Multiple UAVs as relays : multi-hop single link versus multiple dual-hop links

Unmanned aerial vehicles (UAVs) have found many important applications in communications. They can serve as either aerial base stations or mobile relays to improve the quality of services. In this paper, we study the use of multiple UAVs in relaying. Considering two typical uses of multiple UAVs as relays that form either a single multi-hop link or multiple dual-hop links, we first optimize the placement the UAVs by maximizing the end-to-end signal-to-noise ratio for three useful channel models and two common relaying protocols. Based on the optimum placement, the two relaying setups are then compared in terms of outage and bit error rate. Numerical results show that the dual-hop multi-link option better than the multi-hop single link option when the air-to-ground path loss parameters depend on the UAV positions. Otherwise, the dual-hop option is only better when the source-to-destination distance small. Also, decode-and-forward UAVs provide better performances than amplify-and-forward UAVs. The investigation also reveals the effects of important system parameters on the optimum UAV positions and the relaying performances to provide useful design guidelines

Performance evaluation of next generation wireless UAV relay with millimeter-wave in access and backhaul

Future wireless communication, particularly densified 5G networks, will bring numerous innovations to the telecommunication industry and will support 100-fold gain in throughput rates, 100-fold in capacity (for at least 100 billion devices), individual user data rate of up-to 10 Gb/s, extremely low latency and response times. In such a scenario, the use of Unmanned Aerial Vehicle (UAV) as a Base Station (gNB) becomes a viable option for providing 5G services, both on-demand and on a regular basis. Recent development of UAVs have made its deployment faster and reliable, resulting in a shift in its usage from traditional military to more commercial and corporate industries. On the other hand, due to the abundant availability of bandwidth in the millimeter-wave band (mmWave), there is an immense potential to utilize this band for next generation radio systems. In this case, smart integration of UAVs in 5G network provides immense potential, however, such network require efficient placement mechanism for providing blazingly fast wireless cellular network services. In this study, we analyze and describe the distinctive characteristics of mmWave propagation. The main goal is to investigate and evaluate the use of mmWave in Access and Back-haul communication links simultaneously for Amplify-and-Forward relays deployed on UAVs. We formulate the required mathematical framework for calculating the UE received power for direct path (gNB-UE) and relay path (gNB-UAV-UE) based on two cases; (i) Friis Transmission Equation and (ii) Log-Distance Path loss Model. We conduct simulations using ray-tracing simulator in different scenarios while comparing and verifying the simulation results vs mathematical equations. For the proposed system architecture, International Telecommunication Union (ITU) recommendation city model is used to calculate the probability for Line of Sight (LoS) and Non Line of Sight (NLoS) paths in different urban environments. Furthermore, we study and identify different parameters i.e., UAV location, and amplification factor to maximize the performance of an Amplify-and-Forward UAV based relay for providing enhanced coverage to the users. Similarly, the optimum UAV-gNB height is evaluated in different urban environments while providing coverage to the users via an Amplify-and-Forward relay. The study concludes with the Signal to Noise Ratio (SNR) analysis for the relay path compared with the direct path where we identify the constraints for effective relaying

Методи збору даних з безпроводових сенсорних мереж телекомунікаційними аероплатформами

В дисертаційній роботі отримали подальший розвиток два класи методів збору даних моніторингу з безпроводових сенсорних мереж (БСМ) телекомунікаційними аероплатформами (ТА) в умовах відсутності телекомунікаційної інфраструктури загального користування. Отримані результати є вирішенням науково-прикладної задачі підвищення ефективності процесу збору даних моніторингу з БСМ ТА. В роботі представлено вдосконалений метод безпосереднього збору даних моніторингу з вузлів безпроводової сенсорної мережі з їх кластеризацією телекомунікаційними аероплатформами. Відмінність вдосконаленого методу, що визначає його новизну, є: застосування двох алгоритмів кластерного аналізу FOREL та k-середніх для здійснення віртуальної кластеризації мережі ТА; нова траєкторно-позиційна модель обміну даними між ТА і вузлами кластера. В роботі вдосконалено метод збору даних ТА з головних вузлів кластерів мережі за рахунок нового підходу до кластеризації мережі (запропоновані нова множина метрик вибору головних вузлів, правила знаходження енергоефективних структур кластерів та метрик побудови маршрутів в кластері)

5G wireless network support using umanned aerial vehicles for rural and low-Income areas

>Magister Scientiae - MScThe fifth-generation mobile network (5G) is a new global wireless standard that enables state-of-the-art mobile networks with enhanced cellular broadband services that support a diversity of devices. Even with the current worldwide advanced state of broadband connectivity, most rural and low-income settings lack minimum Internet connectivity because there are no economic incentives from telecommunication providers to deploy wireless communication systems in these areas. Using a team of Unmanned Aerial Vehicles (UAVs) to extend or solely supply the 5G coverage is a great opportunity for these zones to benefit from the advantages promised by this new communication technology. However, the deployment and applications of innovative technology in rural locations need extensive research