SUPL - [6]Secure User Plane Location - is an Enabler which utilizes existing standards where available and possible, to transfer assistance data and positioning data over a User Plane bearer, such as IP, to aid network and SUPL Enabled Terminal (SET) based positioning technologies in the calculation of a SET's position. SUPL includes but is not limited to the definition of a Location User Plane (Lup) Reference Point and corresponding interface between the SUPL Location Platform (SLP) and SET, security functions (e.g., authentication, authorization), charging functions, roaming functions, and privacy functions, SUPL utilizes existing standards where available and possible, and SUPL should be extensible to enabling more positioning technologies as the need arises so that they utilize the same mechanism.

SUPL is used by Location Server via a SUPL Agent to determine the position of a SET. SET could be Mobile Phone, PDA or other mobile communication device. SLP is server in the network that carries out authentication, location requests, charging and roaming. SUPL handles localization of clients in network. Location Information is then exchanged with GMLC or other SLP. Location information is carried in MLP. Only one services from MLP is implemented: SLIS.

Communication between SLP and MS is performed by UserPlane Location Protocol (ULP) [7].

SS7 - [8]Signalling System No.7 - The objective of SS No.7 is to provide an internationally standardized, general purpose, common channel signalling (CCS) system, that is optimized for operation in digital telecommunications networks in conjunction with stored program controlled exchanges.