r) 111010 BSR (Buffer Status Report) memory status (truncated short report) 111011 BSR memory status (truncated long report) 111100 BSR memory status (short report) 111101 BSR memory status (long report) 111110 Filling 111111 Table 8.3. LCID field values for the UL-SCH transport channel 5G-NR Radio Interface - Data Link Layer Description Value MCCH logical channel identifier 000000 MTCH logical channel identifier 00001-11100 Reserved 11101 11110 Filling 11111 Table 8.4. LCID field values for the MCH transport channel In case of LCID values for the DL-SCH channel, the activation or deactivation concerns: - ZP CSI-RS (Zero Power CSI-RS) resource elements (LCID = 110000); - transmission diversity for the PUCCH channel (LCID = 110001); - SRS (Sounding Reference Signal) resource elements (LCID = 110010); - the CSI report transmitted by the PUCCH channel (LCID = 110011); - indication of the TCI (Transmission Configuration Indicator) transmission state for the PDSCH channel (LCID = 110101); - all CSI-RS/CSI-IM resources (LCID = 110111); - duplication (LCID = 111000); - the SCell (secondary cell) (LCID = 111001-111010). The MAC Random Access Response (RAR) frame is a specific frame used by the gNB entity in response to receiving a random access attempt by the mobile. Figure 8.20 describes the general structure of an MAC RAR frame with a delay indication. BI (Backoff Indicator): this field coded on 4 bits provides the value of the delay between two consecutive transmissions of the preamble on the Physical Random Access Channel (PRACH). Extension (E): this bit indicates whether the next header unit is present (bit value ONE) or not (bit value ZERO). Random Access Preamble Identifier (RAPID): this field coded on 6 bits contains the identifier of the preamble used by the mobile for random access to the gNB entity. 232 NG-RAN and 5G-NR Type (T): this bit provides an indication of the header unit structure (T=0 for BI and T = 1 for RAPID). The RAR message contains the following information: - Timing Advance (TA) which enables 