Priority-based transmission rate control with a fuzzy logical controller in wireless multimedia sensor networks

Wireless multimedia sensor networks (WMSNs) are usually troubled by network congestion due to large packet transmission amounts, and such congestion will not only lose data packets but also lead to too much energy consumption. Therefore, in order to enhance the transmission performance of WMSNs and reduce the delay time, it is necessary to adjust the transmission rate and control network congestion. WMSNs use different kinds of sensor nodes to collect different kinds of data. In multimedia applications, it is necessary to provide a reliable and fair protocol so as to meet the requirements of quality of service (QoS) of different formats of data. In past research, for WMSNs, priority-based rate control (PBRC) algorithms and exponential weight (EW) algorithms were used to control congestion through the adjusting of the transmission rate among different data formats. However, the weight parameter of the EW algorithm is fixed; when the change in data transmission amount is large, the difference between input transmission rate and estimated output transmission rate for the sink node will be large. In this paper, we have proposed an algorithm where a fuzzy logical controller (FLC) is used to estimate the output transmission rate of the sink node. The FLC is associated with the EW algorithm for selecting the appropriate weight parameter, and then, on the basis of the priority of each child node, an appropriate transmission rate is assigned. Simulation results show that the performance of our proposed algorithm has a better transmission rate as compared to that of PBRC, and hence, the transmission delay and loss probability are reduced; in addition, our proposed algorithm can control effectively the different transmission data types in order to achieve the QoS requirement of the system. (C) 2011 Elsevier Ltd. All rights reserved.