Enabling Cooperative Awareness for UAVs: ETSI CAM Protocol Extension

Abstract

The use cases involving single or multiple Unmanned Aerial Vehicles (UAVs) controlled by a pilot or operating autonomously are becoming more and more common these days. To support UAVs' safe and efficient operations, the enablement of cooperative awareness (CA) is crucial. In this paper, we approach this challenge by proposing a modification of the Cooperative Awareness Message (CAM) protocol developed by the European Telecommunications Standards Institute (ETSI) for enabling CA for Intelligent Transportation Systems (ITSs) to support UAVs. First, we identify the information required to provide UAV CA. Then, we introduce a messaging architecture with data fields specifically designed to support 3D mobility. We follow the rules of the existing CAM specification so that the proposed messaging structure can be added with minimum modifications to the existing CAM structure. Finally, we assess the proposed modified CAM operating performance on top of the physical (PHY) and medium access control (MAC) layers specified by the IEEE 802.11p radio access technology, which is widely used for vehicular communications. Our results show that air-to-air communications can be effectively used and provide coverage up to 150 m distance with 64-QAM and 1200 m with BPSK modulations. Furthermore, analysis of the MAC layer suggests that the technology can offer a packet reception probability above 0.9 for 10000 UAVs in the same area transmitting at 1 Hz frequency and 800 devices at 10 Hz transmission frequency.