Novel Channel Assignment Mechanisms for WSNs in Congested ISM Bands Based on QoS
Densely populated urban areas are continuously demanding an increase in the number of new services, many of them involving wireless sensor networks (WSNs), whose applications have considerably multiplied in recent years. This dramatic increase in the use of WSNs, next to the development of considerable numbers of other technological devices that involve WSNs in their operation, such as surveillance cameras, applications for Smart Cities or smart traffic control among others, overcrowd the same ISM spectrum band used by the WSNs. Parallel to this, other very important wireless devices of massive use, such as local area networks (WLAN), Blue Tooth among others occupy the same already congested spectrum band. This congested scenario could be subject to uncontrollable levels of interference, leading to severe limitations on its performance. On this basis, it is imperative the analysis of these type of future scenarios, under extreme capacities; and, evaluate their operational limits, to be able to find the appropriate mechanisms that will allow WSNs to overcome these restrictions. This paper analyzes the performance of WSNs considering dense urban scenarios under severe levels of congestion; then, under these extreme considerations, two novel channel assignment mechanisms have been presented; one Optimum solution considered as benchmarking and a heuristic one that allows the improvement of the performance of the WSNs.