We claim:
1. A method for a node in a wireless adhoc network (100) comprising the
procedures of;
subscribing by said node to at least one multicast group, said multicast group including at least a portion of a plurality of nodes in the wireless ad hoc network, each said nodes being designated with a dynamically determined role, a plurality of said nodes being designated with the role of a super-node (102,106,110,112,116,118) and the remaining of said nodes being designated with the role of ordinary-nodes (104,108,114,120,122), said super-node designated nodes forming a routing backbone of said network, each of said nodes storing multicast information, each ordinary-node attempts to have at least a minimal one-hop local super-node number of one-hop super-node neighbors and each super-node attempts to have at least a minimal one-hop backbone super-node number of one-hop super-node neighbors, at least some of said ordinary nodes have at least two one-hop super-nodes neighbors;
updating said stored multicast information; and
synchronizing respective stored multicast information among said super-nodes by producing at least one backbone multicast update messages and flooding said backbone with said backbone multicast update message when a node is designated with said role of super-node, said backbone multicast update message at least including changes that occurred to said stored multicast information, said flooding including determining by a super-node designated node the next hops of a flood packet in said backbone of said network, said flood packet at least including said backbone multicast update message,
wherein said determining by a super-node designated node the next hops of the flood packet in said backbone of said network includes the sub-procedures of:
receiving a trailer list, said received trailer list including entries of identification representations of a portion of super-nodes that received said flood packet;
producing a transmission list, said transmission list including one-hop super-node neighbors of said receiving super-node not listed in said received trailer list, and to which said receiving super-node intends to transmit said flood packet;

producing an updated trailer list; and
transmitting said flood packet, including said updated trailer list, to said one-hop super-node neighbors listed in said transmission list.
2. The method as claimed in claim 1, wherein said procedure of updating
said stored multicast information when said node is designated with said role of super-node includes the sub-procedures of:
detecting an event in a one-hop neighborhood of said super-node designated node, said super-node designated node being registered with said at least one multicast-group, said event being either an ordinary-node designated node joining said one-hop neighborhood, or an ordinary-node designated node leaving said one-hop neighborhood, or a subscriber subscribing with said super-node designated node to one of said at least one multicast group, or a subscriber un-subscribing with said super-node designated node to either said or another one of said at least one multicast group;
transmitting a local multicast update message to said one-hop ordinary-node when said event is detected as an ordinary-node designated node joining said one-hop neighborhood or said super-node designated node;
repeating from said procedure of detecting an event;
determining if said subscribing subscriber is the first subscriber with said super-node designated node to one of said at least one multicast group, when said event is detected as said subscriber subscribing with said at least one multicast group;
repeating from said procedure of detecting an event when said subscriber is not said first subscriber;
determining if said un-subscribing subscriber is the last remaining subscriber to said multicast group, either when said event is detected as a one-hop ordinary-node neighbor leaving said one-hop neighborhood of said super-node designated node, or when said event is detected as said subscriber un-subscribing to either said or another one of said at least one multicast group;
repeating from said procedure of detecting an event when said subscriber is not said last subscriber;

updating a backbone multicast registration table when said subscriber is either the last subscriber or the first subscriber, with said super-node designated node, to said multicast group; and
repeating from said procedure of detecting an event.
3. The method as claimed in claim 2, wherein said subscriber is an ordinary-node designated node.
4. The method as claimed in claim 2, wherein said subscriber is a host coupled with said super-node designated node.
5. The method as claimed in claim 1, wherein said local multicast update message includes a list of all of said at least one multicast group in said network, and which of said at least one multicast group said super-node designated node serves.
6. The method as claimed in claim 1, wherein said backbone multicast update message further includes multicast groups that said super-node serves.
7. The method as claimed in claim 4, wherein said backbone multicast update message further includes new ones of said at least one multicast group that said super-node serves.
8. The method as claimed in claims 1, wherein, when said node is designated with said role of ordinary-node, said procedure of subscribing to a multicast group further includes the sub-procedures of:
determining a multicast group for subscription;
detecting a one-hop super-node designated node neighbor, of said ordinary-node, serving said determined multicast group;
detecting one-hop super-node designated node neighbors, of said ordinary-node, when a one-hop super-node designated node neighbor, serving said determined multicast group, is not detected;

selecting at least one of said detected one-hop super-node designated node neighbors for multicast subscription; and
transmitting a multicast subscription request message to said selected at least one one-hop super-node designated node neighbor after said procedure of selecting.
9. The method according to claim 1, wherein said flood packet further
includes the originating source super-node designated node of said flood packet
and an identifier of said flood packet or said flood packet.
10. The method as claimed in claim 9, further comprising the procedures of:
determining said originating source super-node of said flood packet;
determining if said flood packet was previously received; and
disregarding said flood packet when said receiving super-node is the
originating source super-node of said flood packet, or when said receiving super-node previously received said flood packet.
11. The method as claimed in claim 9, wherein said super-node determines that said flood packet was previously received according to said identifier of said flood packet.
12. The method as claimed in claim 1, wherein said transmission list excludes said receiving super-node.