BRX-VDSL2 User Guide
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Figure 6: Optimum Upstream BRX-VDSL2 / BRX-VDSL2-X Placement vs Loop Length (feet)
As can be seen, there is a general trend that drives towards the midpoint of the loop as the total loop
length increases. Having said that, service providers have a finite amount of locations per loop
where they can install a BRX-VDSL2 device which will not always be at the optimum point. Positron
Access has designed the BRX-VDSL2 Calculator tool to assist in determining the optimum location
for any given loop along with many suggested alternative placements with predicted performances.
The BRX-VDSL2 calculator can also be used to select which version of the BRX-VDSL2 is best for a
specific application or loop length.
3.4
BRX-VDSL2 Calculator
To view the impact related to the installation of a BRX-VDSL2 unit on a given loop whether it is a 26
AWG (0.40mm), 24 AWG (0.51mm) or a 22 AWG (0.64mm) copper pair, a Windows application tool is
available. You can request access to the Positron Customer Portal to download the BRX-VDSL2
Calculator. Sign up on the Portal at
http://www.positronaccess.com/Portal.php
You will then be sent
a username and password to access the Portal.
The BRX-VDSL2 Calculator has three tabs at the bottom that can be used for the following objectives:
Calculate the achievable bandwidth based on the location of the BRX-VDSL2 device (from the
DSLAM) and the distance to the subscriber CPE;
Calculate the optimal bandwidth for a specific total loop length and gauge of wire and
recommend the location where the BRX-VDSL2 device should be installed (usually a range of
distances from the DSLAM) to achieve the target bandwidth;
Calculate the best placement of a BRX-VDSL2 device to achieve a target bandwidth to
multiple subscribers over a total loop length from a single location. For instance, the BRX-
VDSL2-8 / BRX-VDSL2-X-8 is ideal to serve up to 8 subscribers on a single pair (or 4
