Optimizing segment routing using evolutionary computation

Segment Routing (SR) combines the simplicity of Link-State routing protocols with the flexibility of Multiprotocol Label Switching (MPLS). By decomposing forwarding paths into segments, identified by labels, SR improves Traffic Engineering (TE) and enables new solutions for the optimization of network resources utilization. This work proposes an Evolutionary Computation approach that enables Path Computation Element (PCE) or Software-defined Network (SDN) controllers to optimize label switching paths for congestion avoidance while using at the most three labels to configure each label switching path.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT Fundac¸˜ao para a Ciˆencia e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results

Fixed and mobile telecom operators, enterprise network operators and cloud providers strive to face the challenging demands coming from the evolution of IP networks (e.g. huge bandwidth requirements, integration of billions of devices and millions of services in the cloud). Proposed in the early 2010s, Segment Routing (SR) architecture helps face these challenging demands, and it is currently being adopted and deployed. SR architecture is based on the concept of source routing and has interesting scalability properties, as it dramatically reduces the amount of state information to be configured in the core nodes to support complex services. SR architecture was first implemented with the MPLS dataplane and then, quite recently, with the IPv6 dataplane (SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering of packets across nodes to a general network programming approach, making it very suitable for use cases such as Service Function Chaining and Network Function Virtualization. In this paper we present a tutorial and a comprehensive survey on SR technology, analyzing standardization efforts, patents, research activities and implementation results. We start with an introduction on the motivations for Segment Routing and an overview of its evolution and standardization. Then, we provide a tutorial on Segment Routing technology, with a focus on the novel SRv6 solution. We discuss the standardization efforts and the patents providing details on the most important documents and mentioning other ongoing activities. We then thoroughly analyze research activities according to a taxonomy. We have identified 8 main categories during our analysis of the current state of play: Monitoring, Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL

3D flight route optimization for air-taxis in urban areas with evolutionary algorithms

Dissertation submitted in partial fulfilment of the requirements for the degree of Master of Science in Geospatial TechnologiesElectric aviation is being developed as a new mode of transportation for the urban areas of the future. This requires an urban air space management that considers these aircraft and restricts the vehicles’ flight routes from passing nofly areas. Flight routes need to be determined that avoid the no-fly areas and are also optimally planned in regard to minimize the flight time, energy consumption and added noise. The no-fly areas and the flight routes can be best modelled as three-dimensional geographical objects. The problem of finding a good flight route that suits all three criteria is hard and requires an optimization technique. Yet, no study exists for optimizing 3D-routes that are represented as geographical objects while avoiding three-dimensional restricted areas. The research gap is overcome by optimizing the 3D-routes with the multi-criteria optimization technique called Nondominated Sorting Genetic Algorithm (II).We applied the optimization on the study area of Manhattan (New York City) and for two representatives of different electrical aircraft, the Lilium Jet and the Ehang 184. Special procedures are proposed in the optimization process to incorporate the chosen geographical representations. We included a seeding procedure for initializing the first flight routes, repair methods for invalid flight routes and a mutation technique that relocates points along a sine curve. The resulting flight routes are compromise solutions for the criteria flight time, energy emission and added noise. Compared to a least distance path, the optimized flight routeswere improved for all three objectives. The lowest observed improvementwas a noise reduction by 36% for the Ehang 184. The highest improvement was an energy consumption reduction by 90% for the Lilium Jet. The proposed representation caused high computation times, which lead to other limitations, e.g. a missing uncertainty analysis.With the proposed methods, we achieved to optimize 3D-routes with multiple objectives and constraints. A reproducibility self-assessment1 resulted in 2, 2, 2, 2, 1 (input data, preprocessing, methods, computational environment, results)

A grid-based ant colony algorithm for automatic 3D hose routing

Ant Colony Algorithms applied to difficult combinatorial optimization problems such as the traveling salesman problem (TSP) and the quadratic assignment problem. In this paper we propose a grid-based ant colony algorithm for automatic 3D hose routing. Algorithm uses the tessellated format of the obstacles and the generated hoses in order to detect collisions. The representation of obstacles and hoses in the tessellated format greatly helps the algorithm towards handling free-form objects and speed up the computations. The performance of the algorithm has been tested on a number of 3D models

Method For Creating A Control Cabinet Model With Realistic Wires

During the assembly of a control cabinet, a major time-consuming step is the wiring of the included components. Hence, automating this step will noticeably reduce production costs. According to the planning, wires are routed through wire ducts and connected to components. While a comprehensive digital twin can be computed for the included components, this twin is missing a proper modelling of the connecting wires. For these, only a rough route through the wire ducts is given. However, a physically plausible model is an important prerequisite to perform reliable path planning for automated assembly. The paper addresses this need for accurate wire path computation during automated cabinet assembly and introduces a method to compute realistic wire paths through the wire ducts. Different models with and without a fixed wire length are presented and compared. An evolutionary algorithm optimizes the corresponding variables of the models. As described, both approaches yield valid paths, although the fixed length model appears to be able to compute more realistic paths

Natural computing for vehicular networks

La presente tesis aborda el diseño inteligente de soluciones para el despliegue de redes vehiculares ad-hoc (vehicular ad hoc networks, VANETs). Estas son redes de comunicación inalámbrica formada principalmente por vehículos y elementos de infraestructura vial. Las VANETs ofrecen la oportunidad para desarrollar aplicaciones revolucionarias en el ámbito de la seguridad y eficiencia vial. Al ser un dominio tan novedoso, existe una serie de cuestiones abiertas, como el diseño de la infraestructura de estaciones base necesaria y el encaminamiento (routing) y difusión (broadcasting) de paquetes de datos, que todavía no han podido resolverse empleando estrategias clásicas. Es por tanto necesario crear y estudiar nuevas técnicas que permitan de forma eficiente, eficaz, robusta y flexible resolver dichos problemas. Este trabajo de tesis doctoral propone el uso de computación inspirada en la naturaleza o Computación Natural (CN) para tratar algunos de los problemas más importantes en el ámbito de las VANETs, porque representan una serie de algoritmos versátiles, flexibles y eficientes para resolver problemas complejos. Además de resolver los problemas VANET en los que nos enfocamos, se han realizado avances en el uso de estas técnicas para que traten estos problemas de forma más eficiente y eficaz. Por último, se han llevado a cabo pruebas reales de concepto empleando vehículos y dispositivos de comunicación reales en la ciudad de Málaga (España). La tesis se ha estructurado en cuatro grandes fases. En la primera fase, se han estudiado los principales fundamentos en los que se basa esta tesis. Para ello se hizo un estudio exhaustivo sobre las tecnologías que emplean las redes vehiculares, para así, identificar sus principales debilidades. A su vez, se ha profundizado en el análisis de la CN como herramienta eficiente para resolver problemas de optimización complejos, y de cómo utilizarla en la resolución de los problemas en VANETs. En la segunda fase, se han abordado cuatro problemas de optimización en redes vehiculares: la transferencia de archivos, el encaminamiento (routing) de paquetes, la difusión (broadcasting) de mensajes y el diseño de la infraestructura de estaciones base necesaria para desplegar redes vehiculares. Para la resolución de dichos problemas se han propuesto diferentes algoritmos CN que se clasifican en algoritmos evolutivos (evolutionary algorithms, EAs), métodos de inteligencia de enjambre (swarm intelligence, SI) y enfriamiento simulado (simulated annealing, SA). Los resultados obtenidos han proporcionado protocolos de han mejorado de forma significativa las comunicaciones en VANETs. En la tercera y última fase, se han realizado experimentos empleando vehículos reales circulando por las carreteras de Málaga y que se comunicaban entre sí. El principal objetivo de estas pruebas ha sido el validar las mejoras que presentan los protocolos que se han optimizado empleando CN. Los resultados obtenidos de las fases segunda y tercera confirman la hipótesis de trabajo, que la CN es una herramienta eficiente para tratar el diseño inteligente en redes vehiculares

Fully automated urban traffic system

The replacement of the driver with an automatic system which could perform the functions of guiding and routing a vehicle with a human's capability of responding to changing traffic demands was discussed. The problem was divided into four technological areas; guidance, routing, computing, and communications. It was determined that the latter three areas being developed independent of any need for fully automated urban traffic. A guidance system that would meet system requirements was not being developed but was technically feasible