The low latency is a prime concern for large Network-on-Chips (NoCs) typically used in chip-multiprocessors (CMPs) and multiprocessor system-on-chips (MPSoCs). A significant component of overall latency is the serialization delay for applications which have long packets such as typical video stream traffic. To address the serialization latency, we propose to exploit the inherent path diversity available in a typical 2-D Mesh with our two novel router architectures, Dual-path router and Dandelion router. We observe that, in a 2-D mesh, for any source-destination pair, there are two minimal paths along the edges of the bounding box. We call it XY Dimension Order Routing (DOR) and YX DOR. There are also two non-minimal paths which are non-coinciding and out of the bounding box created by XY and YX DOR paths. Dual-path Router implements two injection and two ejection ports for parallel packet injection through two minimal paths. Packets are split into two halves and injected simultaneously into the network. Dandelion router implements four injection and ejection ports for parallel packet injection. Packets are split into smaller sub-packets and are injected simultaneously in all possible directions which typically include two minimal paths and two non-minimal paths. When all the sub-packets reach the destination, they are eventually recombined. We find that our technique significantly increases the throughput and reduces the serialization latency and hence overall latency of long packets. We explore the impact of Dual-path and Dandelion on various packet lengths in order to prove the advantage of our routers over the baseline. We further implement different deadlock free disjoint path models for Dandelion and develop a switching mechanism between Dual-path and Dandelion based on the traffic congestion.

The goal of this thesis work is to analyze how design elements and wireless attributes affect opportunistic routing, and in this context develop a new protocol. The algorithm developed aims to improve opportunistic elements in comparison to a well-known opportunistic protocol Simple Opportunistic Adaptive Routing (SOAR).

In the multiratecasting problem in wireless sensor networks, the source sensor is usually required to report to multiple destinations at dif- ferent rates for each of them. We present a MST-based rate-aware cost-efficient multiratecast routing protocol (MSTRC). The proposed MSTRC examines only one set partition of destinations at each for- warding step. A message split occurs when the locally-built minimum spanning tree (MST) over the current node and the set of destina- tions has multiple edges originated at the current node. Destinations spanned by each of these edges are grouped together, and for each of these subsets the best neighbor is selected as the next hop. We also suggested a novel face recovery mechanism to deal with void ar- eas, when no neighbor provides positive progress toward destinations. It constructs a MST of current node and destinations without the progress via neighbors, and for each set partition of destinations cor- responding to an edge e in MST, the face routing keeps going until a node that is closer to one of these destinations is found, allowing for greedy continuation, while the process repeats for the remaining desti- nations similarly. Our experimental results demonstrate that MSTRC is highly rate-efficient in all scenarios, and unlike existing solutions, it is adaptive to destination rate deviations.

Face routing is a simple method for routing in wireless ad-hoc networks. It only uses location information about nodes to do routing and it provably guarantees message delivery in static connected plane graphs. However, a static connected plane graph is often difficult to obtain in a real wireless network. This thesis extends face routing to more realistic models of wireless ad-hoc networks. We present a new version of face routing that generalizes and simplifies previous face routing protocols and develop techniques to apply face routing directly on general, non-planar network graphs. We also develop techniques for face routing to deal with changes to the graph that occur during routing. Using these techniques, we create a collection of face routing protocols for a series of increasingly more general graph models and prove the correctness of these protocols.

The increased interest in reducing greenhouse gas emissions has motivated renewed interest in electric vehicles technology as an alternative to current fossil-fuel based transportation equipment. Electric vehicles (EVs) are envisioned as a promising viable technology because of their friendly impact on the environment and higher efficiency over conventional vehicles that rely on fossil fuel. However, the EVs’ limited battery capacity, resulting in limited cruising range and long recharging time, hinders the widespread adoption of EVs. An essential requirement of EV motors is the ability to operate with minimum energy consumption in order to provide at least the same driving range as their Internal Combustion Engine (ICE) counterparts. Energy-optimal routing, which aims to find the least energy consuming routes, under battery constraints has been recognized as a viable approach to prolonging the cruising range of the EV battery. This thesis addresses the problem of optimal routing for EVs and proposes a solution to overcome the difficulties of optimal energy/time routing under battery constraints. A multi-criteria path-finding technique is proposed. The proposed technique functions in two modes and solves the problem of optimal energy/time routing in EVs with worst time complexity of . First, an energy mode to solve the problem of energy-optimal routing under battery constraints is introduced. This mode computes the most energy-efficient route from a source to a destination, thus extending the limited cruising range of a battery. Second, a time mode to solve the problem of optimal travel time routing under battery constraints, by computing the most efficient travel-time route from a source to a destination, is proposed. An EV can operate under these two modes to strike a balance between power consumption and travel time so as to satisfy user constraints and needs. In addition, a technique to reduce the effects of range anxiety on the vehicle operator is proposed. This technique computes a robust estimate of driving range. Furthermore, the technique analyzes an EV’s battery capacity required by the vehicle in order to reach a charging station. The thesis reports experimental work conducted to test and validate the proposed techniques under various driving conditions.

The objective of this project is to improve the performance of the Gnutella peer-to-peer protocol (version 0.4) by introducing a semantic-social routing model and several categories of interest. The Gnutella protocol requires peers to broadcast messages to their neighbours when they search files. The message passing generates a lot of traffic in the network, which degrades the quality of service. We propose using social networks to optimize the speed of search and to improve the quality of service in a Gnutella based peer-to-peer environment. Each peer creates and updates a friends list from its past experience, for each category of interest. Once peers generate their friends lists, they use these lists to semantically route queries in the network. Search messages in a given category are mainly sent to friends who have been useful in the past in finding files in the same category. This helps to reduce the search time and to decrease the network traffic by minimizing the number of messages circulating in the system as compared to standard Gnutella. This project will demonstrate by simulating a peer-to-peer type of environment with the JADE multi-agent system platform that by learning other peers interests, building and exploiting their social networks (friends lists) to route queries semantically, peers can get more relevant resources faster and with less traffic generated, i.e. that the performance of the Gnutella system can be improved.

Face routing is a simple method for routing in wireless ad-hoc networks. It only uses location information about nodes to do routing and it provably guarantees message delivery in static connected plane graphs. However, a static connected plane graph is often difficult to obtain in a real wireless network. This thesis extends face routing to more realistic models of wireless ad-hoc networks. We present a new version of face routing that generalizes and simplifies previous face routing protocols and develop techniques to apply face routing directly on general, non-planar network graphs. We also develop techniques for face routing to deal with changes to the graph that occur during routing. Using these techniques, we create a collection of face routing protocols for a series of increasingly more general graph models and prove the correctness of these protocols.

With the constant expansion of the industrial monitoring system, there is an urgent requirement to reduce investment and operating costs for the development of industrial communication technology. For industrial real-time monitoring systems, wireless technology can be used in a practical industrial production to take advantages of its flexibility and robustness. As wireless sensor networks have many advantages such as low investment costs, flexible structure and ease of transformation, it has become the focus with regards to industrial areas. THVRG is a routing algorithm that selects the routing path based on two-hop information. Since different information sensed by the sensors may have different requirements in order to reach the sink, a priority-based routing algorithm is required in order to adapt to this kind of situation. This thesis has proposed a priority routing algorithm based on the THVRG (Priority-based THVRG). In addition, a simulation of this algorithm was performed in OPNET. Finally, the report provides an evaluation of the proposed algorithm in industrial wireless sensor networks.

In this project the optimization of transport planning has been studied. The approach was that smaller transport companies do not have the capability to fully optimize their transports. Their transport optimization is performed at a company level, meaning that the end result might be optimal for their company, but that potential for further optimization exists. The idea was to build a collaboration of transport companies, and then to optimize the transports globally within the collaboration. The intent was for the collaboration to perform the same driving assignments but at a lower cost, by using fewer vehicles and drivers, or travel shorter distance, or both combined. This should be achieved by planning the assignments in a smarter way, for example using a company's empty return journey to perform an assignment for another company. Due to the complexity of these types of problems, called Vehicle Routing Problem (VRP), shown to be NP-complete, search methods are often used. In this project the method of choice was a PDDL-based planner called LPG-td. It uses enforced hill-climbing together with a best-first search to find feasible solutions. The method was tested for scaling, performance versus another method and against time, as well as together with a real-life based problem. The results showed that LPG-td might not be a suitable candidate to solve the problem considered in this project. The solutions found for the collaboration were worse than for the sum of individual solutions, and used more computational time. Since the solution for the collaboration at most should be equal to the sum of individual solutions, in theory, this meant that the planner failed.

Les xarxes d'interconnexió tenen com un dels seus objectius principals comunicar i enllaçar els nodes de processament dels sistemes de còmput d'altes prestacions. En aquest context, les fallades de xarxa tenen un impacte considerablement alt, ja que la majoria dels algorismes d'encaminament no van ser dissenyats per tolerar aquestes anomalies. A causa d'això, fins i tot una única fallada d'enllaç té la capacitat d'embussar missatges a la xarxa, provocant situacions de bloqueig o, encara pitjor, és capaç d'impedir la correcta finalització de les aplicacions que es trobin en execució en el sistema de còmput. En aquesta tesi presentem polítiques d'encaminament tolerants a fallades basades en els conceptes d'adaptabilitat i evitació de bloquejos, dissenyades per a xarxes afectades per un gran nombre de fallades d'enllaços. Es presenten dues contribucions al llarg de la tesi, a saber: un mètode d'encaminament tolerant a fallades multicamí, i una tècnica nova i escalable d'evitació de bloquejos. La primera de les contribucions de la tesi és un algorisme d'encaminament adaptatiu multicamí, anomenat Fault-tolerant Distributed Routing Balancing (FT-DRB), que permet explotar la redundància de camins de comunicació de les topologies de xarxa actuals, a fi de proveir tolerància a fallades a les xarxes d'interconnexió. La segona contribució de la tesi és la tècnica escalable d'evitació de bloquejos Non-blocking Adaptive Cycles (NAC). Aquesta tècnica va ser específicament dissenyada per funcionar en xarxes d'interconnexió que presentin un gran nombre de fallades d'enllaços. Aquesta tècnica va ser dissenyada i implementada amb la finalitat de servir al mètode d'encaminament descrit anteriorment, FT-DRB. / Las redes de interconexión tienen como uno de sus objetivos principales comunicar y enlazar los nodos de procesamiento de los sistemas de cómputo de altas prestaciones. En este contexto, los fallos de red tienen un impacto considerablemente alto, ya que la mayoría de los algoritmos de encaminamiento no fueron diseñados para tolerar dichas anomalías. Debido a esto, incluso un único fallo de en un enlace tiene la capacidad de atascar mensajes en la red, provocando situaciones de bloqueo o, peor aún, es capaz de impedir la correcta finalización de las aplicaciones que se encuentren en ejecución en el sistema de cómputo. En esta tesis presentamos políticas de encaminamiento tolerantes a fallos basadas en los conceptos de adaptabilidad y evitación de bloqueos, diseñadas para redes de comunicación afectadas por un gran número de fallos de enlaces. Se presentan dos contribuciones a lo largo de la tesis, a saber: un método de encaminamiento tolerante a fallos multicamino, y una novedosa y escalable técnica de evitación de bloqueos. La primera de las contribuciones de la tesis es un algoritmo de encaminamiento adaptativo multicamino, denominado Fault-tolerant Distributed Routing Balancing (FT-DRB), que permite explotar la redundancia de caminos de comunicación de las topologías de red actuales, a fin de proveer tolerancia a fallos a las redes de interconexión. La segunda contribución de la tesis es la técnica escalable de evitación de bloqueos Non-blocking Adaptive Cycles (NAC). Dicha técnica fue específicamente diseñada para funcionar en redes de interconexión que presenten un gran número de fallos de enlaces. Esta técnica fue diseñada e implementada con la finalidad de servir al método de encaminamiento descrito anteriormente, FT-DRB. / Interconnection networks communicate and link together the processing units of modern high-performance computing systems. In this context, network faults have an extremely high impact since most routing algorithms have not been designed to tolerate faults. Because of this, as few as one single link failure may stall messages in the network, leading to deadlock configurations or, even worse, prevent the finalization of applications running on computing systems. In this thesis we present fault-tolerant routing policies based on concepts of adaptability and deadlock freedom, capable of serving interconnection networks affected by a large number of link failures. Two contributions are presented throughout this thesis, namely: a multipath fault-tolerant routing method, and a novel and scalable deadlock avoidance technique. The first contribution of this thesis is the adaptive multipath routing method Fault-tolerant Distributed Routing Balancing (FT-DRB). This method has been designed to exploit the communication path redundancy available in many network topologies, allowing interconnection networks to perform in the presence of a large number of faults. The second contribution is the scalable deadlock avoidance technique Non-blocking Adaptive Cycles (NAC), specifically designed for interconnection networks suffering from a large number of failures. This technique has been designed and implemented with the aim of ensuring freedom from deadlocks in the proposed fault-tolerant routing method FT-DRB.