Middleware Support for Wireless Sensor Networks: A Survey

Wireless sensor networks (WSNs) are gaining visibility due to several sophisticated applications in which they play a key role, such as in pervasive computing and context-aware systems. However, the evolution of WSN capabilities, especially regarding their ability to provide information, brings complexity to their development, in particular for those application developers that are not familiar with the technology underlying and needed to support WSNs. In order to address this issue and allow the use of the full potential of the sensor network capabilities, the use of a middleware that raises the abstraction level and hides much of the WSN complexity is a promising proposal. However, the development of a middleware for WSNs is not an easy task. Systems based on WSNs have several issues that make them quite different from conventional networked computer systems, thus requiring specific approaches that largely differ from the current solutions. The proposal of this chapter is to address the complexity of middleware made for sensor networks, presenting a taxonomy that characterizes the main issues in the field. An overview of the state-of-the-art is also provided, as well as a critical assessment of existing approaches.