Wireless sensor networks are composed of geographically dispersed sensors that work together to monitor physical or environmental conditions, such as air pressure, temperature, or pollution. In addition, wireless sensor networks are used in many industrial, social, and regulatory applications, including industrial process monitoring and control, environment and habitat monitoring, healthcare, home automation, and traffic control. Developers of wireless sensor networks face a number of programming and deployment challenges, such as networking protocol design, application development, and security models. This chapter shows how smartphones can help reduce the development, operation, and maintenance costs of wireless sensor networks, while also enabling these networks to use web services, high-level programming APIs, and increased hardware capability, such as powerful microprocessors. Moreover, this chapter examines key challenges associated with developing and maintaining a large wireless sensor network and presents a novel smartphone wireless sensor network that uses smartphones as sensor nodes. We validate our work in the context of Wreck Watch, which is a smartphone-based sensor network for detecting traffic accidents that we use to demonstrate solutions to multiple challenges in current wireless sensor networks. We also describe common pitfalls of using smartphones as sensor nodes in wireless sensor networks and summarize how we have addressed these pitfalls in Wreck Watch.
TinyCoAP: A Novel Constrained Application Protocol (CoAP) Implementation for Embedding RESTful Web Services in Wireless Sensor Networks Based on TinyOS
