Vehicle-Roadside Component

Hardware

Development and installation of the onboard equipment (OBE) system and components are the responsibility of car company stakeholders. At this writing, the OBE system is notionally given, and further definition and correction as necessary will be included in subsequent iterations.

Figure 3-1 VII California World Congress Demo Architecture

Per Figure 3-1, the vehicle has its onboard equipment suite, consisting of a driver, drivervehicle interface, a suite of equipment comprising the OBE, and other VII positioning and communications components.

The vehicle positioning and time synchronization will be done through an onboard global positioning system (GPS) unit, which will include a coaxial antenna connector. The positioning requirements from use cases, e.g., “WhichLane”, may predicate whether companion roadside equipment is needed, e.g., local differential correction, Wide Area Augmentation System (WASS) or use of High Accuracy Nationwide Differential GPS (HA NDGPS).

For the OBE’s, the basic communication system is a DSRC Wireless Access in Vehicle Environments (WAVE) radio, hereafter defined as a Wave Radio Module (WRM).

To ensure compatibility with the OEM’s test radios for the OBEs, Caltrans has purchased and will install 50 WRM’s developed by the Collision Avoidance Metrics Partnership (CAMP) and Denso. While the Denso WRM do not map completely into the emerging DSRC 802.11p standard, they will be the VII California standard radios through at least the World Congress demonstration.

Outside the WRM and antenna, the OBE will also include other potential principal
components:

• DSRC amp and antenna
  o MCX coaxial DSRC antenna connector
  
• Other wireless transceivers: radio card plus amp and antenna (e.g., 802.11b/g)
  o MCX coaxial 802.11b/g antenna
  
• GPS for positioning and UTC time synchronization
  o Including MCX coaxial GPS antenna connector
  
• OBE processing equipment and software
  
• Power
  o 110 Volt power
  o AC to DC power supply
• Connection point for ground
  
• Separate enclosure (potential)

The above list of components is not complete and needs further definition from car OEM stakeholders, currently DaimlerChrysler and Volkswagen/Audi.

The on-board equipment will assemble information from various sensors inside the participating vehicles and communicate this information to the roadside. The information that will be communicated will be that set of information that meets the requirements of the selected World Congress use cases, as well as the needs of the participating OEMs. For the Vehicles as Probes use case, the following information will be needed:

• Vehicle ID
  
• Location(s)
  
• Heading(s)
  
• Time(s)
  
• Speed(s)

The information sent by the vehicles to the roadside unit will be in the form of a message or block that will contain the above data, as well as data of proprietary interest to the participating OEMs. The roadside unit will send each block of data received to a router which will transmit each block to its intended destinations, including the 511/TravInfo® TIC. In order to protect its proprietary interests, each participating OEM will encrypt its proprietary data and provide a unique identifier such that this data goes only to it and the 511/TravInfo® TIC, and so that the proprietary data cannot be read at the 511/TravInfo® TIC. For the World Congress demo, OEMs will manage data security needs for the OEM specific message sets. Security for non-OEM data will not be implemented but will be evaluated for the subsequent testbed infrastructure and implemented accordingly.

In addition, the OBE will receive travel time and incident information sent from 511/TravInfo™ through the roadside unit and provide it to the driver through either an audio or visual display. Message set definition including site specific broadcast parameters will be developed during the requirements and detailed design stages of the California VII program.