By combining the scenarios in earlier sections, larger-scale and more complex experiments are possible, as illustrated in the adjacent figure, with multiple fixed and mobile nodes. This option requires more testbed resources in the form of UAS pilots, fixed/portable nodes, and spectrum utilization.

As example experiments, one can measure rural connectivity with multi-hop links and long-distance millimeter-wave links. The presence of high altitude platforms (HAPs) at 20 km to 50 km above the ground is considered in the existing literature. While experiments with HAPs may be very challenging in a platform such as AERPAW, the use of helikite aerostat platforms can allow flying UAS at higher altitudes, for longer durations, with larger payloads. Such experiments can consider the coexistence of links from an aerostat platform with terrestrial systems using intelligent techniques to dynamically manage radio resources and mitigate interference.

Some critical aspects of this setup will be considering multiple drones to compare C-V2X Mode 3 (drones communicated through BS) vs. Mode 4 (drones communicate directly) using srsLTE, resource allocation in C-V2X in presence of multiple drones and BSs, testing drone-based multi-hop relay network, among others. At the last stage of the setup, this experimental scenario can test fully operational miniature UAS deployments where UAVs can act as both relays and aerial users.

Multi-hop Rural Connectivity Testing

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Rural Connectivity with mmWave Links

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Experiments with HAP

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Resource Allocation with Different C-V2X Nodes

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