HDR Rate Request Indicator (RRI). RRI provides the
structure of a frame currently being transmitted when frames
are transmitted at different rates. Services at different rates
are reliably provided by the RRI:
unknown(1) - RRI unknown
pilotOnly(2) - pilot channel only
rri9dot6kbps(3) - RRI is 9.6 Kbit/s
rri19dot2kbps(4) - RRI is 19.2 Kbit/s
rri38dot4kbps(5) - RRI is 38.4 Kbit/s
rri76dot8kbps(6) - RRI is 76.8 Kbit/s
rri153dot6kbps(7) - RRI is 153.6 Kbit/s