Routing in Wireless Sensor Networks

Wireless sensor networks are catching up as the primary mode for monitoring and collecting data in physically challenging environments. They find applications in various fields varying from environment monitoring, military applications to monitoring patients in hospitals. The low cost, ad hoc deployment, distributed sensing, and adaptability of wireless sensors have given them a big advantage over other methods. The constraints due to their inherent features make routing in wireless sensor networks a big challenge. This paper covers a number of routing protocols being used in the current systems. The stress is on energy aware routing where the network optimizes between efficient routing and maximizing life of the network. I Introduction Advances in technology have led to a shift of devices from wired to wireless domain. Availability of better battery technology have prolonged the wireless devices service time. With recent advances in ASIC (Application Specific Integrated Circuits) design we are able to create more compact and efficient electronic circuits suitable for specific purposes. Wireless sensors are a fusion of techniques from ASIC designing, wireless protocol designing, MEMS (Micro Electro Mechanical Systems) based sensors, advanced battery technology and robust distributed computing algorithms. Recent improvements in them have lead to a rapid growth in this field. Wireless sensors are small, inexpensive, low power devices which are deployed in large numbers over an area in an ad hoc fashion. Each individual node has a limited processing power, limited view of the environment and limited battery life. Presence of large number of such nodes which can co-ordinate amongst themselves give them huge advantage over centralized single sensor based techniques.