The high speed protocol PACTOR-4 (P4), is THE HF-Data protocol of the 4th generation, using the most modern methods of adaptive channel equalization, channel coding and source compression
The resulting highly adaptive ARQ mode adjusts itself almost perfectly to the varying conditions of the short-wave channel. Due to the narrowly synchronized ARQ grid (like with PACTOR-3, but with more speed levels and a better switching algorithm), it rapidly adapts to changes in channel conditions.
Highlights of PACTOR-4:
- 10500/5500 bps net (PMC/uncompressed)
- At least twice as fast as PACTOR-3 the same power and bandwidth!
- Backwards compatible with PACTOR-1/-2/-3
- 400 Hz bandwidth
- Highly adaptive (10 speed levels)
- High interference immunity (up to -20 dB @ 3 kHz)
- 6 auto-notches
- Adaptive equalizer