Linear multicasting in dynamic networks

Multimedia services, available in wired infrastructure, can now be extended to the users of wireless networks. Emerging solutions make the integration of static and mobile networks applicable, with a guaranteed quality level, but new problems have to be faced in this kind of hybrid architecture. In integrated wired and wireless networks, characterized by a dynamic topology, flooding technique is typically utilized to disseminate information needed by node discovery mechanisms and routing maintenance facilities. As flooding is not efficient in the use of bandwidth, which can be a limiting factor in the successful deployment of multimedia applications, a different approach is proposed in this paper, based on the linear multicasting capabilities of the Depth-First Search (DFS) algorithm. Whenever network information has to be updated at the nodes, to preserve current connections against any occurring topology changes, DFS can be activated to operate in a new and unknown network configuration. In fact, DFS does not need any network information to support multicast communications. Furthermore, unlike flooding, DFS belongs to the family of linear multicast algorithms, that is to say, it provides a multipoint connection through a single path without bifurcations. Such a path, that implies the absence of any packet copying process, crosses hop by hop all the addressed nodes using a low cost route and by minimum use of network resources. (C) 1999 Elsevier Science B.V. All rights reserved.