This section is only applicable to the lab applications.
You can use the test set as a base station or network emulator in a system for testing the A-GPS capability of mobile stations. The test set provides the ability to send A-GPS messages over the air to and receive responses from the mobile station.
To allow the testing of A-GPS capability of a mobile stations, the test set provides an "RRLP pipe" mode. The test set provides a mechanism for passing encoded RRLP messages over the air to the mobile station and retrieving the mobile station's response. The test set does not provide for encoding or decoding the A-GPS messages. It also does not validate the message contents. The complete RRLP message must be encoded and decoded external to the test set. The test set accepts hexadecimal character strings to represent the RRLP binary message content.
You can enable/disable automatic header creation and segmentation of the RRLP binary message by setting the RRLP Header state.
The RRLP pipe can only be setup and controlled using GPIB commands. See CALL:PPRocedure:PMEasurement:PIPE for information about each of the RRLP pipe commands.
When the test set's RRLP layer is in RRLP pipe mode, the standard RRLP message interface for E-OTD testing in the test set is disabled. However, either type of RRLP message (E-OTD or A-GPS) can be sent in the RRLP pipe mode. Messages sent using the RRLP pipe mode must be encoded external to the test set. See E-OTD (Enhanced Observed Time Difference) for more information about the E-OTD testing in the test set.
The TTFF response time measurement is defined in 3GPP TS 51.010 "... starting from the moment that the MS has received the final RRLP MEASURE POSITION REQUEST sent before the MS sends the MEASURE POSITION RESPONSE containing the Location Information or the GPS Measurement Information, and ending when the MS starts sending the MEASURE POSITION RESPONSE ".
In order to achieve an accurate measurement of this response time duration, the time of the final RRLP pipe transmission frame e.g. the MEASURE POSITION REQUEST and the time of the first frame of an MS transmitted RRLP frame e.g. MEASURE TRANSMISSION RESPONSE are stored by the test set and are available to the user. The resolution of both the transmit and receive times is one GSM frame period i.e. 4.615mS. The operation to calculate the TTFF is ((RxTime - TxTime + GSM Hyperframe) modulo GSM Hyperframe) x 4.615 mS.
Query the frame number of the last transmitted RRLP pipe message with GPIB command CALL:PPRocedure:PMEasurement:PIPE:SEND:TSTamp? . Query the received RRLP pipe message with CALL:PPRocedure:PMEasurement:PIPE:DATA:RX:TSTamp? . And remember to clear the transmit timestamp before query the frame number with CALL:PPRocedure:PMEasurement:PIPE:SEND:TSTamp:CLEar .
RRLP messages sent using the RRLP pipe mode pass transparently through the RRLP layer in the test set and are sent over the RF interface to the mobile station using standard GSM control channels via the layer 3 RR entity. Layer 3 segmentation is performed as required.