7.7.2 International Mobile Subscriber Identity (IMSI)

29.0603GPPGeneral Packet Radio Service (GPRS)GPRS Tunnelling Protocol (GTP) across the Gn and Gp interfaceRelease 17TS

The IMSI shall be the subscriber identity of the MS. The IMSI is defined in 3GPP TS 23.003 [2].

Figure 10: IMSI Information Element

The IMSI is TBCD-coded with a fixed length of 8 octets. Bits 8765 of octet n+1 encodes digit 2n, bits 4321 of octet n+1 encodes digit 2n-1. Each unused half octets shall be coded as binary "1 1 1 1". Digits are packed contiguously with no internal padding.