Skip to Main Content
STANAG 4538 defines a third generation (3G) HF system that includes a synchronous Automatic Link Establishment (ALE) system coupled with efficient data link protocols. The data link protocols, collectively known as XDL, have been integrated into the Harris RF-5800H HF man-pack radio system and are included in the Harris radio being produced for the UK BOWMAN program. This paper begins with an overview of the existing XDL data link protocols defined in STANAG 4538. Next, an overview of HDL+ is presented. It is not the goal of this paper to be an overall definition of the protocol but to discuss the major enhancements relative to the XDL protocols. Next, the paper presents some simulated performance results of HDL+ over the nonfading additive white Gaussian noise channel and the fading poor channel. Data are presented for message payloads of 5,000 and 50,000 bytes. Performance are contrasted with that of standard HDL. The paper concludes with a summary and a short discussion of future areas of investigation.