A-GPS is a system where outside sources,help a GPS receiver boost performance beyond that of the same receiver in a stand-alone

The Qstarz BT-818x comes with Assisted GPS (A-GPS) A-GPS is a system where outside sources, such as an assistance server and reference network, help a GPS receiver boost performance beyond that of the same receiver in a stand-alone mode by downloading the almanac data from an assistance server. Device Size: 72.2 (L) X 46.5 (W) X 20 (H) mm LED Function: Bluetooth connection, Navigation Status, and Battery/charger status GPS Chip: MTK GPS Module Frequency: L1, 1575.42MHz C/A Code: 1.023MHz chip rate Channels: 66-CH performance tracking Antenna (Intemal): Built-in patch antenna with LNA Tracking: -165 dBm Built-in rechargeable Li-ion battery Power Charge: Mini USB Operation: 42hrs, after fully charged, in continuous Charging time: 3hrs. (Typical) Position: Without aid: 3.0m 2D-RMS<3m CEP(50%) without SA(horizontal)DGPS (WAAS, EGNOS, MSAS): 2.5m Velocity: Without aid: 0.1m/s, DGPS(WAAS, EGNOS, MSAS): 0.05m/s Time: 50 ns RMS Datum: WGS-84 Update: 1 or 5Hz in hardware (1~5Hz adjustable by software utility) Altitude: <18,000m Bluetooth V1.2 compliant (SPP profile) Class 2 (15 meters in open space) Frequency: 2.4~2.4835 GHz Power On/Off Slide switch(5Hz/Nav/Off) GPS Protocol - NMEA-0183 (V3.01) GGA, GSA,GSV, RMC(default); VTG, GLL(Optional), Baud rate 115200 bps, Data bit : 8, stop bit : 1(Default) in the box: GPS Unit Li-ion Battery Car Charger Multi-language quick guide USB Cable Warranty Card