Geo-addressing and Geo-routing for Vehicular Communications
To increase the road safety in Europe while traffic and driver's concentration demand also rises, the EC and the automotive industry have committed to halve the loss of life by 2010. The GeoNet project set out to significantly contribute to this goal by implementing a reference implementation of a geographic addressing and routing protocol with support for IPv6 to be used to deliver safety messages between cars but also between cars and the roadside infrastructure within a designated destination area.
While the CAR 2 CAR Communication Consortium has invested significant effort into the specification of a car-to-car communications mechanism suitable for safety applications, its mandate does not extend beyond defining a specification. At the same time, ongoing projects like SafeSpot would need an actual implementation to rely on whereas other such as CVIS are developing a communication architecture relying on the maintenance of a constant access to the Internet over IPv6.
GeoNet set otu to bring the basic results from the work of the CAR 2 CAR Communication Consortium to the next step, by further improving these specifications and creating a baseline software implementation interfacing with IPv6.
The goal of GeoNet was to implement and formally test a networking mechanism as a standalone software module which can be incorporated into Cooperative Systems. This implementation shall enable transparent IP connectivity between a vehicle and the infrastructure, even in cases when delivery must be hopped over several vehicles or cached along the way. GeoNet not only benefited from previous work within these projects, but also provided a support for the integration of its solution. This collaboration was sketched in support letters.
Once GeoNet fulfils the existing implementation gap of geo-addressed networking, ongoing and future projects for Cooperative Systems can maintain their focus on architecture design, application development and field trials.
From a safety perspective, GeoNet implemented the networking mechanism for reliable and scalable delivery of such information to all vehicles for whom it is relevant. Its facilitation of cooperative awareness enabled safety applications to initiate warning or mitigation actions when required and to identify transaction partners or destination area for dissemination of their messages.
From IP networking perspective, the design goal is to provide vehicular message routing, which is efficient under quickly changing topology, and works without excessive amount of air interface signalling. At the same time already standardised IPv6 NEMO system may perform its task seamlessly, as underlying geographic networking may present the multi-hop vehicular routing part as a virtual single-hop connection between a road-side unit and vehicles in its service area.
Geographic addressing and routing is a networking mechanism distributing the information to nodes within a designated destination area. A novel routing protocol is in charge of information dissemination over multiple hops until every vehicle has received this information within the destination area. Each vehicle evaluates whether re-transmission is required and executes it with proper timing if needed.
In this concept, individual nodes' addresses are linked to their geographical position which is used by forwarding algorithms to transport data packets towards the destination node ('geographical unicast' or 'geounicast'). Also, geographical positions are used to define a geographical region that can be linked to nodes, either to address all nodes in the region ('geographical broadcast' or 'geocast') or to address anyone of the nodes in the region ('geographical anycast' or 'geoanycast').
Produced a reference GeoNetworking specification for the standardisation within organisations. GeoNet users may use the specification as guidance for performing troubleshooting, if the need for such procedure arises. The final GeoNet specification document has been contributed to the ETSI Intelligent Transport Systems (ITS) standardisation committee.
GeoNet developed two independent implementations (Hitachi+ NEC). The GeoNet partners Hitachi and NEC brought into the GeoNet project a strong background and expertise of earlier developments in the area of GeoNetworking. These partners developed two independent Car to Car (C2C)Net software modules, utility software and corresponding documentation. This is useful for standardisation, but also for exploitation since their characteristics can be compared and a quality competition of implementations is initiated.
An efficient and integrated mobilty system: Secure Transport