Apparatus and method for cell reselection in wireless communication system

Patent metadata

Field	Value
Publication number	US-12507134-B2
Application number	US-202217880030-A
Country	US
Kind code	B2
Filing date	Aug 3, 2022
Priority date	Aug 5, 2021
Publication date	Dec 23, 2025
Grant date	Dec 23, 2025

Abstract

A method performed by a base station (BS) is provided. The method includes transmitting system information including network slice related information, receiving, from a user equipment (UE), a radio resource control (RRC) connection complete message including single network slice selection assistance information (S-NSSAI), and transmitting, to the UE, an RRC connection release message including priority information related to the S-NSSAI.

First claim

What is claimed is:

1 . A method performed by a user equipment (UE) in a wireless communication system, comprising:
receiving, from a base station (BS), first system information including a first slice specific cell reselection priority information; receiving, from the BS, a second system information including a first frequency specific cell reselection priority information; transmitting, to the BS, a radio resource control (RRC) setup request message; receiving, from the BS, a RRC setup message; transmitting, to the BS, a RRC setup complete message including a slice list information for a network slice selection; receiving, from the BS, a RRC release message including information on cell reselection, wherein the information on cell reselection includes a second slice specific cell reselection priority information and a second frequency specific cell reselection priority information; storing the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information; in case that a value of a timer associated with the cell reselection is included in the RRC release message, starting the timer, performing the cell reselection based on the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information while the timer is running; and in case that the timer is expired, discarding the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information and applying the first slice specific priority information and first frequency specific cell reselection priority information for performing the cell reselection.

2 . The method of claim 1 ,
wherein the second system information is one of system information 2 , system information 4 , and system information 5 .

3 . A method performed by a base station (BS) in a wireless communication system, comprising:
transmitting, to a user equipment (UE), first system information including a first slice specific cell reselection priority information; transmitting, to the UE, a second system information including a first frequency specific cell reselection priority information; receiving. from the UE, a radio resource control (RRC) setup request message; transmitting, to the UE, a RRC setup message; receiving, from the UE, a RRC setup complete message including a slice list information for a network slice selection; and transmitting, to the UE, a radio resource control (RRC) RRC release message including information on cell reselection, wherein the information on cell reselection includes a second slice specific cell reselection priority and a value of a timer associated with the cell reselection and a second frequency specific cell reselection priority information, wherein the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information are applied for a cell reselection procedure while the timer is running, and wherein the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information are discarded and the first slice specific cell reselection priority information and first frequency specific cell reselection priority information are applied for performing cell reselection in case that the timer is expired.

4 . The method of claim 3 ,
wherein the second system information is one of system information 2 , system information 4 , and system information 5 .

5 . A user equipment (UE) in a wireless communication system, comprising:
a transceiver; and at least one processor coupled to the transceiver, wherein the at least one processor is configured to:
receive, from a base station (BS), first system information including a first slice specific cell reselection priority information,
receive, from the BS, a second system information including a first frequency specific cell reselection priority information,
transmit, to the BS, a radio resource control (RRC) setup request message,
receive, from the BS, a RRC setup message,
transmit, to the BS, a RRC setup complete message including a slice list information for a network slice selection,
receive, from the BS, a RRC release message including information on cell reselection, wherein the information on cell reselection includes a second slice specific cell reselection priority information and a second frequency specific cell reselection priority information,
store the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information,
in case that a value of a timer associated with the cell reselection is included in the RRC release message, start the timer, perform the cell reselection based on the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information while the timer is running, and
in case that the timer is expired, discard the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information and apply the first slice specific priority information and first frequency specific cell reselection priority information for performing the cell reselection.

6 . The UE of claim 5 ,
wherein the second system information is one of system information 2 , system information 4 , and system information 5 .

7 . A base station (BS) in a wireless communication system, comprising:
a transceiver; and at least one processor coupled to the transceiver, wherein the at least one processor is configured to:
transmit, to a user equipment (UE), first system information including a first slice specific cell reselection priority,
transmit, to the UE, a second system information including a first frequency specific cell reselection priority information,
receive, from the UE, a radio resource control (RRC) setup request message,
transmit, to the UE, a RRC setup message,
receive, from the UE, a RRC setup complete message including a slice list information for a network slice selection, and
transmit, to the UE, a RRC release message including information on cell reselection,
wherein the information on cell reselection includes a second slice specific cell reselection priority and a value of a timer associated with the cell reselection and a second frequency specific cell reselection priority information, wherein the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information are applied for a cell reselection procedure while the timer is running, and wherein the second slice specific cell reselection priority information and the second frequency specific cell reselection priority information are discarded and the first slice specific cell reselection priority information and first frequency specific cell reselection priority information are applied for performing cell reselection in case that the timer is expired.

8 . The BS of claim 7 ,
wherein the second system information is one of system information 2 , system information 4 , and system information 5 .

Assignees

• Samsung Electronics Co Ltd

Inventors

• Jung Sangyeob
• Kang Hyunjeong

Classifications

• H04W76/30

  Connection release · CPC title

• H04W48/16

  Discovering, processing access restriction or access information · CPC title

• H04W60/06

  De-registration or detaching · CPC title

• H04W48/20

  Selecting an access point · CPC title

• H04W48/12

  using downlink control channel · CPC title