Method and apparatus for reduced data block transmission in an automatic repeat request system

Abstract

A wireless transceiver apparatus ( 201, 203 ) and a method of operation in an Automatic Repeat Request (ARQ) mode is disclosed. On the transmitter side a packet of data ( 113 ) is fragmented into a series of sequential data blocks and each data block is assigned a block sequence number ( 601 ). At least a first data block of the series of sequential data blocks is sent to the receiver ( 603 ), and also a first block sequence number corresponding to the first data block. An acknowledgment timer is set ( 605 ) specifying a time interval in which to receive an acknowledgment message from the remote transceiver. If the acknowledgment timer has timed out, the transmitter side sends a discard message ( 607 ) to the receiver specifying at least a second block sequence number corresponding to at least a second data block, and specifying that said second data block is to be discarded.

1 . A method of operating a wireless transceiver, said wireless transceiver operating in an Automatic Repeat Request (ARQ) mode, said method comprising:
 fragmenting a packet of data into a series of sequential data blocks and assigning each of said data blocks a block sequence number;   sending at least a first data block from said series of sequential data blocks, and a first block sequence number corresponding to said first data block, to a remote wireless transceiver;   setting an acknowledgment timer specifying a time interval in which to receive an acknowledgment message from said remote transceiver, said acknowledgment message corresponding to said first data block;   determining that said acknowledgment timer has timed out; and   sending a discard message to said remote transceiver specifying at least a second block sequence number corresponding to at least a second data block, and specifying that said second data block is to be discarded, wherein the at least a second block sequence number corresponds to one or more remaining data blocks forming said packet of data.   
   
   
       2 . The method of  claim 1 , further comprising:
 discarding all remaining data blocks of said series of sequential data blocks.   
   
   
       3 . The method of  claim 2 , further comprising:
 advancing an ARQ transmission window start to the next block sequence number greater than a largest value block sequence number, said largest value block sequence number corresponding to a last in sequence data block of said series of sequential data blocks.   
   
   
       4 . The method of  claim 1 , further comprising:
 receiving from said remote transceiver, an acknowledgment message, said acknowledgment message specifying that said second data block has been discarded by said remote transceiver.   
   
   
       5 . The method of  claim 1 , further comprising:
 setting a retry timer specifying a time interval in which to receive a report message from said remote transceiver, said report message acknowledging receipt of said discard message;   determining that said retry timer has timed out; and   sending a second discard message to said remote transceiver.   
   
   
       6 . A method of operating a wireless transceiver, said wireless transceiver operating in an Automatic Repeat Request (ARQ) mode, said method comprising:
 receiving from a remote transceiver at least a first data block including a first block sequence number, said first data block being from a series of sequential data blocks forming a packet;   receiving from said remote transceiver a discard message specifying at least a second block sequence number corresponding to at least a second data block, said discard message specifying that said second data block is to be discarded, wherein the at least a second block sequence number corresponds to one or more remaining data blocks forming said packet; and   discarding said second data block.   
   
   
       7 . The method of  claim 6 , further comprising:
 sending a discard report message to said remote transceiver reporting that said second data block has been discarded.   
   
   
       8 . The method of  claim 7 , further comprising:
 advancing an ARQ receive window start to the next block sequence number greater than a largest value block sequence number, said largest value block sequence number corresponding to a last in sequence data block of said series of sequential data blocks.   
   
   
       9 . The method of  claim 6 , further comprising:
 receiving from said remote transceiver, a fragmentation information corresponding to said first data block;   setting a data purge timer specifying a time interval in which to receive at least a second data block from said series of sequential data blocks;   determining that said purge timer has timed out;   using said fragmentation information to determine a final block sequence number corresponding to a last in sequence data block of said series of sequential data blocks; and   advancing an ARQ receive window start to the next block sequence number greater than said final block sequence number.   
   
   
       10 . A wireless communication station comprising:
 a transceiver for transmitting and receiving radio signals;   a processor coupled to said transceiver, said processor having a medium access control layer, and configured to:
 fragment a packet of data into a series of sequential data blocks and assign each of said data blocks a block sequence number; 
 send at least a first data block from said series of sequential data blocks, and a first block sequence number corresponding to said first data block, to a remote wireless transceiver; 
 set an acknowledgment timer specifying a time interval in which to receive an acknowledgment message from said remote transceiver, said acknowledgment message corresponding to said first data block; 
 determine that said acknowledgment timer has timed out; and 
 send a discard message to said remote transceiver specifying at least a second block sequence number corresponding to at least a second data block, and specifying that said second data block is to be discarded, wherein the at least a second block sequence number corresponds to one or more remaining data blocks forming said packet of data. 
   
   
   
       11 . The wireless communication station of  claim 10 , wherein said processor is further configured to discard all remaining data blocks of said series of sequential data blocks. 
   
   
       12 . The wireless communication station of  claim 10 , wherein said processor is further configured to advance an ARQ transmission window start to the next block sequence number greater than a largest value block sequence number, said largest value block sequence number corresponding to a last in sequence data block of said series of sequential data blocks. 
   
   
       13 . The wireless communication station of  claim 10 , wherein said processor is further configured to receive from said remote wireless transceiver, an acknowledgment message, said acknowledgment message specifying that said second data block has been discarded by said remote wireless transceiver. 
   
   
       14 . The wireless communication station of  claim 10 , wherein said processor is further configured to:
 receive from said remote transceiver at least a first data block including a first block sequence number, said first data block being from a series of sequential data blocks forming a packet;   receive from said remote transceiver a discard message specifying at least a second block sequence number corresponding to at least a second data block, said discard message specifying that said second data block is to be discarded; and   discard said second data block.   
   
   
       15 . The wireless communication station of  claim 14 , wherein said processor is further configured to send a discard report message to said remote transceiver reporting that said second data block has been discarded. 
   
   
       16 . The wireless communication station of  claim 14 , wherein said processor is further configured to advance an ARQ receive window start to the next block sequence number greater than a largest value block sequence number, said largest value block sequence number corresponding to a last in sequence data block of said series of sequential data blocks. 
   
   
       17 . The wireless communication station of  claim 14 , wherein said processor is further configured to:
 receive from said remote transceiver, a fragmentation information corresponding to said first data block;   set a data purge timer specifying a time interval in which to receive at least a second data block from said series of sequential data blocks;   determine that said purge timer has timed out;   use said fragmentation information to determine a final block sequence number corresponding to a last in sequence data block of said series of sequential data blocks; and   advance an ARQ receive window start to the next block sequence number greater than said final block sequence number.   
   
   
       18 . The wireless communication station of  claim 10 , wherein said transceiver for transmitting and receiving radio signal, transmits and receives radio signals in accordance with an orthogonal frequency division multiple access radio interface. 
   
   
       19 . The wireless communication station of  claim 10 , wherein said packet of data is a Medium Access Control Layer Service Data Unit (MSDU). 
   
   
       20 . The wireless communication station of  claim 10 , wherein said first block sequence number corresponding to said first data block, further includes a fragmentation control information.