DCC Day Two - WINMOR Phase 2
Rick Muething, KN6KB/AAA9WK - WINMOR Phase 2: Demonstration to Deployment
WINMOR (WINlink Message Over Radio) is a replacement for the proprietary Pactor protocols in Winlink networks. It uses standard PC's and soundcards to impliment an ARQ protocl that approaches Pactor 2 and 3 in performance yet is freely available and can be implimented anywhere on any OS.
Originally demo'd in 2008 it was clearly not ready for deplyment but the results were good enough to encourage additional development.
Initial test were done with the SignaLink sound device but when testing was expanded to additional sound cards it was discovered that sound card quality varied from bad to worse. In addition accuracy of sample rates varied according to the sample rate selected. The original codec used 8khz sampling rate, but testing indicated that rates of a multiple of 12khz would be much more accurate.
The Viterbi decoder based on Phil Karn's (KA9Q) C code example was converted to VS .net but proved to have stability problems caused by something in the .NET Kernel. Unable to debug this it was recoded as VB .NET and appears to be stable.
The current implementation uses 8PSK Pragmatic Trellis Code Modulation (PTCM) The outer layer is still using the original Reed-Solomon Block FEC but the inner layer is now using either 4, 8 or 16PSK Modulation and Viterbi Encoding.
No Linux version yet
More details at: http://www.winlink.org/WINMOR