METHOD AND APPARATUS FOR PROVIDING QUALITY OF SERVICE OVER A CONTENTION ACCESS PERIOD OF A WIRELESS PERSONAL AREA NETWORK

• US 20080137684A1
• Filed: 12/07/2006
• Published: 06/12/2008
• Est. Priority Date: 12/07/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Perkins, Matthew R., Huang, Yan, Hester, Lance E.
• Granted Patent: US 7,724,765 B2
• Time in Patent Office: Days
• US Class Current: 370/447
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/10 Small scale networks; Flat hierarchical networks

Abstract

A method and apparatus for providing quality of service over a contention access period of a wireless personal area network is provided herein. Particularly, the layers above the MAC are allowed to reserve portions of a contention access period (CAP) in order to schedule their QoS actions cooperatively thereby avoiding the dependence on the MAC for QoS performance. By using cooperative scheduling, a node can send a QoS packet from the QoS_Layer to the MAC, and know that it will be transmitted according to the specified QoS requirement. As a result, whenever a node sends a QoS packet in the reserved portion of the CAP, the channel will be guaranteed to be free from competing nodes'"'"' packets because those competing nodes will delay their transmissions based on the shared schedule.

Claims

1. A method for assuring a quality of service (QoS) in a system employing a contention access period, the method comprising the steps of:

employing a contention-based medium access technique to communicate within the whole contention access period;

determining that another node has a QoS requirement; and

reserving a portion of the contention access period for the other node'"'"'s transmissions.

2. The method of claim 1 wherein the contention-based access technique comprises a carrier sense multiple access (CSMA) technique.

3. The method of claim 1 further comprising the step of:

employing the CSMA technique to communicate in the contention access period outside the reserved portion of the contention access period while holding off on transmitting within the reserved portion of the contention access period.

4. The method of claim 1 wherein the step of reserving the portion of the contention access period comprises the steps of:

delaying a transmission until after the reserved portion of the contention access period has completed.

5. The method of claim 1 wherein the step of employing the CSMA technique to communicate comprises the step of transmitting when a channel is idle otherwise backing off a random period of time before attempting to transmit again.

6. The method of claim 1 wherein the step of determining that another node has the QoS requirement comprises the step of receiving a message indicating that the other node has the QoS requirement.

7. The method of claim 1 wherein the contention access period comprises a period of time where nodes utilize the CSMA technique to communicate.

8. A method for a node to assure quality of service (QoS) in a system employing a contention access period, the method comprising the steps of:

notifying a network of the QoS requirement;

reserving a portion of the contention access period for transmissions only by the node; and

transmitting within the reserved portion of the contention access period.

9. The method of claim 8 wherein the step of transmitting within the reserved portion of the contention access period comprises the step of transmitting utilizing a carrier sense multiple access (CSMA) technique.

10. The method of claim 9 wherein CSMA technique comprises transmitting when a channel is idle otherwise backing off a random period of time before attempting to transmit again.

11. The method of claim 8 wherein the step of notifying comprises the step of additionally notifying the network how much of the contention access period to reserve.

12. The method of claim 8 further comprising the step of:

transmitting outside the contention access period using the CSMA technique.

13. The method of claim 8 wherein the step of notifying the network of the QoS requirement comprises the step of notifying the network via a layer higher than a MAC sub-layer.

14. The method of claim 8 wherein the step of reserving a portion of the contention access period comprises the step of negotiating with other nodes what portion of the contention access period is going to be reserved via a higher layer than a MAC sub-layer.

15. The method of claim 8 wherein the step of notifying the network comprises the step of transmitting a message notifying the network.

16. A node comprising:

a transmitter notifying a network of a quality of service (QoS) requirement;

logic circuitry reserving a portion of a contention access period for transmissions only by the node; and

a transmitter transmitting within the reserved portion of the contention access period.

17. The node of claim 16 wherein the transmitter transmits within the reserved portion of the contention access period utilizing a carrier sense multiple access (CSMA) technique.

18. The node of claim 17 wherein the CSMA technique comprises transmitting when a channel is idle otherwise backing off a random period of time before attempting to transmit again.

19. The node of claim 16 wherein the transmitter additionally transmits outside the contention access period using the CSMA technique.

20. The node of claim 16 wherein the transmitter notifies the network of the QoS requirement via a layer higher than a MAC sub-layer.