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GPS Technology Tech Talk April, 2008 Chad Halvarson

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Agenda Current GPS and Assisted GPS (AGPS) Overview CDMA GPS Service Conclusion Q & A

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GPS Review A GPS receiver determines the travel time of a signal from a satellite Synchronization A Travel Time x c (Speed of Light ~ 3 x 10 9 m/s) = Total Distance

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GPS Requirements GPS is good for open field. Less accurate for blocked or indoor areas (urban locations). Requires line of sight to at least 3 satellites. GPS Receiver requires high processing power. Expensive GPS hardware and Pre-loaded software.

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AGPS Overview Affordable solution Uses an assistance server to calculate locations via Wireless Carrier Backbone Commonly associated with Location Based Services (LBS) over cellular networks. Location Based Servicescellular networksLocation Based Servicescellular networks E911 Mandated by FCC to provide emergency service Mobile Tracking Navigation Ability to download specific information dynamically in real-time

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Assisted GPS Overview Wireless Carrier Internet Data Communication to cellular IP Assistance Server WEB for Operator or Customer

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CDMA GPS Service Replaces expensive typical GPS receivers with inexpensive Handset Provides various mobile services Location Base Service (i.e. E911, Weather, POI etc.) Tracking Navigation

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CDMA Location Hierarchy Cell Sector Fix indoors, edge coverage Cell Sector location reports the center of the cell sector as the current position. AFLT Fix indoors AFLT is a triangulation type fix that requires contact with a minimum of three towers to establish a position. Hybrid Fix partial view of sky CDMA pilot phase measurements can be used as a virtual GPS to determine position. AGPS Fix... open sky AGPS Fix requires a minimum of three GPS measurements. Assisted because network resources are still required. Advanced Forward Link Tri-lateration

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CDMA StrengthWeakness CDMA System delivers best fix available Mid-level quality indoor fixes possible Cell Sector fix, worst case Network utilized for every initial fix Network fixes take more time (non-GPS) No off network capability

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CDMA - Network Initiated Base Station Mobile Station Satellite Features: First fix in tens of seconds Very high accuracy Available during a voice call Fallback modes available Limitations: Each additional fix requires same time as initial fix Limited to specific devices Network resources needed for every location request Network does the math to calculate position 1 R 1 R 1 R Satellite Data No Ranging Location Application Satellite Acquisition and Sensitivity Assistance Data requested & passed Network HW Raw GPS data collected & passed

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CDMA CDMA Assigns dynamic IP address for each phone Java not supported Network dependent Tracking is not supported directly by phone

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Conclusion Current GPS technology Overview GPS vs. AGPS CDMA GPS Service Offerings