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How can I get ground transmitter (GTx) support for my GNSS simulator?


This article is applicable to users with a dual antenna GSS7700 or GSS8000 simulator. GTx is not compatible with single antenna output simulators or STR4760 simulators. To learn about the GTx feature please refer to the appropriate section of the SimGEN user manual, DGP00686AAA.

In 2006 Spirent provided upgrade packs to all customers with a valid support agreement. For those owning a dual antenna GSS7700 a semi-rigid U-link cable was also included with information explaining about a new feature called "Ground Transmitters" (also known as GTx). Customers who were interested in taking advantage of the new feature were then required to send their existing configuration file (sig_gen.txt file) back to Spirent Global Services team, who would then add the necessary modifications and send the updated file back to the user.

If you are a GSS7700 customer who was not under support during the 2006 upgrade program but has since renewed support, or you received the 2006 upgrade pack but did not at the time send your sig_gen.txt file for the necessary modifications, you should:-

  1. Contact Spirent Global Services with a copy of your current sig_gen.txt file (this will be located in the SimGEN or PosApp root directory
        - C:\Program Files\Spirent Communications\SimGEN   OR   C:\Program Files\Spirent Communications\Positioning Application
  2. Confirm the version of SimGEN you are currently using (you need SimGEN v2.60 or later to use GTx)
  3. Confirm if you have the semi-rigid U-link cable (if you have more than one qualifying simulator you must indicate which simulator serial numbers you are intending to use GTx with and that you have a U-link cable for each one) 

All dual antenna GSS7700 and GSS8000 systems shipped after this date will have included the semi-rigid U-link cable and sig_gen.txt settings for GTx operation as standard. Therefore such system have already been provided with everything needed to begin using GTx. Please contact Spirent Global Services with your simulator serial number, if, for whatever reason, part of the required set-up is missing or has been misplaced.

With the U-link cable, the correct version of PosApp (SimGEN) and the necessary configuration in your sig_gen.txt file, which sets your simulator in to GTx mode, you are ready to use GTx:-

  • Connect the U-link cable between the MON/CAL OUT 2 port and AUX RF IN 1 (JAMMER IN 1) port on the rear panel of the simulator.
  • Launch PosApp (SimGEN) and ensure you have selected the GTx hardware configuration, via menu [Tools-->Change hardware configuration].
  • Add GTx signal types to the vehicle antenna in the scenario.
  • If required, open the "Ground Tx signal sources file" in the scenario tree and modify settings to suit your test requirements.

Product : SimGEN,PosApp,Interference