Method for detecting radio link failure for transmission over enhanced dedicated channel in a cell_fach state

Abstract

A method and apparatus are used for detecting a radio link (RL) failure and a post verification process. A quality of a downlink fractional dedicated physical channel (F-DPCH) is monitored once a transmission on an enhanced dedicated channel (E-DCH) has begun. It is determined whether the quality of the downlink F-DPCH is below a predefined threshold. If the quality is below the predefined threshold, then an occurrence of an RL failure is declared and a transmission over the E-DCH in a cell forward access channel (CELL_FACH) state is terminated. In a case of the post verification failure, E-DCH resources are released.

1 - 26 . (canceled) 
     
     
         27 . A wireless transmit receive unit (WTRU), the WTRU comprising:
 a processor configured to:   determine a quality of a downlink channel when operating in a cell forward access channel (CELL_FACH) state;   determine that a RL failure has occurred based on the quality of the downlink channel being below a predefined threshold over a predetermined period of time;   release an enhanced dedicated channel (E-DCH) resource; and   reset a medium access control (MAC) entity.   
     
     
         28 . The WTRU of  claim 27 , wherein the downlink channel comprises a fractional dedicated physical channel (F-DPCH). 
     
     
         29 . The WTRU of  claim 27 , wherein the downlink channel comprises an E-DCH physical control channel (DPCCH). 
     
     
         30 . The WTRU of  claim 27 , wherein the E-DCH comprises an E-DCH dedicated physical control channel (E-DPCCH). 
     
     
         31 . The WTRU of  claim 27 , wherein the E-DCH comprises an E-DCH dedicated physical data channel (E-DPDCH). 
     
     
         32 . The WTRU of  claim 27 , wherein a physical layer indicates to a MAC layer that the RL failure has occurred and the MAC layer stops sending data to the physical layer. 
     
     
         33 . The WTRU of  claim 27 , wherein the processor is configured to stop a transmission associated with an enhanced dedicated channel (E-DCH). 
     
     
         34 . The WTRU of  claim 33 , wherein the processor is further configured to, after stopping the transmission associated with the enhanced dedicated channel (E-DCH):
 wait a predefined amount of time,   start a backoff timer; and   wait for the backoff timer to expire prior to initiating another RACH access.   
     
     
         35 . The WTRU of  claim 34 , wherein the processor is further configured to terminate the backoff timer and perform a cell reselection procedure upon the cell reselection being met. 
     
     
         36 . A method implemented in a wireless transmit receive unit (WTRU) for detecting a radio link (RL) failure in cell forward access channel (CELL_FACH) state, the method comprising:
 determining a quality of a downlink channel when operating in in cell forward access channel (CELL_FACH) state;   determining that a RL failure has occurred based on the quality of the downlink channel being below a predefined threshold over a predetermined period of time;   releasing an enhanced dedicated channel (E-DCH) resource; and   resetting a medium access control (MAC) entity.   
     
     
         37 . The method of  claim 36 , wherein the downlink channel comprises a fractional dedicated physical channel (F-DPCH). 
     
     
         38 . The method of  claim 36 , wherein the downlink channel comprises an E-DCH physical control channel (DPCCH). 
     
     
         39 . The method of  claim 36 , wherein the E-DCH comprises an E-DCH dedicated physical control channel (E-DPCCH). 
     
     
         40 . The method of  claim 36 , wherein the E-DCH comprises an E-DCH dedicated physical data channel (E-DPDCH). 
     
     
         41 . The method of  claim 36 , wherein a physical layer indicates to a MAC layer that the RL failure has occurred and the MAC layer stops sending data to the physical layer. 
     
     
         42 . The method of  claim 36 , further comprising stopping a transmission associated with an enhanced dedicated channel (E-DCH). 
     
     
         43 . The method of  claim 36 , further comprising, after stopping the transmission associated with the enhanced dedicated channel (E-DCH):
 waiting a predefined amount of time;   starting a backoff timer, and   waiting for the backoff timer to expire prior to initiating another RACH access.   
     
     
         44 . The method of  claim 43 , further comprising terminating the backoff timer and performing a cell reselection procedure upon the cell reselection being met.