Efficient assignment of multicast groups to publish-subscribe information topics in tactical networks

A key challenge in a network-centric tactical environment is disseminating information related to sensors, situational awareness, and command and control to the appropriate receivers in a timely, reliable and efficient fashion. IP multicast is the transport mechanism used for information dissemination. It is typically the case in tactical networks that the number of IP multicast addresses available for use is limited and it becomes necessary to assign multiple information topics to each multicast address. This necessitates use of an efficient assignment algorithm during network planning to minimize the dissemination of unwanted information in order to decrease the unnecessary use of network resources and reduce the information load on the receiving nodes. This paper describes an efficient algorithm for assigning information topics to multicast groups taking into consideration the overlapping information needs of subscriber nodes and network bandwidth that will be consumed in the dissemination of each topic based on its size and frequency of publication. The assignment algorithm supports unique requirements of tactical networks: for an information topic, the subscribers may not be related by echelon hierarchy and the criticality of information may vary with subscribers. The assignment algorithm uses the simulated annealing technique to compute an optimal address assignment.