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Many mobile sensing applications consider users reporting and accessing sensing data through the Internet. However, WiFi and 3G connectivities are not always available in remote areas. Existing data dissemination schemes for opportunistic networks are not sufficient for sensing applications as sensing context has not been explored. In this work, we present a novel context-aware sensing data dissemination framework for mobile users in a remote sensing field. It maximizes information utility by considering such sensing context as sensing type, locality, time-to-live, mobility and user interests. Different from existing works, the mobile users not only collect sensing data, but also upload data to sensors for information sharing. We develop a context-aware deployment algorithm and a hybrid data exchange mechanism for generic sensors and mobile users. We evaluate our solution by both analysis and simulations, and show that it can provide high information utility for mobile users at low communication overhead. [ABSTRACT FROM PUBLISHER]

Wireless sensor networks (WSNs) have been widely deployed for environmental monitoring and urban sensing applications. With the advancement of mobile phones, mobile users have increasing demands for sensing data relevant to their locations and activities. It is crucial to support reliable ubiquitous sensing for mobile users to retrieve sensing data of their interests anytime and anywhere. In this paper, we propose a novel location-based publish/subscribe framework for mobile users to subscribe for sensing data by simply specifying the event types and target locations of their interests. The framework is developed on a location-based Distributed Hash Table (DHT) overlay formed by a network of brokers. Event data can be subscribed by mobile users and then multicast to the subscribers through efficient location-based routing. To support client mobility, we further propose a reliable protocol to handle client registration, location look-up and client relocation. It can provide reliable data delivery without causing any data loss even when the users are disconnected or moved to a new place. Extensive simulation are conducted to evaluate the message delay, communication overheads, and the support of client mobility. [ABSTRACT FROM PUBLISHER]

We consider a novel application in wireless sensor networks where mobile phones and wireless sensors can collaborate to collect sensing data. Although mobile phones can perform sensing at different locations, it is a challenge to provide stable sensing quality and availability over the entire area. One approach is to deploy stationary sensors at specific locations to maintain the sensing quality and availability. In this paper, we present a mathematical programming model to minimise the deployment cost by placing a minimum number of sensors at optimal locations. The problem is modelled by integer linear programming considering the sensing capabilities of both the mobile phones and wireless sensors. We evaluated the performance of our solution in terms of sensing quality, number of required sensors, and computation time. The results demonstrate that our approach satisfies the required sensing quality with optimal number of sensors in small sensing fields. It achieves near optimal solution with low computation time for large sensing fields. [ABSTRACT FROM PUBLISHER]

Quality-of-information (QoI) in sensor networks measures attributes such as accuracy, timeliness, completeness and usefulness of data ultimately delivered to users. It is a challenge to provide the required QoI in mobile sensor networks given the large scale and complexity of the networks with heterogeneous mobile and sensing devices. In this paper, we provide a comprehensive study on major QoI metrics for mobile sensor networks and the effect of mobility. Three different mobility scenarios are studied including mobile sensors, mobile sinks and mobile “mules” carrying data between sensors. We conclude that mobility both can improve as well as degrade the QoI metrics. We then discuss how QoI can be optimized through coordination among heterogeneous devices. We also suggest a ubiquitous publish/subscribe system for mobile sensor networks. [ABSTRACT FROM PUBLISHER]

Existing publish/subscribe architectures for wirelesssensors networks only support stationary sensors interconnectedwith each other. They cannot handle mobile sensors or remotesensors that are sparsely deployed. In this paper, we propose anovel ubiquitous publish/subscribe system that supports data accessfrom both mobile sensors and stationary sensors. Our systemutilizes mobile phones as data mules to relay subscriptions andpublished data between broker and remote sensors. It providescontent-based publish/subscribe services from sensors deployedanywhere without depending on any network infrastructure. Weimplement our publish/subscribe platform on real hardwaresand test it in a hiking trail application. The application allowsusers to subscribe for sensing data from both stationary sensorsand mobile sensors along hiking trails. Extensive experimentsare conducted in an outdoor testbed to evaluate the systemperformances such data delay, number of data received andcommunication overhead. [ABSTRACT FROM PUBLISHER]