We offer the notion of application-aware services "on top" of existing overlay networks to support the special requirements of a particular class of application or user community such as global sensing system, multimedia streaming appication users. For example, in emerging Distributed Collaborative Adaptive Sensing (DCAS) systems which are used for detection and prediction of hazardous weather using a network of radars, a variety of data is distributed to geographically distant end-users, sensors, various processing nodes and storage units under dynamic network conditions including network congestion, link degradation/outage, and variable cross-traffic along wired and wireless links. Moreover, in many of these systems, the critical sensor data has to be distributed to multiple end users, and the end-users have differing QoS requirements for the data based on the ultimate use of the data. Such systems with these properties need to employ a new data-dissemination mechanism that is able to adapt to the various network conditions in an application-specific manner to achieve best feasible QoS for the end users, and to provide acceptable communication quality and robustness for the data distribution.

The applications using the overlay network have to be able to configure the functionality of overlay nodes to meet the application-specific goals by deploying application-aware processing. To deploy application-aware services "on top" of existing overlay networks a flexible and efficient mechanism is required. We propose AWON architecture in order to realize such application-aware services on top of overlay networks. The API of the AWON offers a layer of abstraction between an application and the underlying dynamics of the network infrastructure. It is desirable for the API to support application-aware adaptation in the overlay network, with each participating node possibly performing different application-aware operations to meet the overall goals of the application(s). The API has to support node configuration in an application-aware manner, with each node being configurable to support multiple applications concurrently. There is also a need for communication between the application and the underlying overlay layers for supporting application-specific QoS requirements. Using the API the applications can communicate with underlying overlay network.