Mobile hosts have a direct participation multicast group managing unit for managing a multicast group in which the mobile hosts participate in a form of conducting multicast communication directly from a network out of a plurality of networks in which the mobile hosts themselves currently exist, an indirect...http://www.google.co.uk/patents/US6477149?utm_source=gb-gplus-sharePatent US6477149 - Network system and method of controlling multicast group participation of mobile host
