Method to support multicast routing in multi-hop wireless networks
First Claim
1. A method for supporting multicast in a multihop wireless network, the method comprising:
- establishing certain nodes in the network as core source nodes, wherein the establishing step comprises;
determining whether a node should be a core source node for a multicast group, based on criteria comprising a number of activated core sources in the network, a multicast core source number threshold, a distance to a closest activated core source, a number of hop counts from the node to one of the activated core sources, an address of the node, and an address of the closest activated core source;
engaging in a multicast tree discovery or refreshing process by operating at least one of the core source nodes to broadcast a route request (RREQ) message; and
building the multicast tree or refreshing the multicast tree based on the RREQ message, and at least one route reply (RREP) message received by the at least one core source node from another node in response to the RREQ message.
8 Assignments
0 Petitions
Accused Products
Abstract
A system and method for supporting multicast in highly dynamic wireless multi-hop networks, such as ad-hoc networks, with good scalability. The system and method provide a multicast routing algorithm to work in wireless ad-hoc networks without any fixed infrastructure nodes present. In doing so, the system and method provide a technique to build a multicast source specific tree on demand, while using a core source node to limit routing overhead. The system and method further provide a repair process to reduce the latency of discovery of topology change, employ a node sequence number mechanism to differentiate between upstream nodes and downstream nodes on the multicast tree in the repair process, and provide an active joining process to reduce the latency of discovery of membership change.
92 Citations
17 Claims
-
1. A method for supporting multicast in a multihop wireless network, the method comprising:
-
establishing certain nodes in the network as core source nodes, wherein the establishing step comprises; determining whether a node should be a core source node for a multicast group, based on criteria comprising a number of activated core sources in the network, a multicast core source number threshold, a distance to a closest activated core source, a number of hop counts from the node to one of the activated core sources, an address of the node, and an address of the closest activated core source; engaging in a multicast tree discovery or refreshing process by operating at least one of the core source nodes to broadcast a route request (RREQ) message; and building the multicast tree or refreshing the multicast tree based on the RREQ message, and at least one route reply (RREP) message received by the at least one core source node from another node in response to the RREQ message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A multihop wireless communications network, comprising:
-
a plurality of nodes, some of which being multicast source nodes; and a number of core source nodes that is less than a total number of multicast source nodes in the network, the core source nodes engaging in a multicast tree discovery or refreshing process by broadcasting route request (RREQ) messages and receiving route reply (RREP) messages in response to the RREQ messages, and then building or refreshing a multicast tree based on an exchange of the RREQ message and RREP messages, wherein; one of the nodes in the network is a core source node based on criteria comprising a number of activated core sources in the network, a multicast core source number threshold, a distance to a closest activated core source, a number of hop counts from the node to one of the activated core sources, an address of the node, and an address of the closest activated core source, such that; the number of active core source nodes is less than a core source threshold number; the number of hop counts from the node to closest activated core source node is larger than a hop count threshold number;
orthe number of hop counts from the node to an activated core source node is less than a hop count threshold number and the address of the node is larger than the address of the core source node. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
-
Specification