PROTECTION FOR FIBRE OPTIC ACCESS NETWORKS

摘要

An Optical Network Unit, ONU, and an Optical Line Terminal, OLT, as well as a respective method therein, are provided for enabling the ONU to communicate with the OLT. The ONU and at least one OLT are comprised in a passive fibre optic access network. The passive fibre optic access network comprises two fibre paths through the network, a main fibre path and a back-up fibre path, connecting the ONU with the OLT. When a fault is detected in the main fibre path is detected, transmission rate negotiation is performed between the ONU and the OLT over the back-up path. When a transmission rate is agreed upon between the ONU and the OLT during said transmission rate negotiation with regard to communication over the back-up path, the communication between the ONU and the OLT is executed using the agreed transmission rate over the back-up path.