Dedicated Short-Range Communications (DSRC), function

P82.88-2055-76

Function requirements for Dedicated Short-Range Communications in general

 Circuit 15R ON

 Transport mode not active

 Electronic Toll Collection System (ETC) card inserted

Dedicated Short-Range Communications in general

The Dedicated Short-Range Communications (DSRC) system combines the following functions:

 Payment of toll fees from the vehicle in the Electronic Toll Collection (ETC) system

 Advantages of Vehicle Information and Communication System (VICS) services

The ETC system includes not only payment at the tollbooth but also a detailed list of payments made, which is created in the head unit.

The services provided via VICS in the 5.8 GHz reception range include e.g.: 

 Warning of obstacles in stretch ahead

 Information on traffic conditions in stretch ahead

 Warning if separate lanes are merged in the stretch ahead.

 Electronic direction signs

 Messages from catastrophe early warning system (e. g. earthquake and tsunami warnings)

For dynamic route guidance, VICS information in the 2.5 GHz reception range or infrared signals are received from the Vehicle Information and Communication System (VICS) control unit and via the Dedicated Short-Range Communications control unit in the 5.8 GHz reception range. The traffic messages are stored in the traffic data recorder of the head unit, decrypted and forwarded to the navigation processor on request.

Function sequence for Dedicated Short-Range Communications

The DSRC antenna and the Dedicated Short-Range Communications control unit are installed in the vehicle for exchanging ETC and VICS data in the 5.8 GHz frequency range. The DSRC antenna allows the Dedicated Short-Range Communications control unit to communicate with the toll clearing station and to receive the VICS information in the 5.8 GHz range.

For the reception of microwave signals in a reception range of 2.5 Gigahertz or infrared signals, the Vehicle Information and Communication System (VICS) control unit is connected to the Dedicated Short-Range Communications control unit. The Vehicle Information and Communication System (VICS) control unit contains both the receiver and the antenna. The antenna receives VICS information from the VICS beacons installed at the side of the road (transmission masts).

 A special ETC card is required for the ETC system and it has to be inserted in the Dedicated Short-Range Communications control unit. All information concerning the user and the fees that have already been paid are stored on this card.

At the vehicle side, the Dedicated Short-Range Communications control unit is connected to the head unit via a universal serial bus (USB) interface. The acoustic signals, voice outputs, traffic information and display messages as part of the ETC and VICS functions are forwarded via this connection to the head unit. The Audio/COMAND display receives the display message picture signals via an HSVL line from the head unit. The head unit forwards the audio signals to the speaker system. In vehicles with code 810 (Sound system), the head unit forwards the audio signals via MOST to the sound system amplifier control unit; in vehicles with code 811 (Advanced sound system), it forwards them to the Advanced sound system amplifier control unit, which then actuates the speaker system.

In the following cases, an ETC voice message is emitted through the speaker system:

 ETC card not inserted.

 ETC card read error

 ETC card not accepted.

 ETC card reader error

 Fault in the communication with the tollbooth

 Detailed information about recent toll payments available.

 Current information on road and traffic situations available.

In the following cases, a visual ETC message (pop-up window) is shown on the Audio/COMAND display:

 Head unit booted and ETC card not inserted

 Head unit booted and ETC card inserted

 Feedback from tollbooth