Dual-bridge: A mode-adaptive operation for multi-channel utilization in wireless sensor networks

With the increasing demand on wireless communications operating at the shared and unlicensed Industrial, Scientific and Medical (ISM) band of 2.4 GHz, the coexistence problem is one of the most important issues. Wireless Sensor Networks (WSNs) based on the IEEE802.15.4 standard are among such systems which are being affected. For the past years, the idea of multi-channel utilization has been highly focused as a solution to the coexistence problem in WSNs. However, most of the existing methods try to maintain the communication link by using a scheduled channel-switching pattern. As a result, interfered node(s) can only transmit during fractions of time that non-interfered channel is allocated which leads to a low data rate. This paper presents a novel approach to multi-channel utilization called DualBridge, which is aimed at providing smooth data transfer for the sensor node(s) under interference by allowing devices to communicate using multiple channels in a “railroad switching” fashion. The proposed method extends the functionality of traditional single bridge node to allow a higher data rate by using a dual-bridge working together for data transfer across the interfered area. Simulation results show that the proposed method provides a better system performance in terms of system throughput and packet delivery fraction than that of the traditional system as well as the other multi-channel method based on the existing single-bridge node.