scope:

The present document specifies the transmission of IPv6 packets over the ETSI GeoNetworking protocol as defined in ETSI EN 302 636-4-1 [7] 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 ETSI EN 302 636-1 [3]. In particular, these techniques allow for the transport of IPv6 packets by ETSI GeoNetworking protocol given in ETSI EN 302 636-4-1 [7], enabling sub-IP multi-hop delivery of IPv6 packets, e.g. in a vehicular network. As a result, the connectivity provided by points-of-attachment 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 ETSI EN 302 636-1 [3], clause 5.9, by enabling an ITS station including a GeoAdhoc router as given in ETSI EN 302 636-4-1 [7] running the GeoNetworking protocol and an IPv6-compliant protocol layer to:

• exchange IPv6 packets with other ITS stations;

• 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;

• perform the operations required by IETF RFC 3963 [14] for a Mobile Router whenever:

a) an ITS mobile router supporting Network Mobility Basic Support (NEMO BS) as defined in IETF RFC 3963 [14] is present in the ITS station and runs on top of the GN6ASL; and

b) an ITS station including a GeoAdhoc router and including or connected to an access router as defined in ETSI TS 102 636-3 [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 IETF RFC 2460 [8], IETF RFC 4291 [9], IETF RFC 4007 [10], IETF RFC 4861 [11] and IETF RFC 4862 [13] to support new features is outside the scope of the present document. Extensions to NEMO BS as given in IETF RFC 3963 [14] 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 IETF RFC 3963 [14]. A usage example of NEMO BS with the GN6ASL is presented in the informative annex F

 The mechanisms specified in the present document are distinct from but compatible with the IPv6-related functionalities given in ISO 21210-2010 [i.20], 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 ISO 21210-2010 [i.20].