US Patent 7698378 Service diversity for communication system

A communication transaction or use case is broken down into constituent parts, one of which can be provided, at the direction of a master service node, from the master service node or primary service path and the other of which can be provided from a support service node or secondary service path that the client station might happen to be able to communicate with. For instance, the base layer of a multimedia stream might be provided from the master node, but if its bandwidth becomes full, an enhancement layer of the stream can be provided by the support node, as directed by the master node.