Dimensioning of Wireless Sensor and Actuator Networks for Guaranteed Delivery Time

Wireless sensor and actuator network (WSAN) applications are used in many critical scenarios. For instance, upon receiving an over-threshold pressure value, the control station of a gas separation plant issues a command to corresponding actuators to close gas valves to prevent a fire accident. In such control-loop systems, messages must be transported reliably within a tight deadline. This paper presents two components: a new network dimensioning method and a simple MAC protocol, to support control-loop systems in WSANs. The dimensioning method is used to specify the worst-case network topology, traffic and node forwarding rates prior to a network deployment. The MAC protocol is designed to ensure that the specifications and design assumptions are not violated in a subsequent deployment. The experimental evaluation clearly indicates that messages are delivered within the guaranteed delay bound.