LTE_PDCP_协议解读.ppt

* 5.1 PDCP Data Transfer Procedures 5.1.1 UL Data Transfer Procedures 5.1.2 DL Data Transfer Procedures 5.1.2.1 Procedures for DRBs 5.1.2.2 Procedures for SRBs 5.2 Re-establishment procedure 5.2.1 UL Data Transfer Procedures 5.2.2 DL Data Transfer Procedures 5.3 PDCP Status Report 5.4 PDCP discard 5.5 Header Compression and Decompression 5.6 Ciphering and Deciphering 5.7 Integrity Protection and Verification 5.8 Error Handling PDCP procedures Spec 36.323 5.xx Each RB (i.e. DRB and SRB, except for SRB0) is associated with one PDCP entity. Each PDCP entity is associated with one or two (one for each direction) RLC entities depending on the RB characteristic (i.e. uni-directional or bi-directional) and RLC mode. The PDCP entities are located in the PDCP sublayer. PDCP Entity PDCP functions For DRBs mapped on RLC AM, at reception of a PDCP Data PDU from lower layers, the UE shall: -if received PDCP SN – Last_Submitted_PDCP_RX_SN Reordering_Window or 0 = Last_Submitted_PDCP_RX_SN – received PDCP SN Reordering_Window: - if received PDCP SN Next_PDCP_RX_SN: - decipher the PDCP PDU as specified in the subclause 5.6, using COUNT based on RX_HFN - 1 and the received PDCP SN; - else: - decipher the PDCP PDU as specified in the subclause 5.6, using COUNT based on RX_HFN and the received PDCP SN; - perform header decompression (if configured) as specified in the subclause 5.5.5; - discard this PDCP SDU; -else if Next_PDCP_RX_SN – received PDCP SN Reordering_Window: - increment RX_HFN by one; - use COUNT based on RX_HFN and the received PDCP SN for deciphering the PDCP PDU; - set Next_PDCP_RX_SN to the received PDCP SN + 1; -else if received PDCP SN – Next_PDCP_RX_SN = Reordering_Window: - use COUNT based on RX_HFN – 1 and the received PDCP SN for deciphering the PDCP PDU; -else if received PDCP SN = Next_PDCP_RX_SN: - use COUNT based on RX_HFN and the received PDCP SN for deciphering the PDCP PDU; - set Next_PDCP_RX_SN to the received