Sensor network protocols for greener smart environments

Wireless sensor networks (WSNs) have evolved from an area of advanced research at few academic institutions into one of the building blocks of smart environment applications and cyber-physical systems. In a WSN, small computing devices sense the surrounding environment, eventually process the sensed data, and then relay them to a base station over a multi-hop wireless network. In the past two decades, researchers have identified, tackled, and solved many problems along all three dimensions of WSNs: Sensing, processing, and networking. Wsns have been deployed in different domains, such as traffic and transportation, health and well-being, and wildlife and environmental monitoring. This transition from research labs to the marketplace is being made possible by the synthesis of state-of-the-art research into standards, which enable the seamless interoperation of hardware and applications of independent parties.In this chapter, we aim to provide an overview of WSNs at this point in time when many interesting results have been or are being adopted in standards upon which interesting novel applications are built. In particular, we present the research work related to the communication stack with a special focus on the MAC, network, and application layers. In a bottom-up fashion, we offer an analysis of the research work that led/is leading to standards in WSNs with a special focus on energy as the common metric. For each analyzed communication layer, we also discuss some of the open issues and problems that arise from research and proposed standards, and indicate directions for future research.