: one or more tracking areas of the user device registration area, or one or more tracking areas adjacent to the tracking area of the user device registration area.

15. The apparatus of claim 14, wherein the slice assistance information comprises only: network slices that do not belong to the network that are reported in the registration update procedure as a set of allowed network slices.

16. The apparatus of claim 8, wherein the slice assistance information is associated with a trajectory of the user device.

17. The apparatus of claim 8, wherein the mapping information comprises at least one closed access group identifier.

18. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code,

transmitting at least one of the following:

radio mapping information to a user equipment, the radio mapping information comprising mapping information between tracking area identifiers of tracking areas adjacent to a served cell and a list of physical cell identifiers associated with each tracking area, each tracking area being associated with a physical cell identifier corresponding to an adjacent cell to the served cell; or alternatively

Radio mapping information of a mapping between the tracking area identifier of a tracking area adjacent to the served cell and the list of physical cell identifiers associated with each of the tracking areas, wherein a physical cell identifier corresponds to at least one of the adjacent cells of the served cell configured for use by at least one frequency band adjacent to the served cell.

19. The apparatus of claim 18, wherein the radio mapping information is transmitted via system information broadcast by the served cell.

20. The apparatus of claim 18, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

receiving slice assistance information associated with a user equipment, the slice assistance information indicating a mapping between one or more network slices and at least one of: one or more tracking area identifiers of tracking areas in a user device registration area or one or more tracking area identifiers of tracking areas adjacent to the user device registration area supporting the one or more network slices;

Storing the slice auxiliary information; and

and transmitting a radio resource control release message including the slice assistance information to the user equipment.

21. The apparatus of claim 20, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

the stored slice assistance information is communicated to the network entity in response to the at least one handover procedure.

22. The apparatus of claim 20, wherein the radio resource control release message is configured to cause the user equipment to enter a radio resource control inactive state.

23. The apparatus of claim 20, wherein each network slice included in the slice assistance information comprises: at least one of a slice service type or a slice differentiator.

24. The apparatus of claim 20, wherein the slice assistance information is received from a core network.

25. The apparatus of claim 20, wherein the slice assistance information is received in a next generation application protocol initial context setup request message or a next generation application protocol handover request message.

26. A method, comprising:

27. The method of claim 26, wherein the radio mapping information and the slice assistance information are used in the cell reselection procedure when a plurality of neighboring cells are deemed suitable.

28. The method of claim 26, wherein the radio mapping information is received via system information broadcast by the served cell.

29. The method of claim 26, wherein the slice assistance information is inversely encoded as the mapping between a list of tracking area identifiers and at least one network slice supported in each of the corresponding tracking areas, wherein the tracking areas are at least one of: a tracking area of the user equipment registration area or a tracking area adjacent to a tracking area of the user equipment registration area.

30. The method of claim 26, wherein the slice assistance information indicates a network slice corresponding to at least one of: a list of slices requested by the user equipment during the registration update procedure, a list of requested slices that the network has allowed during the registration update procedure, or a list of configured network slices that the network has configured to the user equipment.

31. The method of claim 29, wherein the slice assistance information comprises only: network slices that do not belong to the network that are reported in the registration update procedure as a set of allowed network slices.

32. The method of claim 26, wherein the tracking area identifier comprises a closed access group identifier.

33. A method, comprising:

34. The method of claim 33, wherein each network slice included in the slice assistance information indicates at least one of: a slice service type or a slice differentiator for each of the one or more network slices.

35. The method of claim 33, wherein the slice assistance information is transmitted to at least one user equipment.

36. The method of claim 33, wherein the slice assistance information is transmitted during a registration update procedure.

37. The method of claim 36, wherein the slice assistance information comprises at least one of:

The network configures a list of network slices to the user device.

38. The method of claim 36, wherein the one or more tracking area identifiers of the slice assistance information comprise: a tracking area identifier of a tracking area adjacent to the user device registration area, wherein the network slice list comprises: the network allows for multiple network slices during the registration update procedure.

39. The method of claim 33, wherein the slice assistance information is inversely encoded as the mapping between a list of tracking area identifiers and the network slices supported in each of the corresponding tracking areas, wherein the tracking areas comprise at least one of: one or more tracking areas of the user device registration area, or one or more tracking areas adjacent to the tracking area of the user device registration area.

40. The method of claim 39, wherein the slice assistance information comprises only: network slices that do not belong to the set of network slices that the network reported as allowed in the registration update procedure.

41. The method of claim 33, wherein the slice assistance information is associated with a trajectory of the user device.

42. The method of claim 33, wherein the mapping information comprises at least one closed access group identifier.

43. A method, comprising:

transmitting at least one of the following:

radio mapping information to a user equipment, the radio mapping information comprising mapping information between tracking area identifiers of tracking areas adjacent to a served cell and a list of physical cell identifiers associated with each tracking area, the each tracking area being associated with a physical cell identifier of a neighboring cell corresponding to the served cell; or alternatively

44. The method of claim 43, wherein the radio mapping information is transmitted via system information broadcast by the served cell.

45. The method of claim 43, further comprising:

storing the slice auxiliary information; and

46. The method of claim 43, further comprising:

47. The method of claim 43, wherein the radio resource control release message is configured to cause the user equipment to enter a radio resource control inactive state.

48. The method of claim 43, wherein each network slice included in the slice assistance information comprises: at least one of a slice service type or a slice differentiator.

49. A method as defined in claim 43, wherein the slice assistance information is received from a core network.

50. The method of claim 43, wherein the slice assistance information is received in a next generation application protocol initial context setup request message or a next generation application protocol handover request message.

51. An apparatus, comprising:

means for performing the method of any one of claims 26 to 50.

52. A non-transitory computer readable medium comprising program instructions stored thereon to perform the method of any one of claims 26 to 50.

53. An apparatus comprising circuitry configured to cause the apparatus to perform the method of any one of claims 26 to 50.

54. A computer program product encoded with instructions for performing the method of any of claims 26 to 50.