IP Library Granted Patent US 12,477,608
Granted Patent B2
US 12,477,608 · App. 17/593,722 · Granted Nov 18, 2025

Synchronization of RRC status of a multi-SIM user equipment with a base station

Inventors: Srirang A. Lovlekar (Fremont, CA); Adesh Kumar (San Jose, CA); Birgit Breining (Munich, DE); Dawei Zhang (Saratoga, CA); Fangli Xu (Beijing, CN); Haijing Hu (Los Gatos, CA); Longda Xing (San Jose, CA); Naveen Kumar R. Palle Venkata (San Diego, CA); Sethuraman Gurumoorthy (San Ramon, CA); Yuqin Chen (Beijing, CN); Zhibin Wu (Los Altos, CA)
Assignee: Apple Inc.
H04W76/19H04W8/183H04W76/20H04W76/30
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Quick Facts
Patent No.
US 12,477,608
App. No.
17/593,722
Granted
Nov 18, 2025
Kind
B2
Abstract

A multi-universal subscriber identity module (MUSIM) user equipment (UE) is configured to stay synchronized with a network. The UE registers to a first network for the first SIM, registering to a second network for the second SIM, prior to the UE conducting a high priority activity related to the second SIM, sends, to the first network via a connection associated with the first SIM, a first message comprising an estimated time duration during which the UE conducts the high priority activity related to the second SIM, receives, from the first network, a second message indicating a time period during which the first network will retain a connection context for the connection associated with the first SIM in an RRC Inactive state and when the UE completes the high priority activity, determines the connection context of the first network for the connection associated with the first SIM.

Claims (36)

1 . A user equipment (UE), comprising:

a multi universal subscriber identity module (MUSIM) array having a first SIM and a second SIM;

a transceiver configured to communicate with one or more networks; and

a processor communicatively coupled to the transceiver and the MUSIM and configured to perform operations comprising:

registering to a first network for the first SIM;

registering to a second network for the second SIM;

prior to the UE conducting a high priority activity related to the second SIM, sending, to the first network via a connection associated with the first SIM, a first message related to the second SIM, wherein the first message comprises a UE assistance information message including a preferred RRC state set to Inactive;

receiving, from the first network, a second message indicating that the first network will retain a connection context for the connection associated with the first SIM in an RRC Inactive state; and

determining the connection context of the first network for the connection associated with the first SIM.

2 . The UE of claim 1 , wherein, when the UE completes the high priority activity related to the second SIM before expiration of a time period, the connection context of the first network for the connection associated with the first SIM is an RRC Inactive state, and wherein, when the UE completes the high priority activity related to the second SIM after expiration of the time period, the connection context of the first network for the connection associated with the first SIM is an RRC Idle state.

3 . The UE of claim 2 , wherein, prior to the UE conducting the high priority activity related to the second SIM, the connection associated with the first SIM is in the RRC Inactive state.

4 . The UE of claim 3 , wherein the first message comprises an RRC resume request including a radio access network (RAN)-based notification area (RNA) update.

5 . The UE of claim 2 , wherein, prior to the UE conducting the high priority activity related to the second SIM, the connection associated with the first SIM is in an RRC Connected state.

6 . The method of claim 2 , wherein, prior to the UE conducting the high priority activity related to the second SIM, the connection associated with the first SIM is in the RRC Inactive state.

7 . The method of claim 3 , wherein the first message comprises an RRC resume request including a radio access network (RAN)-based notification area (RNA) update.

8 . The method of claim 2 , wherein, prior to the UE conducting the high priority activity related to the second SIM, the connection associated with the first SIM is in an RRC Connected state.

9 . The UE of claim 1 , wherein the second message comprises a radio resource control (RRC) configuration message.

10 . A processor communicatively coupled to a multi universal subscriber identity module (MUSIM) array having a first SIM and a second SIM of a user equipment (UE), the processor configured to perform operations comprising:

registering to a first network for the first SIM;

registering to a second network for the second SIM;

prior to the UE conducting a high priority activity related to the second SIM, sending, to the first network via a connection associated with the first SIM, a first message related to the second SIM, wherein the first message comprises a UE assistance information message including a preferred RRC state set to Inactive;

receiving, from the first network, a second message indicating that the-first network will retain a connection context for the connection associated with the first SIM in an RRC Inactive state; and

determining a connection context of the first network for the connection associated with the first SIM.

11 . The processor of claim 10 , wherein, when the UE completes the high priority activity related to the second SIM before expiration of a time period, the connection context of the first network for the connection associated with the first SIM is an RRC Inactive state, and wherein, when the UE completes the high priority activity related to the second SIM after expiration of the time period, the connection context of the first network for the connection associated with the first SIM is an RRC Idle state.

12 . The processor of claim 11 , wherein, prior to the UE conducting the high priority activity related to the second SIM, the connection associated with the first SIM is in the RRC Inactive state.

13 . The processor of claim 12 , wherein the first message comprises an RRC resume request including a radio access network (RAN)-based notification area (RNA) update.

14 . The processor of claim 11 , wherein, prior to the UE conducting the high priority activity related to the second SIM, the connection associated with the first SIM is in an RRC Connected state.

15 . The processor of claim 10 , wherein the second message comprises a radio resource control (RRC) configuration message.

16 . A method, comprising:

at a user equipment (UE) configured with a multi universal subscriber identity module (MUSIM) array having a first SIM and a second SIM:

registering to a first network for the first SIM;

registering to a second network for the second SIM;

prior to the UE conducting a high priority activity related to the second SIM, sending, to the first network via a connection associated with the first SIM, a first message related to the second SIM, wherein the first message comprises a UE assistance information message including a preferred RRC state set to Inactive;

receiving, from the first network, a second message indicating that the first network will retain a connection context for the connection associated with the first SIM in an RRC Inactive state; and

determining the connection context of the first network for the connection associated with the first SIM.

17 . The method of claim 16 , wherein, when the UE completes the high priority activity related to the second SIM before expiration of a time period, the connection context of the first network for the connection associated with the first SIM is an RRC Inactive state, and wherein, when the UE completes the high priority activity related to the second SIM after expiration of the time period, the connection context of the first network for the connection associated with the first SIM is an RRC Idle state.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 26, 2021
From: LOVLEKAR, SRIRANG A.; XU, FANGLI; KUMAR, ADESH; BREINING, BIRGIT; ZHANG, DAWEI; HU, HAIJING; XING, LONGDA; PALLE VENKATA, NAVEEN KUMAR R.; GURUMOORTHY, SETHURAMAN; CHEN, YUQIN; WU, ZHIBIN
To: APPLE INC.
Reel/Frame 057916/0416 →
Continuity (1)
Related Publication 20220312531A1 · Sep 29, 2022
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