A joint multi-path and multi-channel protocol for traffic routing in smart grid neighborhood area networks

In order to improve the management mechanisms of the electric energy transport infrastructures, the smart grid networks have associated data networks that are responsible for transporting the necessary information between the different elements of the electricity network and the control center. Besides, they make possible a more efficient use of this type of energy. Part of these data networks is comprised of the Neighborhood Area Networks (NANs), which are responsible for interconnecting the different smart meters and other possible devices present at the consumers' premises with the control center. Among the proposed network technologies for NANs, wireless technologies are becoming more relevant due to their flexibility and increasing available bandwidth. In this paper, some general modifications are proposed for the routing protocol of the wireless multi-hop mesh networks standardized by the IEEE. In particular, the possibility of using multiple paths and transmission channels at the same time, depending on the quality of service needs of the different network traffic, is added. The proposed modifications have been implemented in the ns-3 simulator and evaluated in situations of high traffic load. Simulation results show improvements in the network performance in terms of packet delivery ratio, throughput and network transit time.Peer ReviewedPostprint (published version

A testbed based performance evaluation of smart grid wireless neighborhood area networks routing protocols

Smart Grid networks have a data communication network associated with the electrical energy distribution infrastructure. This network connects all the sub- scribers’ homes with the data control centers of the supplying companies, which in turn have access to the global Internet network. They are in charge of transporting the needed information between the elements that comprise the electricity network and the control centers. A part of these networks is the so-called Neighborhood Area Networks (NANs), which transports the data from the subscriber’s home to some data concentrators. This article presents a comparison of the performance of different routing protocols that can be used in this part of the data network, when a wireless technology is selected. For this comparison, a hardware testbed has been implemented, with a simple initial configuration, which allows the comparison of the OLSR v1, OLSR v2 and HWMP protocols. The numerical results are presented in terms of network throughput, protocol overhead, number of retransmissions, net- work transit and packet transfer times.This work was supported by the Spanish Research Council under project MAGOS (TEC2017-84197-C4-3-R), and Juan Pablo Astudillo León is the recipient of a full scholarship from the Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT), Ecuador.Peer ReviewedPostprint (published version

Emergency aware congestion control for smart grid neighborhood area networks

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The evolution of traditional electricity distribution infrastructures towards Smart Grid networks has generated the need to carry out new research. There are many fields that have attracted the attention of researchers, among which is the improvement of the performance of the so-called Neighborhood Area Networks (NAN). In this sense, and given the critical nature of some of the data transmitted by these networks, maintaining an adequate quality of service (QoS) is absolutely necessary. In emergency situations, this need becomes even more evident. This article presents a congestion control mechanism, whose parameters are modified according to the network state of emergency. The mechanism also applies a multi-channel allocation technique, together with a differentiation in the QoS offered to the different data flows according to their relevance. These proposals have been evaluated in the context of a wireless mesh networks (WMN) made up by a set of smart meter devices, where various smart grids (SG) applications are sending their data traffics. Each SG application must meet its unique quality of service (QoS) requirements, such as reliability and delay. To evaluate the proposals, some NAN scenarios have been built by using the ns-3 simulator and its 802.11s basic model, which was modified to implement the proposed techniques. Compared with the basic Hybrid Wireless Mesh Protocol (HWMP), Emergency Aware Congestion Control proposal (EA-HWMP), shows significant improvements in terms of packet delivery ratio, network throughput and transit time.Peer ReviewedPostprint (published version

Circuit model for mode conversion in coplanar waveguide asymmetric series-impedances

A new `circuit model' for converting between even and odd modes in asymmetric series impedances in the ground plane of a coplanar waveguide is presented. The model is based on the separation of modes into two input and two output ports. In contrast to previous work, it enables a quantitative analysis of the energy exchange between modes to be obtained.Peer Reviewe

Circuit model for slotline-to-coplanar waveguide asymmetrical transitions

A new `circuit-model' for slotline-to-coplanar waveguide asymmetrical transitions is presented and applied to the design of slotline resonators. The model, based on the separation of coplanar-waveguide (CPW) modes into two different ports, overcomes limitations of previous models because it explains the transition behaviour even if CPW air-bridges are not used.Peer Reviewe

A machine learning based Distributed Congestion Control Protocol for multi-hop wireless networks

The application areas of multi-hop wireless networks are expected to experience sustained growth in the next years. This growth will be further supported by the current possibility of providing low-cost communication capabilities to any device. One of the main issues to consider with this type of networks is congestion control, that is, avoiding an excessive volume of data traffic that could lead to a loss of performance. In this work, a distributed congestion control mechanism is proposed for generic multi-hop networks. Different categories of data traffic are taken into account, each of them with different quality of service requirements. The mechanism is based on machine learning techniques, specifically, the CatBoost algorithm that uses gradient boosting on decision trees. The obtained decision trees are used to predict whether the packets to be transmitted over the network will reach their destination on time or not. This prediction will be made based on the network load state, which will be quantified by means of two parameters: the utilization factor of the different transmission channels, and the occupancy of the buffers of the network nodes. To make the values of these parameters available to all nodes in the network, an appropriate dissemination protocol has also been designed. Besides, a method to assign different transmission priorities to each traffic category, based on the estimation of the network resources required at any time, has also been included. The complete system has been implemented and evaluated through simulations, which show the correct functionality and the improvements obtained in terms of packet delivery ratio, network transit time, and traffic differentiation.Peer ReviewedPostprint (published version

SISCOM: smart services for information systems and communication networks

The SISCOM (Smart Services for Information Systems and Communication Networks) research group focuses on technologies that make it possible to provide intelligent services for information services and communication networks. We teach and do research in topics related to privacy, performance evaluation of networks, wireless adhoc and mesh networks, design of routing protocols, among others. Our research activities are funded by public research projects granted by the Spanish Government and the European Commission.Peer ReviewedPostprint (published version

Redes, sistemas y servicios de comunicación : exámenes resueltos

Aquest llibre és una recopilació d'exàmens resolts corresponents als exàmens finals de l'assignatura Xarxes Sistemes i Serveis de Comunicació de la ETSETB, en la qual s'imparteixen els coneixements bàsics per a l'anàlisi, l'avaluació i el dimensionament de xarxes de dades. La col·lecció està formada per dotze exàmens, que comprenen un període de sis anys. En tot moment, s'ha volgut ser fidel als exàmens que es van proposar al seu dia i, per tant, s'ha mantingut íntegrament el contingut de tots els enunciats. Esperem que aquesta obra sigui d'ajuda als estudiants para resoldre possibles dubtes en el desenvolupament dels exercicis i que els permeti augmentar la capacitat d'autoaprenentatge. Com a complement dels exercicis proposats, s'aconsella als estudiants que realitzin altres exercicis dels quals no disposin prèviament de la solució

Optimized path selection in a game-theoretic routing protocol for video-streaming services over MANETs

Mobile ad hoc networks (MANETs) are infrastructureless networks formed by wireless mobile devices. Recently, the demand over multimedia services such as video streaming has increased specially since the number of mobile end users is growing as well. MPEG-2 VBR is one of the most fitting video coding techniques for MANETs which improves the distribution of video streams specially when it is used with a proper multipath routing scheme. In this article, we aimed to design a routing scheme to dynamically select the forwarding paths using a game-theoretic approach over a multipath routing protocol. Our proposal seeks to describe an equation of the probability p of sending video frames through the best available path. p depends on network parameters that vary throughout time. The aim is that the most important video frames (I+P) will be sent through the best path with a certain probability p and will be sent through the second best path with a probability 1-p. To achieve that, we carried out simulations done with fixed values of p and after that we applied a lineal regression method to obtain the coefficients of the equation for p. Simulations have been done to show the benefits of our proposal where interfering traffic and mobility of the nodes are present.Peer ReviewedPostprint (published version

Introducció a les Xarxes Telemàtiques: problemes amb solució

Col·lecció de problemes resolts d'IXT (Introducció a les Xarxes Telemàtiques) amb solució, 1er curs dels graus de l'ETSETB.2022/20232n quadrimestr