Communications from remote areas that may be of interest is still a problem. Many innovative projects applied to remote sites face communications difficulties. The GOLDFISH project was an EU-funded project for river pollution monitoring in developing countries. It had several sensor clusters, with floating WiFi antennas, deployed along a downstream river’s course. Sensor clusters sent messages to a Gateway installed on the riverbank. This gateway sent the messages, through a backhaul technology, to an Internet server where data was aggregated over a map. The communication challenge in this scenario was produced by the antennas’ movement and network backhaul availability. Since the antennas were floating on the river, communications could be disrupted at any time. Also, 2G/3G availability near the river was not constant. For non-real-time applications, we propose a Delay/Disruption Tolerant Network (DTN)-based solution where all nodes have persistent storage capabilities and DTN protocols to be able to wait minutes or hours to transmit. A mechanical backhaul will periodically visit the river bank where the gateway is installed and it will automatically collect sensor data to be carried to an Internet-covered spot. The proposed forwarding protocol delivers around 98% of the messages for this scenario, performing better than other well-known DTN routing protocols.

This paper proposes an optimization model for network management in multihop Wireless Sensor Networks (WSNs). Here, we develop a distributed, braided multipath algorithm to deliver the information from the information sources (targets) to the Base stations (sinks) giving the network the ability to adapt to changes or failures. The Base Stations are robust nodes with capabilities for positioning themselves and communicating outside the network, which grants them the benefit of knowing other Base Stations’ position in the area of interest. Targets are nodes that generate information and need a fixed amount of bandwidth to convey this information to a Base Station. Every element in the network is static. This paper shows the mathematical optimization model for the network's energy minimization and resilience maximization. To increase network's resilience, the devices within the network will try to create multiple paths from the beginning trying to reach at least one Base Station. The model is solved through a heuristic algorithm based on the nearest neighbor and minimum hop concepts and it is implemented in Java. Results show that the proposed algorithm finds multiple braided paths for most of the instances proposed and some backup nodes for nodes in the paths that can help the network to extend its lifetime operation and adapt to failures

Energy Optimization in Mobile Wireless Sensor Networks with Mobile Targets Achieving Efficient Coverage for Critical Applications

Routing Optimization for Delay Tolerant Networks in Rural Applications Using a Distributed Algorithm

Rural networking connectivity is a very dynamic and attractive research field. Nowadays big IT companies like Google and Facebook are working to help connect all these rural disconnected people to Internet. Our research work is another effort in this direction. We are building a new solution based on previously tested ideas that can bring no real-time Internet connectivity to rural users using Delay/Disruption Tolerant Networking technologies. The advantage of our solution is that it is a low cost technology that uses locally available infrastructure to reach even the most remote towns. This paper introduces the problem, the current and previous efforts to solve it, and describes our solution, mathematically and algorithmically. Simulation results show that our algorithm delivers more messages than two of the most known DTN routing protocols for this rural connectivity scenario.

Rural networking connectivity is a very dynamic and attractive research field. Nowadays big IT companies and many governments are working to help connect all these rural, disconnected people to Internet. This paper introduces a new routing algorithm that can bring non-real-time Internet connectivity to rural users. This solution is based on previously tested ideas, especially on Delay/Disruption Tolerant Networking technologies, since they can be used to transmit messages to and from difficult to access sites. It introduces the rural connectivity problem and its context. Then, it shows the proposed solution with its mathematical model used to describe the problem, its proposed heuristic, and its results. The advantage of our solution is that it is a low-cost technology that uses locally available infrastructure to reach even the most remote towns. The mathematical model describes the problem of transmitting messages from a rural, usually disconnected user, to an Internet connected node, through a non-reliable network using estimated delivery probabilities varying through time. The forwarding algorithm uses local knowledge gathered from interactions with other nodes, and it learns which nodes are more likely to connect in the future, and which nodes are more likely to deliver the messages to the destination. Our algorithm achieves an equal or better performance in delivery rate and delay than other well-known routing protocols for the rural scenarios tested. This paper adds more simulation results for the proposed rural scenarios, and it also extends the explanation of the mathematical model and the heuristic algorithm from the conference paper "Delay/Disruption Tolerant Networks Based Message Forwarding Algorithm for Rural Internet Connectivity Applications" [1] (doi: 10.1109/ICCCC. 2016.7496732).