Mobile Intelligence

4.5 EXAMPLE APPLICATION

In this section, we describe how the publish/subscribe model can be used to implement an example scenario. While the previous section illustrated the performance of the publish/subscribe system, here we point out the benefits of the model by showing how the publish/subscribe messaging abstractions provide a simple and powerful mechanism to achieve complex interactions among the various services.

We consider a scenario in which a municipality develops an integrated system where information about its transportation infrastructure, including road conditions, highway traffic patterns, and transit operations. Such systems have been implemented by jurisdictions such as Georgia's Department of Transportation and the Commonwealth of Pennsylvania. The goal of such a system would be to provide an integrated platform where a rich, diverse, and large volumes of data can be filtered and delivered to the interested parties in a flexible and efficient manner.

In our scenario, the information producing entities, or publishers, include sensors that monitor traffic volumes and speeds, citizens who can report on road congestion during their commute, police officers who file electronic reports from the scene of an accident or request for backup at a crime scene, or meteorological organizations that send important weather alerts. Correspondingly, subscribers include emergency response personnel that need to be notified of accidents on roads, taxi drivers that would like to know ...