Method and apparatus for performing backoff in wireless communication system

• US 9,532,385 B2
• Filed: 10/23/2013
• Issued: 12/27/2016
• Est. Priority Date: 10/23/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Youngdae, Park, Sungjun, Yi, Seungjune, Jung, Sunghoon
• Primary Examiner(s): Alia, Curtis A
• Application Number:
  US14/437,328
• Publication Number:
  US 20150282214A1
• Time in Patent Office: 1,161 Days
• US Class Current: 1/1
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 74/085 collision avoidance

Abstract

A method and apparatus for performing backoff in a wireless communication system is provided. A user equipment (UE) identifies a prioritized access, receives a backoff parameter from a network, and determines whether or not to apply the received backoff parameter according to the prioritized access. The prioritized access corresponds to one of emergency access, high priority access, control element/information in media access control (MAC), radio link control (RLC) or packet data convergence protocol (PDCP), data radio bearer (DRB) for voice/video service, signaling radio bearer (SRB) 0, SRB 1, SRB 2, multimedia telephony service (MMTEL)-voice, MMTEL-video, and voice over long-term evolution (VoLTE).

Claims

1. A method for performing, by a user equipment (UE), backoff in a wireless communication system, the method comprising:

identifying a prioritized access;

receiving a backoff parameter, a special backoff parameter, and a probability factor from a network,

wherein the backoff parameter and the special backoff parameter are received together via one random access response message; and

determining whether or not to apply the received backoff parameter according to the special backoff parameter, the prioritized access and the received probability factor,

wherein a Medium Access Control (MAC) protocol data unit (PDU) for the random access response message includes a special backoff indicator field for indicating an existence of the special backoff parameter in a MAC subheader.

2. The method of claim 1, wherein the prioritized access corresponds to one of emergency access, high priority access, control element/information in media access control (MAC), radio link control (RLC) or packet data convergence protocol (PDCP), data radio bearer (DRB) for voice/video service, signaling radio bearer (SRB) 0, SRB 1, SRB 2, multimedia telephony service (MMTEL)-voice, MMTEL-video, and voice over long-term evolution (VoLTE).

3. The method of claim 1, wherein it is determined to not apply the received backoff parameter if the prioritized access is identified.

4. The method of claim 3, further comprising:

ignoring the received backoff parameter before transmitting a random access preamble to the network.

5. The method of claim 1, wherein it is determined to apply the received backoff parameter if the prioritized access is not identified.

6. The method of claim 5, further comprising:

performing backoff based on the received backoff parameter before transmitting a random access preamble to the network.

7. The method of claim 1, wherein it is determined to not apply the received backoff parameter for the prioritized access if the received backoff parameter has a larger value than a specific value.

8. The method of claim 1, wherein it is determined to apply the received backoff parameter for the prioritized access if the received backoff parameter has a value equal to a specific value or a lower value than the specific value.

9. The method of claim 1, further comprising:

receiving an indication of one or more access classes from the network; and

wherein whether or not to apply the received backoff parameter is determined further according to the indication of one or more access classes.

10. The method of claim 1, further comprising:

receiving a backoff configuration from the network via one of system information, a paging, and a radio resource control (RRC) connection reconfiguration message.

11. The method of claim 10, wherein the backoff configuration indicates the prioritized access.

12. A user equipment (UE) in a wireless communication system, the UE comprising:

a radio frequency (RF) unit that transmits and receives a radio signal; and

a processor, coupled to the RF unit, that;

identifies a prioritized access;

controls the RF unit to receive a backoff parameter, a special backoff parameter, and a probability factor from a network,

wherein the backoff parameter and the special backoff parameter are received together via one random access response message; and

determines whether or not to apply the received backoff parameter according to the special backoff parameter, the prioritized access and the received probability factor,

wherein a Medium Access Control (MAC) protocol data unit (PDU) for the random access response message includes a special backoff indicator field for indicating an existence of the special backoff parameter in a MAC subheader.

13. The UE of claim 12, wherein the prioritized access corresponds to one of emergency access, high priority access, control element/information in media access control (MAC), radio link control (RLC) or packet data convergence protocol (PDCP), data radio bearer (DRB) for voice/video service, signaling radio bearer (SRB) 0, SRB 1, SRB 2, multimedia telephony service (MMTEL)-voice, MMTEL-video, and voice over long-term evolution (VoLTE).