... DV 4 ch Bus security system with 3g ,GPS,wifi ,G-sensor Features audio/video compression technology;. 4-channel audio/video ... such asCDMA, TD-SCDMA, EVDO,HSPA+ and WIFIG-SensorBuilt-in G-Sensor moduleOthersPower ManagementSystem auto power on/off modeVehicle acc on ... Definitions 4 ch Bus security system with 3g ,GPS,wifi ,G-sensor