Openreach Pause Plans to Test XdB Boost on UK ECI FTTC Broadband Lines

Last month we revealed that Openreach were preparing to test a ‘Proof of Concept’ upgrade that could boost the performance of ECI based FTTC (VDSL2) “fibre broadband” lines by adopting a default target downstream noise margin of 3dB (here). However the plan for this test has now been paused.

The XdB upgrade itself is a tweak to the SNR (Signal to Noise Ratio) of a DSL based broadband line, which reflects the balance (measured in decibels) between the useful information coming down a line (good signal) and unwanted interference (bad signal / noise). Previously Openreach only adopted a default target downstream noise margin of 6dB, but by dropping this to 3dB you could deliver a modest speed boost to stable lines (especially very short ones).

The issue is that Openreach’s Fibre-to-the-Cabinet (FTTC / VDSL2) lines tend to be split between hardware built by Huawei and kit from ECI. Unfortunately the latter often throws up problems when the operator tries to introduce new enhancements and as such the “XdB” upgrade has so far only been rolled out across their Huawei based network (around 1.6 million users are on strong enough lines to benefit).

However last month the operator revealed that they had developed a potential fix for the SNR enhancement and planned to test it on a single ECI DSLAM (FTTC street cabinet) from 20th October 2017. Unfortunately this plan has now been paused for an unspecified reason, although we expect them to return to it again. Sadly the related briefing (here) is password protected, but we will try to learn more.