Assisted GPS (A-GPS) is an enhanced position location method that uses the satellite-
based global positioning system (GPS).? A-GPS allows much faster position location by
using more precise positioning information obtained from base stations that monitor
GPS satellites constantly.? This information is called Assistance Data and allows the
mobile to determine and report back to the network its exact location within seconds as
opposed to minutes using unassisted GPS techniques.? Its development was driven by
the U.S. Federal Communication Commission (FCC) E911 requirement for quickly
providing the location of a cell phone to emergency call dispatchers.
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In addition to emergency-related position location, more mobile device applications are
emerging that use GPS technology.? Some examples are mapping, voice navigation, etc.?
More service providers around the world are implementing A-GPS in their networks to
meet emergency and customer-convenience needs.? As a result, more A-GPS capable
devices are being introduced into the marketplace.? It is important to service providers
that A-GPS operation does not interfere with cellular phone calls, especially emergency
calls.? As a result, service providers require their mobile phone suppliers provide proof of
correct operation prior to accepting these phones on their networks.
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This application note describes a test system that uses and 8960 Wireless
Communications Test Set in conjunction with an E4438C ESG Vector Signal Generator
with GPS Personality to perform the types of functional testing needed to meet service
provider proof requirements.?