ECCO aims to build an event-based middleware system over peer-to-peer networks using a multi-event broker model that adapts to mobile computing environments. Our current focus is on a delay/connection tolerant mobile ad hoc network (MANET Mesh) constructing a event-based middleware to bridge wireless sensor networks (or mobile devices carrying sensors) to Internet. A significant increase of event monitoring capabilities by wireless devices and sensors add another dimension on ubiquitous computing, requiring more complex communication mechanisms and data management. The integration of a smart WSN with the Internet or a wireless infrastructure network increases the coverage area. Without infrastructure support of end-to-end communication to convey the sensed data from a sink node to any Internet backbone node, a new type of communication is desired. Networks will be structure-less and rely on ad hoc connections between nearby nodes to establish multi-hop dynamic routes to propagate data and messages between out-of-range nodes.
MANET Mesh can collect the sensed data and pass them to invisible devices, eventually arriving to the Internet backbone node. The combination of mobile devices and ad hoc networks in MANET Mesh is best managed by the creation of highly dynamic, self-organizing, mobile peer-to peer (P2P) systems. Especially with the recent evolution of distributed event-based middleware over a P2P overlay network, the construction of event broker grids will extend a seamless asynchronous communication capability over heterogeneous network environments. As cluster heads in Wireless Sensor and Actor Networks (WSAN) become more powerful, they will join as peers in such environments.
When constructing MANET Mesh, a robust data routing protocol is understood as an important issue, but data semantics should also be integrated for efficient and accurate information dissemination. The information sensed by the devices must be aggregated and combined into higher-level information or knowledge at the appropriate point. Thus, there is a strong need of an event correlation service. In event based middleware systems, an event correlation service allows consumers to subscribe patterns of events (composite events). This provides an additional dimension of data management, improvement of scalability and performance in distributed systems. At the same time, complex temporal and spatial relationships among correlated events from heterogeneous network environments must be addressed and coordinated with WSN In-network data aggregation process. Temporal ordering in real-time is a critical aspect for event correlation in wireless ad hoc network environments.
MANET Mesh supports publish/subscribe communication, event correlation, and an ontology based event model. Epidemic style of asynchronous communication creates a backbone of MANET Mesh. Integration with event correlation will bring the mobile middleware onto the next level to perform data aggregation and distributed data filtering based on contents. Ultimately the middleware offers an open platform for users to seamlessly utilize various resources in physically interacting environments, and the total system will provide efficient coordination of data flow over dynamic heterogeneous network environments.
Publications are listed in together with other Opera publications, as well as Eiko Yoneki's homepage .