Architecture for an efficient integration of wireless sensor networks to the Internet through Internet of Things gateways

International audienceIn recent years, Internet of Things has changed the way people work and live, thereby opening new opportunities. This article describes a framework architecture for interconnecting several wireless sensor networks to the Internet to achieve the vision of Internet of Things. Connecting things together is done through gateways that act as single points of failure to bridge the connection between wireless sensor network and the traditional wired Internet. To cope with the unreliable nature of wireless links and scale to a large number of sensors and wireless sensor networks, several gateways should be installed. Given a number of previously deployed gateways, the contribution of this article is twofold. First, it focuses on choosing the most suitable ones for connecting wireless sensor networks to the Internet in a efficient and cost-effective manner, using integer linear programming to develop the mathematical model. Second, a network topology that puts the integration of wireless sensor networks to the Internet in place is built. A three-layer architecture is used in such a way that the intermediate layer adapts dynamically to network changes and evolution. Gateway selection procedure at this layer was implemented using CPLEX linear solver, and the gateway was integrated on Raspberry Pi cheaper hardware which serves as the routing protocol for low-power and lossy network root for the wireless sensor network configuration. Experiments and real deployments have been conducted to demonstrate the effectiveness of the proposed scheme

Survey on RPL enhancements: a focus on topology, security and mobility

International audienceA few years ago, the IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) was proposed by IETF as the routing standard designed for classes of networks in which both nodes and their interconnects are constrained. Since then, great attention has been paid by the scientific and industrial communities for the protocol evaluation and improvement. Indeed, depending on applications scenarios, constraints related to the target environments or other requirements, many adaptations and improvements can be made. So, since the initial release of the standard, several implementations were proposed, some targeting specific optimization goals whereas others would optimize several criteria while building the routing topology. They include, but are not limited to, extending the network lifetime, maximizing throughput at the sink node, avoiding the less secured nodes, considering nodes or sink mobility. Sometimes, to consider the Quality of Service (QoS), it is necessary to consider several of those criteria at the same time. This paper reviews recent works on RPL and highlights major contributions to its improvement, especially those related to topology optimization, security and mobility. We aim to provide an insight into relevant efforts around the protocol, draw some lessons and give useful guidelines for future developments

Multichannel Cross-Layer Routing for Sensor Networks

Wireless Sensor Networks are ad-hoc networks that consist of sensor nodes that typically use low-power radios to connect to the Internet. The channels used by the low-power radio often suffer from interference from the other devices sharing the same frequency. By using multichannel communication in wireless networks, the effects of interference can be mitigated to enable the network to operate reliably. This thesis investigates an energy efficient multichannel protocol in Wireless Sensor Networks. It presents a new decentralised multichannel tree-building protocol with a centralised controller for ad-hoc sensor networks. The proposed protocol alleviates the effect of interference, which results in improved network efficiency, stability, and link reliability. The protocol detects the channels that suffer interference in real-time and switches the sensor nodes from those channels. It takes into account all available channels and aims to use the spectrum efficiently by transmitting on several channels. In addition to the use of multiple channels, the protocol reconstructs the topology based on the sensor nodes’ residual energy, which can prolong the network lifetime. The sensor nodes’ energy consumption is reduced because of the multichannel protocol. By using the lifetime energy spanning tree algorithm proposed in this thesis, energy consumption can be further improved by balancing the energy load in the network. This solution enables sensor nodes with less residual energy to remain functional in the network. The benefits of the proposed protocol are described in an extensive performance evaluation of different scenarios in this thesis