It is used to check whether the MS is camping on a cell of the network
operator the SIM card is subscribed
and to define the training sequence that is used further on with the normal burst.
| BSIC | = | NCC | + | BCC |
| | 3 bits | | 3 bits |
| NCC | = | Network Color Code | 0 .. 7 |
| BCC | = | Base Station Color Code | 0 .. 7 |
It is used to prevent use of stolen MS or restrict terminals that are causing
interference.
This number is created by the manufacturer.
| IMEI | = | TAC | + | FAC | + | SNR | + | SP |
| | 6 digits | | 2 digits | | 6 digits | | 1 digit |
| TAC | = | Type Approval Code |
| FAC | = | Final Assembly Code |
| SNR | = | Serial Number |
| SP | = | Spare |
The range of this number is:
| Standard | ARFCN |
| E-GSM 900 | 1 .. 124
975 .. 1023 |
| P-GSM 900 | 1 .. 124 |
| GSM 1800 | 512 .. 885 |
| GSM-R | 955 .. 974 |
It defines the service of a subscriber.
The number is independent of the internally used
IMSI
, but linked to it in HLR and SIM card.
| MSISDN | = | CC | + | NDC | + | SN |
| | 1-3 digits | | 2-3 digits | | 6-7 digits |
| CC | = | Country Code (e.g. Germany +49) |
| NDC | = | National Destination Code (e.g. 171 T-D1) |
| SN | = | Subscriber Number (first 2 digits distinguish between different HLR) |
The IMSI is stored in HLR, AC and SIM card.
It is used to identify the subscriber and the particular services.
| IMSI | = | MCC | + | MNC | + | MSIN |
| | 3 digits | | 2-3 digits | | |
| MCC | = | Mobile Country Code (e.g. Germany 262) |
| MNC | = | Mobile Network Code |
| MSIN | = | MS Identification Number (first 2 digits define HLR) |
The TMSI is used together with LAI and only a local signification.
It is smaller than 32 bits (4 octets) and changed at least every location update.
A temporary allocated number in GMSC to route calls to MSC/VLR.
| MSRN | = | CC | + | NDC | + | SN* |
| | 1-3 digits | | 2-3 digits | | 6-7 digits |
| CC | = | Country Code (e.g. Germany +49) |
| NDC | = | National Destination Code (e.g. 171 T-D1) |
| SN* | = | Subscriber Number (first 2 digits distinguish between different HLR) |
Used for inter MSC handover.
The number is generated by target MSC and exists only temporarily.
| MSRN | = | CC | + | NDC | + | SN** |
| | 1-3 digits | | 2-3 digits | | 6-7 digits |
| CC | = | Country Code (e.g. Germany +49) |
| NDC | = | National Destination Code (e.g. 171 T-D1) |
| SN** | = | Subscriber Number (first 2 digits distinguish between different HLR) |
Indicates the Location Area the MS is in.
The design decision is to balanced between amount of paging
and amount of location updates.
The LAI may be set for one or many cells.
| LAI | = | MCC | + | MNC | + | LAC |
| | 3 digits | | 2-3 digits | | |
| MCC | = | Mobile Country Code (e.g. Germany 262) |
| MNC | = | Mobile Network Code |
| LAC | = | Location Area Code |
This number is used to distinguish between cells within a location area.
| CGI | = | MCC | + | MNC | + | LAC | + | CI |
| = | LAI | + | CI |
| | 3 digits | | 2-3 digits | | | | 2 octets |
| MCC | = | Mobile Country Code (e.g. Germany 262) |
| MNC | = | Mobile Network Code |
| LAC | = | Location Area Code |
| CI | = | Cell Identity |
| LAI | = | Location Area Indication |
