MC561 = intracell HO congestion failure
Ok, that makes sense. For best HR usage and less congestion, set:
EN_TFO = Enable
EN_TFO_AMR_WB = Enable (are you using that yet ?? :)) )
EN_TFO_MATCH = Enable
EN_TFO_OPT = Disable
FORCE_TFO_HR_WHEN_LOADED = 1 (TFO HR only)
FORCE_TFO_VS_AMR = 0 (disabled)
KEEP_CODEC_HO = 0 (free choice of the codec)
Keep Codec HO = free choice means that when MS is in FR and goes into a loaded cell, then it’ll get a HR channel. Then, thanks to the TFO_Match, the other MS will downgrade to HR (if it was previously in FR also), so that both sides are in HR. TFO will then resume.
Beautiful 🙂