GMLC (Gateway Mobile Location Center) is a telecom node that provides the functionality required to support location-based services (LBS). A single Public Land Mobile Network (PLMN) can have multiple GMLCs. This functionality is integrated in 2G and 3G through SIGTRAN and through DIAMETER in 4G and LTE networks.

GMLC can be integrated with LBS to locate any user at a given time that is connected to the network. It can provide network services and authorized third parties with standardized subscriber location information access.

The GMLC may request routing information from the HLR (Home Location register) or HSS (Home Subscriber Server). After performing registration authorization, it sends positioning requests to either the VMSC (Visited Mobile Switching Centre), SGSN (Serving GPRS Support Node) MSC (Mobile Switching Centre) Server or MME (Mobility Management Entity) and receives final location estimates from the corresponding network node.

Some real time applications of GMLC can include the use of location services in smart weather reporting. GMLC can also improve advertisements by pushing area related advertisements. It can also help telecom companies to generate mobile alerts when a user is in a specific area or to introduce tracking e.g., fleet tracking. The location information can also be of prime importance to LEAs, emergency situations such as medical help, accidental reporting etc.