WO2023131907A1

WO2023131907A1 - Cell reselection based on network slicing considering mobility

Info

Publication number: WO2023131907A1
Application number: PCT/IB2023/050116
Authority: WO
Inventors: Prateek Basu Mallick; Ravi Kuchibhotla
Original assignee: Lenovo (Singapore) Pte. Ltd.
Priority date: 2022-01-06
Filing date: 2023-01-06
Publication date: 2023-07-13

Abstract

Apparatuses, methods, and systems are disclosed for cell reselection based on network slicing considering mobility. An apparatus (500) includes a memory (510) and a processor (505) coupled to the memory (510). The processor (505) performs legacy-based cell reselection for a cell of a wireless communication network. The processor (505) determines at least one network slice associated with the apparatus, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the apparatus. The processor (505) switches to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell.

Description

CELL RESELECTION BASED ON NETWORK SLICING CONSIDERING

MOBILITY

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application Serial Number 63/297,107 entitled “CELL RESELECTION BASED ON NETWORK SLICING CONSIDERING MOBILITY” and filed on January 6, 2022, for Prateek Basu Mallick et al., which is incorporated herein by reference in its entirety.

FIELD

[0002] The subject matter disclosed herein relates generally to wireless communications and more particularly relates to cell reselection based on network slicing considering mobility.

BACKGROUND

[0003] In certain wireless communication systems, when slice-based cell reselection does not yield e.g.., no cell reselection takes place, a user equipment (“UE”) can start legacy cell reselection. Since legacy cell reselection can continue for a long time unless a reselection is made, the UE will not be able to revert to slice-based cell reselection. This can be suboptimal if the UE, due to mobility, is now in the coverage of a frequency whose highest ranked cell supports a (high priority) slice from the slice list.

BRIEF SUMMARY

[0004] Disclosed are procedures for cell reselection based on network slicing considering mobility. Said procedures may be implemented by apparatus, systems, methods, and/or computer program products.

[0005] In one embodiment, a first apparatus includes a memory and a processor coupled to the memory. In one embodiment, the processor is configured to cause the apparatus to perform legacy-based cell reselection for a cell of a wireless communication network. In one embodiment, the processor is configured to cause the apparatus to determine at least one network slice associated with the apparatus, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the apparatus. In one embodiment, the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell. [0006] In one embodiment, a first method performs legacy-based cell reselection for a cell of a wireless communication network. In one embodiment, the first method determines at least one network slice associated with a UE, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the UE. In one embodiment, the first method switches to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell.

[0007] In one embodiment, a second apparatus includes a memory and a processor coupled to the memory. In one embodiment, the processor is configured to cause the apparatus to determine reselection priority frequencies for at least one network slice associated with a UE. In one embodiment, the processor is configured to cause the apparatus to transmit slice reselection information to the UE, the slice reselection information comprising the reselection priority frequencies for the at least one network slice associated with the UE. In one embodiment, the processor is configured to cause the apparatus to transmit at least one value indicating to the UE whether to switch from legacy-based cell reselection to slice-based cell reselection using the slice reselection information.

[0008] In one embodiment, a second method determines reselection priority frequencies for at least one network slice associated with a UE. In one embodiment, the second method transmits slice reselection information to the UE, the slice reselection information comprising the reselection priority frequencies for the at least one network slice associated with the UE. In one embodiment, the second method transmits at least one value indicating to the UE whether to switch from legacy-based cell reselection to slice-based cell reselection using the slice reselection information.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0010] Figure 1 is a schematic block diagram illustrating one embodiment of a wireless communication system for cell reselection based on network slicing considering mobility;

[0011] Figure 2 is an example of cell and frequency deployment; [0012] Figure 3 depicts an example procedure flow for cell reselection based on network slicing considering mobility;

[0013] Figure 4 depicts another example procedure flow for cell reselection based on network slicing considering mobility with triggers;

[0014] Figure 5 is a block diagram illustrating one embodiment of a user equipment apparatus that may be used for cell reselection based on network slicing considering mobility;

[0015] Figure 6 is a block diagram illustrating one embodiment of a network apparatus that may be used for cell reselection based on network slicing considering mobility;

[0016] Figure 7 is a flowchart diagram illustrating one embodiment of a method for cell reselection based on network slicing considering mobility; and

[0017] Figure 8 is a flowchart diagram illustrating one embodiment of a method for cell reselection based on network slicing considering mobility.

DETAILED DESCRIPTION

[0018] As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects.

[0019] For example, the disclosed embodiments may be implemented as a hardware circuit comprising custom very-large-scale integration (“VLSI”) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. The disclosed embodiments may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function.

[0020] Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred hereafter as code. The storage devices may be tangible, non- transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

[0021] Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0022] More specific examples (a non-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (“RAM”), a read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM” or Flash memory), a portable compact disc readonly memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0023] Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object- oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages. The code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (“LAN”), wireless LAN (“WLAN”), or a wide area network (“WAN”), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider (“ISP”)).

[0024] Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment.

[0025] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.

[0026] As used herein, a list with a conjunction of “and/or” includes any single item in the list or a combination of items in the list. For example, a list of A, B and/or C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one or more of’ includes any single item in the list or a combination of items in the list. For example, one or more of A, B and C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one of’ includes one and only one of any single item in the list. For example, “one of A, B and C” includes only A, only B or only C and excludes combinations of A, B and C. As used herein, “a member selected from the group consisting of A, B, and C,” includes one and only one of A, B, or C, and excludes combinations of A, B, and C. As used herein, “a member selected from the group consisting of A, B, and C and combinations thereof’ includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C.

[0027] Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. This code may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the fimctions/acts specified in the flowchart diagrams and/or block diagrams.

[0028] The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the flowchart diagrams and/or block diagrams.

[0029] The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the fimctions/acts specified in the flowchart diagrams and/or block diagrams.

[0030] The flowchart diagrams and/or block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods, and program products according to various embodiments. In this regard, each block in the flowchart diagrams and/or block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function(s).

[0031] It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated Figures.

[0032] Although various arrow types and line types may be employed in the flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code.

[0033] The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements.

[0034] Generally, the present disclosure describes systems, methods, and apparatus for cell reselection based on network slicing considering mobility. In certain embodiments, the methods may be performed using computer code embedded on a computer-readable medium. In certain embodiments, an apparatus or system may include a computer-readable medium containing computer-readable code which, when executed by a processor, causes the apparatus or system to perform at least a portion of the below described solutions.

[0035] More particularly, the subject matter disclosed herein relates to cell reselection based on network slicing considering mobility. When slice-based cell reselection does not yield e.g., no cell reselection takes place, the UE can start legacy cell reselection. Since legacy cell reselection can continue for a very long time unless a reselection is made, the UE will not be able to revert to slice-based cell reselection. This can be suboptimal if the UE, due to mobility, is now in the coverage of a frequency whose highest ranked cell supports a (high priority) slice from the slice list.

[0036] The proposed solutions disclose multiple trigger conditions for UEs to (re)start slice-based cell reselection, which may include the UE receiving new information, the downlink (“DL”) radio condition of the serving cell changing by a threshold, and/or timer-based reselection.

[0037] As one conventional solution, legacy cell reselection priorities are used until a cell reselection takes place, irrespective of how long it takes. Once the UE is on the new cell, it will check the slice-based trigger conditions afresh in the new cell based on available slice reselection information. However, this solution will not be optimal if a UE, at some point before legacy-based reselection, arrived in the coverage of a frequency whose highest ranked cell supports a (high priority) slice from the slice list.

[0038] In one embodiment disclosed herein, a UE stops legacy-based cell reselection and starts slice-based cell reselection when a DL radio condition of the serving cell has changed by a threshold. The change can be measured in Measured cell RX level value (e.g., reference signal received power (“RSRP”)) or using Measured cell quality value (e.g., reference signal received quality (“RSRQ”)) or similar using pathloss calculation. The threshold can be configured by the network using radio resource control (“RRC”) signaling or can be specified. In another embodiment, the UE stops legacy-based cell reselection and starts slice-based cell reselection when a time-period-threshold e.g., as 300 seconds has elapsed.

[0039] In one embodiment, a new condition to start legacy-based cell reselection is introduced - if there’s not a single inter-frequency assigned a priority higher than the lowest frequency priority, the UE shall not use slice-based cell reselection. In further embodiments, the following new triggers to start slice-based cell reselection are introduced: a. UE receives new information e.g., when at least one of “Slice reselection information” or “slice and/or slice group priorities received from NAS” has changed b. DL radio condition of the serving cell has changes by a threshold c. Timer based d. When the UE has measured frequencies based on legacy-based cell reselection: i. All frequencies ii. Remaining frequencies (e.g., not yet measured during slice-based cell reselection) iii. High priority frequencies only

[0040] Figure 1 depicts a wireless communication system 100 for cell reselection based on network slicing considering mobility, according to embodiments of the disclosure. In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a Fifth -Generation Radio Access Network (“5G-RAN”) 115, and a mobile core network 140. The 5G-RAN 115 and the mobile core network 140 form a mobile communication network. The 5G- RAN 115 may be composed of a 3GPP access network 120 containing at least one cellular base unit 121 and/or a non-3GPP access network 130 containing at least one access point 131. The remote unit 105 communicates with the 3GPP access network 120 using 3GPP communication links 123 and/or communicates with the non-3GPP access network 130 using non-3GPP communication links 133. Even though a specific number of remote units 105, 3GPP access networks 120, cellular base units 121, 3GPP communication links 123, non-3GPP access networks 130, access points 131, non-3GPP communication links 133, and mobile core networks 140 are depicted in Figure 1, one of skill in the art will recognize that any number of remote units 105, 3 GPP access networks 120, cellular base units 121, 3 GPP communication links 123, non-3GPP access networks 130, access points 131, non-3GPP communication links 133, and mobile core networks 140 may be included in the wireless communication system 100.

[0041] In one implementation, the RAN 120 is compliant with the 5G system specified in the Third Generation Partnership Project (“3GPP”) specifications. For example, the RAN 120 may be a NG-RAN, implementing NR RAT and/or LTE RAT. In another example, the RAN 120 may include non-3GPP RAT (e.g., Wi-Fi® or Institute of Electrical and Electronics Engineers (“IEEE”) 802.11-family compliant WLAN). In another implementation, the RAN 120 is compliant with the LTE system specified in the 3GPP specifications. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication network, for example Worldwide Interoperability for Microwave Access (“WiMAX”) or IEEE 802.16-family standards, among other networks. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0042] In one embodiment, the remote units 105 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), smart appliances (e.g., appliances connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. In some embodiments, the remote units 105 include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the remote units 105 may be referred to as the UEs, subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, user terminals, wireless transmit/receive unit (”WTRU”), a device, or by other terminology used in the art. In various embodiments, the remote units 105 include a subscriber identity and/or identification module (“SIM”) and the mobile equipment (“ME”) providing mobile termination functions (e.g., radio transmission, handover, speech encoding and decoding, error detection and correction, signaling and access to the SIM). In certain embodiments, the remote units 105 may include a terminal equipment (“TE”) and/or be embedded in an appliance or device (e.g., a computing device, as described above).

[0043] In one embodiment, the remote units 105 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), smart appliances (e.g., appliances connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. In some embodiments, the remote units 105 include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the remote units 105 may be referred to as UEs, subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, user terminals, wireless transmit/receive unit (“WTRU”), a device, or by other terminology used in the art.

[0044] The relay units 105 may communicate directly with one or more of the cellular base units 121 in the 3GPP access network 120 via uplink (“UL”) and downlink (“DL”) communication signals. Furthermore, the UL and DL communication signals may be carried over the 3GPP communication links 123. Similarly, the relay units 105 may communicate with one or more access points 131 in the non-3GPP access network(s) 130 via UL and DL communication signals carried over the non-3GPP communication links 133. Here, the access networks 120 and 130 are intermediate networks that provide the relay units 105 with access to the mobile core network 140.

[0045] In some embodiments, the relay units 105 communicate with a remote host (e.g., in the data network 150 or in the data network 160) via a network connection with the mobile core network 140. For example, an application 107 (e.g., web browser, media client, telephone and/or Voice-over-Internet -Protocol (“VoIP”) application) in a remote unit 105 may trigger the remote unit 105 to establish a protocol data unit (“PDU”) session (or other data connection) with the mobile core network 140 via the 5G-RAN 115 (i.e., via the 3GPP access network 120 and/or non- 3GPP network 130). The mobile core network 140 then relays traffic between the remote unit 105 and the remote host using the PDU session. The PDU session represents a logical connection between the remote unit 105 and a User Plane Function (“UPF”) 141.

[0046] In order to establish the PDU session (or PDN connection), the remote unit 105 must be registered with the mobile core network 140 (also referred to as “attached to the mobile core network” in the context of a Fourth Generation (“4G”) system). Note that the remote unit 105 may establish one or more PDU sessions (or other data connections) with the mobile core network 140. As such, the remote unit 105 may have at least one PDU session for communicating with the packet data network 150. Additionally - or alternatively - the remote unit 105 may have at least one PDU session for communicating with the packet data network 160. The remote unit 105 may establish additional PDU sessions for communicating with other data networks and/or other communication peers.

[0047] In the context of a 5G system (“5GS”), the term “PDU Session” refers to a data connection that provides end-to-end (“E2E”) user plane (“UP”) connectivity between the remote unit 105 and a specific Data Network (“DN”) through the UPF 131. A PDU Session supports one or more Quality of Service (“QoS”) Flows. In certain embodiments, there may be a one-to-one mapping between a QoS Flow and a QoS profile, such that all packets belonging to a specific QoS Flow have the same 5G QoS Identifier (“5QI”).

[0048] In the context of a 4G/LTE system, such as the Evolved Packet System (“EPS”), a Packet Data Network (“PDN”) connection (also referred to as EPS session) provides E2E UP connectivity between the remote unit and a PDN. The PDN connectivity procedure establishes an EPS Bearer, i.e., a tunnel between the remote unit 105 and a Packet Gateway (“PGW”, not shown) in the mobile core network 130. In certain embodiments, there is a one-to-one mapping between an EPS Bearer and a QoS profile, such that all packets belonging to a specific EPS Bearer have the same QoS Class Identifier (“QCI”).

[0049] As described in greater detail below, the remote unit 105 may use a first data connection (e.g., PDU Session) established with the first mobile core network 130 to establish a second data connection (e.g., part of a second PDU session) with the second mobile core network 140. When establishing a data connection (e.g., PDU session) with the second mobile core network 140, the remote unit 105 uses the first data connection to register with the second mobile core network 140. [0050] The cellular base units 121 may be distributed over a geographic region. In certain embodiments, a cellular base unit 121 may also be referred to as an access terminal, a base, a base station, a Node-B (“NB”), an Evolved Node B (abbreviated as eNodeB or “eNB,” also known as Evolved Universal Terrestrial Radio Access Network (“E-UTRAN”) Node B), a 5G/NRNode B (“gNB”), a Home Node-B, a Home Node-B, a relay node, a device, or by any other terminology used in the art. The cellular base units 121 are generally part of a radio access network (“RAN”), such as the 3GPP access network 120, that may include one or more controllers communicably coupled to one or more corresponding cellular base units 121. These and other elements of radio access network are not illustrated but are well known generally by those having ordinary skill in the art. The cellular base units 121 connect to the mobile core network 140 via the 3GPP access network 120.

[0051] The cellular base units 121 may serve a number of remote units 105 within a serving area, for example, a cell or a cell sector, via a 3GPP wireless communication link 123. The cellular base units 121 may communicate directly with one or more of the remote units 105 via communication signals. Generally, the cellular base units 121 transmit DL communication signals to serve the remote units 105 in the time, frequency, and/or spatial domain. Furthermore, the DL communication signals may be carried over the 3GPP communication links 123. The 3GPP communication links 123 may be any suitable carrier in licensed or unlicensed radio spectrum. The 3GPP communication links 123 facilitate communication between one or more of the remote units 105 and/or one or more of the cellular base units 121. Note that during NR operation on unlicensed spectrum (referred to as “NR-U”), the base unit 121 and the remote unit 105 communicate over unlicensed (i.e., shared) radio spectrum.

[0052] The non-3GPP access networks 130 may be distributed over a geographic region. Each non-3GPP access network 130 may serve a number of remote units 105 with a serving area. An access point 131 in a non-3GPP access network 130 may communicate directly with one or more remote units 105 by receiving UL communication signals and transmitting DL communication signals to serve the remote units 105 in the time, frequency, and/or spatial domain. Both DL and UL communication signals are carried over the non-3GPP communication links 133. The 3GPP communication links 123 and non-3GPP communication links 133 may employ different frequencies and/or different communication protocols. In various embodiments, an access point 131 may communicate using unlicensed radio spectrum. The mobile core network 140 may provide services to a remote unit 105 via the non-3GPP access networks 130, as described in greater detail herein. [0053] In some embodiments, anon-3 GPP access network 130 connects to the mobile core network 140 via an interworking entity 135. The interworking entity 135 provides an interworking between the non-3GPP access network 130 and the mobile core network 140. The interworking entity 135 supports connectivity via the “N2” and “N3” interfaces. As depicted, both the 3GPP access network 120 and the interworking entity 135 communicate with the AMF 143 using a “N2” interface. The 3GPP access network 120 and interworking entity 135 also communicate with the UPF 141 using a “N3” interface. While depicted as outside the mobile core network 140, in other embodiments the interworking entity 135 may be a part of the core network. While depicted as outside the non-3GPP RAN 130, in other embodiments the interworking entity 135 may be a part of the non-3GPP RAN 130.

[0054] In certain embodiments, a non-3GPP access network 130 may be controlled by an operator of the mobile core network 140 and may have direct access to the mobile core network 140. Such a non-3GPP AN deployment is referred to as a “trusted non-3GPP access network.” A non-3GPP access network 130 is considered as “trusted” when it is operated by the 3GPP operator, or a trusted partner, and supports certain security features, such as strong air-interface encryption. In contrast, a non-3GPP AN deployment that is not controlled by an operator (or trusted partner) of the mobile core network 140, does not have direct access to the mobile core network 140, or does not support the certain security features is referred to as a “non-trusted” non-3GPP access network. An interworking entity 135 deployed in a trusted non-3GPP access network 130 may be referred to herein as a Trusted Network Gateway Function (“TNGF”). An interworking entity 135 deployed in a non-trusted non-3GPP access network 130 may be referred to herein as a non-3GPP interworking function (“N3IWF”). While depicted as a part of the non-3GPP access network 130, in some embodiments the N3IWF may be a part of the mobile core network 140 or may be located in the data network 150.

[0055] In one embodiment, the mobile core network 140 is a 5G core (“5GC”) or the evolved packet core (“EPC”), which may be coupled to a data network 150, like the Internet and private data networks, among other data networks. A remote unit 105 may have a subscription or other account with the mobile core network 140. Each mobile core network 140 belongs to a single public land mobile network (“PLMN”). The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0056] The mobile core network 140 includes several network functions (“NFs”). As depicted, the mobile core network 140 includes at least one UPF (“UPF”) 141. The mobile core network 140 also includes multiple control plane functions including, but not limited to, an Access and Mobility Management Function (“AMF”) 143 that serves the 5G-RAN 115, a Session Management Function (“SMF”) 145, a Policy Control Function (“PCF”) 146, an Authentication Server Function (“AUSF”) 147, a Unified Data Management (“UDM”) and Unified Data Repository function (“UDR”).

[0057] The UPF(s) 141 is responsible for packet routing and forwarding, packet inspection, QoS handling, and external PDU session for interconnecting Data Network (“DN”), in the 5G architecture. The AMF 143 is responsible for termination of non-access stratum (“NAS”) signaling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The SMF 145 is responsible for session management (i.e., session establishment, modification, release), remote unit (i.e., UE) IP address allocation & management, DE data notification, and traffic steering configuration for UPF for proper traffic routing.

[0058] The PCF 146 is responsible for unified policy framework, providing policy rules to CP functions, access subscription information for policy decisions in UDR. The AUSF 147 acts as an authentication server.

[0059] The UDM is responsible for generation of Authentication and Key Agreement (“AKA”) credentials, user identification handling, access authorization, subscription management. The UDR is a repository of subscriber information and can be used to service a number of network functions. For example, the UDR may store subscription data, policy-related data, subscriber- related data that is permitted to be exposed to third party applications, and the like. In some embodiments, the UDM is co-located with the UDR, depicted as combined entity “UDM/UDR” 149.

[0060] In various embodiments, the mobile core network 140 may also include an Network Exposure Function (“NEF”) (which is responsible for making network data and resources easily accessible to customers and network partners, e.g., via one or more APIs), a Network Repository Function (“NRF”) (which provides NF service registration and discovery, enabling NFs to identify appropriate services in one another and communicate with each other over Application Programming Interfaces (“APIs”)), or other NFs defined for the 5GC. In certain embodiments, the mobile core network 140 may include an authentication, authorization, and accounting (“AAA”) server.

[0061] In various embodiments, the mobile core network 140 supports different types of mobile data connections and different types of network slices, wherein each mobile data connection utilizes a specific network slice. Here, a “network slice” refers to a portion of the mobile core network 140 optimized for a certain traffic type or communication service. A network instance may be identified by a single - network slice selection assistance information (“S- NSSAI”), while a set of network slices for which the remote unit 105 is authorized to use is identified by NSSAI. In certain embodiments, the various network slices may include separate instances of network functions, such as the SMF and UPF 141. In some embodiments, the different network slices may share some common network functions, such as the AMF 143. The different network slices are not shown in Figure 1 for ease of illustration, but their support is assumed.

[0062] Although specific numbers and types of network functions are depicted in Figure 1 , one of skill in the art will recognize that any number and type of network functions may be included in the mobile core network 140. Moreover, where the mobile core network 140 comprises an EPC, the depicted network functions may be replaced with appropriate EPC entities, such as an MME, S-GW, P-GW, HSS, and the like.

[0063] While Figure 1 depicts components of a 5G RAN and a 5G core network, the described embodiments for using a pseudonym for access authentication over non-3GPP access apply to other types of communication networks and RATs, including IEEE 802. 11 variants, GSM, GPRS, UMTS, LTE variants, CDMA 2000, Bluetooth, ZigBee, Sigfoxx, and the like. For example, in an 4G/LTE variant involving an EPC, the AMF 143 may be mapped to an MME, the SMF mapped to a control plane portion of a PGW and/or to an MME, the UPF 141 may be mapped to an SGW and a user plane portion of the PGW, the UDM/UDR 149 may be mapped to an HSS, etc.

[0064] As depicted, a remote unit 105 (e.g., a UE) may connect to the mobile core network (e.g., to a 5G mobile communication network) via two types of accesses: (1) via 3GPP access network 120 and (2) via a non-3GPP access network 130. The first type of access (e.g., 3GPP access network 120) uses a 3GPP-defmed type of wireless communication (e.g., NG-RAN) and the second type of access (e.g., non-3GPP access network 130) uses a non-3GPP -defined type of wireless communication (e.g., WLAN). The 5G-RAN 115 refers to any type of 5G access network that can provide access to the mobile core network 140, including the 3GPP access network 120 and the non-3GPP access network 130.

[0065] As used herein, 5G network slicing is a network architecture that enables the multiplexing of virtualized and independent logical networks on the same physical network infrastructure. Each network slice is an isolated end-to-end network tailored to fulfil diverse requirements requested by a particular application.

[0066] For this reason, this technology assumes a central role to support 5G mobile networks that are designed to efficiently embrace a plethora of services with very different service level requirements (“SLR”). The realization of this service-oriented view of the network leverages on the concepts of software-defined networking (“SDN”) and network function virtualization (“NFV”) that allow the implementation of flexible and scalable network slices on top of a common network infrastructure.

[0067] In one embodiment, strong demand in wireless communication has been expected in vertical markets, as connectivity and mobility empower the transformation and innovation in industries such as manufacturing, transportation, energy and civil services, healthcare, and many more. These diverse vertical services bring about a wide range of performance requirements in throughput, capacity, latency, mobility, reliability, position accuracy, etc. NR technology promises a common RAN platform to meet the challenges of current and future use cases and services, not only for those that we can envision today but also for those that we cannot yet imagine. And the works of network slicing in Rel-15 further advance network architecture towards more flexibility and higher scalability for a multitude of services of disparate requirements.

[0068] While Rel-15 specifications can provide the foundation of a common connectivity platform for various services, more efforts should be made in Rel-17 on RAN support of network slicing, to make it a tool that network operators can apply to meet the challenge of opening new source of revenue in addition to the one derived from customer subscription. More particularly, the new works should provide technical tools in RAN for network operators to get application providers involved in customizing RAN’s design, deployment and operation for better support of the applications providers’ business.

[0069] The 3GPP work item on network slicing, RP-210912 (incorporated herein by reference), sets one of the work objectives as: i. Support slice-based cell reselection, specify mechanisms and signalling including:

1. To assist cell reselection, broadcast the supported slice info of the current cell and neighbour cells, and cell reselection priority per slice in system information message.

2. To assist cell reselection, include slice info (with similar information as in SI message) in RRCRelease message.

[0070] Slice (S-NSSAI) based cell reselection and the following solution was agreed for cell reselection for the normative phase in RAN2#115e:

• The “slice info” (for a single slice or slice group) agreed to be provided to the UE using both broadcast and dedicated signaling are provided for the serving as well as neighboring frequencies. The following steps are used for slice-based cell (re)selection in access stratum (“AS”): o Step 0: NAS layer at UE provides slice information to AS layer at UE, including slice priorities. o Step 1 : AS sorts slices in priority order starting with highest priority slice. o Step 2: Select slices in priority order starting with the highest priority slice. o Step 3: For the selected slice assign priority to frequencies received from network. o Step 4: Starting with the highest priority frequency, perform measurements (same as legacy). o Step 5: If the highest ranked cell is suitable (as defined in 38.304) and supports the selected slice in step 2 then camp on the cell and exit this sequence of operation. o Step 6: If there are remaining frequencies then go back to step 4. o Step 7 : If the end of the slice list has not been reached go back to step 2. o Step 8: Perform legacy cell reselection.

[0071] The above set of agreements mean that the slice-based cell reselection procedure is done in the following way: a. The UE selects the slice group with highest priority slice. b. The UE assigns the slice frequency priority corresponding to the selected slice group for NR frequencies received in RRCRelease or in the system information messages. c. The UE performs measurements and selects the highest ranked and suitable cell as candidate for camping according to clauses 5.2.4 of 3GPP TS38.304 (incorporated herein by reference) using the slice group specific NR frequency priorities. d. If the highest ranked and suitable cell supports the selected slice, then the UE camps on the cell. If the highest ranked suitable cell does not support the selected slice, then the UE excludes the frequency of that cell from cell reselection with frequency priorities of the selected slice group and continues the search for suitable cells with the assigned slice group specific frequency priorities on other frequencies if there is any. e. If no suitable cell is found using slice group specific frequency priorities, then the UE continues to perform cell reselection according to clause 5.2.4 of 3GPP TS38.304 without considering slice group specific frequency priorities. [0072] Figure 2 depicts an example of RRC Connected mobility from a serving cell 202 to one or more neighboring cells 204a-f, where cells may belong to different Tracking Areas and may have different slice support. A UE may not find any suitable cell using slice (or slice group) specific frequency priorities when one or more of the following applies: a. The frequency(ies) supporting its Slice list is not available in the neighborhood e.g., none of the inter-frequency cell is detectable according to the conditions defined in Annex B. 1.3 of 3GPP TS 38. 133 (incorporated herein by reference). b. The highest rank cell of the frequency (ies) supporting its Slice list do not support any of the slices (or slice group) listed in the Slice list. c. The highest rank cell of the frequency(ies) supporting its Slice list is not considered suitable according to section 4.5 of 3GPP TS 38.304 (incorporated herein by reference).

[0073] When the slice-based cell reselection does not yield e.g., no cell reselection takes place, the UE can start legacy cell reselection according to section 5.2.4 of 3GPP TS38.304-g70 e.g., based on cellreselectionpriority configured to the UE using broadcast or dedicated (RRCRelease message) signaling. Since the legacy cell reselection can continue for very long time (according to section 5.2.4 of 3GPP TS38.304-g70 and 3GPP TS 38. 133-g90) unless a reselection is made, the UE will not be able to revert to slice-based cell reselections anymore. This can be sub- optimal if the UE due to mobility is now in the coverage of a frequency whose highest ranked cell supports a (high priority) slice from the Slice list.

[0074] In addition, regarding NR sidelink relays, the following two types of relays have been identified: a. UE-to-network coverage extension: Uu coverage reachability is necessary for UEs to reach server in PDN network or counterpart UE out of proximity area. However, UE-to-network relay may be limited to Evolved Universal Terrestrial Radio Access (“EUTRA”)-based technology, and thus cannot be applied to NR-based system, for both NG-RAN and NR- based sidelink communication. b. UE-to-UE coverage extension: Currently proximity reachability is limited to single-hop sidelink link, either via EUTRA-based or NR-based sidelink technology. However, that is not sufficient in the scenario where there is no Uu coverage, considering the limited singlehop sidelink coverage.

[0075] In one embodiment, an NR sidelink Relay would also be responsible to provide the remote UE with required System Information (“SI”) - as was the case for LTE. For LTE, 3GPP TR 36.746 (incorporated herein by reference) describes SI reception for evolved ProSe Remote UE where in the evolved ProSe UE-to-Network Relay UE supports relaying of system information for the linked evolved ProSe Remote UEs located in-coverage of E-UTRAN coverage as well as out of E-UTRAN coverage.

[0076] Regarding system information reception for evolved ProSe Remote UE (e.g., as described in TR 36.746 clause 5. 1.2.3 (incorporated herein by reference)), the evolved ProSe UE- to-Network Relay UE supports relaying of system information for the linked evolved ProSe Remote UEs located in-coverage of E-UTRAN coverage as well as out of E-UTRAN coverage. The eNB can configure the evolved ProSe UE-to-Network Relay UE whether it can forward the system information to linked in-coverage evolved ProSe Remote UEs. Alternatively, the evolved ProSe UE-to-Network Relay UE is expected to forward the system information to the in-coverage evolved ProSe Remote UE. The linked evolved ProSe Remote UE utilizes the system information of the serving cell of the evolved ProSe UE-to-Network Relay UE.

[0077] Not all system information is relayed to the linked evolved ProSe Remote UE via the evolved ProSe UE-to-Network Relay UE. Essential SIBs are required to be relayed from the evolved ProSe UE-to-Network Relay UE to all linked evolved ProSe Remote UEs commonly. At least the following SIBs can be considered as essential SIBs: MIB (SFN, bandwidth), SIB1 (PLMN, cell information), SIB2 (Access Barring information), FeD2D SIB related info (e.g. SIB 18/19 or new SIBs). Evolved ProSe UE-to-Network Relay UE can optionally forward other SIBs (e.g., SIB10/11/12/13/14/15) depending on the linked evolved ProSe Remote UEs.

[0078] The evolved ProSe UE-to-Network Relay UE is expected to purely forward the SIBs without changing the information and format of the SIB. This approach is recommended. Alternatively, the evolved ProSe UE-to-Network Relay UE can only forward a subset of information of the SIB to the evolved ProSe Remote UE. An evolved ProSe UE-to-Network Relay UE forwards SIB over sidelink using broadcast/multi-cast.

[0079] The system information is not delivered periodically to the evolved ProSe Remote UE, but only when deemed necessary. The evolved ProSe UE-to-Network Relay UE can determine that SIB delivery is deemed necessary for the evolved ProSe Remote UE when system information is updated.

[0080] While LTE text mentioned "Relay UE forwards SIB over sidelink using broadcast/multi-casf\ details of “how” are not covered e.g., if/how/when a group for SI distribution is formed. NR has different challenges/opportunities while providing the SI efficiently to the remote UEs e.g., during the Relay discovery phase, a remote UE should be able to determine the PLMN IDs and SIBs/features shared/supported by the serving cell of a relay UE. It is not clear, however, how this can be efficiently done. [0081] As one possibility of a conventional solution, legacy-based cell reselection priorities are used until a cell reselection takes place, irrespective of how long it would take. Once the UE is on the new cell, it will check the slice-based trigger conditions afresh in the new cell based on available slice reselection information. This solution will not be optimum if a UE at some point before legacy-based reselection came in the coverage of a frequency whose highest ranked cell supports a (high priority) slice from the slice list.

[0082] This disclosure uses the following two terms: i. Slice reselection information (also referred to as “slice info”): defined as frequency priority mapping for each of the slices (slice frequency (ies)

absolute priority of each of the frequency) and therefore consists of three elements - slice, frequency, and an absolute frequency priority. The slice info (for a slice or slice group) may be provided to the UE using both broadcast and dedicated signaling. Slice info is provided for the serving as well as neighboring frequencies. ii. Slice support: This term is used in this document to signify the slice(s)/slice group(s) supported in a particular cell or frequency.

[0083] Though most of this document mentions “slice”, the embodiments discussed below are equally applicable to a “slice group”. A slice group, as used herein, consists of one or multiple slices, one slice belongs to one and only one slice group and each slice group is uniquely identified by a slice group identifier. This can avoid publishing slice identities (S-NSSAI) in SI, which may be a security concern and SI size concern. In one embodiment, the signaling of such slice grouping and slice group identity would be indicated in NAS signaling to the UE.

[0084] In a first embodiment, shown in Figure 3, slice-based cell reselection starts in response to a triggering event wherein the UE decides if there are any inter-frequencies with higher priority than the priority of the serving frequency. If so, the UE starts with inter frequency measurements 302 for frequencies with higher priority. For a UE supporting slice-based cell reselection 306 (following yes at 304), the reselection priority of a NR frequency (current NR frequency or NR inter-frequency) is defined as the frequency priority from slice reselection information corresponding to the UE’s highest priority slice or slice group (among “slice and/or slice group priorities received from NAS”) supported on at least one frequency present in the slice reselection information. If UE’s highest priority slice or slice group, supported on at least one frequency listed in slice reselection information, is not supported on a certain NR frequency, the UE shall consider that frequency to be the lowest priority frequency (i.e., lower than any of the network configured values) for the purpose of slice-based cell reselection. [0085] For the purpose of actual measurements, priority of a “selected slice” is considered. For slice-based cell reselection 308, priority of a NR frequency is the frequency priority corresponding to a selected slice or slice group. If the selected slice is not supported on an NR frequency, the UE shall consider the serving frequency to be the lowest priority frequency (e.g., lower than any of the network configured values) for the purpose of slice-based cell reselection. If the selected slice is not supported on the current serving cell, the UE shall consider the serving frequency to be the lowest priority frequency (e.g., lower than any of the network configured values) for the purpose of slice-based cell reselection. If there’s not a single inter-frequency assigned a priority higher than the lowest frequency priority (no at 308), the UE shall not use slicebased cell reselection and legacy cell reselection 310 is used instead. When performing slice-based cell reselection, the “selected slice” is determined during the following slice-based cell reselection procedure 306:

[0086] UE selects 308 the highest priority slice or slice group among the slice(s) and slice group(s) indicated by NAS, supported on at least one frequency present in the slice reselection information. For the selected slice or slice group UE assigns frequency priority to each of this slice’s supporting frequency from the slice reselection information. Then, starting with the highest priority frequency, for each supporting frequency of the selected slice or slice group, UE performs cell search and selects the highest ranked and suitable cell as candidate for camping. UE camps on the highest ranked and suitable cell if it supports the selected slice. If no such cell is found, the UE goes on to select the next lower priority slice or slice group among the slice(s) and slice group(s) priorities indicated by NAS, which is supported on at least one frequency present in the slice reselection information and repeats the procedure and while doing so, the UE can use stored slice information and measurements from immediate past to minimize measurements.

[0087] If the slice-based cell reselection does not lead to a cell reselection, the UE shall consider reselection based on cellReselectionPriority and slice-based cell reselection shall not be used. To enable going back to slice-based cell reselection, one of the following embodiments (described as triggers 402 in Figure 4) can be used:

[0088] In a second embodiment, a UE stops legacy-based cell reselection (based on cellReselectionPriority) and starts slice-based cell reselection when at least one of “Slice reselection information” or “slice and/or slice group priorities received from NAS” has changed.

[0089] In a third embodiment, a UE stops legacy-based cell reselection (based on cellReselectionPriority and starts slice-based cell reselection when DL radio condition of the serving cell has changes by a threshold. The change can be positive or negative. The change can be measured with reference to a first measurement taken at the start of legacy -based cell reselection procedure or as another possibility when slice-based reselection in this cell was first started, or any time in between. Filtering rules as defined in TS 38.133 (incorporated herein by reference) may apply. The change can be measured in Measured cell RX level value (RSRP) or using Measured cell quality value (RSRQ) or similar using Pathloss calculation. The said threshold can be configured by the network using RRC signaling or can be specified.

[0090] In a fourth embodiment, a UE stops legacy-based cell reselection (based on cellReselectionPriority) and starts slice-based cell reselection when a time-period-threshold has elapsed since the start of legacy cell reselection procedure or as another possibility since when slice-based reselection in this cell was first started, or any time defined point in between these. The time-period-threshold can be configured by the network using RRC signaling or can be specified e.g., as 300 seconds.

[0091] In a fifth embodiment, a UE stops legacy-based cell reselection (based on cellReselectionPriority) and starts slice-based cell reselection after the UE has searched every layer of higher priority at least once e.g., after Thigher priority search = (60 * Niayers) seconds, where Niayers is the total number of higher priority NR and E-UTRA carrier frequencies broadcasted in system information. A higher priority frequency may be measured if threshServingLowQ is broadcast in system information and more than one second has elapsed since the UE camped on the current serving cell, cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if a cell of a higher priority NR or EUTRAN RAT/frequency fulfils Squal > Threshx, HighQ during a time interval TreselectionRAT.

[0092] Otherwise, cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency may be performed if a cell of a higher priority RAT/ frequency fulfils Srxlev > Threshx, High? during a time interval TreselectionRAT and more than one second has elapsed since the UE camped on the current serving cell.

[0093] As another variation of this embodiment, slice-based cell reselection is started after the UE has measured any remaining frequency that was not yet measured during the slice-based cell reselection procedure. Some frequencies may not have been measured/evaluated since these do not have corresponding frequency priority from UE’s slices (e.g., slice or slice group signaled by NAS to AS).

[0094] As another variation of this embodiment, slice-based cell reselection is started after the UE has measured not only the higher (than the current frequency) priority frequencies but also the lower priority frequencies if threshServingLowQ is broadcast in system information and more than one second has elapsed since the UE camped on the current serving cell, cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if the serving cell fulfils Squal < Threshseiving, LowQ and a cell of a lower priority NR or E-UTRAN RAT/ frequency fulfils Squal > Threshx, LowQ during a time interval TreselectionRAT.

[0095] Otherwise, cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if the serving cell fulfils Srxlev < Threshseiving, LowP and a cell of a lower priority RAT/frequency fulfils Srxlev > Threshx, LOWP during a time interval TreselectionRAT and more than 1 second has elapsed since the UE camped on the current serving cell.

[0096] In a sixth embodiment, regarding sidelink relay communication, a relay UE periodically broadcasts discovery signals to help a potential remote UE establish contact with it. A remote UE may select or reselect a UE to Network relay (U2N relay) served by a cell that provides the SIBs required by the remote UE e.g., the serving cell of the relay supports the feature (s) MBS, sidelink communication, or any other vertical feature supporting SIB of interest to the remote UE. To avoid hit and trial based relay (re)selection, after selecting a U2N relay, the remote UE receives the SI via the relay and determines that the required SIB is provided or not provided, the Discovery message from the relay may at least include one of the IE systemlnformationAreciID or a bitmap indicating which SIBs or which features are supported by the relay UE’s serving cell.

[0097] In addition, to support a reasonable PLMN selection performance, Discovery message contains the first PLMN ID appearing in the SIB 1 of the serving cell. In one embodiment, this is performed because inserting 12 PLMNs in the Discovery message will go against its range performance and/or consume excessive physical resources and battery power. The remaining 11 PLMNs can be signaled as part of the SIB1 signaling from the relay UE to remote UE. In an enhancement, the relay UE can choose a different PLMN ID to be broadcasted as part of discovery message. So, if there are 12 PLMN IDs from the serving cell’s SIB1 (cellAccessRelatedlnfo), each transmission of Discovery message contains only one or more of these. A remote UE may keep collecting the PLMN IDs from the discovery message of a particular relay, identified using Relay ID, until either a home or equivalent PLMN of the remote UE is found or until the PLMN IDs start to repeat.

[0098] Figure 5 depicts a user equipment apparatus 500 that may be used for cell reselection based on network slicing considering mobility, according to embodiments of the disclosure. In various embodiments, the user equipment apparatus 500 is used to implement one or more of the solutions described above. The user equipment apparatus 500 may be one embodiment of the remote unit 105, described above. Furthermore, the user equipment apparatus 500 may include a processor 505, a memory 510, an input device 515, an output device 520, and a transceiver 525.

[0099] In some embodiments, the input device 515 and the output device 520 are combined into a single device, such as a touchscreen. In certain embodiments, the user equipment apparatus 500 may not include any input device 515 and/or output device 520. In various embodiments, the user equipment apparatus 500 may include one or more of: the processor 505, the memory 510, and the transceiver 525, and may not include the input device 515 and/or the output device 520.

[0100] As depicted, the transceiver 525 includes at least one transmitter 530 and at least one receiver 535. In some embodiments, the transceiver 525 communicates with one or more cells (or wireless coverage areas) supported by one or more base units 121. In various embodiments, the transceiver 525 is operable on unlicensed spectrum. Moreover, the transceiver 525 may include multiple UE panel supporting one or more beams. Additionally, the transceiver 525 may support at least one network interface 540 and/or application interface 545. The application interface(s) 545 may support one or more APIs. The network interface(s) 540 may support 3GPP reference points, such as Uu, Nl, PC5, etc. Other network interfaces 540 may be supported, as understood by one of ordinary skill in the art.

[0101] The processor 505, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 505 may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, the processor 505 executes instructions stored in the memory 510 to perform the methods and routines described herein. The processor 505 is communicatively coupled to the memory 510, the input device 515, the output device 520, and the transceiver 525. In certain embodiments, the processor 505 may include an application processor (also known as “main processor”) which manages applicationdomain and operating system (“OS”) functions and a baseband processor (also known as “baseband radio processor”) which manages radio functions.

[0102] The memory 510, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 510 includes volatile computer storage media. For example, the memory 510 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 510 includes non-volatile computer storage media. For example, the memory 510 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 510 includes both volatile and non-volatile computer storage media. [0103] In some embodiments, the memory 510 stores data related to cell reselection based on network slicing considering mobility. For example, the memory 510 may store various parameters, panel/beam configurations, resource assignments, policies, and the like as described above. In certain embodiments, the memory 510 also stores program code and related data, such as an operating system or other controller algorithms operating on the user equipment apparatus 500.

[0104] The input device 515, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 515 may be integrated with the output device 520, for example, as a touchscreen or similar touch -sensitive display. In some embodiments, the input device 515 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 515 includes two or more different devices, such as a keyboard and a touch panel.

[0105] The output device 520, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 520 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 520 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the output device 520 may include a wearable display separate from, but communicatively coupled to, the rest of the user equipment apparatus 500, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 520 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0106] In certain embodiments, the output device 520 includes one or more speakers for producing sound. For example, the output device 520 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 520 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all, or portions of the output device 520 may be integrated with the input device 515. For example, the input device 515 and output device 520 may form atouchscreen or similar touch-sensitive display. In other embodiments, the output device 520 may be located near the input device 515.

[0107] The transceiver 525 communicates with one or more network functions of a mobile communication network via one or more access networks. The transceiver 525 operates under the control of the processor 505 to transmit messages, data, and other signals and also to receive messages, data, and other signals. For example, the processor 505 may selectively activate the transceiver 525 (or portions thereof) at particular times in order to send and receive messages.

[0108] The transceiver 525 includes at least transmitter 530 and at least one receiver 535. One or more transmitters 530 may be used to provide UL communication signals to a base unit 121, such as the UL transmissions described herein. Similarly, one or more receivers 535 may be used to receive DL communication signals from the base unit 121, as described herein. Although only one transmitter 530 and one receiver 535 are illustrated, the user equipment apparatus 500 may have any suitable number of transmitters 530 and receivers 535. Further, the transmitter(s) 530 and the receiver(s) 535 may be any suitable type of transmitters and receivers. In one embodiment, the transceiver 525 includes a first transmitter/receiver pair used to communicate with a mobile communication network over licensed radio spectrum and a second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum.

[0109] In certain embodiments, the first transmitter/receiver pair used to communicate with a mobile communication network over licensed radio spectrum and the second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum may be combined into a single transceiver unit, for example a single chip performing functions for use with both licensed and unlicensed radio spectrum. In some embodiments, the first transmitter/receiver pair and the second transmitter/receiver pair may share one or more hardware components. For example, certain transceivers 525, transmitters 530, and receivers 535 may be implemented as physically separate components that access a shared hardware resource and/or software resource, such as for example, the network interface 540.

[0110] In various embodiments, one or more transmitters 530 and/or one or more receivers 535 may be implemented and/or integrated into a single hardware component, such as a multitransceiver chip, a system-on -a-chip, an ASIC, or other type of hardware component. In certain embodiments, one or more transmitters 530 and/or one or more receivers 535 may be implemented and/or integrated into a multi -chip module. In some embodiments, other components such as the network interface 540 or other hardware components/circuits may be integrated with any number of transmitters 530 and/or receivers 535 into a single chip. In such embodiment, the transmitters 530 and receivers 535 may be logically configured as a transceiver 525 that uses one more common control signals or as modular transmitters 530 and receivers 535 implemented in the same hardware chip or in a multi -chip module.

[0111] In one embodiment, the processor 505 is configured to cause the apparatus 500 to perform legacy-based cell reselection for a cell of a wireless communication network. In one embodiment, the processor 505 is configured to cause the apparatus 500 to determine at least one network slice associated with the apparatus 500, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the apparatus 500. In one embodiment, the processor 505 is configured to cause the apparatus 505 to switch to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell.

[0112] In one embodiment, the processor 505 is configured to cause the apparatus 500 to select a network slice of the at least one network slice with a highest reselection priority frequency during slice-based cell reselection.

[0113] In one embodiment, for the selected network slice, the processor 505 is configured to cause the apparatus 500 to assign frequency priorities to each of the frequencies that the selected network slice supports based on slice reselection information for the network slice.

[0114] In one embodiment, the processor 505 is configured to cause the apparatus 500 to select a network cell of the selected network slice corresponding to the highest assigned priority frequency.

[0115] In one embodiment, the processor 505 is configured to cause the apparatus 500 to select a second network slice of the at least one network slice with a next highest reselection priority frequency in response to the selected network cell of the selected slice not being suitable for the apparatus 500.

[0116] In one embodiment, the processor 505 is configured to cause the apparatus 500 to switch to slice-based cell reselection in response to further detecting a change in slice reselection information, slice priorities received from non-access stratum, or a combination thereof.

[0117] In one embodiment, the processor 505 is configured to cause the apparatus 500 to switch to slice-based cell reselection in response to further detecting that a downlink radio condition of the serving cell changed by a threshold.

[0118] In one embodiment, the processor 505 is configured to cause the apparatus 500 to measure the change with reference to a measurement taken at a beginning of legacy-based cell reselection, at a beginning of slice-based cell reselection, or anytime in between.

[0119] In one embodiment, the processor 505 is configured to cause the apparatus 500 to measure the change based on a cell reception level value, a cell quality value, or a combination thereof using a pathloss calculation.

[0120] In one embodiment, the processor 505 is configured to cause the apparatus 500 to switch to slice-based cell reselection in response to further detecting that a temporal threshold has elapsed since a beginning of legacy-based cell reselection, a beginning of slice-based cell reselection, or anytime in between.

[0121] In one embodiment, the processor 505 is configured to cause the apparatus 500 to switch to slice-based cell reselection in response to further searching each layer of higher priority frequencies or lower priority frequencies, relative to a frequency of the serving cell, a priority frequency measured in response to a threshServingLowQ parameter broadcast in system information and more than one second elapsing since the apparatus camped on the serving cell.

[0122] In one embodiment, the processor 505 is configured to cause the apparatus 500 to switch to slice-based cell reselection in response to further measuring remaining frequencies that have yet to be measured during slice-based cell reselection.

[0123] In one embodiment, the frequency of the serving cell is assigned a lowest reselection priority in response to the network slice comprising the serving cell not being supported on a new radio frequency.

[0124] Figure 6 depicts a network apparatus 600 that may be used for cell reselection based on network slicing considering mobility, according to embodiments of the disclosure. In one embodiment, network apparatus 600 may be one implementation of a RAN node, such as the base unit 121, the RAN node 210, or gNB, described above. Furthermore, the base network apparatus 600 may include a processor 605, a memory 610, an input device 615, an output device 620, and a transceiver 625.

[0125] In some embodiments, the input device 615 and the output device 620 are combined into a single device, such as a touchscreen. In certain embodiments, the network apparatus 600 may not include any input device 615 and/or output device 620. In various embodiments, the network apparatus 600 may include one or more of: the processor 605, the memory 610, and the transceiver 625, and may not include the input device 615 and/or the output device 620.

[0126] As depicted, the transceiver 625 includes at least one transmitter 630 and at least one receiver 635. Here, the transceiver 625 communicates with one or more remote units 105. Additionally, the transceiver 625 may support at least one network interface 640 and/or application interface 645. The application interface(s) 645 may support one or more APIs. The network interface(s) 640 may support 3GPP reference points, such as Uu, Nl, N2 and N3. Other network interfaces 640 may be supported, as understood by one of ordinary skill in the art.

[0127] The processor 605, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 605 may be a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or similar programmable controller. In some embodiments, the processor 605 executes instructions stored in the memory 610 to perform the methods and routines described herein. The processor 605 is communicatively coupled to the memory 610, the input device 615, the output device 620, and the transceiver 625. In certain embodiments, the processor 805 may include an application processor (also known as “main processor”) which manages application-domain and OS functions and a baseband processor (also known as “baseband radio processor”) which manages radio function.

[0128] In various embodiments, the network apparatus 600 is a RAN node (e.g., gNB) that provides on-demand SIBs. In one embodiment, the network apparatus 600 includes a transceiver 625 that receives, at a mobile wireless communication network from a first UE device, a request for an on-demand SIB for a second UE device, the first UE device comprising a relay UE device and the second UE device comprising a remote UE device and broadcasts the on-demand SIB to the first UE device for a predetermined period of time.

[0129] The memory 610, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 610 includes volatile computer storage media. For example, the memory 610 may include a RAM, including DRAM, SDRAM, and/or SRAM. In some embodiments, the memory 610 includes non-volatile computer storage media. For example, the memory 610 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 610 includes both volatile and nonvolatile computer storage media.

[0130] In some embodiments, the memory 610 stores data related to cell reselection based on network slicing considering mobility. For example, the memory 610 may store parameters, configurations, resource assignments, policies, and the like, as described above. In certain embodiments, the memory 610 also stores program code and related data, such as an operating system or other controller algorithms operating on the network apparatus 600.

[0131] The input device 615, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 615 may be integrated with the output device 620, for example, as a touchscreen or similar touch -sensitive display. In some embodiments, the input device 615 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 615 includes two or more different devices, such as a keyboard and a touch panel.

[0132] The output device 620, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 620 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 620 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the output device 620 may include a wearable display separate from, but communicatively coupled to, the rest of the network apparatus 600, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 620 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0133] In certain embodiments, the output device 620 includes one or more speakers for producing sound. For example, the output device 620 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 620 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all, or portions of the output device 620 may be integrated with the input device 615. For example, the input device 615 and output device 620 may form atouchscreen or similar touch-sensitive display. In other embodiments, the output device 620 may be located near the input device 615.

[0134] The transceiver 625 includes at least transmitter 630 and at least one receiver 635. One or more transmitters 630 may be used to communicate with the UE, as described herein. Similarly, one or more receivers 635 may be used to communicate with network functions in the NPN, PLMN and/or RAN, as described herein. Although only one transmitter 630 and one receiver 635 are illustrated, the network apparatus 600 may have any suitable number of transmitters 630 and receivers 635. Further, the transmitter(s) 630 and the receiver(s) 635 may be any suitable type of transmitters and receivers.

[0135] In one embodiment, the processor 605 is configured to cause the apparatus 600 to determine reselection priority frequencies for at least one network slice associated with a UE. In one embodiment, the processor 605 is configured to cause the apparatus 600 to transmit slice reselection information to the UE, the slice reselection information comprising the reselection priority frequencies for the at least one network slice associated with the UE. In one embodiment, the processor 605 is configured to cause the apparatus 600 to transmit at least one value indicating to the UE whether to switch from legacy-based cell reselection to slice-based cell reselection using the slice reselection information.

[0136] Figure 7 is a flowchart diagram of a method 700 for cell reselection based on network slicing considering mobility. The method 700 may be performed by a UE as described herein, for example, the remote unit 105, the UE 205 and/or the user equipment apparatus 500. In some embodiments, the method 700 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0137] In one embodiment, the method 700 begins and performs 705 legacy-based cell reselection for a cell of a wireless communication network. In one embodiment, the method 700 determines 710 at least one network slice associated with a UE, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the UE. In one embodiment, the method 700 switches 715 to slicebased cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell, and the method 700 ends.

[0138] Figure 8 is a flowchart diagram of a method 800 for cell reselection based on network slicing considering mobility. The method 800 may be performed by a network node as described herein, for example, a base unit 121, a gNB, and/or the network equipment apparatus 600. In some embodiments, the method 800 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0139] In one embodiment, the method 800 begins and determines 805 reselection priority frequencies for at least one network slice associated with a UE. In one embodiment, the method 800 transmits 810 slice reselection information to the UE. In one embodiment, the method 800 transmits 815 at least one value indicating to the UE whether to switch from legacy-based cell reselection to slice-based cell reselection using the slice reselection information, and the method 800 ends.

[0140] A first apparatus is disclosed for cell reselection based on network slicing considering mobility. The first apparatus may include a UE as described herein, for example, the remote unit 105, the UE 205 and/or the user equipment apparatus 500. In some embodiments, the first apparatus may include a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0141] In one embodiment, a first apparatus includes a memory and a processor coupled to the memory. In one embodiment, the processor is configured to cause the apparatus to perform legacy-based cell reselection for a cell of a wireless communication network. In one embodiment, the processor is configured to cause the apparatus to determine at least one network slice associated with the apparatus, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the apparatus. In one embodiment, the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell.

[0142] In one embodiment, the processor is configured to cause the apparatus to select a network slice of the at least one network slice with a highest reselection priority frequency during slice-based cell reselection.

[0143] In one embodiment, for the selected network slice, the processor is configured to cause the apparatus to assign frequency priorities to each of the frequencies that the selected network slice supports based on slice reselection information for the network slice.

[0144] In one embodiment, the processor is configured to cause the apparatus to select a network cell of the selected network slice corresponding to the highest assigned priority frequency.

[0145] In one embodiment, the processor is configured to cause the apparatus to select a second network slice of the at least one network slice with a next highest reselection priority frequency in response to the selected network cell of the selected slice not being suitable for the apparatus.

[0146] In one embodiment, the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further detecting a change in slice reselection information, slice priorities received from non-access stratum, or a combination thereof.

[0147] In one embodiment, the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further detecting that a downlink radio condition of the serving cell changed by a threshold.

[0148] In one embodiment, the processor is configured to cause the apparatus to measure the change with reference to a measurement taken at a beginning of legacy-based cell reselection, at a beginning of slice-based cell reselection, or anytime in between.

[0149] In one embodiment, the processor is configured to cause the apparatus to measure the change based on a cell reception level value, a cell quality value, or a combination thereof using a pathloss calculation.

[0150] In one embodiment, the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further detecting that a temporal threshold has elapsed since a beginning of legacy-based cell reselection, a beginning of slice-based cell reselection, or anytime in between.

[0151] In one embodiment, the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further searching each layer of higher priority frequencies or lower priority frequencies, relative to a frequency of the serving cell, a priority frequency measured in response to a threshServingLowQ parameter broadcast in system information and more than one second elapsing since the apparatus camped on the serving cell.

[0152] In one embodiment, the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further measuring remaining frequencies that have yet to be measured during slice-based cell reselection.

[0153] In one embodiment, the frequency of the serving cell is assigned a lowest reselection priority in response to the network slice comprising the serving cell not being supported on a new radio frequency.

[0154] A first method is disclosed for cell reselection based on network slicing considering mobility. The first method may be performed by a UE as described herein, for example, the remote unit 105, the UE 205 and/or the user equipment apparatus 500. In some embodiments, the first method may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0155] In one embodiment, the first method performs legacy-based cell reselection for a cell of a wireless communication network. In one embodiment, the first method determines at least one network slice associated with a UE, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the UE. In one embodiment, the first method switches to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell.

[0156] In one embodiment, the first method selects a network slice of the at least one network slice with a highest reselection priority frequency during slice-based cell reselection.

[0157] In one embodiment, for the selected network slice, the first method assigns frequency priorities to each of the frequencies that the selected network slice supports based on slice reselection information for the network slice.

[0158] In one embodiment, the first method selects a network cell of the selected network slice corresponding to the highest assigned priority frequency.

[0159] In one embodiment, the first method selects a second network slice of the at least one network slice with a next highest reselection priority frequency in response to the selected network cell of the selected slice not being suitable for the UE.

[0160] In one embodiment, the first method switches to slice-based cell reselection in response to further detecting a change in slice reselection information, slice priorities received from non-access stratum, or a combination thereof. [0161] In one embodiment, the first method switches to slice-based cell reselection in response to further detecting that a downlink radio condition of the serving cell changed by a threshold.

[0162] In one embodiment, the first method measures the change with reference to a measurement taken at a beginning of legacy-based cell reselection, at a beginning of slice-based cell reselection, or anytime in between.

[0163] In one embodiment, the first method measures the change based on a cell reception level value, a cell quality value, or a combination thereof using a pathloss calculation.

[0164] In one embodiment, the first method switches to slice-based cell reselection in response to further detecting that a temporal threshold has elapsed since a beginning of legacybased cell reselection, a beginning of slice-based cell reselection, or anytime in between.

[0165] In one embodiment, the first method switches to slice-based cell reselection in response to further searching each layer of higher priority frequencies or lower priority frequencies, relative to a frequency of the serving cell, a priority frequency measured in response to a threshServingLowQ parameter broadcast in system information and more than one second elapsing since the UE camped on the serving cell.

[0166] In one embodiment, the first method switches to slice-based cell reselection in response to further measuring remaining frequencies that have yet to be measured during slicebased cell reselection.

[0167] In one embodiment, the frequency of the serving cell is assigned a lowest reselection priority in response to the network slice comprising the serving cell not being supported on a new radio frequency.

[0168] A second apparatus is disclosed for cell reselection based on network slicing considering mobility. The second apparatus may include a network node as described herein, for example, a base unit 121, a gNB, and/or the network equipment apparatus 600. In some embodiments, the second apparatus may include a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0169] In one embodiment, the second apparatus includes a memory and a processor coupled to the memory. In one embodiment, the processor is configured to cause the apparatus to determine reselection priority frequencies for at least one network slice associated with a UE. In one embodiment, the processor is configured to cause the apparatus to transmit slice reselection information to the UE, the slice reselection information comprising the reselection priority frequencies for the at least one network slice associated with the UE. In one embodiment, the processor is configured to cause the apparatus to transmit at least one value indicating to the UE whether to switch from legacy-based cell reselection to slice-based cell reselection using the slice reselection information.

[0170] A second method is disclosed for cell reselection based on network slicing considering mobility. The second method may be performed by a network node as described herein, for example, a base unit 121, a gNB, and/or the network equipment apparatus 600. In some embodiments, the second method may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0171] In one embodiment, the second method determines reselection priority frequencies for at least one network slice associated with a UE. In one embodiment, the second method transmits slice reselection information to the UE, the slice reselection information comprising the reselection priority frequencies for the at least one network slice associated with the UE. In one embodiment, the second method transmits at least one value indicating to the UE whether to switch from legacy-based cell reselection to slice-based cell reselection using the slice reselection information.

[0172] Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

35 CLAIMS

1 . An apparatus, comprising: a memory; and a processor coupled to the memory, the processor configured to cause the apparatus to: perform legacy-based cell reselection for a cell of a wireless communication network; determine at least one network slice associated with the apparatus, based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the apparatus; and switch to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell.

2. The apparatus of claim 1, wherein the processor is configured to cause the apparatus to select a network slice of the at least one network slice with a highest reselection priority frequency during slice-based cell reselection.

3. The apparatus of claim 2, wherein, for the selected network slice, the processor is configured to cause the apparatus to assign frequency priorities to each of the frequencies that the selected network slice supports based on slice reselection information for the network slice.

4. The apparatus of claim 3, wherein the processor is configured to cause the apparatus to select a network cell of the selected network slice corresponding to the highest assigned priority frequency.

5. The apparatus of claim 4, wherein the processor is configured to cause the apparatus to select a second network slice of the at least one network slice with a next highest reselection priority frequency in response to the selected network cell of the selected slice not being suitable for the apparatus. 36 The apparatus of claim 1, wherein the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further detecting a change in slice reselection information, slice priorities received from non-access stratum, or a combination thereof. The apparatus of claim 1, wherein the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further detecting that a downlink radio condition of the serving cell changed by a threshold. The apparatus of claim 7, wherein the processor is configured to cause the apparatus to measure the change with reference to a measurement taken at a beginning of legacybased cell reselection, at a beginning of slice-based cell reselection, or anytime in between. The apparatus of claim 7, wherein the processor is configured to cause the apparatus to measure the change based on a cell reception level value, a cell quality value, or a combination thereof using a pathloss calculation. The apparatus of claim 1, wherein the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further detecting that a temporal threshold has elapsed since a beginning of legacy-based cell reselection, a beginning of slice-based cell reselection, or anytime in between. The apparatus of claim 1, wherein the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further searching each layer of higher priority frequencies or lower priority frequencies, relative to a frequency of the serving cell, a priority frequency measured in response to a threshServingLowQ parameter broadcast in system information and more than one second elapsing since the apparatus camped on the serving cell. The apparatus of claim 1, wherein the processor is configured to cause the apparatus to switch to slice-based cell reselection in response to further measuring remaining frequencies that have yet to be measured during slice-based cell reselection. The apparatus of claim 1, wherein the frequency of the serving cell is assigned a lowest reselection priority in response to the network slice comprising the serving cell not being supported on a new radio frequency. od, comprising: performing legacy-based cell reselection for a cell of a wireless communication network; determining at least one network slice associated with a user equipment (“UE”), based on slice reselection information, that comprises a higher reselection priority frequency than a reselection priority frequency of a cell serving the UE; and switching to slice-based cell reselection in response to determining that the at least one network slice has a higher reselection priority frequency than the reselection priority frequency of the network slice serving cell.aratus, comprising: a memory; and a processor coupled to the memory, the processor configured to cause the apparatus to: determine reselection priority frequencies for at least one network slice associated with a user equipment (“UE”); transmit slice reselection information to the UE, the slice reselection information comprising the reselection priority frequencies for the at least one network slice associated with the UE; and transmit at least one value indicating to the UE whether to switch from legacy-based cell reselection to slice-based cell reselection using the slice reselection information.