Spectrum handoff strategy for cognitive radio-based MAC for real-time industrial wireless sensor and actuator networks

摘要

A spectrum handoff or channel switching mechanism for Industrial Wireless Sensor and Actuator Networks (IWSAN) which is capable of detecting interference and hopping to another channel (in the same or other band) in a deterministic time is proposed. This is possible because the spectrum handoff strategy detects interference in the MAC layer, and can ensure the high requirements in terms of time and reliability demanded by real-time IWSAN applications. An existing cognitive radio-based MAC is used as the basis. It has been evaluated with and without the proposed spectrum handoff mechanism to assess its performance. Using Network Calculus, a theoretical analysis has been provided to determine bounds on the delay, and simulations in OPNET have been carried out in order to validate the theoretical results. Several environments have been considered in the simulation (lognormal shadowing, Rice and Rayleigh fading and interference) so as to characterize the performance of the algorithm under the most common conditions of industrial channels. The results prove the benefits of using the proposed spectrum handoff, which provides robustness and guarantees delay bounds in industrial environments with interference. (C) 2019 Elsevier B.V. All rights reserved.