Periodic Reporting for period 1 - HERMES (enHanced connEctivity with aeRial networks in eMergency EventS)
Okres sprawozdawczy: 2021-03-01 do 2023-02-28
In addition to improving connectivity in everyday scenarios, the proposed framework also has the potential to handle emergency situations. For example, in the event of a natural disaster, such as an earthquake that destroys the ground telecommunication infrastructure, UAVs can rapidly create an ad hoc network to assist rescue efforts during the first hours until the infrastructure is restored. However, before this vision can be fully realized, there are several issues that must be addressed:
Issue #1: The UAV communications should be enhanced.
Issue #2: Reliable and autonomous UAV orchestration is crucial.
Issue #3: Energy supply and availability is a major issue in UAV networks.
Thus, a better understanding of UAV networks is needed in order to fully realize their potential benefits. The HERMES objectives are:
i) To define a UAV communication framework that provides a sustainable and effective operation in terms of coverage both in stand-alone and complementary scenarios.
ii) To devise an orchestration framework that provides a reliable UAV network operation, while proving that this solution can be profitable.
iii) To research and develop state-of-the-art (SoA) technologies that allow an uninterrupted and autonomous aerial network operation.
In the end, all the novel communication and hardware technologies were fused into one integrated platform for orchestration and monitoring of the UAV system.
i) Enhanced Connectivity: The objective was to define a UAV communication framework that provides a sustainable and effective operation in terms of coverage both in stand-alone and complementary scenarios. This objective was tackled successfully in WP2 and it was the most challenging WP as it required the investigation of state-of-the-art (SoA) technologies in a very rapidly changing scientific environment. Hence, confident decisions had to be made that shaped the HERMES communication framework. More specifically, the fellow decided to employ UAV-mounted reconfigurable intelligent surfaces (RIS) in the research, as they are more sustainable and can provide similar or higher communication performance compared to other solutions. Numerous experiments with the HERMES solution were carried out in the anechoic chamber of the university to verify the performance. This work resulted in two journal publications (Theoretical framework at IEEE TCOM/accepted, Experimental evaluation at IEEE Access/submitted) and a conference (IEEE VTC Spring 2022/Accepted).
ii) High Reliability: The objective was to devise an orchestration framework that provides a reliable UAV network operation, while proving that this solution can be profitable. This work was carried out successfully in WP3 and WP4 and it was the most challenging in terms of development and prototyping. The fellow implemented the UAV orchestrator that allows autonomous operation and monitoring of the UAV network. As a result of this work, a software program was developed, which was utilized also in the experiments. At the same time, the fellow worked on an optimization framework for the orchestration and trajectory of the UAVs that resulted in two journal publications (Orchestration and profitability at IEEE IoT journal/Submitted, Trajectory optimization at IEEE TVT/Under preparation) and one conference (IEEE CSCN 2022/Accepted). Then, the fellow focused on the design and implementation of the hardware platform that synergizes with the outcomes of WP2 and WP3. Initially, the fellow implemented the UAV and then worked on the integration with the HERMES UAV orchestrator of WP3. The integrated platform transceives data through the SiK telemetry radio using the MAVlink protocol and updates in real-time the positions of the UAVs, their information details (i.e. battery level and status), as well as device-specific KPIs, as shown in the attached image.
iii) High Availability: The objective was to research and develop state-of-the-art (SoA) technologies that allow an uninterrupted and autonomous aerial network operation, which was tackled successfully in WP3 and WP4. The fellow investigated ways to increase the energy efficiency of UAVs through simultaneous light information and power transfer (SLIPT), while proposed the use of charging stations that solves the UAV energy issues. This work resulted in one conference publication (IEEE ICC 2023/Accepted).
In the end, all these novel technologies were fused in WP5 into one integrated platform for UAV orchestration and monitoring that was presented in the end of the project at the IEEE Infocom 2023.
i) Design and theoretical analysis of the UAV communication framework: This work included the investigation for the communication requirements and limitations of UAVs that identified risks and requirements for the future UAV networks. The communication solution involved the use of UAV-mounted reconfigurable intelligent surfaces (RIS) as an important and timely topic. Therefore, the investigation was focused on the use of reconfigurable intelligent surfaces (RIS) mounted on UAVs to assist the communication of a remote area that has no direct link with the end user. Furthermore, the fellow devised an energy model that considers the UAV and the RIS weight as well as the UAV’s velocity and environment. In the results, the average throughput and the average data per flight were analyzed to prove that there exists a unique number of reflecting elements that optimizes the data collection procedure. Therefore, increasing the RIS size may lead to deteriorated data collection, which indicates the importance of the energy model.
ii) After the implementation of the HERMES platform, there was a need for a use case to demonstrate the benefits of the solution. The idea that was employed was that UAVs can be used to power Internet of Things (IoT) devices in inaccessible locations. Specifically, there are cases where the IoT devices are inaccessible and, thus, charging them is prohibitive. For instance, powering IoT devices attached on rotating machinery, dams, bridges, or contaminated areas by physical access would not only be expensive, but also dangerous. Therefore, novel ways of charging inaccessible IoT devices have to be studied that are safe and inexpensive. UAVs with wireless power transfer capabilities could provide a safe and inventive solution to the charging problem, but as the number of IoT nodes grows exponentially, the UAV network scales horizontally too, requiring an autonomous UAV orchestration to handle the large-scale IoT charging operation. Therefore, the fellow devised an architecture in which a UAV swarm covers the energy demand of an IoT network, while the UAVs fulfil their energy needs through charging stations (CSs).
The main benefit of the HERMES solution is that it provides the flexibility to be used like a UAV-network-as-a-service. Therefore, it can be applied in a multiverse of use cases, allowing to create new market opportunities and provide important benefits for society.