No abstract

No abstract

No abstract

Abstract-This paper presents a novel method to disseminate sensor data in a wireless sensor network, called D3 (Data-centric Data Dissemination). The method combines the advantages of data-centric routing like SPIN and directed diffusion and energyefficient MAC protocols such as S-MAC and T-MAC. The protocol's strengths are its energy-efficiency and its simplicity. Messages are transmitted using broadcasting only, reaching as many nodes as possible with the least energy. Furthermore, D3 easily accommodates energy-dependent traffic balancing and data aggregation, crucial to prolong the lifetime of a sensor network. I. INTRODUCTION Wireless sensor networks [1], [2]have experienced increasing attention in academic, industrial and military environments over the past few years. These networks promise an easy-todeploy, easy-to-use and moreover, low-cost means to remotely monitor environments. Furthermore, sensing accuracy can be improved significantly by processing and combining collected data within the network itself. Finally, the network can be made robust to the failure of individual nodes, which ensures that the lifetime and proper operation of the network is not limited to the lifetime of one node in particular.Applications, either envisioned or already realized, are generally related to the remote monitoring of a, possibly inaccessible or hostile, environment. Examples are an aqueous surveillance system for a drinking water reservoir [3], a wildlife habitat observation system [4], and a network to monitor the behavior of glaciers [5]. Additionally, numerous military applications are envisioned such as a battlefield data collection network as described in [6].In all the aforementioned applications, the network consists of tens to millions of tiny devices. Each device carries one or more sensors and has limited signal processing and communication capabilities. Usually, the devices are powered by batteries and can thus only operate for a limited time period. Key to implementing a network with such devices is that energy, computing power and communication bandwidth are scarce. Therefore, light-weight, scalable, energy-conserving communication protocols are essential to the successful operation of the network. Fast deployment of such a network and robustness against device failures require an ad-hoc network that is self-organizing. In general, radio communication (both transmitting and receiving) is generally the operation that consumes the most energy in a device.Conventional ad-hoc address-oriented communication protocols, such as IEEE 802.11 [7], generally consume too much energy or poorly support multi-hop networks. In [8] and [9] the authors propose a new data-centric approach for the dissemination of data in sensor networks. At the same time, numerous

This paper presents the results of a study on the effects of data aggregation for multi-target tracking in wireless sensor networks. Wireless sensor networks are normally limited in communication bandwidth. The nodes implementing the wireless sensor network are themselves limited in computing power and usually have a limited battery life. These observations are recognized and combined to come to efficient target tracking approaches. The main question to be answered is how to accurately track multiple targets crossing an area observed by a wireless sensor network, while limiting the amount of network traffic. Limiting the amount of network traffic reduces the required bandwidth and reduces the required energy. Various computing power aware data aggregation strategies are researched. They have been tested in a simulation environment and compared with each other. The results of the simulations clearly show the benefit of the new data aggregation strategies in terms of energy consumption and tracking accuracy.