8.5.89 HS-SCCH DRX operation in CELL_FACH state (FDD only)

25.3313GPPProtocol specificationRadio Resource Control (RRC)Release 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

The HS-SCCH DRX operation in CELL_FACH state determines the occasions in which the UE is allowed to discontinuously receive only HS-SCCH orders and not have to decode HS-DSCH in CELL_FACH state. This is possible only in a UE that is capable of supporting HS-SCCH DRX operation in CELL_FACH state and HS_SCCH_DRX_CELL_FACH_STATUS is set to TRUE.

If the variable HS_SCCH_DRX_CELL_FACH_STATUS is set to TRUE, the UE shall:

1> if E-DCH resource index information is received from lower layers and the "E-DCH resource index" received from MAC with the CMAC-STATUS primitive is not equal to -1; or

1> if "Fallback transmission initiation" is received from MAC with the CMAC-STATUS primitive:

2> stop the timer T333, if it is ongoing;

2> continuously receive HS-DSCH.

1> if "Fallback transmission termination" is received from MAC with the CMAC-STATUS primitive; or

1> if E-DCH enhanced random access process termination information is received from lower layers:

2> start the timer T333.

1> if the UE does not have an E-DCH resource assigned and data on HS-DSCH or HS-SCCH order for NodeB triggered HS-DPCCH transmission is received:

2> start or, if the timer is running, restart the timer T333 at the end of the HS-SCCH subframe addressed to this UE;

2> if HS-SCCCH based DRX operation is active and received valid HS-SCCH order as defined by [27]:

3> start receiving HS-SCCH/HS-DSCH continuously 8 ms after the end of the subframe carrying the HS-SCCH order.

2> else:

3> continue to receive HS-DSCH.

Upon timer T333 expiry:

1> the UE shall only receive the HS-SCCH order during the subframe(s) with the Subframe_Number and SFN value fulfilling the following equation:

((5*SFN) + Subframe_Number – H-RNTI + 65536) mod (DRX_cycle) < Rx burst

Where:

– H-RNTI is the value stored in the variable H_RNTI;

– Rx burst is the period in subframes within the DRX_cycle, signalled by the IE "HS-SCCH RX burst_FACH".

– DRX_cycle is the length of the DRX cycle in subframes, signalled by the IE "HS-SCCH DRX cycle_FACH"

For FDD when in CELL_FACH state, when the variable HS_DSCH_RECEPTION_CELL_FACH_STATE is set to TRUE and the variable HS_SCCH_DRX_CELL_FACH_STATUS is set to TRUE, then the UE in FDD mode shall perform measurements as specified in subclauses 8.4.1.6 and 8.4.1.9, according to the requirements in [4] and [19].