An Routing Algorithm in Wireless Sensor Networks Using Cluseter Tree Topology

Introduction

At present, there has been a mounting requirement for connectivity between the distributed devices employed for remote instantaneous monitoring and control.

This requirement and the development in electronics and wireless communications have encouraged the growth of Wireless Sensor Network (WSN) technology as explained in Alwan& Agarwal (2009). A WSN is an integration of embedded system technology together with sensor technology, distributed computing and wireless communication technology. They allow superior grain inspection of the ambient surroundings at an inexpensive cost much lesser than currently possible. In case of hostile surroundings where human involvement may perhaps be too hazardous, sensor networks might offer a robust service. Sensor networks are intended to send out data from an array of sensor nodes to a data storehouse on a server. The developments in the integration of Micro-Electro-Mechanical System (MEMS), moreover Microprocessor and Wireless Communication technology have facilitated the use of large-scale WSNs. WSN has the adequate power to design several new applications for the purpose of managing emergency, military, and tragedy relief processes that necessitates real time information for effective coordination and planning.

Sensor nodes have the potential of sensing, data processing, and transmission, which facilitate instantaneous monitoring of the phenomenon of attention, and control by actuators inside a large-scale area by collaborating with each other as discussed in Megerian & Potkonjak (2003) WSNs possibly will include numerous categories of sensors like thermal, magnetic, seismic, infrared, visual and acoustic radar, capability to supervise an extensive variety of ambient circumstances. Despite the fact that every individual sensor possibly will have severe resource restriction in terms of memory, communication, energy and computation capabilities; huge number of them might together observe the physical world, distribute information upon critical environmental occurrences, and process the information on the fly as discussed in Akyildiz et al (2002).

The major characteristics of sensor networks comprise low energy consumption, low cost, cooperative effort and self-organizing operation as mentioned in Lambrou & Panayiotou (2009). These characteristics make it feasible to organize sensor nodes in harsh and unreachable surroundings, at the same time achieving long lifetime operation with the help of batteries and solar panels as the energy supply. The characteristics described above allow an extensive range of potential applications for WSNs, like industrial control and monitoring, precision agriculture, home automation, health and environmental observation. The overview of the WSN architecture is portrayed in the figure 1.1.

Figure 1. An Overview of a WSN

Figure 1.1 The Components of a Sensor Node

A sensor node normally includes a processing unit, a sensing unit, a radio frequency transceiver unit and a power supply unit. Figure 1.2 illustrates the component chart of a sensor node. In case of the processing unit, which typically incorporates an on-board microprocessor and also memory, manages the function of the other units and executes simple data processing. In case of the sensing unit, the sensors are linked to the processing unit by means of analog-to-digital converters, which transform the analog signals produced by the sensors into digital signals that the microprocessor can understand. The radio frequency transceiver unit is the gateway that swaps over data with other sensor nodes by means of a wireless communication channel. These components might possess different features in terms of input voltage and current utilization, and the power supply unit offers the suitable voltage and current intensities. In case of the power supply unit, energy storage constituents (e.g., a battery) are adjusted by the appropriate electrical circuitry and energy harvesting constituents (e.g., a solar panel). In accordance with the particular application, other units can be too added to the sensor node, like a location finding system and a mobilize, as discussed in Chalhoub & Mission (2010) which maintain the request for precise geographical information and the mobility of a sensor node, correspondingly