VDSL2 with bonding or vectoring - Top wireline technologies in 2013


What is it? VDSL2 (Very-high-speed Digital Subscriber Line 2) is the latest technology to emerge in the long-running DSL family, offering greater rate and reach over a telco's existing copper plant to deliver higher speeds, as well as IPTV and OTT services.

Defined under the ITU standard ITU-T G.993, VDSL2 allows service providers to deliver both asymmetric and symmetric aggregate data rates up to 200 Mbps downstream and upstream on existing copper wiring using a bandwidth up to 30 MHz. Service providers can deliver VDSL2 in three main scenarios: a traditional CO (central office), fiber-connected RT (remote terminal) cabinets, or within a MDU (multi-dwelling unit) complex like an apartment or office building.

Typically, VDSL2 is deployed on short copper loops via a FTTC (Fiber-to-the-Curb) or FTTN (Fiber to the Node) scenario where a telco will run fiber to a RT cabinet or from a DSLAM (digital subscriber line access multiplier) device inside a building that uses the remaining copper pairs to deliver services to each home or business.

Many service providers deploying VDSL2 are augmenting those deployments with both bonding and vectoring.

Bonding can be used to either combine multiple wire pairs to increase capacity or extend the copper network's reach. Vectoring focuses on mitigating crosstalk issues that can affect large-scale deployments of DSL lines delivering 15 Mbps and above speeds. With the advent of Dynamic Spectrum Management (DSM) Level 3, a combination of DSM with vectored DSL, proponents claim the technology can not only help service providers enhance their respective DSL speeds, but also provide information on how to isolate faults on the copper plant.

Why is it important? By using VDSL2 in combination with emerging techniques like vectoring and DSM, a service provider can extend the life of its embedded copper plant investments while meeting emerging residential and business customer needs.

Already, the momentum for VDSL2 with vectoring and DSM is rising. While U.S.-based telcos such as AT&T (NYSE: T) and TDS Telecom (NYSE: TDS) have cited interest in augmenting their VDSL2 deployments with vectoring, much of the early adoption has been in Europe. Belgacom, TDC Denmark, Telekom Austria and Türk Telekom are taking the lead with various deployments and trials. One of the most highly anticipated deployments of VDSL2 and vectoring will take place at Deutsche Telekom (DTE.DE), which announced earlier this month that it would spend €6 billion ($7.9 billion) to build out a FTTC network to expand download speeds on its copper lines from 50 to 100 Mbps.

Although Verizon (NYSE: VZ) is the most daring U.S. service provider with its FiOS FTTH rollout, other service providers have taken a more conservative approach that provides a near-term method to increase speeds leveraging an asset they already have.