The Design Of Pervasive Computing Systemunder Ip-enabled Wireless Sensor Network

Pervasive Computing is the current trend that calculation mode focuses on the human beings in place of calculation in the center mode previously. Context retrieving is the key element of pervasive computing and the technology of wireless sensor network is fundamental to context retrieving. For the characteristics of wireless sensor network, IEEE proposed 6LoWPAN protocol as an adaptation layer between 802.15.4 and IPv6. 6LoWPAN makes wireless sensor network could be routed by IP and get involved into current IP network. With the IP-Enabled sensor network, new problems have come to pervasive computing system design. The application on the sensor with IP functions will become more complex than ever before. So there is a requirement for operating system on sensors for decreasing the development complexity. Each node in IP-Enabled sensor network could be routed from external networks and each node will become a service provider for the whole networks. How to discovery and manage these services on sensors becomes a problem. Meanwhile, security is another issue for IP-Enabled sensor network. End to end security is a problem for open network architecture. In this paper, we analyze the implementation virtue of Contiki, a lightweight embedded operating system particular for tiny embedded devices. Its multithread implementation is quite effective for sensors with so small memory. We design a new priority event mechanism and revise the scheduling algorithm provided by the Contiki for our specific application. We propose lightweight service architecture for IP-Enabled sensor networks to address the issue of discovering and managing service. We use the lightweight web services approach for sensors to provide services for external request calls. Xml is used as the data format in our service architecture to eliminate the difference among the platforms and applications. In security, we provide a multi-layer authentication mechanism with effective Symmetric-Key Cryptography to minimize the impact of efficiency. We also use ticket to accelerate authentication process.IP-Enabled sensor network has not attracted much attention from academe and industry. The innovation points for this paper are: analyze the operating system design for sensors, propose lightweight service architecture to manage data provided by sensors and authentication mechanism for IP-Enabled sensor network...