LAI (Location area identity)

Introduction:

Location Area Identity (LAI) is a code that identifies a specific geographical area in which a mobile station (MS) can communicate with a cellular network. It is an essential parameter for mobile communication systems and is used to manage the network's location-based services. The LAI provides a unique identifier to the network's location area and helps to maintain the accuracy of location-based services such as emergency services and location tracking. This essay aims to provide a comprehensive explanation of LAI, including its purpose, structure, and function.

Purpose:

The primary purpose of LAI is to identify the geographical area in which a mobile station is located. The LAI is used by the mobile station to communicate with the cellular network and to obtain various location-based services. The LAI is also used by the network to route calls and messages to the appropriate location area. The LAI is an essential parameter for various network operations, such as handover, paging, and location registration.

Structure:

The LAI consists of two parts, the Mobile Country Code (MCC) and the Location Area Code (LAC). The MCC identifies the country where the mobile station is located, while the LAC identifies the specific location area within the country. The structure of the LAI is illustrated in Figure 1.

cssCopy code                        Figure 1: Structure of LAI

The MCC is a three-digit code that is assigned by the International Telecommunication Union (ITU). The MCC identifies the country in which the mobile station is located. For example, the MCC for the United States is 310, and for Canada, it is 302.

The LAC is a two- or three-digit code that identifies a specific location area within a country. The LAC is assigned by the network operator and is unique within the country. The LAC is used by the network to route calls and messages to the appropriate location area.

Function:

The LAI has several functions in a cellular network. Some of the main functions of LAI are:

Location registration:

The LAI is used by the network to register the location of a mobile station. When a mobile station enters a new location area, it sends a location update to the network, including the LAI. The network updates the mobile station's location information in its database, allowing it to route calls and messages to the appropriate location area.

Handover:

The LAI is used by the network to perform handover between cells. When a mobile station moves from one cell to another, the network performs a handover to maintain the call or data connection. The LAI is used by the network to determine the appropriate target cell for the handover.

Paging:

The LAI is used by the network to page a mobile station. When a call or message is received for a mobile station, the network pages the mobile station in the appropriate location area based on the LAI.

Emergency services:

The LAI is used by emergency services to determine the location of a mobile station. When a mobile station makes an emergency call, the network uses the LAI to determine the location area of the mobile station. This information is then used to dispatch emergency services to the appropriate location.

Conclusion:

In conclusion, the Location Area Identity (LAI) is a critical parameter in cellular networks. It is used to identify the geographical area in which a mobile station is located and is essential for managing location-based services such as emergency services and location tracking. The LAI consists of two parts, the Mobile Country Code (MCC) and the Location Area Code (LAC). The MCC identifies the country, while the LAC identifies the specific location area within the country. The LAI has several functions in a cellular network, including location registration, handover, paging, and emergency services.