Media handling aspects of multimedia conferencing in broadband wireless ad hoc networks

The emergence of broadband wireless technologies has made broadband wireless ad hoc networks a reality. Broadband wireless ad hoc networks are infrastructure-less and can be used in a wide range of scenarios in private, public, commercial, and military settings. Multimedia conferencing is an important application area. Its two main components are signaling and media handling. This article focuses on the media handling aspects or multimedia conferencing in broadband wireless ad hoc networks, with a critical review of the state of the art and a proposed novel architecture. The main components of this architecture are a distributed mixing system and a self-organizing system. The distributed mixing system is a two-level structure. The first level is a full mesh network of active nodes that act as media mixers. The second level is made up of passive nodes that rely on the mixers in the first level. Each second-level node is connected to a first-level node. The self-organizing system is based on a resource efficient scheme that provides for the automatic allocation (or deallocation) of mixers when the network grows (or shrinks). Furthermore, it enables the automatic assignment of new nodes to mixers when they join the conference. We have built a proof-of-concept prototype of the architecture and have evaluated the self-organizing system through simulations. We have simulated conferences and observed how mixers are allocated and deallocated. The simulations show that our self-organizing system utilizes resources efficiently in most cases