Performance analysis of error detection and correction code for wireless sensor networks

Recent advances in wireless communications and electronics have enabled the development of low-cost, low-power, self-organizational, multifunctional wireless sensor networks. Wireless sensor networks can be applied to a wide range of application areas including heath, military and homeland security, environment, industry and commercial, and home. A typical wireless sensor network consists of one or more sink nodes and a large number of sensor nodes scattered in a sensor field. Each of these sensor nodes is capable to collect the data and relay the data back to the sink through a multi-hop architecture. The key challenge in sensor networks is to overcome the energy constraint since each sensor node has limited power. Hence, it is important to minimize the energy used to transmit packets over wireless links; The data transmitted from the sensor nodes are vulnerable to be corrupted by errors induced by noisy channels and other factors. Hence it is necessary to provide a proper error control scheme to reduce the bit error rate (BER) to a desired level without sacrificing other performance. Energy required for error control code has a direct impact on battery power consumption. Since high error rates are inevitable in the wireless environment, energy efficient error detection and correction scheme is vital in wireless sensor networks. However, in the literature, limited work has been focused on the study of energy efficient error control scheme; This thesis is focused on energy-efficient error detection and correction schemes for wireless sensor networks. (Abstract shortened by UMI.)

H-MAC: A Hybrid MAC Protocol for Wireless Sensor Networks

In this paper, we propose a hybrid medium access control protocol (H-MAC) for wireless sensor networks. It is based on the IEEE 802.11's power saving mechanism (PSM) and slotted aloha, and utilizes multiple slots dynamically to improve performance. Existing MAC protocols for sensor networks reduce energy consumptions by introducing variation in an active/sleep mechanism. But they may not provide energy efficiency in varying traffic conditions as well as they did not address Quality of Service (QoS) issues. H-MAC, the propose MAC protocol maintains energy efficiency as well as QoS issues like latency, throughput, and channel utilization. Our numerical results show that H-MAC has significant improvements in QoS parameters than the existing MAC protocols for sensor networks while consuming comparable amount of energy.Comment: 10 pages, IJCNC Journal 201

Does the assumption of exponential arrival distributions in wireless sensor networks hold?

Wireless Sensor Networks have seen a tremendous growth in various application areas despite prominent performance and availability challenges. One of the common configurations to prolong the lifetime and deal with the path loss phenomena having a multi-hop set-up with clusters and cluster heads to relay the information. Although researchers continue to address these challenges, the type of distribution for arrivals at the cluster head and intermediary routing nodes is still an interesting area of investigation. The general practice in published works is to compare an empirical exponential arrival distribution of wireless sensor networks with a theoretical exponential distribution in a Q-Q plot diagram. In this paper, we show that such comparisons based on simple eye checks are not sufficient since, in many cases, incorrect conclusions may be drawn from such plots. After estimating the Maximum Likelihood parameters of empirical distributions, we generate theoretical distributions based on the estimated parameters. By conducting Kolmogorov-Smirnov Test Statistics for each generated inter-arrival time distributions, we find out, if it is possible to represent the traffic into the cluster head by using theoretical distribution. Empirical exponential arrival distribution assumption of wireless sensor networks holds only for a few cases. There are both theoretically known such as Gamma, Log-normal and Mixed Log-Normal of arrival distributions and theoretically unknown such as non-Exponential and Mixed cases of arrival in wireless sensor networks. The work is further extended to understand the effect of delay on inter-arrival time distributions based on the type of medium access control used in wireless sensor networks