Section: 8.51.10 en-gNB ID
Content: The Target Type is an en-gNB ID for: - a TNL address discovery request of a candidate en-gNB via the S1 interface or via inter-system signalling (see clauses 22.3.6.2 and 22.3.6.3 of 3GPP TS 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [19]). In this case, the Target ID field shall be coded as depicted in Figure 8.51.10-1. Figure 8.51.10-1: Target ID for Type en-gNB ID The en-gNB ID Length field, in bits 1 to 6 of octet 9, indicates the length of the en-gNB ID in number of bits. Bits 7 and 8 of octet 9 shall be encoded as follows: - Bit 7 - ETAC: when set to "1", octets p to (p+1) shall be present and encode a TAC (EPS); otherwise, octets p to (p+1) shall be absent. - Bit 8 - 5TAC: when set to "1", octets q to (q+2) shall be present and encode a 5GS TAC; otherwise, octets q to (q+2) shall be absent. The en-gNB ID consists of 22 to 32 bits. The en-gNB ID shall be coded as the gNodeB ID field of the gNodeB ID in clause 8.51.7. When present, the TAC shall consist of 2 octets and shall be coded as the TAC field of the Macro eNodeB ID in clause 8.51.3. When present, the 5GS TAC shall consist of 3 octets and shall be coded as the 5GS TAC field of the gNodeB ID in ubclause 8.51.7.