A system and method for performing power management in a communication system
without
losing data is disclosed. The G.Lite system is an exemplary system suitable for
implementing the present invention because it includes at least one operational
state and an idle state in which no data is transmitted. The G.Lite standard defines
ATU states. The defined states are full on state L0, low power state L1 and idle
state L3. In L0 state, the ADSL link is fully operational at full data rate. In
L1 state, the ADSL link is fully operational at a lower data rate. In L3 state,
no signal is transmitted. Because no signal is transmitted, no idle cells are transmitted.
This will result in losing the cell delineation and ATM link connectivity. Therefore,
when data is received for an ATU in L3 state, data cells may be lost. The present
invention solves the problem of lost data cells by allowing interaction between
the control path and the data path by requesting that the micro-controller be interrupted
when a data cell arrives for an ATU-C that is in L3 state. When a data cell arrives
for an ATU-C in L3 state, the micro-controller is interrupted. The micro-controller
then ensures that a sufficient number of idle cells are sent to the ATU-C prior
to any data cells being sent to the ATU-C.