Opportunistic wireless access networks

Today, intermittent connectivity is common in wireless access networks and it seems like mobile users will have to deal with discontinuous network access in the future. But existing network protocol architectures are not resilient to disruption of communication links and often communication fails when faced with sporadic connectivity. We discuss a new paradigm for wireless access called opportunistic collaborative networking, where communication is disruption-tolerant and wireless devices exploit any opportunity of communication, albeit temporary, to forward messages towards the destination. For developing protocols for these innovative networks requires understanding of their structure and dynamics. We present some results from analysis of real-life traces representing two such mobile network environments with ad-hoc, intermittent connectivity. Categories and Subject Descriptors D.3.3 [Network architecture and Design]: Wireless communication

A REVIEW ON - SOLAR CONCENTRATORS, PERFORMANCE OF SOLAR COLLECTORS & ENERGY STORAGE

Parabolic trough concentrators are one type of concentrators which reflects the sunlight on the receiver (Line type) and gives us wet steam for water. It can be tried with any type of fluid. Presently solar collectors are used for residential and commercial use. These solar collectors require high maintenance and high installation cost, solar concentrators help us in these disadvantages. This review paper concentrates on solar concentrators and various fluids that can be used in receiver. It also focuses on surface shape measurement of solar concentrator in solar thermal power application. In order to capture maximum amount of solar energy it is required to orient the concentrator as per the position of the sun i.e. tracking is required .However some of the concentrators do not track and are referred as fixed concentrators. The objective of the project is to track the receiver instead of solar concentrator