Search

V zadnjih desetletjih je tehnološki napredek povzročil razvoj številnih novih idej in področij, ki pomembno prispevajo k izboljšanju kakovosti življenja ljudi. Ena od takšnih, ki se obeta v bližnji prihodnosti, je tudi avtonomna vožnja. Čeprav so v preteklosti znanstveniki že poskušali uresničiti izdelavo samovozečega avtomobila, razpoložljive tehnologije do danes niso zmogle izpolnjevati potrebnih zahtev. Peta generacija mobilnih sistemov, poznana kot 5G, je prvo tehnološko področje, ki predstavlja obetaven element pri realizaciji popolnoma avtonomne vožnje. Cilj tega magistrskega dela je bil raziskati, ali je omrežje 5G iz 3GPP Release 15 sposobno zagotoviti potrebna sredstva za popolno podporo avtonomni vožnji in drugih družin primerov uporabe C-V2X, hkrati pa delovati v izjemno zahtevnih (omrežnih) scenarijih cestnega prometa. V teoretičnem delu magistrskega dela smo najprej predstavili nekaj najpomembnejših konceptov v paradigmi avtonomnih vozil, ki nam bodo kasneje pomagali bolje razumeti praktični del. Najprej smo s komunikacijskega stališča definirali avtonomno vozilo in njegove komunikacijske potrebe in storitve. Nato smo našteli nekaj najpomembnejših prednosti avtonomnih vozil, pa tudi nekatere najbolj zaskrbljujoče izzive, s katerimi se srečujejo strokovnjaki, ki se razlikujejo od tehnoloških in okoljskih do zakonodajnih in filozofskih. Na kratko smo predstavili tudi Vehicular ad hoc networks, Intelligent transport systems, Vehicle-to-everything in kako bi nadaljnji razvoj takšnih konceptov pozitivno vplival na človeštvo. V zadnjem delu teoretičnega dela smo podrobneje razdelali tehnologijo C-V2X, kjer smo začeli s kratkim pregledom njenega razvoja skozi zgodovino. Gre za tehnologijo, ki uporablja obstoječe celično omrežje za zagotavljanje povezave med vozili, med vozili in infrastrukturo, med vozili in omrežjem ter med vozili in pešci. Vsak nov korak k popolnoma avtonomnemu vozilu prinaša nove sklope še bolj zapletenih izzivov. Na začetku sta bili najpomembnejši tehnologiji, ki sta bili uporabljeni za V2X, DSRC in LTE-based V2X. Čeprav ima LTE-based V2X več 18 Povzetek prednosti v primerjavi z DSRC, sta bila oba presežena z vidika zmogljivosti, ko je bil 5G NR-V2X predstavljen skupaj s 5G celičnim omrežjem. Aplikacije V2X, kot so kooperativno zaznavanje in manevriranje med vozili, vodenje z visoko gostoto vozil in daljinsko vodenje vozil, podajajo težko dosegljive računalniške in komunikacijske zahteve, ki presegajo LTE in DSRC. Večina varnostnih aplikacij V2X zahteva izjemno majhno zakasnitev (pod 10 ms), izjemno visoko zanesljivost (blizu 100 %) in visoko hitrost prenosa podatkov (v območju Gbps). Celično omrežje 5G ima edino dovolj napredno tehnologijo, ki lahko doseže takšne pragove zmogljivosti. Poleg tega smo predstavili načrt 5GAA, ki prikazuje rezultate in napovedi na ključnih prednostnih področjih, kot je pospešek razvoja celičnih tehnologij iz LTEbased V2X v 5G NR-V2X. Teoretični del se konča s prikazom, kako je 5G omogočil več primerov uporabe C-V2X, ki jih prej ni bilo mogoče vzdrževati z LTE kot nosilno tehnologijo, pa tudi kako lahko podpre novejše, bolj zapletene primere uporabe z višjimi zahtevami. Spoznali smo, da so nekateri primeri uporabe C-V2X izjemno zahtevni za omrežje, in sicer do te mere, da se pojavi dvom, ali bodo sploh sposobni delovati v resničnih situacijah. Teoretične raziskave smo dopolnili z vrsto simulacij, z namenom, da bi spremljali zakasnitev paketov in zanesljivost simuliranega omrežja 5G, in jo kasneje primerjali z zahtevami QoS družin primerov uporabe C-V2X. Simulacije so bile izvedene s pomočjo ogrodja OMNeT ++ 5G-Sim-V2I/N, ki omogoča simulacijo primerov uporabe 5G V2I / V2N z aplikacijami, ki obsegajo celotno uporabniško ravnino 5G. Simulirali smo dva različna scenarija cestnega prometa. V prvem scenariju smo simulirali avtocesto, kjer avtomobili vozijo z večjo hitrostjo, kar močno vpliva na delovanje omrežja. V drugem scenariju je bila pobuda izbrati nekaj povsem drugačnega, z namenom, da bi opazovali različne rezultate med dvema skrajnostnima. Zato je bila izbira za drugi scenarij urbano okolje, kjer je veliko ovir, kot so stavbe ali visoka drevesa, ki bi lahko motila komunikacijo. V obeh scenarijih sta bila izmerjena dva parametra QoS za štiri različne aplikacije UDP, ki delujejo vzporedno na več vozilih. Vzporedno izvajane aplikacije so vključevale aplikacije V2X, VoIP klic, video predvajanje in prenos podatkov od in k uporabniku, medtem ko so merjeni KPI vključevali zakasnitev in zanesljivost paketov. Izziv je bil spremljati zmogljivost omrežja v celotnem simulacijskem času in na koncu primerjati končne rezultate s celotnimi zahtevami glede zakasnitve in zanesljivosti nekaterih najzahtevnejših družin primerov uporabe C-V2X, ki naj bi bile Povzetek 19 s pomočjo 5G omrežja izvedljive. Cilj je bil ugotoviti, za katere od teh družin primerov uporabe simulirano omrežje 5G izpolnjuje zahteve. Simulirali smo omrežje 5G po specifikacijah 3GPP Release 15 in rezultate ocenili glede na zakasnitev na celotni komunikacijski poti in zanesljivost. Rezultati so pokazali, da omrežje ne izpolnjuje zahtev, potrebnih za podporo tako skrajnih primerov uporabe v simuliranih scenarijih. Te ugotovitve so nas pripeljale do zaključka, da simulirano omrežje potrebuje nadaljnje izboljšave zmogljivosti, zlasti z vidika znižanja zakasnitev in povečanja zanesljivosti, kar je bilo tudi obljubljeno za prihodnje izdaje 3GPP. In recent decades, technological advances have led to the development of many new ideas and areas that have made an important contribution to improving people's quality of life. Autonomous driving is one area that has resulted from these advances. While attempts have been made in the past to try and facilitate the realization of the self-driving car, the available technologies have never met the needed requirements. However, the recently introduced 5G is believed to be a promising enabler for the fully autonomous vehicle. The goal of this thesis was to investigate whether the 5G network from 3GPP Release 15 is capable of providing the needed resources to fully support autonomous driving and other C-V2X use-case families while simultaneously operating in extremely demanding (network-wise) road traffic scenarios. In the theoretical part of the thesis (in the first four chapters), we firstly introduced some of the most relevant concepts in the autonomous vehicle paradigm, which would later help us better understand the practical part. We begin by defining the autonomous vehicle from a communication standpoint, and its communication needs and services. We continue by listing some of the most important benefits of autonomous vehicles, as well as some of the most troubling challenges that experts face, varying from technological and environmental challenges to legislative and philosophical ones. We also briefly present Vehicular Ad Hoc Networks, Intelligent Transport Systems, Vehicle-to-Everything and how the further development of such concepts would have a positive impact on humanity. The fourth chapter discusses the C-V2X technology, beginning with a brief overview of its evolution throughout history. It is a technology that uses the existing cellular network to provide the vehicle-to-vehicle, vehicle-to-infrastructure, vehicleto-network, and vehicle-to-pedestrian connections. Every new step towards a fully autonomous vehicle brings about new sets of even more complicated challenges. In the very beginning, the two most relevant technologies used for V2X were DSRC and the LTE-based V2X. Although the LTE- 22 Abstract based V2X has multiple advantages compared to DSRC, they both got outclassed, in terms of performance, once 5G NR-V2X was introduced along with the 5G cellular network. V2X applications, such as cooperative sensing and maneuvering, high-density platooning and teleoperated driving, show hard-to-meet computing and communication demands, well beyond what LTE and DSRC can provide. Most V2X safety applications demand ultra-low latency (below 10 ms), ultra-high reliability (near 100%), and a high data rate (in the Gbps range). The 5G cellular network is the only cellular technology advanced enough to be capable of reaching such performance thresholds. In addition, we presented the 5GAA roadmap which shows the results and predictions in the key priority areas, such as the acceleration of the evolution of cellular technologies from the LTE-based V2X towards the 5G NR-V2X. The theoretical part ends by showing how 5G has enabled more C-V2X use cases that were previously impossible to sustain with LTE as the underlying technology, as well as how it has introduced newer, more complex use cases with higher requirements. It quickly became clear that some of the C-V2X use cases are extremely demanding on the network, to the point where a lot of doubts arose whether they would be able to operate in real-life situations. The theoretical research was complemented with a series of simulations in order to monitor the packet delay and reliability of the simulated 5G network, which would later be compared to the QoS requirements of the C-V2X use-case families. The simulations were executed with the help of the OMNeT++ framework 5G-Sim-V2I/N which enables to simulate 5G V2I/V2N use cases with applications comprising the whole 5G user plane. We have simulated two different road-traffic scenarios. In the first scenario, we simulated a motorway where the cars drive at higher speeds, which can have a huge effect on the network's performance. In the second scenario, the initiative was to choose something completely different from the first one in order to observe different results between two extremes. Hence, the choice for the second scenario was an urban environment with heterogeneous road characteristics and buildings that act as obstacles which interfere with the signals. In both scenarios, two QoS parameters were measured for four different UDP applications running in parallel, on multiple cars. The running parallel applications included a V2X application, a VoIP call, a video stream, and a data download/upload, while the measured KPIs included packet delay and reliability. The challenge was to monitor the network performance throughout the simulation, and in the end compare Abstract 23 the final results with the end-to-end latency and reliability requirements of some of the most demanding C-V2X use-case families, which were said to have been enabled by the 5G network. The objective was to find out for which of these C-V2X use-case families the simulated network met the requirements. We have simulated the 5G network from 3GPP Release 15 and have evaluated our results in terms of end-to-end-latency and reliability it quickly became clear that the network did not meet the requirements needed to support such extreme use-case families in the simulated scenarios. These findings brought us to the conclusion that the simulated network is in need of serious performance enhancements, in terms of lowering its latency and increasing its reliability, both of which have been promised for future 3GPP releases