Power efficient channel scheduling in a wireless network

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.

1 . A method for scheduling data transmission in a wireless network, wherein the wireless network comprises at least one wireless computing device, the wireless computing device supporting a primary communication channel and a secondary communication channel, the secondary communication channel requiring less power to utilize than the primary communication channel, the method comprising: 
 establishing a connection between a host transceiver operating at a host computer and a low power transceiver operating at the wireless computing device, the connection being established over the secondary channel;    receiving a first data packet at the host computer from the low power transceiver over the secondary channel, the first data packet comprising transmission control information related to the primary channel;    in response to receipt of the control information, applying a scheduling algorithm at the host computer to determine a channel access schedule for the wireless computing device; and    sending the channel access schedule to the low power transceiver over the secondary channel, wherein the channel access schedule notifies the wireless computing device as to when the wireless computing device has access to the primary communication channel in order to transmit data.    
   
   
       2 . The method according to  claim 1  wherein the host computer is a wireless access point to. a second network.  
   
   
       3 . The method according to  claim 2  wherein the second network comprises at least one wired link between two nodes of the network.  
   
   
       4 . The method according to  claim 1  wherein the control information comprises an indication of the number of packets waiting in a queue for transmission over the primary channel.  
   
   
       5 . The method according to  claim 1  wherein the control information comprises data packet priority information assigning a transmission priority to at least one packet.  
   
   
       6 . The method according to  claim 1  wherein the control information comprises data packet transmission deadline information.  
   
   
       7 . The method according to  claim 1  wherein the secondary channel is a low frequency channel.  
   
   
       8 . The method according to  claim 1  wherein the primary channel comprises an 802.11 based channel.  
   
   
       9 . The method according to  claim 1  wherein the primary channel supports a radio range and data rate higher than those of the secondary channel.  
   
   
       10 . The method according to  claim 1 , wherein in response to receipt of the scheduling information the network interface card transmits data over the primary channel.  
   
   
       11 . The method according to  claim 1 , wherein the primary channel employs a higher frequency carrier than the secondary channel.  
   
   
       12 . A wireless network system for bandwidth scheduling in a wireless network, the system comprising: 
 an access point, wherein the access point is an interface to a network;    a host computer interfaced with the network through the access point, wherein the host computer is logically connected to a host transceiver communicably linkable to a plurality of wireless computing devices over a low power radio channel, the host computer being used to schedule the access of the plurality of wireless devices to a high power radio channel; and    a wireless computing device comprising a high power radio that communicates over the high power radio channel, and a low power radio that communicates control information to the access point via the low power radio channel to communicate the scheduling of the access of the plurality of wireless network devices to the high power radio channel.    
   
   
       13 . The wireless network system according to  claim 12  wherein a first one of the plurality of wireless computing devices is out of direct radio range of the host computer with respect to the low power radio channel and wherein a second one of the plurality of wireless computing devices is within direct radio range of the host computer with respect to the low power radio channel, and whereby the second one of the plurality of wireless computing devices facilitates communication of control and scheduling information between the out of range wireless computing device and the host computer.  
   
   
       14 . An access point for interfacing a plurality of wireless devices to a network comprising; 
 an interface to a first 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.    
   
   
       15 . The access point according to  claim 14 , wherein the interface to the first wireless channel consumes more power, to transmit a bit over the first channel than the interface to the second channel consumes to transmit a bit over the second channel.  
   
   
       16 . The access point according to  claim 14 , further comprising a network interface card comprising both the interface to the first wireless channel and the interface to the second wireless channel.