APRÈN. Portal de la producció docent del professorat de la UPC

Given the exponential expansion of air transport that pressures the existing infrastructure and makes the current systems over-capacitated, it is no surprise that automated Air Traffic Control (ATC) Systems are on the rise. These systems will improve the situational awareness of Air Traffic Controllers (ATCOs) while reducing their workload and potentially allowing for capacity increases. An example of such a system is the prototype ATC Real Ground-Breaking Operational System (ARGOS), entirely designed by EUROCONTROL Maastricht Upper Area Control Centre (MUAC). The system is evolving daily, and it will become MUAC¿s most intelligent agent to support ATCOs in their decision-making process. It is built to take complete care of basic Controller-Pilot Data-Link Communications (CPDLC), i.e., flights logged onto CPDLC not involved in any complex scenario, and to provide support for complex traffic scenarios. The current version provides conflict detection tools and suggests conflict-free trajectories. The prototype lacks a metrics-based system to evaluate its performance to be able to tune its parameters; thus, the focus of this project is to design a scoring mechanism to assess its performance based on the instructions given to the pilot. The first part is represented by the development of a concept that incorporates the current safety criteria in ATC and introduces new performance criteria relevant to ARGOS (and ATC). In contrast, the second part is a posteriori analysis of the output log files of the prototype that store the coordinates of all current simulated flights along with the commands given by ARGOS. Two types of scores were considered. The D-Score or the decreasing score measures the efficiency of ARGOS concerning operational safety. In this case, a score of 100% is perfect. It is conceptualized according to safety ATC requirements. The I-Score or the increasing score measures the inefficiency of ARGOS, so higher is less effective. It provides information related to the performance of the trajectory proposed by ARGOS.

The objective of this project is the design of a Web App where the main characteristics of the orbiting Earth satellites can be intuitively, didactically and easily visualized. It has been sought to stablish a theoretic guide and brief explanations about how they operate, as well as a set of different maps where the basic information of the satellite can be available. The main source of information are the well-known Two-Lines-Elements (TLEs), a data format with a list of elements for a chosen object in a certain date, which, along with the propagator (Simplified General Perturbations, SGP4) provides every necessary data for the orbit characterization. The information of these TLEs is officially and publicly provided by Space-Track (project initially developed by the US Air Force) and the Celestrak Company (coworker of Space-Track). In addition, every component and library used in this project are for public use. Multiple functionalities were aimed to be integrated in the Web App: different views, information filtering, history, comparisons and calculations. But it is the 'families' section the one which has been developed extensively, since it can be the more attractive feature for the web users in the future. With this special feature, fields such as coverage, orbit description or the occupation of the space used are addressed. This project intends to clarify the outer space to the average user and bring the aerospace industry closer to those who have interest in the subject. That is why this web is listed as a disclosure project, given that, although it is a scientific project and deals with complex issues, it is created for all audiences and no deep prior knowledge is required to make use of it. For more sophisticated and complex studies, there are more appropriate tools than the project that is planned to be carried out.

For commercial demands, common use cases such as shopping in malls, or supermarkets, warehouse management, game development and so on, are continuously improved. This is where positioning systems, or more specifically indoor positioning systems play an important role. For outdoor environmentws the Global Positioning System (GPS) is nowadays the most relyable technology, but indoor location and navigation remain unresolved issues, and alternative methods are needed. In this scenario the Wi-Fi positioning system is a pretty widely used technology, indeed since large buildings mostly already have a high number of Wi-Fi routers distributed, it makes sense to use the Wi-Fi signals for positioning. Namely, it is possible to employ Received Signal Strength (RSS) signals from any 802.11 device, while Round-Trip Time (RTT) signals from any 802.11mc device. This study investigates the implementation of a 802.11-based indoor positioning system that will follow a fingerprinting approach: the Wi-Fi signal collected at a given point will be compared with a map of measurements previously recorded at several reference points and, by means of machine learning, the most probable location will be extracted from the database. The objective will be to study the real potential of a Wi-Fi based indoor positioning system that simultaneously exploits RTT and RSS information from IEEE 802.11 devices. In order to build the required database, a data collection campaign has been implemented in one of the buildings of Universitat Politècnica de Catalunya. Subsequently, two machine learning algorithms have been implemented using Python¿s scikit-learn and xgboost libraries, and the related predictive performances have been tested. The positioning errors referring to the use of different datasets (e.g., RTT dataset, RSS dataset, the combined RTT/RSS dataset) have been estimated. Next, the results related to positional errors will be outlined, together with the relative benefits, if any, of using a coupled dataset for both considered classifiers.

The recently introduced disaggregation model is gaining interest due to its benefits when compared with traditional models.In essence, it consists on the separation of traditional hardware appliances (e.g. servers, network nodes) into commodity components, which then are mounted independently for their exploitation into customized physical infrastructures. Such an approach allows telecommunication operators and service providers to appropriately size their infrastructure and grow as needed. One of the main key benefits of the disaggregation model is the break of the vendor lock-in, pushing towards interoperability between equipment from different vendor with minimum standardization of software and hardware specifications, allowing operators to build the best solutions for their needs. Moreover, efficient scaling is also an important benefit introduced by the disaggregation approach. Due to these benefits, among others, the disaggregation model is gaining momentum and is being adopted into multiple fields and domains of nowadays telecom infrastructures. In this regard, the scenario under study of this master thesis focuses on disaggregated optical transport networks. Disaggregation allows for more open and customized optical networks, reducing both capital and operational expenditures for infrastructure owners.However, despite of these positive aspects, disaggregated optical networks face several challenges, beingthe degradation of the network performance when compared to traditional integrated solutions the most important one. In this regard, this thesis investigates the impact of disaggregation in optical networks and investigates regeneration as a potential solution to compensate the performances' degradation. Under this premise, optimal solutions for regenerator placement, exploiting the inherent grooming capabilities of regenerators, are proposed and evaluated

In the first part is described the LTE system containing a description of all the aspects and parameters that should be taken into account when planning. Then there is a Software Planning Tool named Mentum Planet guidelines with detailed and ordered description of all the steps that someone should do to reproduce the LTE planning, with explanations, screen captures to show different panels and with figures obtained explaining the technical details. In the Second part there is a description of the migration from the 4G scenario to 5G. Indeed, eNodeBs become RRHs and are placed some BBU-Pools. Then is introduced the C-RAN architecture and following the work of [11] C-RAN optimization is treated with explanation of the concepts, the algorithms and the results.

In the last decade, wireless communications have seen a dramatic growth of the traffic demand and the radio spectrum seems to not be able to keep this pace alone due to the limited available bandwidth. For this reason, Visible Light Communication is being considered as a potential access option for the next-generation of wireless communication technologies (5G) and it is gaining an increasing attention: this technology, which works modulating the intensity of the light in the “visible” part of the EM spectrum, use LEDs for the dual-purpose of illumination and communication. VLC shows great features such as ultra-high bandwidth, robustness to electromagnetic interference, a virtually unlimited frequency reuse and a cost effectiveness due to the unregulated spectrum and the use of the LEDs. The aim of this work is to further analyze the performance of the TCP protocol in the VLC networks and to provide a tool for the simulation of complex VLC networks. Using the NS3 framework, an existing module has been further developed and tested to simulate a VLC network and a simple scenario, with an AP and a user moving in random walk on the boundaries. The TCP performance has been evaluated, comparing two congestion control algorithms (New Reno and Westwood) and analyzing different parameters such as throughput, dropped packets, congestion window behavior and end-to-end delay. After that, a new module has been designed and developed to overcome the limitations of the previous one, such as the two devices per channel limit and the inadequate interference model, and to allow more complex simulation scenarios. The results obtained demonstrated the good qualities of the VLC channel, where the main limitations are due to the physical devices parameters, like the FOV and the semi-angle at half-power, that strictly define the coverage area. About the TCP performance analysis, the results showed that TCP works very well in the coverage, it has several problems handling the movement of the receiver among the boundaries. However, by analyzing different parameters such as the sender buffer size, the channel delay and the source application data rate, Westwood showed to have a better performance than New Reno, especially in terms of mean delay and BER.

Nowadays business and users traffic demands are getting higher and higher, leaving optical fiber as the only reliable solution to meet its demands, and in access networks the dominating technology is Passive Optical Networks (PONs) where currently exists two main families of standards, the GPON (ITU-T standard) and the EPON (IEEE standard). In this work we tackle the latest version oof the GPON family, the NG-PON2. We analyse the Physical Media Dependent (PMD) and Transmission Convergence (TC) layer requirements and what is standardized in each one. We also have a look into the SDN paradigm, which decouples the control and data plane of network equipment concentrating the intellegence and complexity in a centralized controller, the OpenFlow protocol that is one of the main enablers of SDN, since it is the communication protocol betwwen the network devices and the SDN controller, and the SIEPON (IEEE 1904.1) standard which gives interoperability of the transport, service, and control planes in a multi-vendor environment. The introduction of the SDN paradigm in the xPON world is a hot research topic because it would add the total controllability of the PON infrastructure, and the coordination with the SDN-based control plane of the core networks. It would allow a centralized optimization of the different resources managed by the OLTs and a seamless coordination between OLTs and the core network. In the TC layer specifications, of NG-PON2, it is not standardized the bandwidth allocation of the system, we set ourselves to create a simple Dynamic Bandwidth Allocation (DBA) algorithm that would optimize the use of channels and wavelengths. Taking into account the NG-PON2 technology and all its features, the emerging trend to extend SDN to the optical access networks, the multi-vendor adaptation provided by the SIEPON stantdard, and the need to have a platform to develop and test DBA scheduling algorithms made that thecreation and deployment of a fully SIEPON-SDN-NG-PON2 emulation environment became the main goal of this work. To create this environment we employed the use of MikroTiks, where OpenWRT was installed as well as a set of packages that menabled the behaviour of a CPqD switch (or ofsoftswitch13), and the use of Raspberry Pis which maintained its original OS and only required the installation of a sepecific set of tools. The results obtained were quite positive confirming the possibility of not only creating but also testing different DBA scheduling algorithms in the deployed environment and matching the results expected to our created algorithm.