%0 Journal Article
%T MAC-Aware and Power-Aware Image Aggregation Scheme in Wireless Visual Sensor Networks
%A Yui-Liang Chen
%A Hong-Hsu Yen
%J Journal of Sensors
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/414731
%X Traditional wireless sensor networks (WSNs) transmit the scalar data (e.g., temperature and irradiation) to the sink node. A new wireless visual sensor network (WVSN) that can transmit images data is a more promising solution than the WSN on sensing, detecting, and monitoring the environment to enhance awareness of the cyber, physical, and social contexts of our daily activities. However, the size of image data is much bigger than the scalar data that makes image transmission a challenging issue in battery-limited WVSN. In this paper, we study the energy efficient image aggregation scheme in WVSN. Image aggregation is a possible way to eliminate the redundant portions of the image captured by different data source nodes. Hence, transmission power could be reduced via the image aggregation scheme. However, image aggregation requires image processing that incurs node processing power. Besides the additional energy consumption from node processing, there is another MAC-aware retransmission energy loss from image aggregation. In this paper, we first propose the mathematical model to capture these three factors (image transmission, image processing, and MAC retransmission) in WVSN. Numerical results based on the mathematical model and real WVSN sensor node (i.e., Meerkats node) are performed to optimize the energy consumption tradeoff between image transmission, image processing, and MAC retransmission. 1. Introduction 1.1. Motivation The wireless sensor networks (WSNs) are a blooming technology where it can probe and collect environmental information, such as temperature, atmospheric pressure, and irradiation to provide ubiquitous sensing, computing, and communication capabilities. Besides collecting these scalar data (e.g., temperature) from the environment, a newer trend on the WSN is to deploy sensor node with camera to capture and transmit the image data back to the sink node. Thanks to the rapid advancement of sensor technology and the proliferation of consumer electronic devices (e.g., smartphones) equipping the sensors, sensor nodes can send the captured images to provide richer information on sensing and monitoring. This kind of camera-based sensor networks is known as the wireless visual sensor networks (WVSNs). WVSN consists of tiny camera sensor nodes, embedded processor, and wireless transceiver [1]. The WVSN is totally different from traditional WSN in three ways. (1) New definition of data source nodes: in traditional WSN, when event occurs, the nodes within the sensing range of the event will sense the event and become the data source nodes
%U http://www.hindawi.com/journals/js/2013/414731/