Channel Access Control

• US 20120300712A1
• Filed: 10/19/2011
• Published: 11/29/2012
• Est. Priority Date: 05/24/2011
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Renesas Mobile Corporation (Renesas Electronics Corporation)
• Inventors: Koskela, Timo K., Turtinen, Samuli, Hakola, Sami-Jukka
• Granted Patent: US 8,780,835 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/008 with additional processing of random access related information at receiving side

Abstract

There are provided measures for channel access control. Such measures may exemplarily comprise obtaining a contention window assignment including at least an assignment of a size of a contention window for contention-based channel access, accessing at least one logical channel in a contention-based manner according to the contention window assignment, including allocating resources to the at least one logical channel for data transmission, and modifying the size of the contention window based on a result of the resource allocation in terms of an aggregated bit rate allocated for data transmission and an aggregate target bit rate requirement of prioritized bit rates of the at least one logical channel.

Claims

1. A method of controlling channel access, said method comprising:

obtaining a contention window assignment including at least an assignment of a size of a contention window for contention-based channel access;

accessing at least one logical channel in a contention-based manner according to the contention window assignment, including allocating resources to the at least one logical channel for data transmission; and

modifying the size of the contention window based on a result of the resource allocation in terms of an aggregated bit rate allocated for data transmission and an aggregate target bit rate requirement of prioritized bit rates of the at least one logical channel.

2. The method according to claim 1, the method further comprising evaluating a relationship between a value indicative of the aggregated bit rate allocated for data transmission after the resource allocation and a value indicative of the aggregate target bit rate requirement,

wherein the contention window size modification comprises increasing the size of the contention window, if the values are evaluated to have a predetermined relationship, and decreasing the size of the contention window, if the values are evaluated not to have a predetermined relationship.

3. The method according to claim 2, wherein the method further comprises:

detecting a conflict in that the size of the contention window is to be decreased, as the values are evaluated not to have a predetermined relationship, while increasing the size of the contention window would be necessary in terms of a congestion status of the resources, and/or a predetermined amount of allocated data is discarded;

reporting the detected conflict, at the time of detection or after a predetermined recovery timer period, to a device involved in the transmission or an access node of a cellular communication system; and

receiving, from the device or the access node, conflict resolving instructions, and applying the received conflict resolving instructions in contention-based channel access.

4. The method according to claim 2 or 3, wherein the method further comprises:

receiving, from a device involved in the transmission, a report of a conflict in contention-based channel access; and

adapting, as conflict resolving measures, the contention window assignment based on the reported conflict, and applying the conflict resolving measures in contention-based channel access.

5. The method according to any of claims 1 to 4, wherein at least one of the following applies:

the contention window assignment is based on a quality-of-service requirement of at least one of the at least one logical channel to be accessed and the data to be transmitted on the at least one logical channel;

the contention window assignment further includes a minimum size and a maximum size of the contention window, and the contention window size is modified so as to be within the range extending from the minimum size to the maximum size of the contention window;

the contention window assignment is received from an access node of a cellular communication system; and

the resources are allocated in a protocol data unit of medium access control.

6. The method according to any of claims 1 to 5, wherein the method is operable at or by a terminal, and at least one of the following applies:

the data transmission is part of a device-to-device communication between terminals or an uplink communication between a terminal and an access node of a wireless local area network;

the resources are resources of an unlicensed band; and

the terminal is configured for operation in accordance with at least one of long-term evolution specifications and wireless local area network specifications.

21. Computer software adapted to perform the method of any of claims 1 to 10.

22. A computer program product comprising a non-transitory computer-readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform a method of controlling channel access according to any of claims 1 to 10.

7. A method of controlling channel access, said method comprising providing, to at least one device involved in a data transmission, a contention window assignment including at least an assignment of a size of a contention window for contention-based channel access.

8. The method according to claim 7, wherein the contention window assignment is based on a quality-of-service requirement of at least one of at least one logical channel to be accessed by the at least one device and data to be transmitted on the at least one logical channel, and/or the method further comprises:

mapping a quality-of-service requirement of a first radio access technology to a quality-of-service requirement of a second radio access technology, wherein at least one logical channel to be accessed by the at least one device and resources usable for allocating data to be transmitted on the at least one logical channel are related to the second radio access technology; and

establishing the contention window assignment based on the mapped quality-of-service requirement of the second radio access technology.

9. The method according to claim 7 or 8, wherein the method further comprises:

receiving, from a device involved in the transmission, a report of a conflict in contention-based channel access;

adapting, as conflict resolving measures, the contention window assignment based on the reported conflict; and

sending, to said device, the adapted contention window assignment as conflict resolving measures instructions.

10. The method according to any of claims 7 to 9, wherein the method is operable at or by an access node of a cellular communication system, and at least one of the following applies:

the data transmission is part of a device-to-device communication between terminals or an uplink communication between a terminal and an access node of a wireless local area network on an unlicensed band;

the contention window assignment further includes a minimum size and a maximum size of the contention window; and

the access node is configured for operation in accordance with long-term evolution specifications.

11. An apparatus for use in controlling channel access, said apparatus comprising:

an interface configured for communication with at least another apparatus; and

a processing system configured to;

obtain, via the interface, a contention window assignment including at least an assignment of a size of a contention window for contention-based channel access;

perform accessing of at least one logical channel in a contention-based manner according to the contention window assignment, including allocating resources to the at least one logical channel for data transmission, and

modify the size of the contention window based on a result of the resource allocation in terms of an aggregated bit rate allocated for data transmission and an aggregate target bit rate requirement of prioritized bit rates of the at least one logical channel.

12. The apparatus according to claim 11, wherein the processing system is further configured to:

evaluate a relationship between a value indicative of the aggregated bit rate allocated for data transmission after the resource allocation and a value indicative of the aggregate target bit rate requirement; and

for contention window size modification, increase the size of the contention window, if the values are evaluated to have a predetermined relationship, and decrease the size of the contention window, if the values are evaluated not to have a predetermined relationship.

13. The apparatus according to claim 12, wherein the processing system is further configured to:

detect a conflict in that the size of the contention window is to be decreased, as the values are evaluated not to have a predetermined relationship, while increasing the size of the contention window would be necessary in terms of a congestion status of the resources, and/or a predetermined amount of allocated data is discarded;

report, via the interface, the detected conflict, at the time of detection or after a predetermined recovery timer period, to a device involved in the transmission or an access node of a cellular communication system; and

receive, from the device or the access node via the interface, conflict resolving instructions, and apply the received conflict resolving instructions in contention-based channel access.

14. The apparatus according to claim 12 or 13, wherein the processing system is further configured to:

receive, from a device involved in the transmission via the interface, a report of a conflict in contention-based channel access; and

adapt, as conflict resolving measures, the contention window assignment based on the reported conflict, and apply the conflict resolving measures in contention-based channel access.

15. The apparatus according to any of claims 11 to 14, wherein at least one of the following applies:

the contention window assignment is based on a quality-of-service requirement of at least one of the at least one logical channel to be accessed and the data to be transmitted on the at least one logical channel;

the contention window assignment further includes a minimum size and a maximum size of the contention window, and the processing system is further configured to modify the contention window size so as to be within the range extending from the minimum size to the maximum size of the contention window;

the processing system is further configured to receive, via the interface, the contention window assignment from an access node of a cellular communication system; and

the processing system is further configured to allocate the resources in a protocol data unit of medium access control.

16. The apparatus according to any of claims 11 to 15, wherein the apparatus is operable as or at a terminal, and at least one of the following applies:

the data transmission is part of a device-to-device communication between terminals or an uplink communication between a terminal and an access node of a wireless local area network;

the resources are resources of an unlicensed band; and

the apparatus is configured for operation in accordance with at least one of long-term evolution specifications and wireless local area network specifications.

17. An apparatus for use in controlling channel access, said apparatus comprising:

an interface configured for communication with at least another apparatus; and

a processing system configured to provide, to at least one device involved in a data transmission via the interface, a contention window assignment including at least an assignment of a size of a contention window for contention-based channel access.

18. The apparatus according to claim 17, wherein the contention window assignment is based on a quality-of-service requirement of at least one of at least one logical channel to be accessed by the at least one device and data to be transmitted on the at least one logical channel, and/or the processing system is further configured to:

map a quality-of-service requirement of a first radio access technology to a quality-of-service requirement of a second radio access technology, wherein at least one logical channel to be accessed by the at least one device and resources usable for allocating data to be transmitted on the at least one logical channel are related to the second radio access technology; and

establish the contention window assignment based on the mapped quality-of-service requirement of the second radio access technology.

19. The apparatus according to claim 17 or 18, wherein the processing system is further configured to:

receive, from a device involved in the transmission via the interface, a report of a conflict in contention-based channel access;

adapt, as conflict resolving measures, the contention window assignment based on the reported conflict; and

send, to said device via the interface, the adapted contention window assignment as conflict resolving measures instructions.

20. The apparatus according to any of claims 17 to 19, wherein the apparatus is operable as or at an access node of a cellular communication system, and at least one of the following applies:

the data transmission is part of a device-to-device communication between terminals or an uplink communication between a terminal and an access node of a wireless local area network on an unlicensed band;

the contention window assignment further includes a minimum size and a maximum size of the contention window; and

the apparatus is configured for operation in accordance with long-term evolution specifications.

23. Apparatus substantially as herein described with reference to the accompanying drawings.