Seamless interconnection of WSN and IP networks

In this thesis, an interconnection approach, named as WiSEGATE (Wireless Sensor Gateway), with addressing the end-to-end reliable interconnection problem between multiple internet entities and sensor nodes is proposed. For the derivation of proposed approach, firstly, we analyze the recent interconnection approaches and highlight their advantages and disadvantages, secondly, we combine their advantages . A prototype of a new web server which supports three tier service scheme with a data acquisition mechanism of WSN to access the physical data in a particular location by remote entities is developed. In the proposed model, an interconnection gateway handles operations required for the interoperability. Since, this gateway maintains reliable TCP/IP connections of the interconnected entities, the resource constrained sensor nodes do not require a TCP/IP stack for handling end-to-end connections. A lightweight service layer is implemented on a sensor node for operations required by the interconnection. The strength and novelty of the proposed model lies in the fact that this lightweight service layer relieves extra memory usage for end-to-end connection management. For determining the limits of the proposed model, firstly, we examined steps for request/response mechanism and formulize the queuing system. By doing this, we derived a definition of the request traffic. As a proof of concept, we have performed comprehensive tests in simulation and real environments. WiSEGATE can achieve reasonable response times up to 80 simultaneous connections from remote entities to WSN when WiFi PER is less than 0.2.