The heart (and brain) of the Hughes Telematics system is the Telematics Control Unit (TCU). The TCU is a small computer that listens in on the communications of other electronic systems in the car, then interprets and disperses that data as necessary. It accomplishes this by piggy-backing onto the Controller Area Network (CAN-bus) a communication system found in all modern cars. The CAN-bus acts as a communications bridge between all of the ECUs within the vehicle. Hughes' TCU pulls data from the CAN-bus -- this simplifies the system because it doesn't need to be wired into every single ECU in the car. It can get data from any ECU by simply listening in on the CAN-bus network. In some ways, it acts much like a mechanic's diagnostic scan tool, but it makes the data available to the driver in a number of user-friendly ways that are comprehensible to the average car owner.
The TCU itself is roughly the size and weight of a paperback book. It's designed with heat and vibration shielding, so it could be mounted anywhere theoretically, including in the engine compartment. Exact positioning depends on the model of car. Hughes has not released any details on the operating system or specific architecture of the unit, although Hughes Telematics President Erik Goldman reported that the processing power would be "in the 500 megahertz (MHz) range," similar to the ARM11 chips used in other automotive applications. Hughes has announced partnerships with IBM and Oracle, who were involved in developing the hardware and software used in the TCU and in user interface systems [source: Hughes Telematics]. It will carry on-board RAM and was designed with flexibility in mind. Via Bluetooth or possibly a USB port, the device will be able to interface with "virtually every form of human machine," according to Goldman.
Keep reading to find out how Hughes intends to keep you your vehicle hooked up.