Method to Reduce Service Interruption

• US 20150264741A1
• Filed: 03/11/2015
• Published: 09/17/2015
• Est. Priority Date: 03/12/2014
• Status: Active Grant

• Current Assignee: HFI Innovation, Inc. (MediaTek, Inc.)
• Original Assignee: MediaTek, Inc.
• Inventors: Jheng, Yu-Syuan, Huang-Fu, Chien-Chun, Chang, Hung-Lin, Lin, Yuan-Chieh
• Granted Patent: US 9,814,090 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 36/0066 of control information between different types of networks in order to establish a new radio link in the target network
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 76/38 triggered by timers

Abstract

Methods and apparatus are provided to reduce service interruption for intra-RAT and inter-RAT handover procedures. The UE performs a NAS signaling procedure via a NAS signaling connection in a mobile communication network. The UE monitors a radio resource status and determines whether a radio bearer has been or is being established for a RRC connection for data transmission. The UE determines whether to release the NAS signaling connection after completing the NAS signaling procedure based on whether the radio bearer has been established. In one embodiment, the UE monitors a radio resource status and determines whether a radio bearer has been established for a RRC connection for data transmission. The UE determines whether to start a timer upon completing the NAS signaling procedure based on whether the radio bearer has been or is being established.

Claims

1. A method comprising:

performing a non-access stratum (NAS) signaling procedure via a NAS signaling connection by a user equipment (UE) in a mobile communication network;

monitoring a radio resource status;

determining whether a radio bearer has been or is being established for a radio resource control (RRC) connection for data transmission; and

determining whether to release the NAS signaling connection after completing the NAS signaling procedure based on whether the radio bearer has been or is being established.

2. The method of claim 1, wherein the NAS signaling procedure involves sending a routing area update request to the network.

3. The method of claim 2, wherein the completing of the NAS signaling procedure involves receiving a routing area update accept message from the network, and wherein the accept message comprises a “

no follow-on proceed”

indication.

4. The method of claim 1, wherein the UE starts a timer upon completing the NAS signaling procedure, and wherein the UE determines whether to release the NAS signaling connection upon the timer expires.

5. The method of claim 1, further comprising:

performing an inter-radio access technology (RAT) handover procedure before performing the NAS signaling procedure.

6. The method of claim 5, wherein the UE receives a handover command for establishing the radio bearer in a target network.

7. The method of claim 1, wherein the UE receives an RRC radio bearer setup message from the network during the NAS signaling procedure, and wherein the UE determines that the radio bearer is being established.

8. The method of claim 6, wherein the UE transmits an RRC radio bearer setup complete message to the network after the radio bearer has been established.

9. A method comprising:

performing a non-access stratum (NAS) signaling procedure via a NAS signaling connection by a user equipment (UE) in a mobile communication network;

monitoring a radio resource status;

determining whether a radio bearer has been or is being established for a radio resource control (RRC) connection for data transmission; and

determining whether to start a timer upon completing the NAS signaling procedure based on whether the radio bearer has been or is being established.

10. The method of claim 9, wherein the NAS signaling procedure involves sending a routing area update request to the network.

11. The method of claim 10, wherein the completing of the NAS signaling procedure involves receiving a routing area update accept message from the network, and wherein the accept message comprises a “

no follow-on proceed”

indication.

12. The method of claim 9, wherein the UE starts the timer if no radio bearer has been established, and wherein the UE releases the NAS signaling connection upon the timer expires.

13. The method of claim 9, wherein the UE does not starts the timer if the radio bearer has been established.

14. The method of claim 9, further comprising:

performing an inter-radio access technology (RAT) handover procedure before performing the NAS signaling procedure.

15. The method of claim 14, wherein the UE receives a handover command for establishing the radio bearer in a target network.

16. The method of claim 9, wherein the UE receives an RRC radio bearer setup message from the network during the NAS signaling procedure, and wherein the UE determines that the radio bearer is being established.

17. The method of claim 16, wherein the UE transmits an RRC radio bearer setup complete message to the network after the radio bearer has been established.

18. A user equipment (UE), comprising:

a non-access stratum (NAS) layer module that performs a NAS signaling procedure via a NAS signaling connection in a mobile communication network;

a radio resource control (RRC) layer module that monitors a radio resource status and thereby determining whether a radio bearer has been or is being established for an RRC connection for data transmission; and

a service continuity module that determines whether to release the NAS signaling connection after completing the NAS signaling procedure based on whether the radio bearer has been or is being established.

19. The UE of claim 18, wherein the NAS signaling procedure involves sending a routing area update request to the network.

20. The UE of claim 19, wherein the completing of the NAS signaling procedure involves receiving a routing area update accept message from the network, and wherein the accept message comprises a “

no follow-on proceed”

indication.

21. The UE of claim 18, wherein the UE starts a timer upon completing the NAS signaling procedure, and wherein the UE determines whether to release the NAS signaling connection upon the timer expires.

22. The UE of claim 18, wherein the UE starts a timer if no radio bearer has been established, and wherein the UE releases the NAS signaling connection upon the timer expires, and wherein the UE does not starts the timer if the radio bearer has been or is being established.