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Operating Principle

In the US version, the telematic control unit features a combined transceiver module NAD (network access device). The NAD operates in accordance with the AMPS/CDMA standard with the frequencies 800/1900 MHz.

The TCU features an antenna selector switch for the AMPS/CDMA antenna. The TCU operates in the digital CDMA network. If a sufficient network supply cannot be ensured, the TCU switches over to the AMPS network. The widespread AMPS network is used especially in rural areas.

If the option Professional navigation system is not installed, the TCU will be fitted with an internal GPS receiver. The GPS receiver is connected to the GPS antenna that is integrated in the roof antenna. In the US version, the telephone/telematics functions are available in three stages:

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