A code-division-multiple-access (CDMA) system employing spread-spectrum
modulation. The CDMA system has a base station, and a plurality of
subscriber units. The signals transmitted between the base station and
subscriber unit use spread-spectrum modulation. The system and method
transmits from the base station, a synchronization channel having a
chip-sequence signal used by the plurality of subscriber units for
synchronization. A first subscriber unit receives the synchronization
channel, and determines timing from the synchronization channel. In order
to initiate communications with the base station, the first subscriber
unit transmits an access signal. The access signal has a plurality of
power levels, which typically ramp up. The base station receives the
access signal at a particular-power level. The base station then
transmits to the first subscriber unit an acknowledgment signal. The
first subscriber unit receives the acknowledgment signal, and transmits
to the base station, a spread-spectrum signal.