Fri, 2012-06-22 15:44 | 
Short Abstract of the thesis
The main purpose of this thesis is the design, development and implementation of networks that are organized based on the content of the information carrying namely based on the publish/subscribe communication standard.
The publish/subscribe communication standard is a popular way for designing distributed systems. Applications that exploit this model organized as a collection of autonomous components (customers) that interact by publishing events and by subscribing to events they are interested in. The event dispatcher (Broker - Event Broker) is responsible for the collection of subscriptions and for sending the events to subscribers. In a Pub/Sub system the delivery of the content is defined entirely by the customer, who uses expressions (filters) that allow a complex matching between the published content and the subscription of a client.
In this thesis we will consider caching techniques (caching) to enhance the performance of networks organized according to the communication standard publish/subscribe. We will also present ways to serve Subscription requesting content that is posted in the past, a feature that is not supported by any current experimental implementation of the publish/subscribe communication standard.
Finally we will discuss the problem of reliable message delivery in such networks. Specifically we will develop techniques which will ensure the proper receipt of a message to the users of an unstructured mobile network (ad-hoc networks) using the standard publish/subscribe scheme regardless of the user’s mobility or the mobility of the the brokers.
The techniques and architectures to be developed will be evaluated to their correctness and performance with experimental measurements both in a network simulator and in real experimental network (testbed) that operates based on the publish/subscribe communication standard.
