Using multimedia sensor nodes in wireless sensor networks (WSNs) can significantly enhance the capability of WSNs for event description. Different kinds of holes can easily appear in WSNs. How to efficiently transmit multimedia streaming data and bypass all kinds of holes is a challenging issue. Moreover, some applications do not need WSNs to work for a long lifetime, e.g. monitoring an erupting volcano. These applications generally expect that WSNs can provide continuous streaming data during a relatively short expected network lifetime. Two basic problems are: (1) gathering as much data as possible within an expected network lifetime; (2) minimizing transmission delay within an expected network lifetime. In this paper, we proposed a cross-layer approach to facilitate the continuous one shot event recording in WSNs. We first propose the maximum streaming data gathering (MSDG) algorithm and the minimum transmission delay (MTD) algorithm to adjust the transmission radius of sensor nodes in the physical layer. Following that the two-phase geographical greedy forwarding (TPGF) routing algorithm is proposed in the network layer for exploring one/multiple optimized holebypassing paths. Simulation results show that our algorithms can effectively solve the identified problems.

Using multimedia sensor nodes in wireless sensor networks (WSNs) can significantly enhance the capability of WSNs for event description. Different kinds of holes can easily appear in WSNs. How to efficiently transmit multimedia streaming data and bypass all kinds of holes is a challenging issue. Moreover, some applications do not need WSNs to work for a long lifetime, e.g. monitoring an erupting volcano. These applications generally expect that WSNs can provide continuous streaming data during a relatively short expected network lifetime. Two basic problems are: (1) gathering as much data as possible within an expected network lifetime; (2) minimizing transmission delay within an expected network lifetime. In this paper, we proposed a cross-layer approach to facilitate the continuous one shot event recording in WSNs. We first propose the maximum streaming data gathering (MSDG) algorithm and the minimum transmission delay (MTD) algorithm to adjust the transmission radius of sensor nodes in the physical layer. Following that the two-phase geographical greedy forwarding (TPGF) routing algorithm is proposed in the network layer for exploring one/multiple optimized holebypassing paths. Simulation results show that our algorithms can effectively solve the identified problems.

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During the development of context aware applications a context management component must traditionally be created. This task requires specialist context lifecycle management expertise and hence can be a significant deterrent to application development. It also removes the developers focus from differentiation of their application to an oft repeated development task. This issue can be addressed by encapsulating the context management lifecycle within a web-service, thus providing applications with a low-overhead alternative to managing their context data. The adoption of a web-based approach maximizes the potential number of interacting applications, including smart spaces, web and mobile applications, due to ease of access and widespread support of web technologies. The contribution of this paper is the development of a lifecycle, based on existing work on enterprise data and context aware lifecycles, which is optimized for web-based context management services (WCXMS) and the provision of a web-service implementation of the lifecycle.

No abstract