Base station assistance for random access performance improvement

Abstract

A base station (BS) may be configured to assist in the detection of a random access (RA) request failure and in clued an antenna configured to receive a RA request; a processor configured to decode the RA request; and a transmitter configured to transmit an aggregate RA response message comprising one or more RA responses that respond to one or more received and decoded RA requests.

1 . A base station (BS) configured to assist in the detection of a random access (RA) request failure comprising:
 an antenna configured to receive a RA request;   a processor configured to decode the RA request; and   a transmitter configured to transmit an aggregate RA response message comprising one or more RA responses that respond to one or more received and decoded RA requests.   
     
     
         2 . The BS of  claim 1 , wherein the RA request comprises an initial ranging request. 
     
     
         3 . The BS of  claim 2 , wherein the initial ranging request comprises an initial ranging code in an initial ranging channel. 
     
     
         4 . The BS of  claim 2 , wherein the one or more RA responses comprise a ranging status notification. 
     
     
         5 . The BS of  claim 4 , wherein the one or more RA responses comprise uplink (UL) parameter adjustments. 
     
     
         6 . The BS of  claim 1 , wherein the RA request comprises a handover (HO) ranging request. 
     
     
         7 . The BS of  claim 6 , wherein the HO ranging request comprises a HO ranging code in a HO ranging RA channel. 
     
     
         8 . The BS of  claim 7 , wherein the one or more RA responses comprise a ranging status notification. 
     
     
         9 . The BS of  claim 8 , wherein the one or more RA responses comprise uplink (UL) parameter adjustments. 
     
     
         10 . The BS of  claim 1 , wherein the RA request comprises a periodic ranging request. 
     
     
         11 . The BS of  claim 10 , wherein when the BS receives and decodes the periodic ranging request, the BS estimates the channel strength and the time/frequency of the received UL signals corresponding to the periodic ranging request. 
     
     
         12 . The BS of  claim 10 , wherein the one or more RA responses comprise a ranging status notification. 
     
     
         13 . The BS of  claim 12 , wherein the one or more RA responses comprise uplink (UL) parameter adjustments. 
     
     
         14 . A wireless transmit/receive unit (WTRU) that detects failure of a random access (RA) request comprising:
 a transmitter configured to transmit a RA request;   a receiver configured to receive an aggregate RA response message; and   a processor configured to determine whether the RA request was successful by determining if the aggregate RA response message comprises a RA response corresponding to the RA request.   
     
     
         15 . The WTRU of  claim 14 , wherein the RA request comprises an initial ranging request. 
     
     
         16 . The WTRU of  claim 14 , wherein the RA request comprises a handover ranging request. 
     
     
         17 . The WTRU of  claim 14 , wherein the RA request comprises a periodic ranging request. 
     
     
         18 . A base station (BS) that assists in random access (RA) collision detection comprising:
 an antenna configured to receive a RA request and to receive an uplink (UL) data burst;   a processor configured to decode the RA request, construct and schedule an RA response to the RA request, schedule UL data allocation in response to the RA request, and decode the UL data burst; and   a transmitter configured to transmit a RA response to the RA request, the transmitter further configured to transmit an UL allocation in response to the RA request, and also transmit a RA-initiated UL data negative acknowledgement (NACK) on a condition that data was not received in an UL data region corresponding to the RA request.   
     
     
         19 . A method to assist in detection of random access (RA) request failure comprising:
 receiving and decoding a RA request; and   transmitting an aggregate RA response message comprising one or more RA responses that respond to one or more of the received and decoded RA requests.   
     
     
         20 . A method for detecting a random access (RA) failure, the method comprising:
 transmitting a RA request;   receiving an aggregate RA response message comprising one or more RA responses; and   determining whether the RA request was successfully transmitted by determining if the aggregate RA response message comprises a RA response corresponding to the RA request.