Section: 19.6 E-UTRAN Cell Identity (ECI) and E-UTRAN Cell Global Identification (ECGI)
Content: The E-UTRAN Cell Global Identification (ECGI) shall be composed of the concatenation of the PLMN Identifier (PLMN-Id) and the E-UTRAN Cell Identity (ECI) as shown in figure 19.6-1 and shall be globally unique: Figure 19.6-1: Structure of E-UTRAN Cell Global Identification The ECI shall be of fixed length of 28 bits and shall be coded using full hexadecimal representation. The exact coding of the ECI is the responsibility of each PLMN operator. For more details on ECI and ECGI, see 3GPP TS 36.413[ Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP) ]  [84]. NOTE: In the 5G Core Network protocols, when the ECGI needs to be identified in the context of Standalone Non-Public Networks (SNPN), the Network Identifier (NID) of the SNPN is included as part of the ECGI Information Element (see 3GPP TS 29.571[ 5G System; Common Data Types for Service Based Interfaces; Stage 3 ]  [129]); this is a protocol aspect that does not imply any change on the system-wide definition of the ECGI.