Multi-frequency backhaul analysis for UABS in disaster situations

When a disaster occurs, the land-based cellular network could go offline for some days. Using an Unmanned Aerial Base Station (UABS) network is a promising solution to serve unconnected ground users. In this article, we propose a multifrequency backhaul architecture, which considers power and capacity constraints, to support the UABS network in a realistic 3D scenario in the city of Ghent, Belgium. Simulations results show that at the optimal flight height (80 m), up to 87% of the users could be supported using the multifrequency scenario compared with single frequency scenarios where coverage is about 70%

System assessment of WUSN using NB-IoT UAV-aided networks in potato crops

Unmanned Aerial Vehicles (UAV) are part of precision agriculture; also, their impact on fast deployable wireless communication is offering new solutions and systems never envisioned before such as collecting information from underground sensors by using low power Internet of Things (IoT) technologies. In this paper, we propose a (Narrow Band IoT) NB-IoT system for collecting underground soil parameters in potato crops using a UAV-aided network. To this end, a simulation tool implementing a gateway mounted on a UAV using NB-IoT based access network and LTE based backhaul network is developed. This tool evaluates the performance of a realistic scenario in a potato field near Bogota, Colombia, accounting for real size packets in a complete IoT application. While computing the wireless link quality, it allocates access and backhaul resources simultaneously based on the technologies used. We compare the performance of wireless underground sensors buried in dry and wet soils at four different depths. Results show that a single drone with 50 seconds of flight time could satisfy more than 2000 sensors deployed in a 20 hectares field, depending on the buried depth and soil characteristics. We found that an optimal flight altitude is located between 60 m and 80 m for buried sensors. Moreover, we establish that the water content reduces the maximum reachable buried depth from 70 cm in dry soils, down to 30 cm in wet ones. Besides, we found that in the proposed scenario, sensors & x2019; battery life could last up to 82 months for above ground sensors and 77 months for the deepest buried ones. Finally, we discuss the influence of the sensor & x2019;s density and buried depth, the flight service time and altitude in power-constrained conditions and we propose optimal configuration to improve system performance

Coexistence for LTE-advanced and FSS services in the 3.5GHz band in Colombia

The 3.5GHz band is an optimal candidate for 5G networks due to its propagation characteristics and massive bandwidth. However, services like the Fixed Satellite Service (FSS) are using this band in several countries. Therefore, this paper presents a coexistence study of the Long Term Evolution - Advanced (LTE-A) and FSS services in the 3500-3700 MHz in Colombia. Simulations were done in realistic scenarios in the city of Bogota, Colombia. Preliminary results show that critical scenarios are the ones from the LTE eNodeB (eNB) and Users Equipment (UE) nodes to the FSS earth stations. The study includes the analysis of Guard Bands (GB) and arrival angles into the Protection Distances (PD). Results show that the PD is highly dependent on the angle of the interfering signal and the GB used. The PD for a cochannel interference in a suburban scenario is higher than 250km, in the worst-case scenario, and could be reduced down to 17.5 km if a 25 MHz GB is included and the angular difference of the interfering LTE-A signal is 42 square. Moreover, our results show that the PD needed for interference from UE are 100 times less compared to the eNB ones

Wireless network design for 5G networks and beyond

Dit proefschrift richt zich op het plannen van 5G en toekomstige netwerken. Het doel is om inzicht te krijgen in de uitdagingen van netwerkplanning en om de vereiste dekking te bieden terwijl de infrastructuur, het energieverbruik en de menselijke blootstelling tot een minimum worden beperkt. Drone gebaseerde netwerken, die gebruik maken van Unmanned Aerial Base Stations (UABSs) worden geïntroduceerd als een nieuwe oplossing om de betrouwbaarheid van mobiele netwerken te vergroten. UABSs bieden voordelen zoals een betere signaalkwaliteit en snelle implementatie, en ze kunnen mobiele connectiviteit ondersteunen in noodsituaties of tijdens een hoge vraag. Het aansluiten van de UABS op het kernnetwerk blijft een uitdagend aspect. Het proefschrift evalueert verschillende benaderingen om het netwerk te optimaliseren, waaronder het optimaliseren van het backhaul-netwerk, het gebruik van Mobile Edge Computing-technologie om de meest populaire inhoud te bewaren, en het gebruik van Massive Multiple-Input Multiple-Output-technologie om de kanaalsterkte te vergroten. Het proefschrift onderzoekt ook de impact van elektromagnetische straling op de menselijke blootstelling door 5G-implementaties en modelleert een optimalisatie voor blootstelling

60 GHz network planning for fixed wireless access

Fixed wireless access (FWA) using mmWave bands, mainly the unlicensed 60 GHz spectrum, is presented to compete with fiber development while delivering lower costs. The deployment of FWA networks in the 60 GHz band in realistic urban and rural areas in Belgium is assessed in this study. In order to maximize user coverage, provide a minimum of 1 Gbps of bandwidth, and reduce the needed network infrastructure, we built a network planning tool with a novel mesh backhaul based on the IEEE 802.11ay standard. We assess various serving node locations, also known as Edge Nodes (EN), and how environmental variables like rain and vegetation impact the network design. The position of the ENs must be appropriately defined to obtain a viable user coverage of more than 95\%, especially in urban settings where the geometry of street canyons affects propagation. While urban situations need four times as much infrastructure, rural scenarios only need about 75 ENs per km2. Lastly, depending on the node deployment approach used, vegetation can decrease coverage by 3\% or increase infrastructure by up to 7\%. In comparison, severe rainfall can decrease coverage by 5\% or increase infrastructure by 15\%

60 GHz network planning for fixed wireless access

Fixed wireless access (FWA) using mmWave bands, mainly the unlicensed 60 GHz spectrum, is presented to compete with fiber development while delivering lower costs. The deployment of FWA networks in the 60 GHz band in realistic urban and rural areas in Belgium is assessed in this study. In order to maximize user coverage, provide a minimum of 1 Gbps of bandwidth, and reduce the needed network infrastructure, we built a network planning tool with a novel mesh backhaul based on the IEEE 802.11ay standard. We assess various serving node locations, also known as Edge Nodes (EN), and how environmental variables like rain and vegetation impact the network design. The position of the ENs must be appropriately defined to obtain a viable user coverage of more than 95\%, especially in urban settings where the geometry of street canyons affects propagation. While urban situations need four times as much infrastructure, rural scenarios only need about 75 ENs per km2. Lastly, depending on the node deployment approach used, vegetation can decrease coverage by 3\% or increase infrastructure by up to 7\%. In comparison, severe rainfall can decrease coverage by 5\% or increase infrastructure by 15\%

MmWave physical layer network modeling and planning for fixed wireless access applications

The large bandwidths that are available at millimeter-wave frequencies enable fixed wireless access (FWA) applications, in which fixed point-to-point wireless links are used to provide internet connectivity. In FWA networks, a wireless mesh is created and data are routed from the customer premises equipment (CPE) towards the point of presence (POP), which is the interface with the wired internet infrastructure. The performance of the wireless links depends on the radio propagation characteristics, as well as the wireless technology that is used. The radio propagation characteristics depend on the environment and on the considered frequency. In this work, we analyzed the network characteristics of FWA networks using radio propagation models for different wireless technologies using millimeter-wave (mmWave) frequencies of 28 GHz, 60 GHz, and 140 GHz. Different scenarios and environments were considered, and the influence of rain, vegetation, and the number of subscribers was investigated. A network planning algorithm is presented that defines a route for each CPE towards the POP based on a predefined location of customer devices and considering the available capacity of the wireless links. Rain does not have a considerable effect on the system capacity. Even though the higher frequencies exhibit a larger path loss, resulting in a lower power of the received signal, the larger bandwidths enable a higher channel capacity

Multi-objective optimisation of human exposure for various 5G network topologies in Switzerland

The constant increase in the required user capacity and the evolution of wireless network technologies impact the exposure that users experience from wireless networks. This paper evaluates various 5G network topologies regarding human exposure, mobile communication quality, and sustainability. We assess human exposure, based on a novel Exposure Ratio (ER) metric, in 5G networks that include Massive Multiple-Input MultipleOutput (MaMIMO) and compare them with existing 4G deployments in three environments in Switzerland. The quality and sustainability of mobile communication are evaluated by extrapolating data rates from mobile operators to the year 2030. A multi-objective optimisation algorithm is implemented to design the 5G network topologies, maximising the user coverage while minimising the downlink (DL) and uplink (UL) exposure. An extensive set of simulations investigated three municipalities, three operators plus one unified network, three use cases (UL/DL data rates), three scenarios (indoor and outdoor coverage), and two optimisation methods. The study results confirm that the human exposure in a 5G network is dominated by the UL being ten times larger than the DL exposure. Furthermore, comparing a 5G deployment with 10 times the traffic capacity of a real 4G network, DL exposure increases by 36% on average, and UL exposure decreases by up to 75% depending on the scenario. Regarding indoor coverage versus outdoor only, our results show that DL exposure can be reduced by a factor of 10 if only outdoor coverage is targeted. Finally, the study concludes that from the human exposure perspective, the ideal network should use 5G MaMIMO and be optimised for both UL and DL exposure

Evaluation of beamsteering performance in multiuserMIMO unmanned aerial base stations networks

Future wireless communication networks can benefit from Unmanned Aerial Base Stations (UABSs) to provide enhanced capacity to ground users (GU) in large and remote locations. Connecting UABSs to the terrestrial network presents several challenges, such as the limited gain traditional antennas need to maintain suitable wireless links between the core network, UABS, and GU. A convenient solution is to use MaMIMO (Massive Multiple Input Multiple Output) since it improves spectral and energy efficiency, thus providing high data rates while reducing power consumption. This paper proposes a Multi-user MIMO (MuMIMO) model for UABS aided networks to increase service range and served capacity. It uses hybrid beamforming and beamsteering on Terrestrial Base Stations (TBSs) and UABSs to grant access to mobile GU in a bicycle race scenario. Results show that using the mobile operators' locations will benefit the backhaul network's performance by duplicating the capacity compared to using a private operator. Furthermore, user coverage increases by 400% if MuMIMO is used, compared to a single beam MaMIMO network. The proposed scenario could achieve a channel efficiency of 6.5 bit/s/Hz in the access network and 8.6 bit/s/Hz in the backhaul network. Finally, the average UABS transmitted power is reduced by 2/3, increasing the number of used beams