Synchronization of timing advance and deviation

Abstract

Apparatus and method for reducing the latency from timing deviation (TD) measurement to time advance (TA) adjustment. A deterministic procedure to coordinate time advance (TA) commands and timing deviation (TD) measurements is used so that failed transmissions or mobile terminals signal propagation changes can be recognized and corrected much more rapidly. Radio resource efficiency is maximized by minimizing signaling overhead through effectively reducing the frequency of time advance commands. This is accomplished by using TA command signals which include a Connect Frame Number (CFN) to specify particular radio frames for time advance (TA) adjustment. The potential for timing deviation (TD) measurements to be incorrectly processed in conjunction with adjusting a physical reception window and calculating mobile termination location is minimized, without excessive command signaling requirements.

1 . An apparatus for wireless communication comprising:
 a transmitter configured to transmit selectively formatted communication data to mobile terminals within system radio frames;   a receiver configured to receive communication data from mobile terminals within system radio frames;   a controller configured to measure timing deviation of received mobile terminal transmissions in identified radio frames in which communication data is received from a selected mobile terminal;   the transmitter configured to transmit timing advance command signals which include:
 timing advance data which is calculated based upon measured timing deviation in an identified radio frame for a selected mobile terminal, and 
 information specifying a particular radio frame for effectuating a timing adjustment by the selected mobile terminal; and 
   the controller configured to measure the timing deviation for communication data received from a selected mobile terminal to which a timing advance command signal had been transmitted in the particular radio frame specified by the transmitted timing advance command signal.   
   
   
       2 . The apparatus according to  claim 1  wherein the controller is configured to generate timing advance command signals that include a Connect Frame Number as the information specifying a particular radio frame. 
   
   
       3 . The apparatus according to  claim 2  wherein the controller is configured to only generate a timing advance command signal for a selected mobile terminal when a measured timing deviation of a transmission received from the selected mobile terminal is not within a selected timing synchronization range. 
   
   
       4 . The apparatus according to  claim 1  further comprising a geographic locator configured to calculate a geographic location of the selected mobile terminal during the specified time frame in conjunction with the timing advance data of a most recent successful timing advance command signal transmitted to the selected mobile terminal. 
   
   
       5 . The apparatus of  claim 4  including a base station coupled with a radio network controller wherein the base station includes the transmitter and receiver and the radio network controller includes the controller and the geographic locator. 
   
   
       6 . The apparatus of  claim 1  including a base station coupled with a radio network controller wherein the base station includes the transmitter and receiver and the radio network controller includes the controller. 
   
   
       7 . A method for synchronizing signals in wireless communications comprising:
 transmitting a timing advance command signal to a selected mobile terminal that includes:
 timing advance data calculated based upon measured timing deviation in an identified radio frame from the selected mobile terminal, and 
 information specifying a particular radio frame for effectuating a timing adjustment by the selected mobile terminal. 
   
   
   
       8 . The method according to  claim 7  wherein the timing advance command signals include a Connect Frame Number as the information specifying the particular radio frame. 
   
   
       9 . The method according to  claim 7  further comprising:
 receiving communication data from the selected mobile terminal in the particular radio frame specified by the transmitted timing advance command signal; and   measuring timing deviation for communication data received from the selected mobile terminal in the particular radio frame specified by the transmitted timing advance command signal to determine if further timing adjustment is required for the selected mobile terminal.   
   
   
       10 . The method according to  claim 9  further comprising:
 generating a timing advance command signal when a measured timing deviation of a transmission received from the selected mobile terminal is not within a selected timing synchronization range.   
   
   
       11 . The method according to  claims 10  further comprising:
 using measured timing deviation with respect to communication data received from the selected mobile terminal in a specified time frame to calculate a geographic location of the selected mobile terminal during the specified time frame in conjunction with the timing advance data of a most recent successful timing advance command signal transmitted to the selected mobile terminal.   
   
   
       12 . The method according to  claim 10  wherein the timing advance command signals include a Connect Frame Number as the information specifying the particular radio frame. 
   
   
       13 . The method according to  claim 12  wherein the transmitting and receiving is performed by a base station and the measuring and generating is performed by a radio network controller 
   
   
       14 . The method according to  claim 7  further comprising: 
     receiving communication data from the selected mobile terminal in the particular radio frame specified by the transmitted timing advance command signal. 
   
   
       15 . The method according to  claim 14  performed by a base station. 
   
   
       16 . The method according to  claim 7  performed by a base station. 
   
   
       17 . A base station comprising:
 a transmitter configured to transmit selectively formatted communication data to mobile terminals within system radio frames;   a receiver configured to receive communication data from mobile terminals within system radio frames; and   the transmitter configured to transmit timing advance command signals which include:
 timing advance data which is calculated based upon measured timing deviation in an identified radio frame for a selected mobile terminal, and 
 information specifying a particular radio frame for effectuating a timing adjustment by the selected mobile terminal. 
   
   
   
       18 . The base station according to  claim 15  wherein the transmitter is configured to transmit timing advance command signals which include a Connect Frame Number as the information specifying a particular radio frame.