Scheduling of retuning gaps for occurring after harq feedback transmission

Abstract

A method and apparatus for operation by a wireless transmit/receive unit is disclosed for detecting a retuning triggering event, wherein the retuning triggering event is an activation of at least one secondary serving cell, determining a period of time when a retuning gap occurs, on a condition that the retuning triggering event is detected, wherein the retuning gap is a time period in which the WTRU may retune a radio frequency front end to accommodate the activation of the at least one secondary serving cell, transmitting hybrid automatic repeat request (HARQ) acknowledgement feedback after detecting the retuning triggering event, and performing radio frequency front end retuning during the retuning gap, after transmitting the HARQ acknowledgement feedback.

What is claimed is: 
     
         1 . A method for operation by a wireless transmit/receive unit (WTRU), the method comprising:
 detecting a retuning triggering event, wherein the retuning triggering event is an activation of at least one secondary serving cell;   determining a period of time when a retuning gap occurs, on a condition that the retuning triggering event is detected, wherein the retuning gap is a time period in which the WTRU may retune a radio frequency front end to accommodate the activation of the at least one secondary serving cell;   transmitting hybrid automatic repeat request (HARQ) acknowledgement feedback after detecting the retuning triggering event; and   performing radio frequency front end retuning during the retuning gap, after transmitting the HARQ acknowledgement feedback.   
     
     
         2 . The method according to  claim 1 , wherein the retuning triggering event is further based on a media access control (MAC) control element (CE) command received by the WTRU. 
     
     
         3 . The method according to  claim 1 , wherein transmitting HARQ acknowledgement feedback includes transmitting feedback for all pending uplink and downlink HARQ processes. 
     
     
         4 . The method according to  claim 1 , wherein the retuning gap corresponds to a fixed value. 
     
     
         5 . The method according to  claim 4 , wherein the fixed value is 1 millisecond. 
     
     
         6 . The method according to  claim 1 , wherein the determining of the period of time when the retuning gap occurs is based on a determination that the at least one secondary serving cell occupies a same frequency band as a primary cell. 
     
     
         7 . The method according to  claim 1 , wherein the determining of the period of time when the retuning gap occurs is based on a determination that the at least one secondary serving cell does not occupy a same frequency band as a primary cell. 
     
     
         8 . The method according to  claim 1 , wherein the determining of the period of time when the retuning gap occurs is based on detecting an idle period from an end of a prior active transmission or retransmission on all active component carriers. 
     
     
         9 . The method according to  claim 8 , wherein the period of time when the retuning gap occurs is determined on a condition that the detected idle period has a length that is greater than or equal to a length corresponding to the period of time when the retuning gap occurs. 
     
     
         10 . The method according to  claim 1 , wherein the determining of the period of time when the retuning gap occurs is based on discontinuous reception (DRX) cycles. 
     
     
         11 . A wireless transmit/receive unit (WTRU) comprising:
 a processor configured to:   detect a retuning triggering event, wherein the retuning triggering event is an activation of at least one secondary serving cell;   determine a period of time when a retuning gap occurs, on a condition that the retuning triggering event is detected, wherein the retuning gap is a time period in which the WTRU may retune a radio frequency front end to accommodate the activation of the at least one secondary serving cell;   direct a transmission of hybrid automatic repeat request (HARQ) acknowledgement feedback after the retuning triggering event is detected; and   perform radio frequency front end retuning during the retuning gap, after the transmission of the HARQ acknowledgement feedback is directed.   
     
     
         12 . The WTRU of  claim 11 , wherein the retuning triggering event is based on MAC CE command received by the WTRU. 
     
     
         13 . The WTRU of  claim 11 , wherein the transmission of the HARQ acknowledgement feedback includes feedback for all pending uplink and downlink HARQ processes. 
     
     
         14 . The WTRU of  claim 11 , wherein the retuning gap corresponds to a fixed value. 
     
     
         15 . The WTRU of  claim 14 , wherein the fixed value is 1 millisecond. 
     
     
         16 . The WTRU of  claim 11 , wherein the at least one secondary serving cell occupies a same frequency band as a primary cell. 
     
     
         17 . The WTRU of  claim 11 , wherein the at least one secondary serving cell does not occupy a same frequency band as a primary cell. 
     
     
         18 . A method for operation by a wireless transmit/receive unit (WTRU), the method comprising:
 receiving a media access control (MAC) control element (CE) command, wherein the MAC CE command indicates activation of at least one secondary serving cell;   determining a period of time when a retuning gap occurs, wherein the retuning gap is a time period in which the WTRU may retune a radio frequency front end to accommodate the activation of the at least one secondary serving cell;   transmitting hybrid automatic repeat request (HARQ) acknowledgement feedback after receiving the MAC CE command; and   performing radio frequency front end retuning during the retuning gap, after transmitting the HARQ acknowledgement feedback.   
     
     
         19 . The method according to  claim 18 , wherein transmitting HARQ acknowledgement feedback includes transmitting feedback for all pending uplink and downlink HARQ processes. 
     
     
         20 . The method according to  claim 18 , wherein the determining of the period of time when the retuning gap occurs is based on discontinuous reception (DRX) cycles.