Visual Sensor Networks: Critical Infrastructure Protection

Introduction

The modern advancements in CMOS technology and micro electro mechanical systems, the traditional scalar Wireless Sensor Network (WSN) equipped with low cost digital cameras, fostered it to sense and transmit the visual data and conceived as Visual Sensor Network (VSN).The camera attached sensor nodes are called as VS node, and each such node has the ability to capture, manipulate and transmit image data to the base station or sink node using intermediate forwarding nodes in multi hop fashion. Usually the sink node will act as aggregator, it is more powerful and it will act as a gateway. The schematic architecture of VSN can be as shown in Figure 1. A sensor node defined as an embedded system with one or more sensors, micro controller, transceiver and a battery unit capable of sensing, processing and transmitting. Figure 2 shows the architecture of sensor node or mote.

The VSN differs from their predecessor scalar wireless sensor networks basically in two aspects. They are type and volume of pixel data being captured and transmitted. The inherent resource constraint nature of WSN in computation, memory, bandwidth and energy makes the visual sensor network designs more challenging for image transmission.

Figure 1.

Visual Sensor Network

Figure 2.

Sensor mote architecture

Vsn Applications

In Visual Sensor Network the VS nodes are arrayed in places where they can be used to monitor environmental conditions by cooperating and communicate with each other over the wireless communication channels.

Visual Sensor Networks will enrich the existing sensor network applications such as tracking, environmental monitoring, industrial control and smart home systems. Yet quite a lot of new commercial applications are emerging out (Hemant, Subhas, Xiang & Nagender (2015), (Bambang & Song, 2010). Figure 3 shows some of the applications of VSN. They are: