Motorola 8900 User Manual - Page 68

GPS Interface GPS Interface The C24's integrated GPS receiver can provide location and position information based on the Global Positioning System satellites. The GPS interface supports the following modes of operation: • Autonomous - In this mode the GPS receiver operates stand alone, regardless of CDMA network availability. The C24 searches and detects available satellites, and calculates the positioning information on its own. • Assisted - In this mode the C24 operates in conjunction with the CDMA network to search for satellites and calculate the positioning data. • MS Assisted - The calculation is performed by the network and the position is send to the C24 device. • MS Based - C24 receive initial satellites information form the network and calculatse the position by itself. Number of satellites: 2D - When the GPS receiver is using three satellites to determine a position solution. 3D - When the GPS receiver is using four or more satellites to determine a position solution and the accurate time. Serial Configuration: The C24 has two modes of data: Binary and NMEA. Binary Mode is reported through UART1 or USB while the NMEA is through UART2 and USB. Accuracy: The accuracy must be less than 50 meters 67% of the time, and 150 meters 95% of the time. Table 2-21 gives the GPS Receiver Specifications. Table 2-21: GPS Receiver Specifications Parameter Receiver Sensitivity TTFF Autonomous TTFF Assisted Conditions Cold Start Warm Start Cold Start Warm Start Typ -155 XX = 7.5 YY = 10 XX = 8 YY = 3 Unit dBm Min Sec Sec 44 C24 Module Hardware Description December 15, 2008