An Opportunistic MAC Protocol for Energy-Efficient Wireless Communication in a Dynamic, Cyclical Channel

As wind energy continues to expand to new frontiers in terms of the location, number, and size of wind turbines, the industry has begun to seek smarter operations and management solutions. Low-cost wireless sensing nodes could be used to support data-driven techniques for optimizing production and reducing maintenance costs, among other benefits. Wireless instrumentation makes particular sense for wind turbine blades; however, traditional wireless sensor network deployment approaches are not suitable for blades, due to physical constraints and the resulting extremely limited energy supply. Alternatively, a sensor node attached to a rotating blade could opportunistically and efficiently offload its data to a sink node, attached to the turbine tower, as the blade passes the tower. This approach results in a channel with a cyclical signal strength pattern that existing medium access control (MAC) protocols are not designed to handle. We thus present BladeMAC, a MAC-layer protocol that efficiently handles the cyclical channel problem by dynamically identifying duty-cycling opportunities based on received signal strength. In this paper, we describe the details of BladeMAC's design and our implementation and evaluation in Contiki OS and the Cooja simulation tool. We also discuss practical considerations for our deployment scenario.