Power efficient channel scheduling in a wireless network

• US 7,142,855 B2
• Filed: 12/13/2004
• Issued: 11/28/2006
• Est. Priority Date: 04/17/2002
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bahl, Paramvir, Adya, Atul, Pahhye, Jitendra D.
• Primary Examiner(s): Cumming, William D.
• Application Number:
  US11/011,011
• Publication Number:
  US 20050101320A1
• Time in Patent Office: 715 Days
• Field of Search: 455/434, 455/41.2, 455/432, 455/432.2, 370/338
• US Class Current: 455/432.2
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 52/0241 where no transmission is received, e.g. out of range of the transmitter
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and system for optimizing channel access scheduling for multiple wireless computing devices over a wireless network improves channel access efficiency with respect to a primary channel. An access point, or host computer, includes a host transceiver for receiving control information from the wireless computing devices over a low power channel. Upon receiving the control information, the access point applies a scheduling algorithm to schedule channel access for the wireless computing devices to transmit data over the primary communication channel. The wireless computing devices include a low power radio for receiving scheduling information via the low power channel during idle periods. When the scheduling information is received, the wireless computing device activates its primary channel network interface components to communicate data through the primary channel. When the computing device is idle, the device is configured to power down all of its components with the exception of the circuitry required to power the low power channel. As such, the low power channel is maintained in an active state for receiving scheduling information, such as an access schedule, during both idle and non-idle periods.

Claims

1. An access point for interfacing a plurality of wireless devices to a network comprising:

an interface to a wireless channel for transmitting and receiving data over the first wireless channel, wherein the data omits scheduling information related to scheduling access to the first wireless channel; and

an interface to a second wireless channel for transmitting and receiving scheduling information, wherein the scheduling information comprises scheduling information related to scheduling access to the first wireless channel, wherein the interface to the first wireless channel consumes more power to transmit a bit on the first wireless channel than the interface to the second wireless channel consumes to transmit a bit on the second wireless channel, wherein the scheduling information is derived based at least in part on the number of packets waiting in a queue for transmission over the first wireless channel.

2. The access point according to claim 1, further comprising a network interface card comprising both the interface to the first wireless channel and the interface to the second wireless channel.

3. The access point according to claim 1, wherein the scheduling information comprises data packet priority information.

5. The access point according to claim 1, wherein the first wireless channel and the second wireless channel employ different carrier frequencies.

6. The access point according to claim 1, wherein the first wireless channel comprises an 802.11 based communication channel.

4. An access point for interfacing a plurality of wireless devices to a network comprising:

an interface to a wireless channel for transmitting and receiving data over the first wireless channel, wherein the data omits scheduling information related to scheduling access to the first wireless channel; and

an interface to a second wireless channel for transmitting and receiving scheduling information, wherein the scheduling information comprises scheduling information related to scheduling access to the first wireless channel, wherein the interface to the first wireless channel consumes more power to transmit a bit on the first wireless channel than the interface to the second wireless channel consumes to transmit a bit on the second wireless channel, wherein the scheduling information comprises data packet transmission deadline information.