Remote Powering of Broadband Multimedia Service Networks

Abstract

Remote powering is a concept for distributing DC power over existing twisted pair copper networks. The concept is typically for use in broadband applications like Internet, video on demand, real-time broadcast TV and other applications. Especially in centralised telecom networks with large central offices and long distances to remote nodes, remote powering can prove a lot of benefits. The paper shows why remote powering is attractive for a lot of broadband applications and customers. The general principles of remote power systems are described, including the typical design requirements like safety aspects and scalability, The paper is intended to explain the most important safety requirements according to the safety standards for remote power systems like IEC60950-21. Due to high voltage levels on the twisted pair copper network safety aspects are very important particularly for service persons. The architecture of a safe remote power system consisting of a DC/DC converter from 48 V up to plusmn190 V, a VA-limiter, the telecom copper network and a remote end converter from plusmn190 V down to 48 V will be introduced. Thanks to the modularity of the system the output power at the remote end is scaleable by paralleling modules and twisted copper pairs. It is always important to consider how much power will be used in the remote site and how long is the distance to the feeding central office. So the paper gives an overview about the relation between cable length, cable size and load power and which sizes of remote power plants are available