location area in gsm

In GSM (Global System for Mobile Communications), a Location Area (LA) is a geographical area within which a mobile device can move freely without updating its location information with the network. The concept of Location Area is designed to reduce signaling overhead in the network by grouping multiple cells into a larger area.

Here's a more detailed technical explanation of how Location Area works in GSM:

1. Cell and Location Area:
   • In GSM, the basic network infrastructure is organized into cells, where each cell is served by a Base Transceiver Station (BTS). A group of cells is grouped into a Location Area.
2. Location Area Identity (LAI):
   • Each Location Area is uniquely identified by a Location Area Identity (LAI). The LAI is composed of three parts:
     • Mobile Country Code (MCC): A unique code assigned to each country.
     • Mobile Network Code (MNC): Identifies the specific mobile network within the country.
     • Location Area Code (LAC): Identifies the Location Area within the network.
3. Tracking Area (TA):
   • The concept of Tracking Area is closely related to Location Area. A Tracking Area is a group of neighboring Location Areas. It represents an even larger area within which a mobile device can move without triggering a Location Update. This is a further optimization to reduce signaling overhead.
4. Location Update Procedure:
   • When a mobile device powered on or moves to a new Location Area, it initiates a Location Update procedure. The mobile device sends a Location Update Request to the GSM network, providing its current Location Area Identity.
5. Network's Update:
   • The GSM network updates its Visitor Location Register (VLR) and Home Location Register (HLR) databases with the new location information of the mobile device.
6. Area Updates and Paging:
   • The network periodically performs Area Updates to keep track of the mobile device's location. When a call or message is destined for a mobile device, the network uses paging to locate the device within its current Location Area.
7. Handover:
   • If a mobile device moves from one cell to another within the same Location Area, it is known as an intra-LA handover and doesn't trigger a Location Update. If it moves to a new Location Area, an inter-LA handover occurs, and a Location Update is triggered.

The Location Area in GSM is a geographical area that helps manage the mobility of mobile devices efficiently. It allows the network to reduce signaling overhead by updating the location information in larger groups, improving the overall performance and efficiency of the GSM system.