Download Free PDF View PDF
Download Free PDF View PDF
In current scenarios the demand for WSN had rapidly increased in various applications like weather monitoring, petroleum and military due to low power, small size, light weight, and wireless sensors. However, these inexpensive sensors are equipped with limited battery power and thus constrained in energy. One of the major issues with WSN is that one need to increase the lifetime of network. Generally, lifetime of network is defined as the time whenever the first node fails to send its information to base station. This issue can be resolved by implementing data aggregation technique as it decreases data traffic and further saves energy by merging multiple incoming packets into a single packet whenever the sensed information are highly correlated. Numerous researches have been carried out to further extent network lifetime. I. INTRODUCTION A wireless sensor network is typically composed of a large number of sensor nodes, which may be densely deployed either inside the phenomenon or very close to it, depending on the field of their usage. The position of sensor nodes need not be engineered or predetermined. This envisages random deployment in inaccessible terrains or disaster relief operations. On the other hand, this also indicates that sensor network protocols and algorithms need to possess self-organizing capabilities. Another unique feature of sensor networks is the cooperative effort of sensor nodes. Instead of sending the raw data to the nodes responsible for the fusion, sensor nodes use their processing abilities to locally carry out simple computations and transmit only the required and partially processed data. Realization of these and other sensor network applications require wireless ad hoc networking techniques. Although there have been a number of protocols and algorithms proposed for traditional wireless ad hoc networks, they are not well suited for the unique features and application requirements of wireless sensor networks. The differences between sensor networks and ad hoc networks are outlined below: The number of sensor nodes in a sensor network is higher than the nodes in an ad hoc network. Sensor nodes are densely deployed as compared to ad-hoc nodes. Sensor nodes are more prone to failures. The topology of a sensor network changes very frequently. Sensor nodes mainly use broadcast or multi-hop communication paradigm whereas most ad hoc networks are based on point-to-point communications. Sensor nodes have limitations of power, computational capacities, and memory. Sensor nodes may not have global identification (ID) because of the large amount of overhead and large number of sensors. Designing suitable routing algorithms for different applications, fulfilling the different performance demands has been considered as an important issue in wireless sensor networks. In these context many routing algorithms have been proposed to improve the performance demands of various applications through the network layer of the wireless sensor networks protocol stack [3, 4], but most of them are based on single-path routing. In single-path routing approach basically source selects a single path which satisfies the performance demands of the application for transmitting the load towards the sink. Though the single path between the source and sink can be developed with minimum computation complexity and resource utilization, the other factors such as the limited capacity of single path reduces the available throughput [5]. Secondly, considering the unreliable wireless links single path routing is not flexible to link failures, degrading the network performance. Finding an alternate path after the primary path has disrupted to continue the data transmission will cause an extra overhead and increase delay in data delivery. Due to these factors single path routing cannot be considered effective technique to meet the performance demands of various applications.
Download Free PDF View PDF
Wireless sensor network is an emerging technology which has an immense scope of research and development. It has the potential of quick capturing, processing and transferring data with high resolution to the base station. WSN consists of multiple sensor nodes, these nodes have low storage capability and limited battery life which dies due to the computation and transmission of data. It is not feasible to replace these batteries due to their placement in isolated areas. In this paper we will emphasize on maximizing energy efficiency and improvement of life span of network. Clustering is the technique which balances the load on sensor network and reduces energy dissipation. LEACH is one of the selforganized clustering routing protocols which will be explored and modified. Further we will compare various LEACH protocols on the basis of their features and we will throw some light on future possibilities and outdo
Download Free PDF View PDF
