The Future of Multi-Constellation GNSS Test Standards for Cellular Location

P. Anderson, E. Anyaegbu and R. Catmur

Abstract:	The paper reviews the current cellular location test standards such as the 3GPP standards TS 34.171 and TS 37.571-1. These standards are primarily “Minimum Performance Standards”, rather than reflecting the performance standards that are now being required as acceptance criteria. Within the cellular location industry, there are a wide range of different types of tests used, and the paper briefly outlines the current state of the art GNSS tests used across the industry, and the issues and benefits of the different tests, together with the type of test equipment used. GNSS Receivers used in the cellular industry have now been enhanced to support both GPS and Glonass, and the infrastructure to support the assistance for A-Glonass is being rolled out. The basic test standards for these types of systems are available, but the specific industry types of tests for these systems are still in development In the near future, GNSS Receivers used in cellular phones will be supporting four or more constellations, and possibly also on frequencies additional to the L1 band, covering some or all of: ? GPS ? Glonass ? Galileo ? Beidou Phase 2 (Compass -1) ? Beidou Phase 3 (Compass -2) ? QZSS ? SBAS ? IRNSS Additionally location information, or at least additional measurements, is rapidly becoming available from sources other than just the GNSS, for example: ? Cellular Location ? MEMs Sensors ? Wi-Fi These additional sources can also aid in providing initial states and information for the position-determination system, in addition to the common assisted-GNSS information provided by the network. This will be particularly important in indoor and other environments where GNSS performance is compromised. Further developments will also allow the sending of additional information to the device in order to improve the accuracy of the position. This additional information could include accurate time, altitude information and other parameters. The other technologies integrated on the cellular platform can give advantages for a combined or hybrid solution, but also present issues such as adjacent channel interference, which require testing as part of the platform approval. The paper proposes several possible test standards covering these new constellations, and also includes the other possible sources of location information. It outlines how the test standards match the industry requirements for repeatable test specifications, but also ensures that the user experience is considered. The proposed test developments particularly focus on the requirements for repeatable tests in the urban environment, and the type of supporting test equipment required will also be discussed. Options for test equipment currently include GNSS Simulators, GNSS RF-Replay systems, cellular and Wi-Fi simulators and possibilities for sensor logging and replay. Suggestions for appropriate levels of test equipment for the different specifications are proposed, together with discussion on any appropriate live signal tests.
Published in:	Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012) September 17 - 21, 2012 Nashville Convention Center, Nashville, Tennessee Nashville, TN
Pages:	141 - 150
Cite this article:	Anderson, P., Anyaegbu, E., Catmur, R., "The Future of Multi-Constellation GNSS Test Standards for Cellular Location," Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012), Nashville, TN, September 2012, pp. 141-150.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In