There is disclosed a radio frequency (RF) modem shelf for use in a fixed wireless
access network comprising a plurality of base stations capable of bidirectional
time division duplex (TDD) communication with wireless access devices disposed
at a plurality of subscriber premises. The radio frequency (RF) modem shelf comprises:
1) a first RF modem capable of communicating with a plurality of the wireless access
devices using TDD frames, each TDD frame having an uplink for receiving data and
a downlink for transmitting data; and 2) a modulation controller associated with
the RF modem shelf capable of determining an optimum modulation configuration for
each of the plurality of wireless access devices communicating with the first RF
modem, wherein the modulation controller causes the first RF modem to transmit
first downlink data to a first wireless access device in a first data block having
a first optimum modulation configuration and to transmit second downlink data to
the first wireless access device in a second data block having a different second
optimum modulation configuration.
