# US 10,455,491 B2 · Method whereby terminal selects PLMN in wireless communication system, and device for same

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- Number: US 10,455,491 B2
- Document ID: US10455491B2
- Status: Granted
- Kind: B2
- Application number: 15/545,443
- Filed: 2016-02-02
- Published: 2018-01-04
- Granted: 2019-10-22
- Earliest claimed: 2015-02-04
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Taehun Kim; Jaehyun Kim; Jinsook Ryu; Hyunsook Kim; Laeyoung Kim
- Web page: https://patentgrep.com/patent/US10455491B2

## CPC

- H04W 48/18: Selecting a network or a communication service
- H04L 67/51: Discovery or management thereof, e.g. service location protocol [SLP] or web services
- H04L 67/52: specially adapted for the location of the user terminal
- H04W 4/023: {using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds}
- H04W 60/00: Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
- H04W 60/001: {Registration rejection or failure}
- H04W 48/02: Access restriction performed under specific conditions
- H04W 84/042: {Public Land Mobile systems, e.g. cellular systems}
- H04W 88/06: adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

One embodiment of the present invention relates to a method whereby a terminal performs an operation related to public land mobile network (PLMN) selection related to ProSe direct communication in a wireless communication system, the method for performing an operation related to PLMN selection comprising the steps of: selecting a first PLMN; performing registration with the first PLMN; and selecting a second PLMN in case of failure to register with the first PLMN, wherein when selecting the second PLMN, the terminal treats a list that did not include the first PLMN at the time of selecting the first PLMN as if the list has included the first PLMN.

## Claims

### Claim 1

A method for performing Public Land Mobile Network (PLMN) selection related to Proximity-based Service (ProSe) direct communication by a User Equipment (UE) in a wireless communication system, the method comprising:
selecting a first PLMN, which is not included in a list related to forbidden PLMNs, by the UE which is outside of coverage; and
selecting a second PLMN after a registration with the first PLMN has failed,
wherein zero or more PLMNs, which are included in the list related to forbidden PLMNs, are excluded in the second PLMN selection, and
wherein the first PLMN with which the registration has failed is further excluded in the second PLMN selection, although the first PLMN is not included in the list related to forbidden PLMNs.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the registration with the first PLMN further comprises transmitting a location registration request to the first PLMN.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the UE recognizes failure in the registration with the first PLMN by receiving a response to the location registration request.

### Claim 4 (depends on 2)

The method according to claim 2, wherein a response to the location registration request includes information about a cause of registration rejection.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the information about the cause indicates ‘PLMN not allowed’.

### Claim 6

A User Equipment (UE) for performing Public Land Mobile Network (PLMN) selection related to Proximity-based Service (ProSe) direct communication in a wireless communication system, the UE which is outside of coverage and comprising:
a memory; and
a processor coupled with the memory,
wherein the processor selects a first PLMN, which is not included in a forbidden PLMN list, and selects a second PLMN after a registration with the first PLMN has failed,
wherein zero or more PLMNs, which are included in the forbidden PLMN list, are excluded in the second PLMN selection, and
wherein the first PLMN with which the registration has failed is further excluded in the second PLMN selection, although the first PLMN is not included in the forbidden PLMN list.

### Claim 7 (depends on 6)

The UE according to claim 6, wherein a location registration request is transmitted to the first PLMN during the registration with the first PLMN.

### Claim 8 (depends on 7)

The UE according to claim 7, wherein the UE recognizes failure in the registration with the first PLMN by receiving a response to the location registration request.

### Claim 9 (depends on 7)

The UE according to claim 7, wherein a response to the location registration request includes information about a cause of registration rejection.

### Claim 10 (depends on 9)

The UE according to claim 9, wherein the information about the cause indicates ‘PLMN not allowed’.