RANDOM BACKOFF FOR EXTENDED ACCESS BARRING

• US 20130170479A1
• Filed: 06/29/2012
• Published: 07/04/2013
• Est. Priority Date: 11/11/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Fong, Mo-Han, Phuyal, Umesh
• Granted Patent: US 9,078,257 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04W 48/02 Access restriction performed under specific conditions
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/085 collision avoidance

Abstract

Technology for initiating a random access procedure by a wireless device after extended access barring (EAB) is disclosed. The wireless device can release a bar on the wireless device. The bar can prevent the wireless device from accessing a node using EAB. The wireless device can count a random backoff time using a random backoff timer. The random backoff time can include a random time between zero and a maximum backoff time period. The wireless device can transmit a random access channel (RACH) message (including physical random access channel (PRACH) preamble) from the wireless device to the node to initiate a random access procedure after the expiry of the random backoff timer.

Claims

1. A method for initiating a random access procedure by a wireless device after extended access barring (EAB), comprising:

releasing a bar on the wireless device, wherein the bar prevents the wireless device from accessing a node using EAB;

counting a random backoff time using a random backoff timer, wherein the random backoff time is a random time between zero and a maximum backoff time period; and

transmitting a random access channel (RACH) message from the wireless device to the node to initiate a random access procedure after the expiry of the random backoff timer.

2. The method of claim 1, further comprising:

receiving a radio resource control (RRC) connection establishment request from upper layers for an originating call at the wireless device in a RRC idle state prior to counting the random backoff time.

3. The method of claim 2, further comprising:

queuing the RRC connection establishment request at the access stratum of the wireless device before the expiry of the random backoff timer.

4. The method of claim 1, further comprising:

establishing a radio resource control (RRC) connection between the wireless device and the node after the expiry of the random backoff timer.

5. The method of claim 1, further comprising:

receiving the maximum backoff time period at the wireless device from the node; and

configuring the random backoff time at the wireless device with the maximum backoff time period.

6. The method of claim 5, wherein receiving the maximum backoff time period is received via broadcast, multicast, or unicast radio resource control (RRC) signaling.

7. The method of claim 1, further comprising:

calculating the random backoff time at the wireless device; and

informing upper layers of the wireless device that access is barred using EAB for the random backoff time.

8. The method of claim 1, further comprising prior to transmitting the RACH message:

verifying the wireless device is still not barred using updated EAB information;

when the wireless device is barred using EAB, waiting for a release of the bar;

releasing the bar on the wireless device; and

counting the random backoff time using a random backoff timer.

9. The method of claim 1, further comprising:

receiving EAB information barring the wireless device from accessing a node while counting a random backoff time;

stopping the random backoff timer;

waiting for a release of the bar;

releasing the bar on the wireless device; and

recounting the random backoff time using a random backoff timer.

10. The method of claim 1, further comprising:

receiving EAB information at the wireless device from the node; and

storing the EAB information at the wireless device.

11. The method of claim 1, further comprising:

receiving EAB information at the wireless device from the node; and

replacing existing EAB information at the wireless device with the received EAB information.

12. At least one non-transitory machine readable storage medium comprising a plurality of instructions adapted to be executed to implement the method according to claim 1.

23. At least one non-transitory machine readable storage medium comprising a plurality of instructions adapted to be executed to implement the method according to claim 1.

13. A method for using adaptive random backoff based on a backoff indicator (BI) at a wireless device, comprising:

receiving the backoff indicator (BI) at the wireless device from a node;

counting a random backoff time using a random backoff timer, wherein the random backoff time is a random time between zero and a maximum backoff time period; and

transmitting a physical random access channel (PRACH) preamble from the wireless device to the node after the expiry of the random backoff timer.

14. The method of claim 13, wherein receiving the BI includes receiving a dedicated machine type communication (MTC) random access response (RAR) media access control (MAC) layer protocol data unit (PDU), wherein the RAR is associated with a PRACH resource, PRACH resources are segregated into dedicated MTC RAR MAC PDUs and dedicated non-MTC RAR MAC PDUs, the dedicated MTC RAR MAC PDU is sent to MTC devices, and a dedicated non-MTC RAR MAC PDU is sent to non-MTC devices.

15. The method of claim 13, wherein the BI is included in a random access response (RAR) media access control (MAC) layer protocol data unit (PDU).

16. The method of claim 15, wherein the BI is included in a machine type communication (MTC) specific BI sub header.

17. The method of claim 13, further comprising:

transmitting a random access channel (RACH) message from the wireless device to the node to initiate a random access procedure prior to retransmitting the PRACH preamble.

18. The method of claim 13, further comprising:

counting the random backoff time using a random backoff timer; and

transmitting a random access channel (RACH) message from the wireless device to the node to initiate a random access procedure after the expiry of the random backoff timer prior to counting the random backoff time a second time and retransmitting the PRACH preamble.

19. The method of claim 13, further comprising:

receiving a radio resource control (RRC) connection establishment request from upper layers for an originating call at the wireless device in a RRC idle state prior to counting the random backoff time.

20. The method of claim 13, further comprising:

establishing a radio resource control (RRC) connection between the wireless device and the node after the expiry of the random backoff timer.

21. The method of claim 13, further comprising:

receiving EAB information at the wireless device from the node; and

storing the EAB information at the wireless device.

22. The method of claim 13, further comprising:

receiving EAB information at the wireless device from the node; and

replacing existing EAB information at the wireless device with the received EAB information.

24. A wireless device configured for extended access barring (EAB), comprising:

a transceiver module configured to receive EAB information from a node and transmit a random access channel (RACH) message to the node;

a processing module configured to bar transmissions and release a bar to transmission to the node using the EAB information, wherein the bar prevents the wireless device from accessing the node using EAB; and

a random backoff timer configured to count a random backoff time, wherein the random backoff time is a random time between zero and a maximum backoff time period and the random backoff timer is configured to delay a radio resource control (RRC) connection after the release of the bar for the random backoff time.

25. The wireless device of claim 24, wherein the processing module is further configured to initiate a random access procedure after the expiry of the random backoff timer.

26. The wireless device of claim 24, wherein the transceiver module is further configured to retransmit a physical random access channel (PRACH) preamble to the node after the expiry of the random backoff timer or the transceiver module is further configured to receive a RRC connection establishment request from upper layers for an originating call at the wireless device in a RRC idle state prior to counting the random backoff time.

27. The wireless device of claim 24, wherein the transceiver module is further configured to receive the maximum backoff time period or a backoff indicator (BI) from the node, wherein the maximum backoff time period is set using the BI, the BI is included in a dedicated machine type communication (MTC) random access response (RAR) media access control (MAC) layer protocol data unit (PDU) or a MTC specific BI subheader, the RAR is associated with a PRACH resource, PRACH resources are segregated into dedicated MTC RAR MAC PDUs and dedicated non-MTC RAR MAC PDUs, a dedicated MTC RAR MAC PDU is sent to MTC devices, and a dedicated non-MTC RAR MAC PDU is sent to non-MTC devices.

28. The wireless device of claim 24, wherein the transceiver module is further configured to receive the maximum backoff time period or a backoff indicator (BI) from the node, wherein the maximum backoff time period is set using the BI, and the BI is included in a random access response (RAR) media access control (MAC) layer protocol data unit (PDU) machine type communication (MTC) specific BI subheader by a specific combination of bits following a type field bit.

29. The wireless device of claim 24, wherein the wireless device is selected from the group consisting of a user equipment (UE) and a mobile station (MS), the wireless device is configured to connect to at least one of a wireless local area network (WLAN) in a long term evolution (LTE), a LTE-Advanced (LTE-A), or a universal mobile telecommunications system (UMTS), a wireless personal area network (WPAN), and a wireless wide area network (WWAN), and the wireless device includes an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor, an application processor, internal memory, a non-volatile memory port, or combinations thereof.

30. A node configured for extended access barring (EAB), comprising:

a transceiver module configured to transmit EAB information to a wireless device, receive a random access channel (RACH) message from the wireless device, and transmit a machine type communication (MTC) specific BI parameter to the wireless device, wherein the MTC-specific BI parameter is transmitted in a random access response (RAR) media access control (MAC) layer protocol data unit (PDU); and

a processing module configured to adaptively change the value of the MTC-specific BI parameter based on traffic conditions, wherein the MTC-specific BI parameter informs the wireless device of a delay between a release of an EAB bar and an attempt for a radio resource control (RRC) connection between the node and the wireless device.

31. The node of claim 30, wherein the node is selected from the group consisting of a base station (BS), a node B (NB), an evolved node B (eNB), a macro-eNB, a micro-eNB, a pico-eNB, a femto-eNB, and a home eNB (HeNB).