US-12621753-B2 - Maintaining in parallel a frequency layer during cell reselection

US12621753B2US 12621753 B2US12621753 B2US 12621753B2US-12621753-B2

Abstract

Apparatuses, methods, and systems are disclosed for performing cell selection/reselection on a radio frequency associated with a network slice. One apparatus includes a processor and a transceiver that camps on a first frequency layer of a RAN while in a RRC idle state, the first frequency layer supporting a first set of network slices, where the first set of network slices is prioritized for use with a first frequency. The processor iteratively performs cell search on a second frequency layer while the apparatus is camped on the first frequency layer, the second frequency layer supporting a second set of network slices, where the second set of network slices is prioritized for use with a second frequency. The processor maintains in parallel the second frequency layer while in the RRC idle state.

Inventors

Prateek Basu Mallick
Ravi Kuchibhotla
Joachim Loehr
Genadi Velev
Hyung-Nam Choi

Assignees

LENOVO (SINGAPORE) PTE. LTD.

Dates

Publication Date: 20260505
Application Date: 20210521

Claims (18)

1 . A method performed by a user equipment (UE), the method comprising: camping on a first frequency of a radio access network (RAN) while in a radio resource control (RRC) idle state, wherein a first frequency layer supports a first set of network slices, and wherein the first set of network slices is prioritized for the first frequency; performing cell search on a second frequency while the UE is camped on the first frequency by performing detection, measurement and evaluation operations on cells on a second frequency layer at reduced performance as compared to detection, measurement and evaluation operations on cells on the first frequency layer, wherein the second frequency layer supports a second set of network slices, and wherein the second set of network slices is prioritized for the second frequency; and performing cell reselection on the second frequency.
2 . The method of claim 1 , wherein the first set of network slices is associated with a first group of applications and the second set of network slices is associated with a second group of applications.
3 . The method of claim 1 , further comprising determining an interval at which the UE performs cell search on the second frequency layer while the UE is camped on the first frequency layer, said interval determined based on: a battery level of the UE, a power consumption level of the UE, or a combination thereof.
4 . The method of claim 1 , further comprising: determining that the second frequency layer has a higher priority than other frequency layers of the RAN; and performing optimized cell search on the second frequency layer by using a shorter interval than a search interval associated with the other frequency layers of the RAN.
5 . The method of claim 4 , further comprising excluding frequency layers that are not associated with a preferred slice from consideration for inter-frequency reselection.
6 . The method of claim 1 , further comprising: determining that the second frequency is of a lower priority based on one of: a dedicated priority for the second frequency or a common priority for the second frequency; and performing inter-frequency reselection for the second frequency even when a quality level of the first frequency satisfies a quality threshold.
7 . The method of claim 1 , further comprising: maintaining a prioritized table that maps network slices to corresponding frequencies; and initiating, at the UE, a frequency scan for the second frequency while camped on the first frequency layer.
8 . The method of claim 7 , wherein a non-access stratum (NAS) layer entity in the UE notifies an access stratum (AS) layer entity in the UE to search for a particular combination of frequency and network slice, the combination corresponding to a preferred network slice.
9 . The method of claim 1 , further comprising: detecting a request to establish a data connection with a network slice of the second set of network slices; and establishing a RRC connection with a cell on the second frequency layer in response to detecting the request, wherein the request is generated by: an application running on the UE, an operating system of the UE, or a combination thereof.
10 . The method of claim 1 , wherein performing cell reselection on the second frequency comprises monitoring both the first and second frequency layers in parallel and evaluating both the first and second frequency layers for cell reselection.
11 . The method of claim 10 , wherein performing cell reselection on the second frequency comprises performing a virtual reselection for the second frequency layer.
12 . A user equipment (UE) for wireless communication, comprising: a memory; and a processor coupled with the memory and configured to cause the UE to: camp on a first frequency of a radio access network (RAN) while in a radio resource control (RRC) idle state, wherein a first frequency layer supports a first set of network slices, and wherein the first set of network slices is prioritized for the first frequency; perform cell search on a second frequency while the UE is camped on the first frequency by performing detection, measurement and evaluation operations on cells on a second frequency layer at reduced performance as compared to detection, measurement and evaluation operations on cells on the first frequency layer, wherein the second frequency layer supports a second set of network slices, and wherein the second set of network slices is prioritized for use with a second frequency; and perform cell reselection on the second frequency.
13 . The UE of claim 12 , wherein the first set of network slices is associated with a first group of applications and the second set of network slices is associated with a second group of applications.
14 . The UE of claim 12 , wherein the processor is configured to cause the UE to determine an interval at which the UE performs cell search on the second frequency layer while the UE is camped on the first frequency layer, said interval determined based on: a battery level of the UE, a power consumption level of the UE, or a combination thereof.
15 . The UE of claim 12 , wherein the processor is configured to cause the UE to: determine that the second frequency layer has a higher priority than other frequency layers of the RAN; and perform optimized cell search on the second frequency layer by using a shorter interval than a search interval associated with the other frequency layers of the RAN.
16 . The UE of claim 12 , wherein the processor is configured to cause the UE to: determine that the second frequency is of a lower priority based on one of: a dedicated priority for the second frequency or a common priority for the second frequency; and perform inter-frequency reselection for the second frequency even when a quality level of the first frequency satisfies a quality threshold.
17 . The UE of claim 12 , wherein the processor is configured to cause the UE to: maintain a prioritized table that maps network slices to corresponding frequencies; and initiate a frequency scan for the second frequency while camped on the first frequency layer.
18 . The UE of claim 12 , wherein the processor is configured to cause the UE to: detect a request to establish a data connection with a network slice of the second set of network slices; and establish a RRC connection with a cell on the second frequency layer in response to detecting the request, wherein the request is generated by: an application running on the UE, an operating system of the UE, or a combination thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63/028,510 entitled “NETWORK-ASSISTED OPTIMAL SLICE SELECTION IN 5G SYSTEM” and filed on May 21, 2020 for Prateek Basu Mallick, Ravi Kuchibhotla, Joachim Loehr, Hyung-Nam Choi, and Genadi Velev, which application is incorporated herein by reference. This application also claims priority to U.S. Provisional Patent Application No. 63/028,511 entitled “UE-BASED OPTIMAL SLICE SELECTION IN 5G SYSTEM” and filed on May 21, 2020 for Prateek Basu Mallick, Ravi Kuchibhotla, Joachim Loehr, Genadi Velev, and Hyung-Nam Choi, which application is incorporated herein by reference. FIELD The subject matter disclosed herein relates generally to wireless communications and more particularly relates to performing cell selection/reselection on a radio frequency associated with a network slice. BACKGROUND In certain wireless communication systems, a network operator may prefer that a user equipment (“UE”) camp on a cell on a first carrier providing coverage, but establish a Radio Resource Control (“RRC”) Connection on a different cell on a second carrier supporting Slice ‘x’ (alternatively, supporting service ‘x’) with minimum delay as soon upper layers initiate a Service Request procedure for the Slice/service ‘x.’ However, monitoring separate radio carriers increases power consumption at the UE. BRIEF SUMMARY Disclosed are procedures for performing cell selection/reselection on a radio frequency associated with a network slice. Said procedures may be implemented by apparatus, systems, methods, or computer program products. One method of a User Equipment device (“UE”) includes configuring the UE to use a first set of network slices and a second set of network slices and camping on a first frequency layer of a Radio Access Network (“RAN”) while in a Radio Resource Control (“RRC”) Idle state, the first frequency layer supporting the first set of network slices, wherein the first set of network slices is prioritized for use with a first frequency. The first method includes iteratively performing cell search on a second frequency layer while the UE is camped on the first frequency layer, the second frequency layer supporting the second set of network slices, wherein the second set of network slices is prioritized for use with a second frequency layer. The first method includes maintaining in parallel the second frequency layer while in the RRC Idle state by performing cell reselection on the second frequency. Another method of a UE includes receiving a broadcast message comprising a persistence check value for a first cell and generating a random value during a cell reselection procedure. The second method includes comparing the generated random value to the persistence check value and selectively stopping the cell reselection based on a result of the comparison. BRIEF DESCRIPTION OF THE DRAWINGS 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: FIG. 1 is a schematic block diagram illustrating one embodiment of a wireless communication system for performing cell selection/reselection on a radio frequency associated with a network slice; FIG. 2 is a block diagram illustrating one embodiment of a 5G New Radio (“NR”) protocol stack; FIG. 3 is a diagram illustrating one embodiment of a RAN deployment; FIG. 4 is a diagram illustrating one embodiment of a user equipment apparatus that may be used for performing cell selection/reselection on a radio frequency associated with a network slice; FIG. 5 is a diagram illustrating one embodiment of a network apparatus that may be used for performing cell selection/reselection on a radio frequency associated with a network slice; FIG. 6 is a flowchart diagram illustrating one embodiment of a first method for parallel maintenance of a second frequency layer; and FIG. 7 is a flowchart diagram illustrating one embodiment of a first method for cell reselection using a persistence check value. DETAILED DESCRIPTION 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. 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, o