Agilent, ETS-Lindgren address A-GPS test
By Rick Nelson, Editor-in-Chief -- EDN, June 11, 2009
Agilent Technologies Inc has introduced GS-9000 A-GPS (assisted-global-positioning-system) test systems employing the company's 8960 wireless-communications-test set's new A-GPS-assistance-data-messaging-test capabilities. Meanwhile, ETS-Lindgren also announced an integrated test capability employing its AMS-8000 series of antenna-measurement systems and A-GPS test equipment from Agilent and other instrument vendors.
A-GPS, an enhanced position-location method, uses positioning-assistance data it obtains from base stations. With assistance data, a mobile device can within seconds determine and report back its exact location to a network. In contrast, unassisted-GPS techniques require minutes to accomplish this task. As service providers move to implement A-GPS in their networks and as vendors introduce A-GPS-capable devices, these devices require testing to demonstrate that A-GPS operation poses no interference to cellular services.
Agilent's GS-9000 A-GPS design-verification-test systems include both hardware and software for testing a device's A-GPS capabilities in a conducted environment. The hardware includes an 8960 test set and an E4438C vector-signal generator to emulate GPS satellites. The GS-9000 enables A-GPS validation, TIS (total-isotropic-sensitivity) testing, and A-GPS preconformance testing for mobile devices; the system also provides fading and SUPL (secure-user-plane-location) support. A GS-9000 Lite version omits SUPL and fading capabilities.
Within the GS-9000, the 8960 test set acts as a base station with an A-GPS message pipe for sending A-GPS-assistance-data messaging to and from the wireless device or phone under test. The phone acknowledges receipt of the data and performs location calculations, returning its location information to the 8960 test set through the appropriate UMTS (universal mobile-telecommunications system) or CDMA (code-division-multiple-access) 2000 technology-dependent protocol messaging. The system supports TIS testing in accordance with Version 3.0 of CTIA's (Cellular Telecommunications Industry Association's) “Test Plan for Mobile Station Over the Air Performance” by antenna-measurement-system providers, such as ETS-Lindgren.
For its part, ETS-Lindgren announced an expansion of the company's AMS-8000 series of antenna-measurement systems, which include a fully anechoic RF-test chamber with DUT (device-under-test) positioning equipment, antennas, instrumentation, and test-automation software. Version 1.07 of its EMQuest EMQ-100 antenna-measurement software adds support for A-GPS and other RSS (received-signal-strength)-based measurement methods. The ETS-Lindgren system supports the Agilent A-GPS test equipment and Spirent Communications' ULTS (UMTS-location-test system).
