Ambient network composition

Ambient networks, a product of a European union sixth framework project, is a novel networking paradigm for beyond 3G. It aims at the ubiquitous provisioning of existing and new services over any access technology and any type of network. Network composition is a core feature of ambient networks. It enables on-demand and transparent cooperation between heterogeneous networks, with little or no pre-configuration or off-line agreement. This article provides an overview of ambient network architecture and discusses composition concepts and techniques. The key concept is the composition degree. It is the level of cooperation between the composing networks. It ranges from network interworking, where each composing network keeps control of its resources, to network integration, where all of the composing networks merge into a single network. Network composition is a phased process. The techniques include the mechanisms that enable the interactions between the composing networks during each phase of the process. These mechanisms rely on general ambient network signaling, a signaling system based on the IETF next step in signaling framework. We introduce the ambient network architecture, review the composition degrees, present the composition techniques, and discuss how ambient network composition has been validated.