Downlink transmission synchronization and data buffer sizing in a radio access network

Abstract

Method and apparatus are disclosed for calculating a target connection frame number (CFN) for a data frame in wireless communications. An update to an offset between the CFN and a radio access network frame number is computed. A target CFN variable is incremented in response to a received timer signal. The value of an update variable is checked to determine whether a new value of the offset has been received since a previous update to the offset. A new target CFN is calculated using a current target CFN and the new value of the offset on a condition that the new value of the offset has been received. The current target CFN is set equal to the new target CFN.

1 . A method for calculating a target connection frame number (CFN) for a data frame in wireless communications, comprising:
 computing an update to an offset between the CFN and a radio access network frame number (RFN);   incrementing a target CFN variable in response to a received timer signal;   determining whether a new value of the offset has been received since a previous update to the offset by checking the value of an update variable;   calculating a new target CFN using a current target CFN and the new value of the offset on a condition that the new value of the offset has been received;   setting the current target CFN equal to the new target CFN; and   changing the update variable to indicate that a new value of the offset has not been received on a condition that the new value of the offset has not been received.   
     
     
         2 . The method of  claim 1 , further comprising
 computing the offset update for each of several multiplexed users; and   using each user's offset update to delay or advance that user's frame transmission relative to the frame transmission of the other users.   
     
     
         3 . The method of  claim 2 , wherein each offset update is computed based on at least one of: quality of service characteristics, or time-of-arrival (TOA) statistics. 
     
     
         4 . A radio network controller (RNC) configured to calculate a target connection frame number (CFN) for a data frame in wireless communications, the RNC comprising a medium access control (MAC) circuitry configured to:
 compute an update to an offset between the CFN and a radio access network frame number (RFN);   increment a target CFN variable in response to a received timer signal;   determine whether a new value of the offset has been received since a previous update to the offset by checking the value of an update variable;   calculate a new target CFN using a current target CFN and the new value of the offset on a condition that the new value of the offset has been received;   set the current target CFN equal to the new target CFN; and   change the update variable to indicate that a new value of the offset has not been received on a condition that the new value of the offset has not been received.   
     
     
         5 . The RNC of  claim 4 , wherein the MAC circuitry is configured to compute the offset update for each of several multiplexed users and to use each user's offset update to delay or advance that user's frame transmission relative to the frame transmission of the other users. 
     
     
         6 . The RNC of  claim 5 , wherein the MAC circuitry is configured to compute each offset update based on at least one of: quality of service characteristics, or time-of-arrival (TOA) statistics.