Title: Challenges in deployment of wireless sensor networks

Summary form only given. Sensor networks are deployed for real-time monitoring of large objects and systems such as volcanoes, bird nesting habitats, chemical plants, bridges and civil structures. A network consists of a large number of sensor nodes, each of which consists of a CPU with memory, a battery, one or more sensors and a radio trans-receiver. The nodes are deployed randomly over the terrain associated with the application. The topology of the network is irregular, and the nodes communicate with the base station through multi-hop paths. In many cases, the environment is hostile, so node failure is significant, occasionally a node is temporarily unavailable, and communication incurs significant packet loss. Once the energy of a node is depleted, it can no longer contribute to the operation of the sensor network; after a significant number of nodes fail, the life of the network is over. All aspects of sensor network design have to take into account the unreliability and unavailability of nodes, the limited available energy at each node, the irregular nature of the network and the packet losses during communication. In this presentation, we will look at some aspects of sensor network topology, communication mechanisms, task allocation, mode localization and other interesting problems. All algorithms that we look at are decentralized, since frequent node failures would make any centralized algorithm unviable. The algorithms also need to be robust, and to take into account the redundancy in the network. Message latency is not a major consideration in most cases, and response times are not critical. The most important consideration is energy usage, since the network life-time is critically dependent on how rapidly the battery power is depleted. The purpose of the talk is to provide an overview of the principles and challenges of wireless network implementation, rather that attempting to provide a specialized state-of-the-art presentation of one or two topics of - elevance.