A location information server is a node within a network that stores and transmits location information for devices that are connected to it. Location services can be necessary for a variety of reasons, ranging from routing emergency calls to submitting location data in response to a warrant from law enforcement. In many nations, suppliers of networking services must use a location information server as part of their framework. Such nodes can also provide important internal functionality and thus may be used even when not required by law.
One important application for this technology is in the handling of calls to emergency services using voice over Internet protocol (VoIP) technology. Normally, when people call for help from a landline, the phone company knows where to route the call because it knows where the subscriber lives. A resident of San Francisco who calls the 911 emergency number will access a dispatch center in San Francisco, not Los Angeles, for example.
When people use VoIP to place emergency calls, their locations are usually unknown. The phone company does not know where to route the call, and precious time may be lost as the caller provides location information to an operator who can forward the call to the right place. The location information server comes into play here by tracking a wired or wireless network to approximate the source of the call and route it appropriately. Levels of precision can vary, but can at least determine the closest network node or wireless transmitter, getting close to the caller's location.
This technology can also be useful for tracking user locations for law enforcement purposes like investigations into hacking or abuse. The Internet provider can turn over location information server data for the benefit of investigators, who can use it to track down people of interest in a case. Such information can also be important for routing purposes; networks need to get information to people as quickly and efficiently as possible and knowing where they are can help the network decide how it wants to route packets of information.
Location data can be sensitive. Internet providers have their own internal policies for handling the location information server to protect the privacy of their users. They may not turn over data without a warrant, for example, and take precautions to ensure that only emergency services can access information data. Users can choose to broadcast their location on their own if they want people to know where they are or they want to hook into systems like games that require them to share location data.