Last updated: January 15, 2009
This section is only applicable to the lab application.
Assisted GPS (A-GPS) consists of techniques for providing information to a UE, to give assistance in making GPS based location measurements. The assistance data may speed up the measurement process or provide greater accuracy. A-GPS can be divided into two categories, User Plane A-GPS and Control Plane A-GPS. These are described in the following sections.
User plane A-GPS provides assistance to the UE using the Secure User Plane Location (SUPL) protocol. SUPL communicates with the UE using a standard packet data connection and does not require any additional cellular functionality. Therefore full support for this capability in the test set is already available using the existing packet data channel features. No additional test set support is currently required. More information on SUPL can be obtained from the Open Mobile Alliance at http://cms.openmobilealliance.org/technical/release_program/supl_v1_0.aspx
Control plane A-GPS makes use of signaling mechanisms defined within a specific radio access technology. For WCDMA, several messages can be used to provide assistance data and retrieve results from the UE. These include:
The test set supports A-GPS by making use of the RRC pipe to transport externally coded messages to and from the UE. The test set does not encode or decode these messages more than is necessary to provide reliable routing.
It is expected you will want to make use of this functionality in conjunction with an external satellite simulator, and will provide GPS information to the UE using the messages listed above. The messages listed above can also be used in conjunction with the RRC Pipe to retrieve assistance data measurement results from the UE.
For more information on the specific messages and commands associated with this feature, refer to CALL:PPRocedure .