A novel concept of powering multiple cabinet remote terminal sites

Telecommunications networks have grown closer to business and residential customers causing the occurrence of multiple Remote Terminals (RT) cabinet sites to grow along with the complexity of powering these sites. Legacy technologies, such as subscriber line cabinets (SLC) remain in the network along side modern technologies consisting of digital loop carriers (DLC) and xDSL. Both distributed and bulk powered cabinets can reside at a single collocated site. The majority of these sites rely solely on installed inter-cabinet battery plants to provide emergency power in the event of a power outage. This battery reserve allows the telecommunications carrier system autonomy of 4 to 8 hours. For power outages beyond the installed battery reserve, trailerable generator sets, are moved from site to site by telephone company craftsperson´s in order to recharge the batteries. The generators range in size from so called manhole generators (<8 kW), to 50 kW diesel powered sets. Since the availability of higher kW generators cannot be predicted, many times a crafts person´s only source of back-up generator is the manhole trailer sets. Unfortunately, in many instances, the manhole generator capacity is not sufficient to power multi-cabinet collocated RT sites. In recognizing the increasing power requirements of collocated RT sites, SBC Southwestern Bell has deployed a novel DC power structure using a bulk power hub and spoke topology, along with a DC engine-generator. This topology allows SBC Southwestern Bell to power an entire site from a single source, reduce truck rolls, improve system autonomy and increase crafts person safety.