Method of communication device initiated frame exchange

• US 20040081133A1
• Filed: 10/02/2003
• Published: 04/29/2004
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Chen, Ye, Emeott, Stephen P., Smavatkul, Nattavut
• Granted Patent: US 7,590,079 B2
• Time in Patent Office: Days
• US Class Current: 370/346
• CPC Class Codes: H04L 1/1664 the supervisory signal being transmitted together with payload signals; piggybacking
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method for accessing a wireless local area network (WLAN) channel and providing quality of service (QoS) for voice in a system supporting both voice and data services. Under the method, a communication device (302, 303) contends for a medium (channel). Upon identifying a transmit opportunity, the device transmits a voice packet to an access point (AP) (304) and polls the AP for downlink traffic. A low power implementation is feasible because the communication device can sleep, wake up to contend for the medium, transmit a voice packet to the AP, request a voice packet from the AP, transmit an acknowledgement, and go back to sleep.

Claims

1. A method of communication device initiated frame exchange every service interval comprising:

transmitting a polling message to an access point at least once per service interval, the polling message requesting a downlink traffic frame; and

determining whether a valid downlink frame is received from the access point.

2. The method of claim 1 wherein when a valid downlink frame is received, the method comprises transmitting an acknowledgement to the access point.

3. The method of claim 2 comprising:

before transmitting the polling message, activating a transceiver of the communication device; and

after transmitting an acknowledgement, deactivating the transceiver.

4. The method of claim 1 wherein when a valid downlink frame is not received, the method comprises:

determining whether it is time to transmit another polling message; and

deactivating the transceiver when it is not time to transmit another polling message.

5. The method of claim 1 wherein the step of transmitting a polling message to the access point comprises transmitting a polling message along with uplink traffic.

6. The method of claim 5 wherein when a valid downlink frame is not received, the method comprises retransmitting the uplink traffic and a polling message.

7. The method of claim 5 wherein when a valid downlink frame is received, the method comprises:

determining whether the frame contains traffic;

when the frame contains traffic,

transmitting an acknowledgement of receipt of the traffic to the AP; and

deactivating a transceiver of the communication device; and

when the frame does not contain traffic, deactivating a transceiver of the communication device.

8. A method of communication device initiated frame exchange comprising:

activating a transceiver of the communication device;

initiating transmission of an uplink traffic frame to an access point;

determining whether a valid response frame is received; and

when a valid response frame is received, deactivating the transceiver.

9. The method of claim 8 wherein when a valid response frame is not received, the method comprises retransmitting the uplink traffic frame to the access point.

10. A method of communication device initiated frame exchange comprising:

receiving a polling message from a communication device, the polling message requesting transmission of a downlink traffic frame; and

responding to the polling message by transmitting a downlink traffic frame to the communication device.

11. The method of claim 10 wherein the step of receiving a polling message from a communication device comprises receiving a polling message and uplink traffic from the communication device.

12. The method of claim 11 further comprising transmitting an acknowledgment of receipt of the uplink traffic to the communication device.

13. The method of claim 10 further comprising:

waiting for an acknowledgement of receipt of the downlink traffic frame from the communication device;

when the acknowledgement is not received, buffering the downlink traffic frame for retransmission to the communication device.