Event monitoring services are rapidly gaining importance in many application domains rangingfrom real time monitoring systems in production, logistics and networking to complex event monitoringin finance and security. However, the current event monitoring services do not have thecapabilities needed for emerging domains of applications. This dissertation is devoted to study andaddress the challenges involved in providing event monitoring services on decentralized and delaytolerant networks.First, we consider the problem of event aggregation and redundancy elimination in decentralizedbroker overlays.We propose two systems for efficient event aggregation and redundancy elimination.The first system, Agele, presents our ideas for event gatherer, a designated broker in therouting graph that acts as a proxy sink for all messages of a particular event. The second system,Caeva, is built on Agele. Caeva exhibits three novel features: multiple distributed aggregators,adaptive aggregator placement and customized subscriber notification schedule.Second, we consider the complex event detection on delay tolerant networks. The existing workon complex event detection employs a centralized approach, whose limitations are exacerbatedwhen the underlying environment is delay tolerant networks with long latency and intermittentconnection. Hence, the event detection system has to be extensively redesigned for the adaptationto underlying environment. We propose a novel multi-level framework called Comet for complexevent detection services on delay tolerant networks.The evaluation has demonstrated that our solutions to the challenges in the advanced eventmonitoring services are effective and efficient.
