Collision avoidance for traffic in a wireless network

Abstract

Techniques for avoiding collision of traffic in a wireless network are described. A station detects for synchronization of its traffic with traffic of other stations. The station may detect for synchronization based on, e.g., percentage of first transmission failures, counters indicative of statistics of transmitted frames, and/or other information. The station may confirm synchronization of its traffic, e.g., by monitoring for traffic from another station during a service period for the station. The station adjusts transmission of its traffic when synchronization is detected to avoid collision with the traffic of the other stations. The station may delay transmission of its traffic by a predetermined amount of time, by a pseudo-random amount, or until after the other stations finish their transmissions.

1 . An apparatus comprising: 
 at least one processor configured to detect for synchronization of traffic of a station with traffic of at least one other station in a wireless network, and to adjust transmission of the traffic of the station when synchronization is detected to avoid collision with the traffic of the at least one other station; and    a memory coupled to the at least one processor.    
   
   
       2 . The apparatus of  claim 1 , wherein the at least one processor is configured to generate frames for the traffic of the station and to send a first transmission and, if necessary, at least one retransmission for each of the frames.  
   
   
       3 . The apparatus of  claim 2 , wherein the at least one processor is configured to detect for synchronization of the traffic of the station based on percentage of first transmission failures for the frames.  
   
   
       4 . The apparatus of  claim 2 , wherein the at least one processor is configured to detect for synchronization of the traffic of the station based on a first counter for the number of frames successfully sent with at least one retransmission and a second counter for the number of frames successfully sent.  
   
   
       5 . The apparatus of  claim 4 , wherein the at least one processor is configured to detect for synchronization of the traffic of the station based further on a third counter for the number of frames successfully sent with multiple retransmissions and a fourth counter for the number of frames unsuccessfully sent.  
   
   
       6 . The apparatus of  claim 1 , wherein the at least one processor is configured to detect for synchronization of the traffic of the station based on counters for a management information base (MIB) in a medium access control (MAC) layer in IEEE 802.11.  
   
   
       7 . The apparatus of  claim 1 , wherein the at least one processor is configured to detect for synchronization of the traffic of the station based on network load information received from an access point in the wireless network.  
   
   
       8 . The apparatus of  claim 1 , wherein the at least one processor is configured to detect for synchronization of the traffic of the station based on reception of frames intended for the at least one other station during time periods when frames intended for the station are expected.  
   
   
       9 . The apparatus of  claim 1 , wherein the at least one processor is configured to confirm synchronization of the traffic of the station prior to adjusting transmission of the traffic.  
   
   
       10 . The apparatus of  claim 9 , wherein the at least one processor is configured to monitor a wireless channel for activity during a service period for the station and to confirm synchronization of the traffic of the station if activity is detected during the service period.  
   
   
       11 . The apparatus of  claim 1 , wherein the at least one processor is configured to adjust transmission of the traffic of the station by a predetermined amount of time when synchronization is detected.  
   
   
       12 . The apparatus of  claim 1 , wherein the at least one processor is configured to adjust transmission of the traffic of the station by a pseudo-random amount of time when synchronization is detected.  
   
   
       13 . The apparatus of  claim 1 , wherein the at least one processor is configured to delay transmission of the traffic of the station until after transmission of the traffic of the at least one other station finishes.  
   
   
       14 . The apparatus of  claim 1 , wherein the at least one processor is configured to detect for idle periods in a wireless channel and to move transmission of the traffic of the station to the idle periods.  
   
   
       15 . The apparatus of  claim 1 , wherein the at least one processor is configured to determine whether to adjust transmission of the traffic of the station or to defer to the at least one other station to adjust transmission to avoid collision.  
   
   
       16 . The apparatus of  claim 1 , wherein the at least one processor is configured to determine whether or not to adjust transmission of the traffic of the station based on medium access control (MAC) addresses of the station and the at least one other station.  
   
   
       17 . The apparatus of  claim 1 , wherein the traffic of the station is for a periodic flow, and wherein the at least one processor is configured to send frames of the periodic flow in service periods spaced apart by a traffic interval.  
   
   
       18 . The apparatus of  claim 1 , wherein the traffic of the station is for voice-over-IP (VoIP).  
   
   
       19 . The apparatus of  claim 17 , wherein for each service period the at least one processor is configured to wake up prior to the service period, to send at least one frame in the service period, and to sleep after the service period.  
   
   
       20 . A method comprising: 
 detecting for synchronization of traffic of a station with traffic of at least one other station in a wireless network; and    adjusting transmission of the traffic of the station when synchronization is detected to avoid collision with the traffic of the at least one other station.    
   
   
       21 . The method of  claim 20 , wherein the detecting for synchronization of the traffic of the station comprises detecting for synchronization of the traffic of the station based on percentage of first transmission failures for the traffic.  
   
   
       22 . The method of  claim 20 , wherein the detecting for synchronization of the traffic of the station comprises detecting for synchronization of the traffic of the station based on counters for a management information base (MIB) in a medium access control (MAC) layer in IEEE 802.11.  
   
   
       23 . The method of  claim 20 , further comprising: 
 confirming synchronization of the traffic of the station prior to adjusting transmission of the traffic.    
   
   
       24 . The method of  claim 20 , wherein the adjusting transmission of the traffic of the station comprises adjusting transmission of the traffic of the station by a predetermined or pseudo-random amount of time when synchronization is detected.  
   
   
       25 . The method of  claim 20 , further comprising: 
 waking up prior to a service period;    sending at least one frame in the service period; and    sleeping after the service period.    
   
   
       26 . An apparatus comprising: 
 means for detecting for synchronization of traffic of a station with traffic of at least one other station in a wireless network; and    means for adjusting transmission of the traffic of the station when synchronization is detected to avoid collision with the traffic of the at least one other station.    
   
   
       27 . The apparatus of  claim 26 , wherein the means for detecting for synchronization of the traffic of the station comprises means for detecting for synchronization of the traffic of the station based on percentage of first transmission failures for the traffic.  
   
   
       28 . The apparatus of  claim 26 , wherein the means for detecting for synchronization of the traffic of the station comprises means for detecting for synchronization of the traffic of the station based on counters for a management information base (MIB) in a medium access control (MAC) layer in IEEE 802.11.  
   
   
       29 . The apparatus of  claim 26 , further comprising: 
 means for confirming synchronization of the traffic of the station prior to adjusting transmission of the traffic.    
   
   
       30 . The apparatus of  claim 26 , wherein the means for adjusting transmission of the traffic of the station comprises means for adjusting transmission of the traffic of the station by a predetermined or pseudo-random amount of time when synchronization is detected.  
   
   
       31 . The apparatus of  claim 26 , further comprising: 
 means for waking up prior to a service period;    means for sending at least one frame in the service period; and    means for sleeping after the service period.    
   
   
       32 . A processor readable media for storing instructions operable in a station to: 
 detect for synchronization of traffic of the station with traffic of at least one other station in a wireless network; and    adjust transmission of the traffic of the station when synchronization is detected to avoid collision with the traffic of the at least one other station.    
   
   
       33 . An apparatus comprising: 
 at least one processor configured to detect for synchronization of a voice-over-IP (VoIP) flow of a station with at least one periodic flow of at least one other station in a wireless network, and to adjust transmission of the VoIP flow when synchronization is detected to avoid collision with the at least one periodic flow of the at least one other station; and    a memory coupled to the at least one processor.    
   
   
       34 . The apparatus of  claim 33 , wherein the at least one processor is configured to transmit frames for the VoIP flow in service periods spaced apart by a traffic interval, to maintain counters for statistics of the transmitted frames, and to detect for synchronization of the VoIP flow based on the counters.  
   
   
       35 . The apparatus of  claim 33 , wherein the at least one processor is configured to shift service times for the VoIP flow to avoid collision with the at least one periodic flow of the at least one other station.