Echelon Lumewave CRD 3000 Street Light Bridge - Manual (Page 12)

2 Introduction
The Echelon Street Lighting Solution
Energy and maintenance costs are increasing for municipal street lighting.
Studies show that the electricity used for street lighting can account for up to
40% of municipal electric bills. With an estimated 90 million street lights in
Europe and 63 million in North America, efficient use of energy for street lighting
is important, both for economic reasons and for environmental reasons.
Fortunately, components and systems are now available to manage, monitor, and
reduce that electricity demand.
Such a system incorporates several key elements: electronic ballasts, power line
communications hardware, and local network controllers that are interconnected
with specialized control and reporting software. Together, they create a flexible
and powerful control system that simplifies day-to-day operations and facilitates
the implementation of cost-cutting strategies. Establishing two-way
communications with each lighting fixture in a street lighting network allows you
to control the lighting level of each fixture, turn it on and off, and monitor its
condition.
Because each luminaire in a street lighting network is already connected to the
power grid, defining a power line communications channel for the network is a
straightforward way to establish two-way communications with each lighting
fixture. However, in many countries, there are a limited number of luminaires
per low-voltage service distribution transformer.
Echelon introduces the Echelon Control Router Device (CRD) 3000 Street Light
Bridge module: a power line and wireless hybrid device that allows
communications to bridge gaps in the power line network created by the low-
voltage service distribution transformers, and manage an extended street
lighting network.
Figure 1 on page 3 shows part of a basic street lighting network, with a
SmartServer Segment Controller, several street lights, and a pair of CRD 3000
Street Light Bridge modules. The Segment Controller uses power line
communications to communicate with the street light luminaires and the CRD
3000 Street Light Bridge modules. The CRD 3000 Street Light Bridge modules
use radio frequency communications to communicate with each other, and thus
provide a communications bridge across the power line gap. Such a gap
represents the end of one transformer’s service distribution and the beginning of
the next transformer’s service distribution.