Performance of US MIL-STD-188-141B appendix C data link protocols

This paper has examined the new HF data link protocols defined in the U.S. MIL-STD-188-141B and being considered for NATO STANAGS 4538 and 4539. The protocols have the characteristics of code combining and synchronous transmission times, which allow them to optimally adapt to HF channel conditions and to minimize protocol misalignment. Performance data illustrates that the World´s first implementation of these protocols closely agrees with previously published simulation results. Additionally, simulation results illustrate that under many standard HF channel conditions, the XDL protocols significantly outperform those of U.S. Federal Standard 1052, a highly optimized adaptive data rate ARQ system. On-air testing aimed at comparing the performance of XDL and FS1052, highlights the improved performance expected from simulation and perhaps illustrates an even greater than expected advantage to XDL in its ability to quickly adapt to and minimize the effects of rapid channel conditions. The XDL protocols are currently available as an option in the RF-5800H manpack radio. Current work is underway to apply these techniques to the higher data rate waveforms defined in the current draft version of the US MIL-STD-188-110B HF modem standard