Software Implementation Of Automatic Link Establishment Capability For Hf Radio Communication

HF radio spectrum, ranging from 3 to 30 MHz can be utilized as a low-cost voice and data communication medium. But due to the unpredictability and propagation problems such as multipath fading, interference and attenuation, communication using HF becomes very challenging. Besides, the availability of the channels varies depending on the time of day, seasons and the condition of the ionosphere. The purpose of this paper is to present the research work on the design and implementation of automatic link establishment (ALE) capability, to enhance the reliability of HF radio communication. This paper also looked at the feasibility of implementing ALE as software, designed using Visual C++ programming language. Equipments used in this research are commercial HF radio and modem, which are both controlled by the software. Field testing is conducted between UTM Skudai and Chemor in the state of Perak to verify the performance of the system