Different unmanned aerial vehicles teams often work independently, leaving a “stove-piped” isolation problem, and the cost of collaboration among them is relatively high. Interoperability has been proposed to study the ability of unmanned aerial systems in working together, of which smooth communication is the fundamental requirement. To construct communication ability of different systems, the protocols they support should be essentially concerned. A novel, lightweight and flexible protocol, named as LAB protocol, is developed in this paper, where we study it and STANAG 4586 and MAVLink for comparision. We propose a bridging method to break isolation and verify interoperability among UASs using different protocols through experiments.