Method of Handling Emergency Bearer Service in Wireless Communication System

• US 20130016607A1
• Filed: 01/18/2012
• Published: 01/17/2013
• Est. Priority Date: 01/19/2011
• Status: Active Grant

• Current Assignee: HTC Corporation
• Original Assignee: HTC Corporation
• Inventors: Tiwari, Kundan
• Granted Patent: US 9,072,075 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 60/06 De-registration or detaching
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A method of handling an emergency bearer service for a mobile station in a wireless communication system is disclosed. The method comprises receiving an attach rejection message with a back-off timer when a network node is applying a non-access stratum (NAS) level congestion control, wherein the attach rejection message is used for rejecting a normal attach procedure; and initiating a packet switch (PS) emergency attach procedure when a PS emergency bearer service is initiated during a time of the back-off timer being running.

Claims

1. A method of handling an emergency bearer service for a mobile station in a wireless communication system, the method comprising:

receiving an attach rejection message with a back-off timer when a network node is applying a non-access stratum (NAS) level congestion control, wherein the attach rejection message is used for rejecting a normal attach procedure; and

initiating a packet switch (PS) emergency attach procedure when a PS emergency bearer service is initiated during a time of the back-off timer being running.

2. The method of claim 1, wherein initiating the PS emergency attach procedure comprises sending a first attach request message with an emergency attach type to the network node.

3. The method of claim 1, wherein the mobile station is camped on a normal cell providing a plurality of normal services.

4. The method of claim 1, wherein the NAS congestion control is applied due to a general NAS level congestion in the network node or an access point name (APN) congestion in the network node.

5. The method of claim 1 further comprising the network node prioritizing the emergency attach procedure for the emergency bear services when the network node receives the first attach request message with the emergency attach type and the back-off timer is running.

6. The method of claim 1, wherein the back-off timer is a (GPRS Mobility Management) GMM back-off timer.

7. A method of handling a congestion control for a network node in a wireless communication system, the method comprising:

receiving a detach request message from a mobile station; and

sending a detach accept message with an International Mobile Subscriber Identity (IMSI) detach type and a back-off timer in response to the detach request message when the network node is applying a non-access stratum (NAS) level congestion control.

8. The method of claim 7, wherein the mobile station is attached for a circuit switched (CS) or packet switched (PS) service on a cell with NMOI (network mode of operation I) or is configured to use to an extend NMOI system information.

9. The method of claim 7, wherein the detach request message is used for the mobile station to detach an IMSI service.

10. The method of claim 7 further comprising the mobile station running the back-off timer up reception of the detach accept message.

11. The method of claim 7 further comprising the mobile station not initiating any GMM signaling for normal services till the back-off timer expires.

12. The method of claim 7 further comprising the mobile station initiating a detach procedure with IMSI detach type, GPRS detach type or combine GPRS/IMSI detach type.