情報指向ネットワークにおけるトラヒック制御方式に関する研究

関西大

Let the Tree Bloom: Scalable Opportunistic Routing with ORPL

Routing in battery-operated wireless networks is challenging, posing a tradeoff between energy and latency. Previous work has shown that opportunistic routing can achieve low-latency data collection in duty-cycled networks. However, applications are now considered where nodes are not only periodic data sources, but rather addressable end points generating traffic with arbitrary patterns. We present ORPL, an opportunistic routing protocol that supports any-to-any, on-demand traffic. ORPL builds upon RPL, the standard protocol for low-power IPv6 networks. By combining RPL's tree-like topology with opportunistic routing, ORPL forwards data to any destination based on the mere knowledge of the nodes' sub-tree. We use bitmaps and Bloom filters to represent and propagate this information in a space-efficient way, making ORPL scale to large networks of addressable nodes. Our results in a 135-node testbed show that ORPL outperforms a number of state-of-the-art solutions including RPL and CTP, conciliating a sub-second latency and a sub-percent duty cycle. ORPL also increases robustness and scalability, addressing the whole network reliably through a 64-byte Bloom filter, where RPL needs kilobytes of routing tables for the same task

Multi-region routing

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresThis thesis proposes a new inter-domain routing protocol. The Internet's inter-domain routing protocol Border Gateway Protocol (BGP) provides a reachability solution for all domains; however it is also used for purposes outside of routing. In terms of routing BGP su ers from serious problems, such as slow routing convergence and limited scalability. The proposed architecture takes into consideration the current Internet business model and structure. It bene ts from a massively multi-homed Internet to perform multipath routing. The main foundation of this thesis was based on the Dynamic Topological Information Architecture (DTIA). We propose a division of the Internet in regions to contain the network scale where DTIA's routing algorithm is applied. An inter-region routing solution was devised to connect regions; formal proofs were made in order to demonstrate the routing convergence of the protocol. An implementation of the proposed solution was made in the network simulator 2 (ns-2). Results showed that the proposed architecture achieves faster convergence than BGP. Moreover, this thesis' solution improves the algorithm's scalability at the inter-region level, compared to the single region case

Efficient content delivery through fountain coding in opportunistic information-centric networks

Opportunistic networks can increase network capacity, support collaborative downloading of content and offload traffic from a cellular to a cellular-assisted, device-to-device network. They can also support communication and content exchange when the cellular infrastructure is under severe stress and when the network is down or inaccessible. Fountain coding has been considered as espe- cially suitable for lossy networks, providing reliable multicast transport without requiring feedback from receivers. It is also ideal for multi-path and multi- source communication that fits exceptionally well with opportunistic networks. In this paper, we propose a content-centric approach for disseminating con- tent in opportunistic networks efficiently and reliably. Our approach is based on Information-Centric Networking (ICN) and employs fountain coding. When tied together, ICN and fountain coding provide a comprehensive solution that overcomes significant limitations of existing approaches. Extensive network simulations indicate that our approach is viable. Cache hit ratio can be increased by up to five times, while the overall network traffic load is reduced by up to four times compared to content dissemination on top of the standard Named Data Networking architecture

Priority-Based Content Delivery in the Internet of Vehicles through Named Data Networking

Named Data Networking (NDN) has been recently proposed as a prominent solution for content delivery in the Internet of Vehicles (IoV), where cars equipped with a variety of wireless communication technologies exchange information aimed to support safety, traffic efficiency, monitoring and infotainment applications. The main NDN tenets, i.e., name-based communication and in-network caching, perfectly fit the demands of time- and spatially-relevant content requested by vehicles regardless of their provenance. However, existing vehicular NDN solutions have not been targeted to wisely ensure prioritized traffic treatment based on the specific needs of heterogeneous IoV content types. In this work, we propose a holistic NDN solution that, according to the demands of data traffic codified in NDN content names, dynamically shapes the NDN forwarding decisions to ensure the appropriate prioritization. Specifically, our proposal first selects the outgoing interface(s) (i.e., 802.11, LTE) for NDN packets and then properly tunes the timing of the actual transmissions. Simulation results show that the proposed enhancements succeed in achieving differentiated traffic treatment, while keeping traffic load under control

A reliable and resource aware framework for data dissemination in wireless sensor networks

Distinctive from traditional wireless ad hoc networks, wireless sensor networks (WSN) comprise a large number of low-cost miniaturized nodes each acting autonomously and equipped with short-range wireless communication mechanism, limited memory, processing power, and a physical sensing capability. Since sensor networks are resource constrained in terms of power, bandwidth and computational capability, an optimal system design radically changes the performance of the sensor network. Here, a comprehensive information dissemination scheme for wireless sensor networks is performed. Two main research issues are considered: (1) a collaborative flow of information packet/s from the source to sink and (2) energy efficiency of the sensor nodes and the entire system. For the first issue, we designed and evaluated a reactive and on-demand routing paradigm for distributed sensing applications. We name this scheme as IDLF-Information Dissemination via Label ForwarDing IDLF incorporates point to point data transmission where the source initiates the routing scheme and disseminates the information toward the sink (destination) node. Prior to transmission of actual data packet/s, a data tunnel is formed followed by the source node issuing small label information to its neighbors locally. These labels are in turn disseminated in the network. By using small size labels, IDLF avoids generation of unnecessary network traffic and transmission of duplicate packets to nodes. To study the impact of node failures and to improve the reliability of the network, we developed another scheme which is an extension to IDLF. This new scheme, RM-IDLF - Reliable Multipath Information dissemination by Label Forwarding, employ an alternate disjoint path. This alternate path scheme (RM-IDLF) may have a higher path cost in terms of energy consumption, but is more reliable in terms of data packet delivery to sink than the single path scheme (IDLF). In the latter scheme, the protocol establishes multiple (alternate) disjoint path/s from source to destination with negligible control overhead to balance load due to heavy data traffic among intermediate nodes from source to the destination. Another point of interest in this framework is the study of trade-offs between the achieved routing reliability using multiple disjoint path routing and extra energy consumption due to the use of additional path/s. Also, the effect of the failed nodes on the network performance is evaluated within the sensor system; Performance of the label dissemination scheme is evaluated and compared with the classic flooding and SPIN. (Abstract shortened by UMI.)

Encaminhamento baseado no contexto em ICNs móveis

Over the last couple of decades, vehicular ad hoc networks (VANETs) have been at the forefront of research, yet still are afflicted by high network fragmentation, due to their continuous node mobility and geographical dispersion. To address these concerns, a new paradigm was proposed - Information-Centric Networks(ICN), whose focus is the delivery of Content based on names, being ideal to attend to high latency environments. However, the main proposed solutions for content delivery in ICNs do not take into account the type of content nor the various available communication interfaces in each point of the network, a factor which can be deciding in mobile networks. The scope of this dissertation lies on the use of ICNs concepts for the delivery of both urgent and non-urgent information in urban mobile environments. In order to do so, a context-based forwarding strategy was proposed, with a very clear goal: to take advantage of both packet names and Data, and node's neighborhood analysis in order to successfully deliver content into the network in the shortest period of time, and without worsening network congestion. The design, implementation and validation of the proposed strategy was performed using the ndnSIM platform simulator along with real mobility traces from communication infrastructure of the Porto city. The results show that the proposed context-based forwarding strategy for mobile ICN presents a clear improvement in performance in terms of delivery, while maintaining network overhead at a constant. Furthermore, by means of better pathing and through cooperation with caching mechanisms, lower transmission delays can be attained.Nas últimas décadas, as redes veiculares ad hoc (VANETs) estiveram na vanguarda da pesquisa, mas continuam a ser afetadas por alta fragmentação na rede, devido à mobilidade contínua dos nós e a sua dispersão geográfica. Para abordar estes problemas, um novo paradigma foi proposto - Redes Centradas na Informação (ICN), cujo foco é a entrega de Conteúdo com base em nomes, sendo ideal para atender ambientes de alta latência. No entanto, as principais soluções propostas para entrega de conteúdo em ICNs não têm em conta o tipo de conteúdo nem as várias interfaces de comunicação disponíveis em cada ponto da rede, fator que pode ser determinante em redes móveis. O objetivo desta dissertação reside no uso dos conceitos de ICNs para a entrega de informações urgentes e não urgentes em ambientes móveis urbanos. Para isso, foi proposta uma estratégia de encaminhamento baseada em contexto, com um objetivo muito claro: tirar proveito do nome e dados dos pacotes, e da análise de vizinhança dos nós, com vista em fornecer com êxito o conteúdo para a rede no menor período de tempo e sem piorar o congestionamento da rede. O desenho, implementação e validação da estratégia proposta foram realizados usando o simulador ndnSIM, juntamente com traces reais de mobilidade da infraestrutura de comunicação da cidade do Porto. Os resultados mostram que a estratégia de encaminhamento baseada em contexto proposta para o ICN móvel apresenta uma clara melhoria no desempenho em termos de entrega, mantendo a carga da rede constante. Além disso, através da escolha de melhores caminhos e através da cooperação com mecanismos de armazenamento em cache, é possível alcançar atrasos de transmissão mais baixos.Mestrado em Engenharia de Computadores e Telemátic

Adaptive real-time predictive collaborative content discovery and retrieval in mobile disconnection prone networks

Emerging mobile environments motivate the need for the development of new distributed technologies which are able to support dynamic peer to peer content sharing, decrease high operating costs, and handle intermittent disconnections. In this paper, we investigate complex challenges related to the mobile disconnection tolerant discovery of content that may be stored in mobile devices and its delivery to the requesting nodes in mobile resource-constrained heterogeneous environments. We propose a new adaptive real-time predictive multi-layer caching and forwarding approach, CafRepCache, which is collaborative, resource, latency, and content aware. CafRepCache comprises multiple multi-layer complementary real-time distributed predictive heuristics which allow it to respond and adapt to time-varying network topology, dynamically changing resources, and workloads while managing complex dynamic tradeoffs between them in real time. We extensively evaluate our work against three competitive protocols across a range of metrics over three heterogeneous real-world mobility traces in the face of vastly different workloads and content popularity patterns. We show that CafRepCache consistently maintains higher cache availability, efficiency and success ratios while keeping lower delays, packet loss rates, and caching footprint compared to the three competing protocols across three traces when dynamically varying content popularity and dynamic mobility of content publishers and subscribers. We also show that the computational cost and network overheads of CafRepCache are only marginally increased compared with the other competing protocols