Architecture of Wireless Sensor Networks The concept of wireless sensor networks is based on a simple equation: Sensing + CPU + Radio = Thousands of potential applications As soon as people understand the capabilities of a wireless sensor network, hundreds of applications spring to mind. It seems like a straightforward combination of modern technology. WSN OSI layers Transport layer: The function of this layer is to provide reliability and congestion avoidance where a lot of protocols designed to provide this function are either applied on the upstream (user to sink, ex: ESRT, STCP and DSTN), or downstream (sink to user, ex: PSFQ and GARUDA). These protocols use different mechanisms for loss detection ((ACK, NACK, and Sequence number)) and loss recovery ((End to End or Hop by Hop)) [4, 5]. This layer is specifically needed when a system is organised to access other networks. Providing a reliable hop by hop is more energy efficient than end to end...
