Back to Main Page, Next: Middleware for the Semantic Web

Mobility in Publish/Subscribe Systems

Publish/Subscribe interaction model provides a data-centric network abstraction for developing distributed applications. By allowing applications to specify data that they are interested in receiving by name, rather then by explicit network location, makes application independent of the underlying network transport. This makes writing distributed application much easier and simpler, since the applications do not need to know explicitly about network reconfiguration. In other words, publish/subscribe paradigm allows creation of application-level network virtualization.

Research goals of this project is to study the role of publish/subscribe communication model in the emerging networking architectures. We concentrate on three areas:

For MAN/WAN networks, we have proposed several protocols that allow any existing distributed pub/sub system to efficiently deal with mobile users. We have also examined the effects of routing computations on performance of distributed pub/sub systems. Routing computations are operations of matching, covering, insertion and intersection for publications, subscriptions and advertisements commonly found in distributed pub/sub systems. For MANETs, we have developed and evaluated a reliable and fault tolerant distributed pub/sub system. This was the first reliable content-based routing solution for ad hoc networks. We think that content-based routing is particularly well suited for this kind of environment as it allows applications to be isolated from network effects.

We use NS2 network simulator as the platform to evaluate the mobility protocols.