Performance Evaluation of Gradient Routing Strategies for Wireless Sensor Networks

International audienceWe consider Wireless Sensor Networks (WSN) applications in which sensors have to send data to a unique sink in a multi-hop fashion. Gradient routing protocol is a scalable way to route data in these applications. Many gradient routing protocols exist, they mainly differ in their performances (delay, delivery ratio, etc.). In this paper, we propose an extensive performance evaluation study of some gradient routing protocols in order to give guidelines for WSN developers

Energy efficient geographic routing for wireless sensor networks.

A wireless sensor network consists of a large number of low-power nodes equipped with wireless radio. For two nodes not in mutual transmission range, message exchanges need to be relayed through a series of intermediate nodes, which is a process known as multi-hop routing. The design of efficient routing protocols for dynamic network topologies is a crucial for scalable sensor networks. Geographic routing is a recently developed technique that uses locally available position information of nodes to make packet forwarding decisions. This dissertation develops a framework for energy efficient geographic routing. This framework includes a path pruning strategy by exploiting the channel listening capability, an anchor-based routing protocol using anchors to act as relay nodes between source and destination, a geographic multicast algorithm clustering destinations that can share the same next hop, and a lifetime-aware routing algorithm to prolong the lifetime of wireless sensor networks by considering four important factors: PRR (Packet Reception Rate), forwarding history, progress and remaining energy. This dissertation discusses the system design, theoretic analysis, simulation and testbed implementation involved in the aforementioned framework. It is shown that the proposed design significantly improves the routing efficiency in sensor networks over existing geographic routing protocols. The routing methods developed in this dissertation are also applicable to other location-based wireless networks

Overlapping Multi-hop Clustering for Wireless Sensor Networks

Clustering is a standard approach for achieving efficient and scalable performance in wireless sensor networks. Traditionally, clustering algorithms aim at generating a number of disjoint clusters that satisfy some criteria. In this paper, we formulate a novel clustering problem that aims at generating overlapping multi-hop clusters. Overlapping clusters are useful in many sensor network applications, including inter-cluster routing, node localization, and time synchronization protocols. We also propose a randomized, distributed multi-hop clustering algorithm (KOCA) for solving the overlapping clustering problem. KOCA aims at generating connected overlapping clusters that cover the entire sensor network with a specific average overlapping degree. Through analysis and simulation experiments we show how to select the different values of the parameters to achieve the clustering process objectives. Moreover, the results show that KOCA produces approximately equal-sized clusters, which allows distributing the load evenly over different clusters. In addition, KOCA is scalable; the clustering formation terminates in a constant time regardless of the network size

On Link Estimation in Dense RPL Deployments

The Internet of Things vision foresees billions of devices to connect the physical world to the digital world. Sensing applications such as structural health monitoring, surveillance or smart buildings employ multi-hop wireless networks with high density to attain sufficient area coverage. Such applications need networking stacks and routing protocols that can scale with network size and density while remaining energy-efficient and lightweight. To this end, the IETF RoLL working group has designed the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL). This paper discusses the problems of link quality estimation and neighbor management policies when it comes to handling high densities. We implement and evaluate different neighbor management policies and link probing techniques in Contiki’s RPL implementation. We report on our experience with a 100-node testbed with average 40-degree density. We show the sensitivity of high density routing with respect to cache sizes and routing metric initialization. Finally, we devise guidelines for design and implementation of density-scalable routing protocols

Wireless Sensor Network Infrastructure: Construction and Evaluation

International audienceLarge area wireless sensor deployments rely on multi-hop communications. Efficient packet transmissions and virtual topologies, which structure sensor networks, are two main features for efficient energy management in wireless sensor networks. This paper aims to present a distributed and low-cost topology construction algorithm for wireless sensor networks, addressing the following issues: large-scale, random network deployment, energy efficiency and small overhead. We propose structuring nodes in zones, meant to reduce the global view of the network to a local one. This zone-based architecture is the infrastructure used by our hierarchical routing protocol. The experimental results show that the proposed algorithm has low overhead and is scalable

Multi-hop Device-to-Device Routing Protocols for Software-Defined Wireless Networks

University of Technology Sydney. Faculty of Engineering and Information Technology.Multi-hop device-to-device (MD2D) communications are an integral part of future wireless networks. Multi-hop communications enable mobile devices in close proximity to communicate directly or through multi-hop connections instead of traversing through a network infrastructure. This provides numerous benefits for cellular networks, such as low-cost communications, enhanced cellular coverage and capacity, reduced total power consumption in devices, and improved spectral efficiency. Consequently, service providers can leverage the advantages of both D2D and cellular networks to enhance the quality of their services. However, tight coupling of control and data functions in cellular equipment and the utilization of proprietary interfaces and protocols in existing cellular infrastructure make integration difficult and rigid. Hence, there is a need for open and reprogrammable frameworks to make the network more flexible and scalable. Software-defined networking (SDN) is a promising technology for future wireless networks that provides an open and reprogrammable framework wherein the control functions are taken from network devices and are logically centralized in a control entity. The open framework of SDN provides an opportunity for service providers to manage networks more intelligently and develop services in a more agile manner. This thesis introduces an SDN-based framework for cellular networks, referred to as virtual ad hoc routing protocol framework (VARP), capable of developing different types of multi-hop routing protocols. In the proposed framework, an SDN controller determines the mode of communication for mobile devices (i.e., cellular or multi-hop modes). Two different multi-hop routing protocols are designed for the proposed framework: source-based virtual ad hoc routing protocol (VARP-S) and SDN-based multi-hop D2D routing protocol (SMDRP). In both protocols, a source of data packet sends a route request to the controller and receives the forwarding information from the controller in response. This thesis then presents a multi-protocol framework capable of developing multiple routing protocols under a single framework. In the proposed framework, an SDN controller logically divides a cell into multiple clusters based on its knowledge of the entire cell. The controller determines which multi-hop routing protocol can provide the best performance for each cluster. The simulation results show that the proposed multi-protocol framework provides better performance than traditional single-protocol architectures. Finally, the thesis presents a novel software-defined adaptive routing algorithm for multi-hop multi-frequency communications in wireless multi-hop mesh networks. The simulation results indicate that the proposed algorithm improves the end-to-end throughput of multi-hop connections by considering the surrounding WiFi traffic and adaptive selection of frequencies and routes