Real world testing of aggregation in publish/subscribe systems

Wireless sensor networks collecting data to monitor real life processes gain increasing attention from the scientific community. These systems promise ubiquitous computing in a digitalized world. However many problems need to be solved to achieve this dream. One of these problems is the limited battery power of the nodes and the limited bandwidth of the communication. Existing work tackle the problem of limited bandwidth by merging communication packets within the network. Based on this approach we investigate the use of application specific aggregation in publish/subscribe wireless sensor systems. We expect this approach to overcome overload situations in the network and decrease packet loss due to bandwidth exhaustion. This paper describes our architecture and evaluates the properties of our approach. We investigated specific topologies theoretically and through real-life experiments. Our results quantify the achievable event count and loss rate reduction.