Standalone and Non-Standalone Beam Management for 3GPP NR at mmWaves

The next generation of cellular networks will exploit mmWave frequencies to dramatically increase the network capacity. The communication at such high frequencies, however, requires directionality to compensate the increase in propagation loss. Users and base stations need to align their beams during both initial access and data transmissions, to ensure the maximum gain is reached. The accuracy of the beam selection, and the delay in updating the beam pair or performing initial access, impact the end-to-end performance and the quality of service. In this paper we will present the beam management procedures that 3GPP has included in the NR specifications, focusing on the different operations that can be performed in Standalone (SA) and in Non-Standalone (NSA) deployments. We will also provide a performance comparison among different schemes, along with design insights on the most important parameters related to beam management frameworks.Comment: 7 pages, 5 figures, 1 table. Please cite it as M. Giordani, M. Polese, A. Roy, D. Castor and M. Zorzi, "Standalone and Non-Standalone Beam Management for 3GPP NR at mmWaves," in IEEE Communications Magazine, vol. 57, no. 4, pp. 123-129, April 201

Non-Terrestrial Networks in the 6G Era: Challenges and Opportunities

Many organizations recognize non-terrestrial networks (NTNs) as a key component to provide cost-effective and high-capacity connectivity in future 6th generation (6G) wireless networks. Despite this premise, there are still many questions to be answered for proper network design, including those associated to latency and coverage constraints. In this paper, after reviewing research activities on NTNs, we present the characteristics and enabling technologies of NTNs in the 6G landscape and shed light on the challenges in the field that are still open for future research. As a case study, we evaluate the performance of an NTN scenario in which satellites use millimeter wave (mmWave) frequencies to provide access connectivity to on-the-ground mobile terminals as a function of different networking configurations.Comment: 8 pages, 4 figures, 2 tables, submitted for publication to the IEE

Fastening the Initial Access in 5G NR Sidelink for 6G V2X Networks

The ever-increasing demand for intelligent, automated, and connected mobility solutions pushes for the development of an innovative sixth Generation (6G) of cellular networks. A radical transformation on the physical layer of vehicular communications is planned, with a paradigm shift towards beam-based millimeter Waves or sub-Terahertz communications, which require precise beam pointing for guaranteeing the communication link, especially in high mobility. A key design aspect is a fast and proactive Initial Access (IA) algorithm to select the optimal beam to be used. In this work, we investigate alternative IA techniques to fasten the current fifth-generation (5G) standard, targeting an efficient 6G design. First, we discuss cooperative position-based schemes that rely on the position information. Then, motivated by the intuition of a non-uniform distribution of the communication directions due to road topology constraints, we design two Probabilistic Codebook (PCB) techniques of prioritized beams. In the first one, the PCBs are built leveraging past collected traffic information, while in the second one, we use the Hough Transform over the digital map to extract dominant road directions. We also show that the information coming from the angular probability distribution allows designing non-uniform codebook quantization, reducing the degradation of the performances compared to uniform one. Numerical simulation on realistic scenarios shows that PCBs-based beam selection outperforms the 5G standard in terms of the number of IA trials, with a performance comparable to position-based methods, without requiring the signaling of sensitive information

A Tutorial on Beam Management for 3GPP NR at mmWave Frequencies

The millimeter wave (mmWave) frequencies offer the availability of huge bandwidths to provide unprecedented data rates to next-generation cellular mobile terminals. However, mmWave links are highly susceptible to rapid channel variations and suffer from severe free-space pathloss and atmospheric absorption. To address these challenges, the base stations and the mobile terminals will use highly directional antennas to achieve sufficient link budget in wide area networks. The consequence is the need for precise alignment of the transmitter and the receiver beams, an operation which may increase the latency of establishing a link, and has important implications for control layer procedures, such as initial access, handover and beam tracking. This tutorial provides an overview of recently proposed measurement techniques for beam and mobility management in mmWave cellular networks, and gives insights into the design of accurate, reactive and robust control schemes suitable for a 3GPP NR cellular network. We will illustrate that the best strategy depends on the specific environment in which the nodes are deployed, and give guidelines to inform the optimal choice as a function of the system parameters.Comment: 22 pages, 19 figures, 10 tables, published in IEEE Communications Surveys and Tutorials. Please cite it as M. Giordani, M. Polese, A. Roy, D. Castor and M. Zorzi, "A Tutorial on Beam Management for 3GPP NR at mmWave Frequencies," in IEEE Communications Surveys & Tutorials, vol. 21, no. 1, pp. 173-196, First quarter 201

User equipment rotation system integration for Frequency Range 2 test environment

Abstract. This thesis work was done for MediaTek Wireless Finland Oy, and it was carried out in the laboratory premises of the company. The work investigated wireless communication, and especially its latest fifth generation mobile communication technology (5G). The purpose of the thesis work was to design and implement a completely new test environment with an integrated a rotation system, which can rotate a device under test. The rotation system can rotate the test device horizontally in three different positions, allowing the device to rotate more than 180 degrees about its axis. In the completed test environment, various measurements and tests were performed, and those test cases can provide information about a performance of the device under research. Those test measurements focused on determining which of the antenna groups of the User equipment (UE) were active during those tests. The test environment was utilizing a Frequency Range 2 (FR2) and a Non-Standalone (NSA) technology, which allowed to use millimeter wave (mmWave) technology during different test cases. The three main antenna groups used by the UE could receive those mmWave signals and performed measurements provided information on which of these antenna groups were active during the measurements. The environment was implemented in an Electro Magnetic Chamber (EMC) laboratory room and the UE rotation system was built in that same room. As part of the work, a Python script was made which can manage the controlling of the rotating system. Five separate test cases were performed in the work. In addition to the active antenna of the device, the tests performed in the work also measured the ability of the test device to utilize wireless network which was used in that test environment. This wireless network used 5G technology, so the related 5G theory and the theory which was needed to perform the tests was explored. The implementation of the test cases and the results obtained from those cases were documented and analyzed. Those analyzes were utilized in the research and development of the test environment. Based on the test results, it can be briefly stated that all the mmWave antenna groups of the device were active during the tests, and the change of the active antenna took place depending on the position of the UE. Those antenna groups were active one at a time. In addition, a change in the active antenna was affected on the performance of the test device. At the end of the work, it was also considered how successful the work was and what improvements could be made to the measurements or the test environment in the future. This environment can also be integrated into the company’s testing plan.Testilaitetta pyörittävän systeemin integroiminen FR2-testiympäristöön. Tiivistelmä. Tämä diplomityö tehtiin MediaTek Wireless Finland Oy:lle ja se suoritettiin yrityksen tarjoamissa laboratoriotiloissa. Työssä tutkittiin langatonta tietoliikennettä ja erityisesti 5G-teknologiaa. Kyseisessä työssä suunniteltiin ja rakennettiin täysin uusi testiympäristö, johon integroitiin tutkittavaa testilaitetta pyörittävä järjestelmä. Se pystyi pyörittämään testattavaa laitetta vaakasuunnassa kolmessa eri asennossa, jolloin laitetta voitiin pyörittää yli 180 astetta oman akselinsa ympäri. Kun testiympäristö oli rakennettu valmiiksi, siinä tehtiin erilaisia mittauksia, joiden avulla kerättiin tietoa testilaitteen suorituskyvystä. Kyseisissä mittauksissa keskityttiin tutkimaan, mitkä testilaitteen antenniryhmistä olivat aktiivisina mittauksen aikana. Testiympäristössä hyödynnettiin FR2-teknologiaa ja NSA-teknologiaa, jotka mahdollistivat millimetrisignaalien käyttämisen mittauksissa. Kolme pääantenniryhmää operoivat millimetriaaltojen avulla ja suoritettavien mittausten sekä testien tulisi antaa tietoa siitä, mitkä kyseisistä antenniryhmistä ovat aktiivisia kunkin mittauksen aikana. Tutkimusympäristö toteutettiin laboratoriotilojen sähkömagneettisessa kammiossa, jonne antenniryhmiä pyörittävä laite rakennettiin. Osana käytännön työtä luotiin Python-ohjelmointikielellä komentojono, jonka avulla testilaitetta pyörittävää järjestelmää pystyttiin hallitsemaan. Työssä suoritettiin viisi erillistä testiä. Laitteen aktiivisen antennin lisäksi testit mittasivat myös laitteen kykyä hyödyntää testiympäristössä käytettävää langatonta verkkoa ja itse testilaitteen toimintakykyä. Ympäristössä käytetty verkko hyödynsi viidennen sukupolven matkaviestintätekniikkaa, joten myös siihen liittyvää teoriaa sekä suoritettavien mittausten kannalta oleellista teoriaa käytiin työssä läpi. Testien toteuttaminen ja niistä saadut tulokset dokumentoitiin sekä analysoitiin. Näitä analyyseja hyödynnettiin testiympäristön tutkimuksessa ja kehittämisessä. Testeistä saatujen tulosten perusteella voitiin lyhyesti todeta aktiivisten antenniryhmien vaihtuvan riippuen testilaitteen asennosta. Kyseiset antenniryhmät olivat aktiivisena yksi kerrallaan. Aktiivisen antennin muutoksella oli myös vaikutusta laitteen suorituskykyyn. Työn lopussa tarkasteltiin sitä, kuinka hyvin työ onnistui, ja mitä parannuksia mittauksiin tai testiympäristöön voitaisiin tehdä tulevaisuudessa. Kyseinen testiympäristö on mahdollista integroida osaksi yrityksen testaussuunnitelmaa

Smart Pattern V2I Handover Based on Machine Learning Vehicle Classification

The mmwave frequencies will be widely used in future vehicular communications. At these frequencies, the radio channel becomes much more vulnerable to slight changes in the environment like motions of the device, reflections or blockage. In high mobility vehicular communications the rapidly changing vehicle environments and the large overheads due to frequent beam training are the critical disadvantages in developing these systems at mmwave frequencies. Hence, smart beam management procedures are desired to establish and maintain the radio channels. In this thesis, we propose that using the positions and respective velocities of the vehicles in the dynamic selection of the beam pair, and then adapting to the changing environments using machine learning algorithms, can improve both network performance and communication stability in high mobility vehicular communications

An initial access optimization algorithm for millimetre wave 5G NR networks

Abstract. The fifth generation (5G) of cellular technology is expected to address the ever-increasing traffic requirements of the digital society. Delivering these higher data rates, higher bandwidth is required, thus, moving to the higher frequency millimetre wave (mmWave) spectrum is needed. However, to overcome the high isotropic propagation loss experienced at these frequencies, base station (BS) and the user equipment (UE) need to have highly directional antennas. Therefore, BS and UE are required to find the correct transmission (Tx) and reception (Rx) beam pair that align with each other. Achieving these fine alignment of beams at the initial access phase is quite challenging due to the unavailability of location information about BS and UE. In mmWave small cells, signals are blocked by obstacles. Hence, signal transmissions may not reach users. Also, some directions may have higher user density while some directions have lower or no user density. Therefore, an intelligent cell search is needed for initial access, which can steer its beams to a known populated area for UEs instead of wasting time and resources emitting towards an obstacle or unpopulated directions. In this thesis, we provide a dynamic weight-based beam sweeping direction and synchronization signal block (SSB) allocation algorithm to optimize the cell search in the mmWave initial access. The order of beam sweeping directions and the number of SSBs transmitted in each beam sweeping direction depend on previously learned experience. Previous learning is based on the number of detected UEs per SSB for each sweeping direction. Based on numerical simulations, the proposed algorithm is shown to be capable of detecting more users with a lower misdetection probability. Furthermore, it is possible to achieve the same performance with a smaller number of dynamic resource (i.e., SSB) allocation, compared to constant resource allocation. Therefore, this algorithm has better performance and optimum resource usage

Initial access with neighbor assistance in 5G mmWave cellular networks

The advent of 5G communications has already started. In order to achieve the objectives of high speed and low latency, mmWave technologies will be adopted in the near future. In this thesis we present a new cell discovery algorithm that takes advantage of context information available through legacy networks in order to achieve a faster initial access. We compute analytically the relevant probabilities and then we implement a 3GPP-compliant and spatially consistent simulation environment.openEmbargo temporaneo per motivi di segretezza e/o di proprietà  dei risultati e/o informazioni sensibil