Scheduling Request (SR)

1. SR is used for requesting UL-SCH for new transmission.
2. When SR is triggered, it is pending until it is cancelled.
3. when a MAC PDU is assembled, all pending SR(s) are cancelled and sr-ProhibitTimer is
stopped, when
               3. MAC PDU includes a BSR(Buffer Status Report) up to event triggering BSR or
               4. UL grant(s) sends all pending data.
4. SR_COUNTER=0, when new SR comes and no pending SR.
5. As long as any SR is pending, for each TTI:
               5. if no UL-SCH resources are available for a transmission in this TTI:
                          1. If no valid PUCCH for SR in any TTI: initiate RA and cancel all pending
                              SRs;
                          2. else if UE has valid PUCCH for SR for this TTI and if sr-ProhibitTimer is
                              not running:
                                    1. if SR_COUNTER < dsr-TransMax:
                                               1. SR_COUNTER++;
                                               2. signal the SR on PUCCH;
                                               3. start the sr-ProhibitTimer.
                                    2. else:
                                                1. notify RRC to release PUCCH/SRS;
                                                2. clear DL/UL grants;
                                                3. initiate RA and cancel all pending SRs.