COLA: A Coverage and Latency Aware Actor Placement for Wireless Sensor and Actor Networks

In addition to the sensors, wireless sensor and actor networks (WSANs) employ significantly more capable actor nodes that can perform application specific actions. In these setups responsiveness to serious events is of utmost importance and thus requires minimal latency in both data gathering and action completion. In addition, since these actions are often taken at or close to where events are detected, which can be any spot within the monitored area, the actors should strive to provide maximal coverage of the area. In this paper, we propose COLA, an actor placement mechanism that considers both the delay requirements of data collection and the coverage. COLA first evenly distributes the actors in the region for maximized coverage. Actors then collaboratively partition the sensors, forming clusters. Each individual actor then repositions itself at a location that enables minimal latency in collecting data. The effectiveness of COLA is evaluated by extensive simulations.