Thursday, March 15, 2012

Keeping Up with DOCSIS 3.0

A guest post by Ariel Caner, Product Marketing Manager, ECI Telecom

The demand for high-bandwidth, next-generation services has gone through the roof in recent years. We now live in a connected world, where consumers expect their voice, data and video needs to be satisfied anywhere at any time.

All this connectivity, however, requires bandwidth. And lots of it. The end users don’t really care (rightly so) about the underlying infrastructure that makes all this bandwidth possible. Whether it’s via copper, fiber or whatever, they just want to know the bandwidth is there when they need it – to stream a high def movie, download that mega PowerPoint file for work or make a Skype call to relatives across the pond.

For the service providers, though, it’s an entirely different matter. Their infrastructure is their lifeblood, and it must be capable of supporting the high-bandwidth, next-gen services that consumers want. Or else they risk churn.

In a perfect world, all operators would be able to deploy fiber end-to-end right now. After all, it enables the highest bandwidth possible and is future ready, with the ability to carry forthcoming connectivity technologies. But fiber isn’t ubiquitous just yet. The cost and time involved with deploying fiber access technologies such as GPON and point-to-point fiber access networks have slowed widespread adoption.

As operators grapple with the issue of how and when to make the move to fiber, they are in the tenuous position of having to balance customer demand for bandwidth and new services with their own need for return on investment. For many, what makes the best economic sense now is optimizing the copper infrastructure that’s already in place.  

The cable companies have found their answer in DOCSIS 3.0 (Data Over Cable Service Interface Specification), a technology that enables speeds of 100 Mbps or more over existing HFC (hybrid fiber coaxial) networks. In an HFC network, optical fiber cable and coaxial cable are used in different parts of the infrastructure to carry broadband services. The advantage is that the desirable characteristics of fiber – high bandwidth and low interference – can be brought closer to homes and businesses without disturbing the coax cable that’s already installed in dwellings. These advances have greatly empowered the cablecos, enabling them to offer multiplay bundles that make available services including HDTV, high-speed internet and voice, thereby allowing them to maintain and even grow market share.

But what about the telcos? How can they keep pace with the cablecos and their DOCSIS 3.0?

In recent years, to increase the capacity and reach of their copper networks, the telcos have been utilizing access technologies such as VDSL (very-high-speed DSL) and its successor VDSL2. While VDSL2 can, in theory, deliver speeds up to 100 Mbps, it very often falls short due to something called crosstalk interference. This is a phenomenon whereby DSL lines become sensitive to the electromagnetic ‘noise’ that comes from adjacent copper pairs and, as a result, the signal that is being transmitted through the wire is degraded.

In an effort to solve to solve this limitation and find a way to extend the useful life of copper networks, a group of top DSL researchers formed the iSmart Consortium to conduct research in the field of dynamic spectrum management (DSM). The result of their work is a technology called ‘vectoring,’ or DSM Level 3. Vectoring is a novel VDSL2 technology that works by mitigating crosstalk interference to boost the speed and range of copper networks to near-fiber performance.

The advancements made possible by this innovative technology are impressive. For loop lengths shorter than 1500 meters, copper wire data rates are improved by 100%, to 50 Mbps or more, and the subscriber coverage area for premium services is expanded by 300%. And what’s more, on copper wire thicker than 0.4 mm, data rates can reach 100 Mbps and can further be doubled using bonding techniques.

What this means for the telcos is that they now have a level playing field with the cablecos. Like DOCSIS 3.0, vectoring opens up numerous application possibilities, many of which were previously unattainable with copper-based networks. Now, even the highest-speed broadband services, such as IPTV and telepresense, can be delivered cost effectively over copper, helping to reduce customer churn and increase ARPU.

For those telcos who are not yet ready to migrate to a full fiber network, vectoring is a viable and cost-effective option that’s sure to play an important role in high-speed broadband strategies throughout the next decade.

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