LAU (Location Area Update)

Location Area Update (LAU) is a process that is utilized in mobile communication networks such as Global System for Mobile Communications (GSM) to update the network about the location of a mobile device. The location area update is a fundamental process in mobile networks, as it ensures that the network can always reach a mobile device whenever it is necessary. In this article, we will explore the concept of LAU, its importance, how it works, and its applications in mobile communication networks.

What is Location Area Update (LAU)?

The location area update (LAU) process is a mechanism used in mobile communication networks to inform the network about the location of a mobile device. This mechanism allows the network to know the current location of a mobile device and to keep track of its movement. The LAU process is important because it allows the network to route calls, messages, and data to the mobile device. The LAU process also ensures that the mobile device can receive calls and messages even when it is not in use.

The LAU process is initiated when a mobile device moves from one location area to another. In GSM networks, a location area is a group of cells that are served by a common base station controller. When a mobile device moves from one location area to another, it must perform a location area update to inform the network about its new location. This process involves the exchange of messages between the mobile device and the network.

Importance of Location Area Update

The location area update is a critical process in mobile communication networks because it ensures that the network can always reach a mobile device. The LAU process allows the network to route calls, messages, and data to the mobile device even when it is not in use. The LAU process also helps to conserve network resources by reducing unnecessary paging and signaling traffic.

Without the location area update process, the network would not be able to route calls, messages, and data to the mobile device. This would result in missed calls, delayed messages, and reduced network efficiency. The LAU process also ensures that the network can locate a mobile device in the event of an emergency.

How Location Area Update Works

The location area update process involves the exchange of messages between the mobile device and the network. When a mobile device moves from one location area to another, it must perform a location area update to inform the network about its new location. The LAU process consists of two types of messages: location update request (LUR) and location update accept (LUA).

Location Update Request (LUR)

The location update request (LUR) is a message sent by the mobile device to the network to inform it about its new location. The LUR message contains information about the mobile device, such as its International Mobile Equipment Identity (IMEI), International Mobile Subscriber Identity (IMSI), and the new location area it has moved to.

Location Update Accept (LUA)

The location update accept (LUA) is a message sent by the network to the mobile device in response to the location update request (LUR). The LUA message acknowledges the receipt of the LUR message and contains information about the location area in which the mobile device is now registered.

The LAU process also involves the use of periodic location area update (PLAU) messages. The PLAU messages are sent by the mobile device to the network at regular intervals to inform it about the device's location. The PLAU messages are used to ensure that the network always has the latest information about the location of the mobile device.

Applications of Location Area Update

The location area update process has several applications in mobile communication networks. Some of the key applications are discussed below.

Call Routing

The location area update process is used to route calls to the mobile device. When a call is made to a mobile device, the network uses the location information obtained from the location area update process to route the call to the correct cell or base station. Without the LAU process, the network would not know the location of the mobile device, and the call would not be properly routed, resulting in missed calls and reduced network efficiency.

Mobile Messaging

The LAU process is also used to route mobile messages, such as SMS (Short Message Service) and MMS (Multimedia Message Service), to the mobile device. When a message is sent to a mobile device, the network uses the location information obtained from the LAU process to deliver the message to the correct cell or base station.

Location-Based Services

Location-based services (LBS) are services that utilize the location information of a mobile device to provide customized services to the user. For example, location-based services can provide users with information about nearby restaurants, shops, or attractions. The LAU process is a crucial component of location-based services, as it provides the network with the current location of the mobile device, enabling it to provide accurate and timely location-based services.

Emergency Services

The location area update process is also critical for emergency services. In the event of an emergency, such as a medical emergency or an accident, the LAU process enables emergency services to locate the mobile device and provide assistance. The LAU process provides emergency services with the current location of the mobile device, allowing them to respond quickly and efficiently.

Conclusion

In conclusion, the location area update (LAU) process is a crucial mechanism used in mobile communication networks to update the network about the location of a mobile device. The LAU process enables the network to route calls, messages, and data to the mobile device, even when it is not in use. The LAU process also helps to conserve network resources and is essential for location-based services and emergency services. The LAU process consists of two types of messages, location update request (LUR) and location update accept (LUA), and involves the use of periodic location area update (PLAU) messages. The LAU process is a fundamental process in mobile communication networks and plays a crucial role in ensuring efficient and effective mobile communication.