ARQ6-90/98
CCIR 476 Variant

Synchronous Simplex ARQ using the 7 bit error correcting CCIR 476 alphabet with two stations (usually) on the same frequency, one of them called the ISS (transmitting), the other the IRS (receiving) station. Complete repetition cycle is as follows:

  ARQ6-90: 450 msec: 6 characters at 35 msec = 210 msec with 240 msec pause.
  ARQ6-98: 490 msec: 6 characters at 35 msec = 210 msec with 280 msec pause.