Mesh networks for handheld mobile devices

Mesh communications emerge today as a very popular networking solution. Mesh networks have a decentralized and multihop design. These characteristics arouse interest in research for relevant novel features, such as cooperation among nodes, distribution of tasks, scalability, communication with limited infrastructure support, and the support of mobile devices as mesh nodes. In addition to the inexistence of a solution that implements mesh networks with mobile devices at the data link layer (Layer 2), there is also a need to reconsider existing metrics with new information to tackle the intrinsic characteristics of mobile devices, e.g., the limited energy resources of their battery. To tackle this problem, this thesis presents a detailed study about projects, routing protocols and metrics developed in the area of mesh networks. In addition, two data link layer solutions, Open802.11s and B.A.T.M.A.N-advanced, have been adapted and deployed in a real mesh network testbed with off the shelf routers devices installed with a customized operating system. From this testbed, Open802.11s has proved to offer better performance than B.A.T.M.A.N-advanced. Following this, a breakthrough in this work has been the integration of the 802.11s on an Android mobile device and its subsequent incorporation in the mesh network. This allowed the study of eventual limitations imposed by the mobile device on the operation of the mesh network, namely performance and energy scarcity. With this, another major novelty has followed, by designing, implementing and evaluating several energy related metrics regarding the battery status of mobile devices. This has enabled the participation of mobile devices in mesh routing paths in an efficient way. Our main objective was to implement a mesh network with mobile devices. This has been achieved and validated through the evaluation of diverse testing scenarios performed in a real mesh testbed. The obtained results also show that the operation of a mesh with mobile devices can be enhanced, including the lifetime of mobile devices, when an energy-aware metric is used.As redes mesh surgem hoje em dia como uma solução de rede em crescimento e expansão. Neste tipo de redes o comportamento entre os nós é descentralizado e numa topologia de multihop. Estas características despertam interesse na pesquisa e desenvolvimento de novas funcionalidades tais como: cooperação entre nós, distribuição de tarefas, escalabilidade da rede e comunicações mesmo em casos de uma infraestrutura limitada e o suporte de dispositivos móveis como nós de uma rede mesh. Associado à inexistência de um projecto que implemente redes mesh em dispositivos móveis na camada de ligação de dados (Layer 2), surge a necessidade de repensar as métricas já existentes com novas informações que façam face às novas características dos dispositivos móveis, neste caso, os recursos limitados de bateria. Por forma a resolver este problema, este trabalho apresenta um estudo detalhado sobre os projetos, protocolos de routing e métricas desenvolvidas na área das redes mesh. Além disso, duas soluções que utilizam a camada de ligação de dados, Open802.11s e BATMAN-advanced, estes foram adaptadao e implementados num testbed real utilizando routers com um sistema operacional costumizado instalado. Deste testbed, concluiu-se que o Open802.11s obtem um melhor desempenho que o BATMAN-advanced. Assim, um dos avanços deste trabalho foi a integração do Open802.11s num dispositivo móvel Android e sua posterior incorporação na rede mesh. Isto permitiu o estudo de eventuais limitações impostas pelo dispositivo móvel ao funcionar numa rede mesh, ou seja, desempenho e a escassez de energia. Com isso, foi concebida outra novidade, através da concepção, avaliação e implementação de várias métricas relacionadas com a energia e que têm por base o estado da bateria do dispositivo. Isto permitiu que os dispositivos móveis participem na rede mesh e a sua gestão de bateria seja feita de forma eficiente. O principal objectivo era a implementação de uma rede mesh com dispositivos móveis. Este foi alcançado e validado através de diversos cenários de teste reais. Os resultados obtidos demonstram também que o funcionamento de uma rede mesh com dispositivos móveis pode ser melhorada, incluindo o tempo de vida dos dispositivos móveis, quando uma métrica que considera a energia é utilizada

A design of variable transmission power control for wireless ad-hoc network

Includes bibliography.Wireless Ad-hoc Network has emanated to be a promising network paradigm that can handle last mile technology due to unprecedented growth of internet users. This network is promising because it extends network to remote areas such as congested environments, rural environments etc. It is known that nodes involved in Wireless Ad-hoc Network rely on battery energy as their source of power. Energy consumption has become one of the major challenges experienced in Wireless Ad-hoc Network, which must be properly tackled. This could be traced to the effect of transmission power on the nodes in the network. Transmission power largely determines the amount of energy consumed by each node in the network. Therefore, a power control technique must be adopted in order to manage and select the optimal transmission power with respect to distance. This transmission power must be sufficient to transfer information from one node to another. Literature have proposed different algorithms for power control technique in Wireless Ad-hoc Network. Some researchers looked at the power control technique in terms of minimising energy consumed from different perspectives, which include power aware routing and power control topology management. However, most of these algorithms were applied at different layers in OSI model such as physical layer, data link layer, network layer and application layer. To achieve a reduced energy consumption at each node in the network, a novel algorithm for transmission power control was designed to select optimal transmission power. The proposed algorithm was designed in such a way that it selects transmission power based on the distance between the nodes without affecting the network throughput. Graph theory is used in this research to model the network topology, and transmission power with respect to the distance

Notes on the Freedom Tower. Current issues in Networking (mesh).

Original research notes on the Freedom Tower by Free Network Foundation. Technical characteristics, as well as social, political and philosophical aspects of a real incarnation of a mesh network. Highlights of shortcomings of the academic literature, textbooks in particular, on mesh networks, peer-to-peer, and related subjects

Robotic Wireless Sensor Networks

In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

Scalable Wireless Mesh Networks

Magister Scientiae - MSc (Computer Science)Wireless Mesh Networks (WMNs) are wireless multi-hop networks built on wireless nodes that operate in an Independent Basic Set Identifier (IBSS) mode of the IEEE 208.11 wireless standard. IBSS is well known as an ad hoc mode which is found to build ad hoc wireless networks with the aid of routing protocols crafted to work in this mode. Ad hoc wireless mesh networks are always described as self-healing, self-configuring, easy to build, etc. However, these features do come at a cost because a WMN suffers performance degradation and scalability issues, which mainly come from the underlying IBSS mode that is used to form the physical network. Furthermore this is exacerbated by routing protocols in the upper layers which are intended to form a flat network architecture. Partitioning or clustering the flat network into smaller units has been proven to be a viable mechanism to counter the scalability problem in the communication network. The wired network for instance, presents a segmented, hierarchical architecture, where end user devices are organized in virtual local area networks (VLANs) using Ethernet switches and then Routers aggregate multiple VLANs. This thesis develops and evaluates a heterogeneous, clustering architecture to enhance WMN scalability and management. In the proposed architecture, the clustering is separated from the routing, where the clustering is done at the physical layer. At the routing level, each cluster is configured as a WMN using layer 2 routing for intra-cluster routing, and layer 3 routing for inter-domain routing between clusters. Prototypes for the proposed architecture have been built in a laboratory testbed. The proposed architecture reported better scalability and performance results compared to the traditional flat architecture

Implementation, Evaluation, and Applications of Mobile Mesh Networks for Platforms in Motion

This thesis explores the selection, implementation, and evaluation of two mobile mesh networks, each involving a different distributed computing problem. In the forthcoming discussion, it will become apparent how system constraints affect the optimal choice of mesh networking design and implementation in these cases. The first problem explores the design and implementation of a distributed computing mesh network that will allow a collection of autonomous land vehicles to gather, process, and exchange information in an unknown environment. This network was established by adapting standard commercial 802.11 routers and by providing a software framework that handles all communication between wireless nodes. The second problem involves the design of a network for tracking and monitoring personnel. This network was implemented utilizing ZigBee modules due to power and custom implementation constraints. Both networks were tested with respect to their specific design constraints and they lay the foundation for additional application development and research

Practical Aggregation in the Edge

Due to the increasing amounts of data produced by applications and devices, cloud infrastructures are becoming unable to timely process and provide answers back to users. This has led to the emergence of the edge computing paradigm that aims at moving computations closer to end user devices. Edge computing can be defined as performing computations outside the boundaries of cloud data centres. This however, can be materialised across very different scenarios considering the broad spectrum of devices that can be leveraged to perform computations in the edge. In this thesis, we focus on a concrete scenario of edge computing, that of multiple devices with wireless capabilities that collectively form a wireless ad hoc network to perform distributed computations. We aim at devising practical solutions for these scenarios however, there is a lack of tools to help us in achieving such goal. To address this first limitation we propose a novel framework, called Yggdrasil, that is specifically tailored to develop and execute distributed protocols over wireless ad hoc networks on commodity devices. As to enable distributed computations in such networks, we focus on the particular case of distributed data aggregation. In particular, we address a harder variant of this problem, that we dub distributed continuous aggregation, where input values used for the computation of the aggregation function may change over time, and propose a novel distributed continuous aggregation protocol, called MiRAge. We have implemented and validated both Yggdrasil and MiRAge through an extensive experimental evaluation using a test-bed composed of 24 Raspberry Pi’s. Our results show that Yggdrasil provides adequate abstractions and tools to implement and execute distributed protocols in wireless ad hoc settings. Our evaluation is also composed of a practical comparative study on distributed continuous aggregation protocols, that shows that MiRAge is more robust and achieves more precise aggregation results than competing state-of-the-art alternatives

BATSEN: Modifying the BATMAN Routing Protocol for Wireless Sensor Networks

The proliferation of autonomous Wireless Sensor Networks (WSN) has spawned research seeking power efficient communications to improve the lifetime of sensor motes. WSNs are characterized by their power limitations, wireless transceivers, and the converge-cast communications techniques. WSN motes use low-power, lossy radio systems deployed in dense, random topologies, working sympathetically to sense and notify a sink node of the detectable information. In an effort to extend the life of battery powered motes, and hence the life of the network, various routing protocols have been suggested in an effort to optimize converge-cast delivery of sensor data. It is well known that reducing the overhead required to perform converge-cast routing and communications reduces the effects of the primary power drain in the mote, the transceiver. Furthermore, WSNs are not well protected; network security costs energy both in computation and in RF transmission. This paper investigates the use of a Mobile Ad-hoc Networking (MANET) routing protocol known as B.A.T.M.A.N. in WSN. This thesis proposes that the features of B.A.T.M.A.N. in the MANET realm may prove beneficial to the WSN routing domain; and that slight modifications to the routing technique may prove beneficial beyond current protocol technologies. The B.A.T.M.A.N. variant will be compared against the contemporary LEACH WSN routing protocol to discern any potential energy savings

Knowledge Networks. From centralized To decentralized

Organization (of the book) : Networks. Knowledge. Pleasure