Granted Patent B1

US 12,471,051 · App. 19/090,606 · Granted Nov 11, 2025

Inventor: Sang Geun Yu (Seoul, KR)

Assignee: Mentats Co., Ltd.

H04W60/04H04W12/106H04W84/042

Abstract

Claims (53)

1 . An operation method of user equipment (UE), comprising

transmitting a tracking area update request message;

receiving a response message:

if the response message is a tracking area update accept message and if the tracking area update accept message includes access technology utilization control information, determining that any public land mobile network (PLMN) and access technologies combination with access technology restriction is not considered as a candidate PLMN for PLMN selection purpose,

wherein the access technology utilization control information is used to restrict an access to a specific access technology,

wherein the access technology utilization control information does not indicate that an access technology of a cell on which the tracking area update request message was transmitted is restricted, and

wherein the access technology utilization control information is for current PLMN and its equivalent PLMN; and

if the tracking area update request message includes information on support of an access technology utilization control, if the response message is the tracking area update accept message and if the tracking area update accept message does not include the access technology utilization control information, deleting a stored access technology utilization control information associated with the current PLMN.

2 . The method of claim 1 , further comprising

if the tracking area update accept message includes the access technology utilization control information, storing the access technology utilization control information together with a PLMN identity of a current PLMN in a list of PLMNs with associated access technology restrictions.

3 . The method of claim 2 , further comprising:

if the UE is switched off, keeping the stored list so that it can be used after switch on.

4 . The method of claim 2 , further comprising:

if a universal subscriber identity module (USIM) is removed from the UE, deleting the stored list.

5 . The method of claim 1 , further comprising

if the response message is a tracking area update reject message, if the tracking area update reject message includes the access technology utilization control information and if the tracking area update reject message is successfully integrity checked, storing the access technology utilization control information together with a PLMN identity of a current PLMN in a list of PLMNs with associated access technology restrictions.

6 . The method of claim 5 , further comprising:

replacing a previously stored access technology utilization control information associated with the currently PLMN with a new access technology utilization control information.

7 . The method of claim 1 , wherein

if the response message is a tracking area update reject message, the tracking area update reject message includes information used to indicate that no suitable cells in tracking area.

8 . A user equipment (UE), the UE comprising:

at least one processor; and

at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations comprising:

transmitting a tracking area update request message;

receiving a response message;

if the response message is a tracking area update accept message and if the tracking area update accept message includes access technology utilization control information, determining that any public land mobile network (PLMN) and access technologies combination with access technology restriction is not considered as a candidate PLMN for PLMN selection purpose,

wherein the access technology utilization control information is used to restrict an access to a specific access technology,

wherein the access technology utilization control information does not indicate that an access technology of a cell on which the tracking area update request message was transmitted is restricted, and

wherein the access technology utilization control information is for current PLMN and its equivalent PLMN; and

if the tracking area update request message includes information on support of an access technology utilization control, if the response message is the tracking area update accept message and if the tracking area update accept message does not include the access technology utilization control information, deleting a stored access technology utilization control information associated with the current PLMN.

9 . The UE of claim 8 , wherein the operations may further comprise:

if the tracking area update accept message includes the access technology utilization control information, storing the access technology utilization control information together with a PLMN identity of a current PLMN in a list of PLMNs with associated access technology restrictions.

10 . The UE of claim 8 , wherein the operations may further comprise:

if the UE is switched off, keeping the stored list so that it can be used after switch on.

11 . The UE of claim 8 , wherein the operations may further comprise:

if a universal subscriber identity module (USIM) is removed from the UE, deleting the stored list.

12 . The UE of claim 8 , wherein the operations may further comprise:

if the response message is a tracking area update reject message, if the tracking area update reject message includes the access technology utilization control information and if the tracking area update reject message is successfully integrity checked, storing the access technology utilization control information together with a PLMN identity of a current PLMN in a list of PLMNs with associated access technology restrictions.

13 . The UE of claim 8 , wherein the operations may further comprise:

replacing a previously stored access technology utilization control information associated with the currently PLMN with a new access technology utilization control information.

14 . The UE of claim 8 , wherein

if the response message is a tracking area update reject message, the tracking area update reject message includes information used to indicate that no suitable cells in tracking area.

15 . A semiconductor chipset, comprising:

at least one processor; and

at least one memory capable of storing instructions and being connected electrically to the at least one processor operably,

wherein operations, performed when the instructions are executed by the at least one processor, includes:

transmitting a tracking area update request message;

receiving a response message:

if the response message is a tracking area update accept message and if the tracking area update accept message includes access technology utilization control information, determining that any public land mobile network (PLMN) and access technologies combination with access technology restriction is not considered as a candidate PLMN for PLMN selection purpose,

wherein the access technology utilization control information is used to restrict an access to a specific access technology,

wherein the access technology utilization control information does not indicate that an access technology of a cell on which the tracking area update request message was transmitted is restricted, and

wherein the access technology utilization control information is for current PLMN and its equivalent PLMN; and

if the tracking area update request message includes information on support of an access technology utilization control, if the response message is the tracking area update accept message and if the tracking area update accept message does not include the access technology utilization control information, deleting a stored access technology utilization control information associated with the current PLMN.

Assignments (2)

Priority Claims (1)

References Cited (13)