These are the identifiers used in LTE technology.
| Identifiers | Full Form | Description | Length of Identifiers |
| IMSI | International Mobile Subscriber Identity | Unique identification of mobile (LTE) subscriber Network (MME) gets the PLMN of the subscriber | IMSI (not more than 15 digits) = PLMN ID + MSIN = MCC + MNC + MSIN |
| PLMN ID | Public Land Mobile Network Identifier | Unique identification of PLMN | PLMN ID (not more than 6 digits) = MCC + MNC |
| MCC | Mobile Country Code | assigned by ITU | 3 digits |
| MNC | Mobile Network Code | assigned by National Authority | 2 or 3 digits |
| MSIN | Mobile Subscriber Identification Number | assigned by operator | 9 or 10 digits |
| GUTI | Globally Unique Temporary UE Identity | To identify a UE between the UE and the MME on behalf of IMSI for security reason | GUTI (not more than 80 bits) = GUMMEI + M-TMSI |
| TIN | Temporary Identity used in Next Update | GUTI is stored in TIN parameter of UE’s MM context. TIN indicates which temporary ID will be used in the next update. | TIN = GUTI |
| S-TMSI | SAE Temporary Mobile Subscriber Identity | To locally identify a UE in short within a MME group (Unique within a MME Pool) | S-TMSI (40 bits) = MMEC + M-TMSI |
| M-TMSI | MME Mobile Subscriber Identity | Unique within a MME | 32 bits |
| GUMMEI | Globally Unique MME Identity | To identify a MME uniquely in globalGUTI contains GUMMEI | GUMMEI (not more than 48 bits)= PLMN ID + MMEI |
| MMEI | MME Identifier | To identify a MME uniquely within a PLMNOperator commissions at eNBMMEI | MMEI (24 bits) = MMEGI + MMEC |
| MMEGI | MME Group Identifier | Unique within a PLMN | 16 bits |
| MMEC | MME Code | To identify a MME uniquely within a MME Group. S-TMSI contains MMEC8 | 8 bits |
| C-RNTI | Cell- Radio Network Temporary Identifier | To identify an UE uniquely in a cell | 0x0001 ~ 0xFFF3 (16 bits) |
| IMEI | International Mobile Equipment Identity | To identify a ME (Mobile Equipment) uniquely | IMEI (15 digits) = TAC + SNR + CD |
| IMEI/SV | IMEI/Software Version | To identify a ME (Mobile Equipment) uniquely | IMEI/SV (16 digits) = TAC + SNR + SVN |
| ECGI | E-UTRAN Cell Global Identifier | To identify a Cell in global (Globally Unique)EPC can know UE location based of ECGI | ECGI (not more than 52 bits) = PLMN I D+ ECI |
| ECI | E-UTRAN Cell Identifier | To identify a Cell within a PLMN | ECI (28 Bits) = eNB ID + Cell ID |
| PGW ID | PDN GW Identity | To identify a specific PDN GW (P-GW)HSS assigns P-GW for PDN (IP network) connection of each UE | IP address (4 bytes) or FQDN (variable length) |
| TAI | Tracking Area Identity | To identify Tracking AreaGlobally uniqueTAI | TAI (not more than 32 bits) = PLMN ID + TAC P-GW |
| TAC | Tracking Area Code | To indicate eNB to which Tracking Area the eNB belongs (per Cell)Unique within a PLMN16 | 16 bits |
| TAI List | Tracking Area Identity List | UE can move into the cells included in TAL list without location update (TA update)Globally unique | Variable length |
| PDN ID | Packet Data Network Identity | To identify an PDN (IP network), that mobile data user wants to communicate withPDN Identity (APN) is used to determine the P-GW and point of interconnection with a PDN With APN as query parameter to the DNS procedures, the MME will receive a list of candidate P-GWs, and then a P-GW is selected by MME with policy |
PDN Identify = APN = APN.NI + APN.OI (variable length) |
| EPS Bearer ID | Evolved Packet System Bearer Identifier | To identify an EPS bearer (Default or Dedicated) per an UE4 | 4 bits |
| E-RAB ID | E-UTRAN Radio Access Bearer Identifier• | To identify an E-RAB per an UE | 4 bits |
| DRB ID | Data Radio Bearer Identifier | To identify a DRB per an UE4 | 4 bits |
| LBI | Linked EPS Bearer ID | To identify the default bearer associated with a dedicated EPS bearer4 | 4 bits |
| TEID | Tunnel End Point identifier | To identify the end point of a GTP tunnel when the tunnel is established | 32 bits |