Distributed drone base station positioning for emergency cellular networks using reinforcement learning

Due to the unpredictability of natural disasters, whenever a catastrophe happens, it is vital that not only emergency rescue teams are prepared, but also that there is a functional communication network infrastructure. Hence, in order to prevent additional losses of human lives, it is crucial that network operators are able to deploy an emergency infrastructure as fast as possible. In this sense, the deployment of an intelligent, mobile, and adaptable network, through the usage of drones—unmanned aerial vehicles—is being considered as one possible alternative for emergency situations. In this paper, an intelligent solution based on reinforcement learning is proposed in order to find the best position of multiple drone small cells (DSCs) in an emergency scenario. The proposed solution’s main goal is to maximize the amount of users covered by the system, while drones are limited by both backhaul and radio access network constraints. Results show that the proposed Q-learning solution largely outperforms all other approaches with respect to all metrics considered. Hence, intelligent DSCs are considered a good alternative in order to enable the rapid and efficient deployment of an emergency communication network

Implementation Aspects of UMTS 900 MHz/2100 MHz for High Altitude Platforms

Projecte realitzat en col.laboració amb el centre Tampere University of TechnologyHigh Altitude Platforms (HAPs) represent an alternative to terrestrial mobile telecommunications. The aim of HAPs is to offer a feasible solution for the radio access layer of this kind of networks. The strong point of HAPs resides in the fact that they bring together the best features of terrestrial and satellite systems. HAPs have been widely proposed for deploying telecommunication services such as third generation mobile networks. In Europe, third generation of mobile communications system is using UMTS. It has being widely deployed in the last years but still there are certain areas where 3G coverage is not available. Especially in rural areas with low population density, where the operators did not find a cost efficient way to deploy UMTS services. As a result, UMTS in 900 MHz band emerges as a possible way to improve UMTS coverage for these areas, and combining with a HAP-based deployment, a cost efficient way for a widely deployment in sparsely populated and remote areas for 3G services. The work shown in this thesis is a comparison of network simulations obtained from the use of HAPs in the radio access network of UMTS using 900 MHz band and 2100 MHz band. The study was aimed to find the impact of carrier frequency on coverage for a single HAP scenario using different deployment strategies. An antenna study has also been done in order to see the impact of antenna beamwidth on UMTS system. The results obtained reveal that the decrease in the carrier frequency caused a clear increase in the coverage, when correct distance between cells was selected. Consequently the results obtained show the variation of the network performance with the separation between cells using both carrier frequencies, 2100 MHz and 900 MHz

Modeling the Use of an Airborne Platform for Cellular Communications Following Disruptions

In the wake of a disaster, infrastructure can be severely damaged, hampering telecommunications. An Airborne Communications Network (ACN) allows for rapid and accurate information exchange that is essential for the disaster response period. Access to information for survivors is the start of returning to self-sufficiency, regaining dignity, and maintaining hope. Real-world testing has proven that such a system can be built, leading to possible future expansion of features and functionality of an emergency communications system. Currently, there are no airborne civilian communications systems designed to meet the demands of the public following a natural disaster. A system allowing even a limited amount of communications post-disaster is a great improvement on the current situation, where telecommunications are frequently not available. It is technically feasible to use an airborne, wireless, cellular system quickly deployable to disaster areas and configured to restore some of the functions of damaged terrestrial telecommunications networks. The system requirements were presented, leading to the next stage of the planned research, where a range of possible solutions were examined. The best solution was selected based on the earlier, predefined criteria. The system was modeled, and a test ii system built. The system was tested and redesigned when necessary, to meet the requirements. The research has shown how the combination of technology, especially the recent miniaturizations and move to open source software for cellular network components can allow sophisticated cellular networks to be implemented. The ACN system proposed could enable connectivity and reduce the communications problems that were experienced following Hurricane Sandy and Katrina. Experience with both natural and man-made disasters highlights the fact that communications are useful only to the extent that they are accessible and useable by the population

成層圏飛翔体通信における無線通信路及びその性能に関する研究

制度:新 ; 文部省報告番号:甲2383号 ; 学位の種類:博士(国際情報通信学) ; 授与年月日:2007/3/15 ; 早大学位記番号:新447

A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

Cognitive relay nodes for airborne LTE emergency networks

This paper is proposing a novel concept of Cognitive Relay Node for intelligently improving the radio coverage of an airborne LTE emergency network, considering the scenarios outlined in the ABSOLUTE research project. The proposed network model was simulated comparing the different cases of deploying relay nodes to complement the coverage of an aerial LTE network. Simulation results of the proposed Cognitive Relay Nodes show significant performance improvement in terms of radio coverage quantified by the regional outage probability enhancement. Also, this paper is presenting the methodology and results of choosing the optimum aerial eNodeB altitude

A Vision and Framework for the High Altitude Platform Station (HAPS) Networks of the Future

A High Altitude Platform Station (HAPS) is a network node that operates in the stratosphere at an of altitude around 20 km and is instrumental for providing communication services. Precipitated by technological innovations in the areas of autonomous avionics, array antennas, solar panel efficiency levels, and battery energy densities, and fueled by flourishing industry ecosystems, the HAPS has emerged as an indispensable component of next-generations of wireless networks. In this article, we provide a vision and framework for the HAPS networks of the future supported by a comprehensive and state-of-the-art literature review. We highlight the unrealized potential of HAPS systems and elaborate on their unique ability to serve metropolitan areas. The latest advancements and promising technologies in the HAPS energy and payload systems are discussed. The integration of the emerging Reconfigurable Smart Surface (RSS) technology in the communications payload of HAPS systems for providing a cost-effective deployment is proposed. A detailed overview of the radio resource management in HAPS systems is presented along with synergistic physical layer techniques, including Faster-Than-Nyquist (FTN) signaling. Numerous aspects of handoff management in HAPS systems are described. The notable contributions of Artificial Intelligence (AI) in HAPS, including machine learning in the design, topology management, handoff, and resource allocation aspects are emphasized. The extensive overview of the literature we provide is crucial for substantiating our vision that depicts the expected deployment opportunities and challenges in the next 10 years (next-generation networks), as well as in the subsequent 10 years (next-next-generation networks).Comment: To appear in IEEE Communications Surveys & Tutorial

On the Performance of Imt-2000 Communication Link Based on Stratospheric Platforms

A new means for providing wireless communication has been currently proposed. It is based on aerial vehicle known asHigh Altitude Platform or Stratospheric Platforms (SPF). The SPF will be operated at an altitude of 17-22 km above theground. Therefore, the channel condition may be different compared with those of the conventional terrestrial orsatellite wireless channel. In this paper, the channel propagation characteristic of such a system is firstly investigated bymeans of ray tracing algorithm. We emphasize our investigation in a typical urban environment, in which the mobileusers mostly exist. We developed building block model for simulation based on building height distribution, which isobtained from measurement inside Tokyo. As a result, propagation loss model and Ricean channel parameter for theSPF channel is reported in different scenarios. By using this result we then estimate the required transmitted power ofSPF to serve the mobile users in a several transmission rate that is used in IMT-2000 services. Finally, an evaluation ofBER of IMT-2000 link is performed in order to estimate the system level performance. From this evaluation, the maincontribution of this paper is to clearly show the critical limitations of both power requirement as well as system levelperformance of mobile communication IMT-2000 by using the concept of the SPF