The Adaptive Demand-Driven Multicast Routing Protocol for Mobile Ad Hoc Networks (ADMR)
Jojeta Jetcheva, David Lloyd Johnson · 2001
The Adaptive Demand-Driven Multicast Routing protocol (ADMR) has been designed specifically for use in the ad hoc network environment. Multicast routing state in ADMR is dynamically established and maintained only for groups that have at least one receiver and one active sender in the network. Each multicast data packet is forwarded along the shortest-delay path with multicast forwarding state, from the sender to the receivers. Senders are not required to announce their intention to start or stop sending data to the group, or to join the group to which they wish to send. Receivers dynamically adapt to the sending pattern of senders and mobility in the network in order to efficiently balance overhead and maintenance of the multicast routing state as nodes in the network move or as wireless transmission conditions in the network change. State for groups whose senders have become inactive or whose receivers have left the group is expired automatically without the need for control signaling or application- level notification at the source. ADMR also detects when mobility in the network is too high to efficiently maintain multicast routing state, and instead reverts to flooding for a short period of time it determines that the high mobility has subsided.