System and Method for Controlling Data Transmission in a Multihop Wireless Network

Abstract

Systems and methods are provided for media access control and rate control to improve data throughput in multihop wireless networks. For controlling media access, an unlocking mechanism is provided that sets the unlocking times at which the scheduling patterns of a MAC protocol is unlocked by requiring all, or a subset of links, to stop transmitting. The unlocking times are set and updated according to quality of service requirements which may change over time. Parameters of the MAC protocol and packet arrivals rates to the links in the network are updated using the parameters of the unlocking mechanism, the queue-sizes, and the utility functions of the links in the network.

1 . A method for controlling transmission of data on a wireless device in a wireless network, the method comprising:
 the wireless device monitoring if a communication channel of the wireless device is in a locked state, the locked state identified by having fewer than a predetermined number of opportunities to initiate a data packet transmission within a predetermined time period; and,   upon the wireless device detecting the locked state, the wireless device unlocking the communication channel by stopping transmission of data along the communication channel.   
     
     
         2 . The method in  claim 1  further comprising the wireless device transmitting to one or more other wireless devices in the wireless network an unlocking signal to stop transmission of data along the communication channel. 
     
     
         3 . The method in  claim 1  wherein the wireless device is a wireless card comprising a wireless radio, and stopping transmission of data along the communication channel comprises stopping transmission of data from the wireless radio. 
     
     
         4 . The method in  claim 1  further comprising the wireless device detecting the locked state by monitoring receipt of an unlocking signal, the unlocking signal indicating that the communication channel is in the locked state and to prompt the wireless device to stop transmission of data along the communication channel. 
     
     
         5 . The method of  claim 4  wherein the unlocking signal is generated by an ancillary wireless device or a third party controller in the wireless network, the unlocking signal transmitted to the wireless device. 
     
     
         6 . The method in  claim 1  further comprising, upon detecting the locked state, the wireless device checking one or more conditions before unlocking the communication channel. 
     
     
         7 . The method in  claim 6  wherein the one or more conditions comprise determining if there are one or more data packets queued on the wireless device to be transmitted over the communication channel and, if so, the wireless device unlocking the channel. 
     
     
         8 . The method in  claim 6  wherein the one or more conditions comprise determining if one or more high priority data packets are queued on the wireless device to be transmitted over the communication channel and, if so, the wireless device unlocking the channel. 
     
     
         9 . The method in  claim 1  further comprising, upon the wireless device stopping transmission of data along the communication channel, the wireless device waiting for a random period of time before attempting to start data transmission. 
     
     
         10 . The method in  claim 9 , wherein there are multiple wireless devices in the wireless network, and wherein the random period of time is in approximate length to a time period beginning from when one of the wireless devices first detects the communication channel is in the locked state and transmits to one or more other wireless devices an unlocking signal to indicate that the channel is in a locked stated and to stop transmission of data along the communication channel, and the time period ending when all the wireless devices in the wireless network detect that the channel is locked. 
     
     
         11 . A computer readable medium for controlling transmission of data in a wireless device in a wireless network, the computer readable medium comprising computer executable instructions for:
 the wireless device monitoring if a communication channel of the wireless device is in a locked state, the locked state identified by having fewer than a predetermined number of opportunities to initiate a data packet transmission within a predetermined time period; and,   upon the wireless device detecting the locked state, the wireless device unlocking the communication channel by stopping transmission of data along the communication channel.   
     
     
         12 . The computer readable medium in  claim 11  further comprising computer executable instructions for the wireless device transmitting to one or more other wireless devices in the wireless network an unlocking signal to stop transmission of data along the communication channel. 
     
     
         13 . The computer readable medium in  claim 11  wherein the wireless device is a wireless card comprising a wireless radio, and stopping transmission of data along the communication channel comprises stopping transmission of data from the wireless radio. 
     
     
         14 . The computer readable medium in  claim 11  further comprising computer executable instructions for the wireless device detecting the locked state by monitoring receipt of an unlocking signal, the unlocking signal indicating that the communication channel is in the locked state and to prompt the wireless device to stop transmission of data along the communication channel. 
     
     
         15 . The computer readable medium in  claim 14  wherein the unlocking signal is generated by an ancillary wireless device or a third party controller in the wireless network, the unlocking signal transmitted to the wireless device. 
     
     
         16 . The computer readable medium in  claim 11  further comprising computer executable instructions for, upon detecting the locked state, the wireless device checking one or more conditions before unlocking the communication channel. 
     
     
         17 . The computer readable medium in  claim 16  wherein the one or more conditions comprise determining if there are one or more data packets queued on the wireless device to be transmitted over the communication channel and, if so, the wireless device unlocking the channel. 
     
     
         18 . The computer readable medium in  claim 16  wherein the one or more conditions comprise determining if one or more high priority data packets are queued on the wireless device to be transmitted over the communication channel and, if so, the wireless device unlocking the channel. 
     
     
         19 . The computer readable medium in  claim 11  further comprising computer executable instructions for, upon the wireless device stopping transmission of data along the communication channel, the wireless device waiting for a random period of time before attempting to start data transmission. 
     
     
         20 . The computer readable medium in  claim 19 , wherein there are multiple wireless devices in the wireless network, and wherein the random period of time is in approximate length to a time period beginning from when one of the wireless devices first detects the communication channel is in the locked state and transmits to one or more other wireless devices an unlocking signal to indicate that the channel is in a locked stated and to stop transmission of data along the communication channel, and the time period ending when all the wireless devices in the wireless network detect that the channel is locked.