Mobile ad hoc networks for intelligent systems

Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. Mobile ad hoc networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. They do not rely on specialized routers for path discovery and traffic routing. Research on ad hoc networks has been extensively investigated in the past few years and related work has focused on many of the layers of the communications architecture. This research intends to investigate applications of MANET for intelligent systems, including intelligent transportation system (ITS), sensor network and mobile intelligent robot network, and propose some approaches to topology management, link layer multiple access and routing algorithms. Their performance is evaluated by theoretical analysis and off-the-shelf simulation tools. Most current research on ad hoc networks assumes the availability of IEEE 802.11. However, the RTS/CTS protocol of 802.11 still leads to packet collision which in turn decreases the network throughput and lifetime. For sensor networks, sensors are mostly battery operated. Hence, resolving packet collision may improve network lifetime by saving valuable power. Using space and network diversity combination, this work proposes a new packet separation approach to packet collision caused by masked nodes. Inter-vehicle communication is a key component of ITS and it is also called vehicular ad hoc network. VANET has many features different from regular MANETs in terms of mobility, network size and connectivity. Given rapid topology changes and network partitioning, this work studies how to organize the numerous vehicular nodes and establish message paths between any pair of vehicular nodes if they are not apart too far away. In urban areas, the inter-vehicle communication has different requirements and constraints than highway environments. The proposed position-based routing strategy for VANETs utilizes the traffic pattern in city environments. Packets are forwarded based on traffic lights timing sequence and the moving direction of relaying vehicles. A multicast protocol is also introduced to visualize the real time road traffic with customized scale. Only vehicles related to a source node\u27s planned trajectory will reply the query packet. The visualized real time traffic information therefore helps the driver make better decision in route planning when traffic congestion happens. Nowadays robots become more and more powerful and intelligent. They can take part in operations in a cooperative manner which makes distributed control necessary. Ad hoc robot communication network is still fresh field for researchers working on networking technology. This work investigates some key issues in robot ad hoc network and evaluate the challenges while establishing robot ad hoc networks

Adoption of vehicular ad hoc networking protocols by networked robots

This paper focuses on the utilization of wireless networking in the robotics domain. Many researchers have already equipped their robots with wireless communication capabilities, stimulated by the observation that multi-robot systems tend to have several advantages over their single-robot counterparts. Typically, this integration of wireless communication is tackled in a quite pragmatic manner, only a few authors presented novel Robotic Ad Hoc Network (RANET) protocols that were designed specifically with robotic use cases in mind. This is in sharp contrast with the domain of vehicular ad hoc networks (VANET). This observation is the starting point of this paper. If the results of previous efforts focusing on VANET protocols could be reused in the RANET domain, this could lead to rapid progress in the field of networked robots. To investigate this possibility, this paper provides a thorough overview of the related work in the domain of robotic and vehicular ad hoc networks. Based on this information, an exhaustive list of requirements is defined for both types. It is concluded that the most significant difference lies in the fact that VANET protocols are oriented towards low throughput messaging, while RANET protocols have to support high throughput media streaming as well. Although not always with equal importance, all other defined requirements are valid for both protocols. This leads to the conclusion that cross-fertilization between them is an appealing approach for future RANET research. To support such developments, this paper concludes with the definition of an appropriate working plan

Predicting topology propagation messages in mobile ad hoc networks: The value of history

This research was funded by the Spanish Government under contracts TIN2016-77836-C2-1-R,TIN2016-77836-C2-2-R, and DPI2016-77415-R, and by the Generalitat de Catalunya as Consolidated ResearchGroups 2017-SGR-688 and 2017-SGR-990.The mobile ad hoc communication in highly dynamic scenarios, like urban evacuations or search-and-rescue processes, plays a key role in coordinating the activities performed by the participants. Particularly, counting on message routing enhances the communication capability among these actors. Given the high dynamism of these networks and their low bandwidth, having mechanisms to predict the network topology offers several potential advantages; e.g., to reduce the number of topology propagation messages delivered through the network, the consumption of resources in the nodes and the amount of redundant retransmissions. Most strategies reported in the literature to perform these predictions are limited to support high mobility, consume a large amount of resources or require training. In order to contribute towards addressing that challenge, this paper presents a history-based predictor (HBP), which is a prediction strategy based on the assumption that some topological changes in these networks have happened before in the past, therefore, the predictor can take advantage of these patterns following a simple and low-cost approach. The article extends a previous proposal of the authors and evaluates its impact in highly mobile scenarios through the implementation of a real predictor for the optimized link state routing (OLSR) protocol. The use of this predictor, named OLSR-HBP, shows a reduction of 40–55% of topology propagation messages compared to the regular OLSR protocol. Moreover, the use of this predictor has a low cost in terms of CPU and memory consumption, and it can also be used with other routing protocols.Peer ReviewedPostprint (published version

Proposta para alocação de canais e para comunicação cooperativa em redes Ad Hoc

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciências da Computação, 2014A popularização de tecnologias sem fio, aliado com aplicações que exigem conexão contínua e altas taxas de transmissão, impulsionam o desenvolvimento de protocolos de Controle de Acesso ao Meio (do Inglês, Medium Access Control - MAC) eficientes em energia. Mecanismos que permitem melhorar o desempenho da rede utilizando a disponibilidade de múltiplos canais de comunicação têm sido explorados na literatura. No entanto, desenvolver protocolos eficientes em energia que permitam realizar a atribuição de canais e agendamento de comunicação, melhorando o desempenho da rede, tem sido uma tarefa desafiadora. Neste contexto, a primeira parte dessa dissertação propõe um protocolo de alocação de canais e de agendamento de comunicação para redes sem fio, chamado EEMC-MAC, que permite reduzir o consumo de energia e o tempo de comunicação. A segunda parte dessa dissertação possui seu foco em mecanismos para melhorar a conectividade em redes ad hoc. Nesse contexto, Comunicação Cooperativa (CC) é utilizada para explorar a diversidade espacial na camada física e permitir que múltiplos nós cooperem na transmissão de um sinal para um mesmo receptor. Uma vez que CC pode reduzir a potência de transmissão e estender o raio de transmissão, a técnica tem sido combinada com protocolos de controle de topologia em redes ad hoc. Os primeiros trabalhos de controle de topologia em redes ad hoc cooperativas buscam aumentar a conectividade da rede, enquanto o consumo de energia é minimizado em cada nó. Trabalhos posteriores focam na eficiência das rotas criadas na topologia final. No entanto, a nosso conhecimento, nenhum trabalho até então explorou CC para aumentar a conectividade com o sorvedouro em redes ad hoc. Na segunda parte dessa dissertação, é proposta uma nova técnica, chamada CoopSink, que utiliza CC e controle de topologia em redes ad hoc para aumentar a conectividade com um nó sorvedouro, além de garantir a eficiência das rotas para o sorvedouro. ________________________________________________________________________________ ABSTRACTThe popularization of wireless technology allied with high throughput and continuousInternet access applications has boosted the development of energy efficient Medium AccessControl (MAC) protocols. Mechanisms to improve network performance using theavailability of multiple communication channels have been explored in the literature. However,the development of energy efficient protocols to perform channel allocation and datascheduling to improve the network performance is a challenging task. In this context, thefirst part of this dissertation proposes a protocol, named EEMC-MAC, for multi-channelallocation and data scheduling for wireless networks that allows the reduction of energyconsumption and communication time. The second part of this dissertation focuses ontechniques to improve connectivity in ad hoc networks. In this context, CooperativeCommunication (CC) is employed to explore spatial diversity in the physical layer, allowingmultiple nodes to cooperatively relay signals to the receiver so that it can combinethe received signals to obtain the original message. Once CC can be used to reduce thepower of the transmission node and extend the transmission range, the technique hasbeen combined with topology control protocols in wireless ad hoc networks. Early worksin topology control in cooperative ad hoc networks aimed to increase network connectivitywhile minimizing energy consumption in each node. Later works focused in routeefficiency in the final topology. Nevertheless, to the best of our knowledge, no work sofar explored CC to increase connectivity to a sink node in wireless networks. As a secondcontribution of this work, a new technique named CoopSink is proposed, that uses CCand topology control in ad hoc networks to increase connectivity to a sink node, whileensuring efficient routes

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

On the Experimental Evaluation of Vehicular Networks: Issues, Requirements and Methodology Applied to a Real Use Case

One of the most challenging fields in vehicular communications has been the experimental assessment of protocols and novel technologies. Researchers usually tend to simulate vehicular scenarios and/or partially validate new contributions in the area by using constrained testbeds and carrying out minor tests. In this line, the present work reviews the issues that pioneers in the area of vehicular communications and, in general, in telematics, have to deal with if they want to perform a good evaluation campaign by real testing. The key needs for a good experimental evaluation is the use of proper software tools for gathering testing data, post-processing and generating relevant figures of merit and, finally, properly showing the most important results. For this reason, a key contribution of this paper is the presentation of an evaluation environment called AnaVANET, which covers the previous needs. By using this tool and presenting a reference case of study, a generic testing methodology is described and applied. This way, the usage of the IPv6 protocol over a vehicle-to-vehicle routing protocol, and supporting IETF-based network mobility, is tested at the same time the main features of the AnaVANET system are presented. This work contributes in laying the foundations for a proper experimental evaluation of vehicular networks and will be useful for many researchers in the area.Comment: in EAI Endorsed Transactions on Industrial Networks and Intelligent Systems, 201