In what modes can the newly online ONT be added on the OLT?
On the OLT, the newly online ONT can be added in two modes: automatic detection and manual adding. In two modes, the added ONT needs to be confirmed for normal use.
The activation process works under the control of the OLT. The ONU responds to the message of OLT start. The activation process is as follows:
1. The ONU receives the US_OVERHEAD message from the OLT, and adjusts its own parameters.
2. The OLT detects the serial number of the newly connected ONU (through broadcasting plus random delay).
3. The OLT assigns an ONU-ID to the ONU.
4. The OLT measures the arrival phase of the upstream transmission from the ONU (measure the RTD).
5. The OLT notifies the ONU of equalization delay (EqD).
6. The ONU calculates the upstream data transmitting window according to the notified EqD and BW Map.
Inband digital switching is implemented through the flag and PLOAM messages transmitted by the upstream or downstream.