Section: 5.4.7.1 Transmission using PUR
Content: Transmission using PUR is initiated by the RRC layer. When transmission using PUR is initiated, RRC layer provides MAC with the following information: - PUR-RNTI; - Duration of PUR response window pur-ResponseWindowTimer; - UL grant information. If the MAC entity has a PUR-RNTI, the MAC entity shall for each TTI for which RRC layer has provided uplink grant for transmission using PUR: - deliver the uplink grant, and the associated HARQ information to the HARQ entity for this TTI. After transmission using PUR, the MAC entity shall monitor PDCCH identified by PUR-RNTI in the PUR response window using timer pur-ResponseWindowTimer: - if PUR was transmitted in a non-terrestrial network and UE supports delaying the start of the pur-ResponseWindowTimer: - the MAC entity shall start pur-ResponseWindowTimer at the subframe that contains the end of the corresponding PUSCH transmission plus 4 subframes plus UE-eNB RTT. - else: - the MAC entity shall start pur-ResponseWindowTimer at the subframe that contains the end of the corresponding PUSCH transmission plus 4 subframes. While pur-ResponseWindowTimer is running, the MAC entity shall: - if the PDCCH transmission is addressed to the PUR-RNTI and contains an UL grant for a retransmission: - if PUR was transmitted in a non-terrestrial network and UE supports delaying the start of the pur-ResponseWindowTimer: - restart pur-ResponseWindowTimer at the last subframe of a PUSCH transmission corresponding to the retransmission indicated by the UL grant plus 4 subframes plus UE-eNB RTT. - else: - restart pur-ResponseWindowTimer at the last subframe of a PUSCH transmission corresponding to the retransmission indicated by the UL grant plus 4 subframes. - if L1 ACK for transmission using PUR is received from lower layers; or - if PDCCH transmission is addressed to the PUR-RNTI and the MAC PDU is successfully decoded: - stop pur-ResponseWindowTimer; - if L1 ACK for transmission using PUR is received from lower layers or the MAC PDU contains only Timing Advance Command MAC control element: - indicate to upper layers the transmission using PUR was successful; - if repetition adjustment for transmission using PUR is received from lower layers: - indicate the value of the repetition adjustment to upper layers. - discard the PUR-RNTI. - else if fallback indication for PUR is received from lower layers: - stop pur-ResponseWindowTimer; - indicate to upper layers PUR fallback indication is received; - if repetition adjustment for transmission using PUR is received from lower layers: - indicate the value of the repetition adjustment to upper layers. - discard the PUR-RNTI. - if the pur-ResponseWindowTimer expires: - if PUR was transmitted in a non-terrestrial network: - if no notification of a reception of a PDCCH transmission addressed to the PUR-RNTI containing an UL grant for a retransmission was received after the start of pur-ResponseWindowTimer: - indicate to upper layers the transmission using PUR has failed; - discard the PUR-RNTI. - else: - indicate to upper layers the transmission using PUR has failed; - discard the PUR-RNTI.