The location area (LA) is the place where the mobile station is currently located. This area, which forms the logical summary of several adjacent radio cells, is checked in GSM systems by the VLR database and can comprise one or more radio zones
. The geographical size of the location area depends on the traffic density and
thecapacity of the visitor directory
. Thesize should be such that the subscriber data does not have to be constantly updated when the mobile station moves locally. Large location areas can be as large as 4,000 sq. km.
In the location area, the mobile subscriber is identified by the location area code (LAC).