Alarm communications for a FITL system remote power source

Bellcore has worked with its clients to define a cost-effective solution for providing an alarm capability for centralized power sources not co-located with host digital terminals (HDTs). This capability considered several constraints (simplicity, economics, and mix-and-match capability). After evaluating several possible methods, it was proposed that a remote centralized power source should communicate alarms to the “closest” optical network unit (ONU) of a fibre in the loop (FITL) system. The ONU should detect alarms and the FITL system should interpret and report these alarms to an OS using its operations communications channels. In order to allow for mix and match between the FITL system and the centralized power source, an open interface was defined and alarms were grouped into three categories: commercial AC power failure (with battery back-up operating properly), major power equipment failure, and minor power equipment failure. This paper summarizes the work that was done for providing an alarm capability for centralized power sources not co-located with HDTs. It presents advantages and disadvantages of all methods considered and then describes the proposed method in detail