Distributed Scheduling for Real-Time Convergecast in Wireless Sensor Networks
Wireless Sensor Networks (WSNs) need to support real time periodic or sporadic queries of physical environments. In this paper, the authors focus on the periodic queries. For each periodic query issued by control applications in a WSN, the data from the source sensors should be collected and/or aggregated to the control center within a certain end-to-end delay. They first propose almost-tight necessary conditions for a set of queries to be schedulable by a WSN. They, then develop a family of efficient and effective data collection/aggregation algorithms that can meet the real-time requirement for Quality of Service (QoS) under resource constraints by addressing three tightly coupled tasks: routing tree construction for data aggregation/collection, link activity scheduling, and packet scheduling at nodes.