Timing and Framing Techniques for Troposcatter and Line of Sight, Volume II.

Abstract : This final report describes the timing and framing developmental model, framing computations, and testing. Phase-lock loop timing and 2-mode framing devices were tested with the exploratory development model which was designed specifically for the purpose. The model was used with GFE simulator and tropo link transmission equipment to demonstrate its ability to meet the requirements and to verify analyses. The tests showed that the model met all performance objectives. The study results indicated that: (1) special techniques are needed for longer patterns in marginal tropo and that AGC threshold control improves marginal tropo framing; (2) emphasis on security may require special retiming considerations; (3) improved sync maintenance during fast fades is possible with an extended range phase lock loop. (Author)