UserPlane Location Protocol

这是ULP2.0协议，是SUPL2.0的技术规范。学习手机移动定位、LBS、SUPL的朋友可以阅读。 Location services based on the location of mobile devices are becoming increasingly widespread. SUPL (Secure User Plane Location) employs user plane data bearers for transferring location information (e.g GPS assistance) and for carrying positioning technology-related protocols between a SUPL Enabled Terminal (SET) and the network. SUPL is considered to be an effective way of transferring location information required for computing the target SET’s location. To serve a location service to a client, considerable signaling and position information are transferred between actors such as a SET and a location server. Currently, assisted-GPS (A-GPS) provides more accurate position of a SET than other available standardized positioning technologies. However, A-GPS over control plane requires modifications to existing network elements, and interfaces (for signaling procedures between the terminal and the network). SUPL needs only an IP capable network and requires minimum modification to the network, and this is an efficient solution that can be deployed rapidly. 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. In the initial phase, SUPL 1.0 provides functionality of A-GPS with minimum changes of current network elements. SUPL 2.0 introduces the A-GNSS concept to allow additional Navigation Satellite System assisted positioning technology to be utilized, e.g. A-Galileo.