scope:

The present document specifies the transmission of IPv6 packets over the ETSI GeoNetworking protocol [i.25] via a protocol adaptation sub-layer referred to as the GN6ASL (GeoNetworking to IPv6 Adaptation Sub-Layer). The scope of the present document is limited to the GN6ASL.

The techniques specified in the present document fulfil the requirements for GeoNetworking and IPv6 integration described in [3], clause 5.9. In particular, these techniques allow for the transport of IPv6 packets by ETSI GeoNetworking protocol [i.25], enabling sub-IP multi-hop delivery of IPv6 packets, e.g. in a vehicular network. As a result, the connectivity provided by point-of-attachments to IPv6 infrastructure networks is extended by means of mobile relay nodes. In addition to that, the techniques described in the present document allow for geocasting of IPv6 multicast packets.

The scope of the GN6ASL is limited to the fulfilment of the requirements for GeoNetworking and IPv6 integration described in [3], clause 5.9, by enabling an ITS station including a Geoadhoc router [5] running GeoNetworking and an IPv6-compliant protocol layer to:

1) exchange IPv6 packets with other ITS stations using link-local IPv6 addresses;

2) acquire globally routable IPv6 unicast addresses and communicate with an arbitrary IPv6 host located in the Internet, whenever an ITS station including a Geoadhoc router and including or connected to an access router [5] providing IPv6 connectivity to the Internet is reachable directly or via other relay ITS stations;

3) to perform the operations required by [20] for a Mobile Router whenever i) an ITS mobile router supporting Network Mobility Basic Support (NEMO BS) [20] is present in the ITS station and runs on top of the GN6ASL and ii) an ITS station including a Geoadhoc router and including or connected to an access router [5] providing IPv6 connectivity to the Internet is reachable directly or via other relay ITS stations.

NOTE: The present document adopts the definition of "IPv6-compliant" and "sub-IP multi-hop delivery" introduced in clause 3.1.

Extending the IPv6 basic standards [7], [8], [9], [10] and [12] to support new features is outside the scope of the present document. Extensions to NEMO BS [15] are outside the scope of the present document. Mechanisms for the dissemination of IPv6 routing information for hosts and routers not directly attaching to the network where GeoNetworking is used are outside the scope of the present document (e.g. discovery of IPv6 in-vehicle prefixes). However, the present document aims at providing the underlying support for the dissemination of such routing information, i.e. IPv6 multicast support for the network where the GeoNetworking protocol is used.

With respect to IPv6 multicast and anycast support, the present document is limited to the support required to enable distribution of IPv6 multicast and anycast traffic on a shared link. Amendments to specific IPv6 multicast forwarding mechanisms are out of the scope of the present document. However, the present document aims at not preventing existing IPv6 multicast forwarding mechanisms from being used in conjunction with the GN6ASL.

In order to facilitate the deployment of ITS systems, the present document aims at maintaining backward compatibility with pre-existent IPv6-compliant protocol implementations and NEMO BS implementations compliant with [15]. An exemplary usage of NEMO BS with the GN6ASL is overviewed in the informative annex F.

The present document does not request any assignment or reservation of IPv6 prefixes or suffixes for specific purposes.

The mechanisms specified in the present document are distinct from but compatible with the IPv6-related functionalities in [i.24], which specifies how IPv6 networking is generally operated in ITS stations. The techniques described in the present document provide a way to transport IPv6 packets that is fully compatible with the IPv6 specifications and pre-existing implementations, and hence is compatible with [i.19].