Hybrid RSS-RTT Localization Scheme for Indoor Wireless Networks

[EN]Nowadays, a variety of information related to the distance between two wireless devices can be easily obtained. This paper presents a hybrid localization scheme that combines received signal strength (RSS) and round-trip time (RTT) information with the aim of improving the previous localization schemes. The hybrid localization scheme is based on an RSS ranging technique that uses RTT ranging estimates as constraints among other heuristic constraints. Once distances have been well estimated, the position of the mobile station (MS) to be located is estimated using a new robust least-squared multilateration (RLSM) technique that combines the RSS and RTT ranging estimates mitigating the negative effect of outliers. The hybrid localization scheme coupled with simulations and measurements demonstrates that it outperforms the conventional RSS-based and RTT-based localization schemes, without using either a tracking technique or a previous calibration stage of the environment.Dirección General de Telecomunicaciones de la Consejería de Fomento de Castilla y Leó

International Conference on Broadband Communications, Networks and Systems

Producción CientíficaNetwork Function Virtualization (NFV) is considered to be one of the enabling technologies for 5G. NFV poses several challenges, like deciding the virtual network function (VNF) placement and chaining, and adding backup resources to guarantee the survivability of service chains. In this paper, we propose a genetic algorithm that jointly solves the VNF-placement, chaining and virtual topology design problem in WDM metro ring network, with the additional capacity of providing node protection. The simulation results show how important is to solve all of these subproblems jointly, as well as the benefits of using shared VNF and network resources between backup instances in order to reduce both the service blocking ratio and the number of active CPUs.Ministerio de Economía, Industria y Competitividad (grant TEC2017-84423-C3-1-P)Ministerio de Industria, Comercio y Turismo (grant BES 2015-074514)INTERREG V-A España-Portugal (POCTEP) (grant 0677_DISRUPTIVE_2_E)

A testbed and a simulation laboratory for training engineering students in optical access network technologies

Producción CientíficaEngineering profiles focused on next-generation optical networks are gaining immense importance due to new emerging services and the amount of data expected in future network scenarios. In fact, not only are optical access networks leading to a major revolution in the network industry, but passive optical networks are the most widely deployed access networks worldwide today. This should be a strong incentive for universities to train their students in these innovative and recent technologies. In this vein, we propose the deployment of an optical communication laboratory with on-site experimental sessions in which students work with commercial equipment and realistic working environments. These working environments are necessary to train professionals in the area of optical networks. However, due to the high cost of the optical communications equipment, it is not possible to have a working place for each group and we combine these experimental sessions with some simulation sessions to complete the training. We present the design of this lab and a qualitative and quantitative study aimed at analyzing students’ experiences, the skills they have acquired, and the potential impact on their future careers. This study shows that students have a very positive perception of the lab, emphasizing that working with real equipment helps them improve technical skills and assimilate theoretical knowledge. They also point out they would like a higher number of subjects in their degrees to employ this type of lab. Finally, students perceive these sessions as very useful for their professional future.Unión Europea a través del programa INTERREG V-A España-Portugal (project 0677_DISRUPTIVE_2_E)Junta de Castilla y León (grant VA085G19)Ministerio de Ciencia, Innovación y Universidades (grants TEC2017-84423-C3-1-P and RED2018-102585-T

PID controller based on a self-adaptive neural network to ensure qos bandwidth requirements in passive optical networks

Producción CientíficaIn this paper, a proportional-integral-derivative (PID) controller integrated with a neural network (NN) is proposed to ensure quality of service (QoS) bandwidth requirements in passive optical networks (PONs). To the best of our knowledge, this is the first time an approach that implements a NN to tune a PID to deal with QoS in PONs is used. In contrast to other tuning techniques such as Ziegler-Nichols or genetic algorithms (GA), our proposal allows a real-time adjustment of the tuning parameters according to the network conditions. Thus, the new algorithm provides an online control of the tuning process unlike the ZN and GA techniques, whose tuning parameters are calculated offline. The algorithm, called neural network service level PID (NNSPID), guarantees minimum bandwidth levels to users depending on their service level agreement, and it is compared with a tuning technique based on genetic algorithms (GASPID). The simulation study demonstrates that NN-SPID continuously adapts the tuning parameters, achieving lower fluctuations than GA-SPID in the allocation process. As a consequence, it provides a more stable response than GA-SPID since it needs to launch the GA to obtain new tuning values. Furthermore, NN-SPID guarantees the minimum bandwidth levels faster than GA-SPID. Finally, NN-SPID is more robust than GA-SPID under real-time changes of the guaranteed bandwidth levels, as GA-SPID shows high fluctuations in the allocated bandwidth, especially just after any change is made.Ministerio de Ciencia e Innovación (Projects TEC2014-53071-C3-2-P and TEC2015-71932-REDT

An Experimental SDN Proposal over Legacy GPONs to Allow Real-Time Service and Residential Network Reconfiguration

Producción CientíficaIn this paper we propose an experimental SDN (Software Defined Networking) solution over legacy GPON (Gigabit Passive Optical Network) equipment that allow a control of the network configuration and its services. On the one hand, the proposal permits to move certain global bandwidth and service configuration policies outside the GPON so that they can be managed centrally by an SDN controller. In legacy PONs the real-time bandwidth allocation process is made inside the network infrastructure cycle by cycle between the OLT (Optical Line Terminal) and the ONTs (Optical Network Terminals) so the network performance could be adversely affected due to the latency between the SDN controller and the PON. In contrast, the control of some global DBA strategies by SDN techniques could lead to better network and management configuration and therefore our proposal is able to dynamically adjust these policies according to the real-time Quality of Service (QoS) requirements of residential users. On the other hand, the designed SDN proposal permits network subscribers to control the performance of their residential homes. In this way, they can set constraints and dynamically customize the bandwidth of their connected devices in a very transparent and efficient way.Junta de Castilla y León (Project VA085G19)Ministerio de Economía, Industria y Competitividad (Project TEC2017-84423-C3-1-P)INTERREG V-A España-Portugal (POCTEP) program (0677_DISRUPTIVE_2_E

2021 International Conference on Optical Network Design and Modeling (ONDM)

Producción CientíficaThe planning of multi-access edge computing (MEC) systems does not only consist in distributing MEC servers among the base stations (BSs) but also in designing the network to interconnect BSs, MEC resources and the wide area network (WAN) gateway. Due to their high bandwidth, fiber links are the best option for those connections in 5G environments. In contrast to previous works, which only solve the server placement problem, in this paper, an integer linear programming (ILP) formulation is proposed for solving both problems while reducing the installation cost (servers and fibers). The fiber deployment cost is especially important in sparsely populated areas as the distance between BSs are much longer than in urban environments. The model was tested using real BSs locations and population data showing that the formulation considerably reduces the installation cost.Interreg V-A Spain-Portugal (POCTEP) programme 2014- 2020 (project 0667_DISRUPTIVE_2_E)Ministerio de Economía, Industria y Competitividad (projects TEC2017-84423-C3-1-P and RED2018- 102585-T)Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (project VA231P20

2023 26th Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN)

Network Slicing (NS) is a key enabler of the 5G network ecosystem due to its potential to provide distinct services over the same physical infrastructure. However, the necessity to optimally orchestrate resources for heterogeneous demands is crucial when dealing with resource constraints and Quality-of-Service (QoS) requirements. We consider a radio access network scenario providing NS over multiple base stations (BS) with limited resources, and we design an efficient resource orchestration technique, based on reinforcement learning, which optimizes resource utilization among different services while satisfying the constraints and complying with Service Level Agreement (SLA) and QoS requirements. The proposed technique makes use of the Trust Region Method to formulate the orchestration objective function and satisfy the constraints and is then optimized via Kronecker Factored Approximate Curvature (K-FAC). Extensive simulations demonstrate that the proposed technique outperforms other Reinforcement Learning (RL) algorithms, reaching 99% of QoS and SLA satisfaction while assuring bandwidth constraints.EU H2020 MSCA ITN-ETN IoTalentum (grant no. 953442)Consejería de Educación de la Junta de Castilla y León y FEDER (VA231P20)Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación (Proyecto PID2020-112675RB-C42 financiado por MCIN/AEI/10.13039/501100011033

2022 32nd International Telecommunication Networks and Applications Conference (ITNAC)

Producción CientíficaThe upcoming Connected and cooperative and automated mobility paradigm (CCAM) requires the deployment of road-side units (RSUs) beside the roads to provide wireless communication to connected-vehicle on board units. The deployment of RSUs along the highways provide low-latency communication, suitable for applications where high-speed response is needed, such as autonomous driving and crash avoidance. These RSUs must be connected to the Internet through a high-bandwidth and reliable access network being the optical fiber technologies the most convenient technology for that. In this paper, we propose a planning scheme for enabling RSUs with optical access networks. The method starts choosing the locations of the access network headers (the connection points to the local service provider facilities), and then defines the connections between the headers and the RSUs in a convenient manner considering the road infrastructure. Then, two deployment technologies based on optical fibers are compared: Point to Point (P2P) and Passive Optical Network (PON). A techno-economic analysis was performed, and results show that P2P and PON approaches are very similar in terms of cost, therefore, due to technical advantages, P2P is recommended as deployment strategy for the described scenario.Consejería de Educación de la Junta de Castilla y León y FEDER (VA231P20)Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación (Proyecto PID2020-112675RB-C42 financiado por MCIN/AEI/10.13039/501100011033 y RED2018-102585-T)FEDER a través del Programa INTERREG V-A España-Portugal 2014-2020 (0677_DISRUPTIVE_2_E

2022 18th International Conference on the Design of Reliable Communication Networks (DRCN)

Producción CientíficaResiliency (fault tolerance) is an important aspect in communication networks: a robust and well-planned network must have a strategy to face equipment failures. The planning of Multi-Access Edge Computing (MEC) systems should not only consider computing resources, but also the fiber connections to base stations (BSs) and to the WAN network gateway. This joint design is particularly important in sparsely populated areas (e.g., rural areas), as the distances are much longer than in urban environments. When solving the planning problem for these systems, reserving backup resources for both computing and networks is a must to ensure resiliency. In this paper, we propose and compare different strategies for the planning of resilient MEC networks assuming that there are backup resources for both MEC servers and fibers. The method provides protection against single-fiber failure or single-MEC node failure (with part or all the servers affected). The different approaches are evaluated in terms of cost and propagation delay from BSs to the primary and backup MEC servers. Results show the advantages of using edge technology instead of a centralized design, and they also suggest that is more convenient to jointly plan the main and backup MEC architecture than to deploy the backup resources over an existent infrastructure.FEDER a través del Programa INTERREG V-A España-Portugal 2014-2020 (0677_DISRUPTIVE_2_E)Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación (Proyecto PID2020-112675RB-C42 financiado por MCIN/AEI/10.13039/501100011033 y RED2018-102585-T)Consejería de Educación de la Junta de Castilla y León y FEDER (VA231P20)

2019 21st International Conference on Transparent Optical Networks (ICTON)

Producción Científica5G technology will provide networks with high-bandwidth, low latency and multitenancy. The integration of computing and storage resources in the edge of the fronthaul network, i.e., multi-access edge computing (MEC), will allow to instantiate some virtual network functions (VNF) in those computing resources. The backhaul of 5G networks will be based on optical technology, in particular WDM, due to its high capacity and flexibility. In this paper, we analyse the problem of VNF-provisioning in a metro ring-topology network equipped with MEC resources and with a WDM network connecting the edge nodes. In contrast to previous proposals, the method decides where VNFs must be instantiated but also the design of the virtual topology for the WDM metro network in order to reduce the service blocking ratio and the number of resources in operation.Ministerio de Economía, Industria y Competitividad (project TEC2017-84423-C3-1-P)Ministerio de Industria, Energía y Turismo (project BES-2015-074514