| Wireless Sensor Networks (WSNs) is a new network that integrates the microelectronics, the computation, the sensing and the wireless communication technology. It consists of the tens of thousands of small nodes, and accomplishes these distributed tasks by them. In recent years it became an active application area in the military and the daily life, such as the enemy surveillance, the soil management, traffic monitoring and the supply chain management, and it caused attentions of the academic circles, the military circles and the industry.The main purpose of middleware for sensor networks is to support the development, maintenance, deployment, and execution of sensing-based applications. This includes mechanisms for formulating complex high-level sensing tasks, communicating this task to the WSN, coordination of sensor nodes to split the task and distribute it to the individual sensor nodes, data fusion for merging the sensor readings of the individual sensor nodes into a high-level result, and reporting the result back to the task issuer.The WSNs has many unique characteristics, for example, the number of nodes are enormous, these nodes are unmanned management after the initial deployment and are limited by the battery supply, simultaneously are restrained to the monitor environment, and the entire network topology is changed frequently, this network contacts closely with the actual physical environment, and its tasks also possible dynamic change and so on. These characteristics cause the design of middleware for this network very differently from the traditional distributed middleware technologies.This paper focuses on these existing middleware technologies, simultaneously bases on the design principles for WSNs, and put emphasis on some new middleware framework that proposed by our own team. This framework mainly divided into two layers, the upper layer is contact with the applications, and the other layer pays attention to the network itself, and associate with the unique... |
PDF Full Text Request