The University of New Hampshire InterOperability Laboratory (UNH-IOL) and Telebyte have announced the opening of a testing lab for VDSL2 vectoring technology. It's the first lab capable of testing VDSL2 vectoring, also known as G.vector.
VDSL2 vectoring is a technique whereby DSL equipment can compensate for crosstalk in twisted-pair wires. The cancellation of crosstalk could increase DSL service to as much as 100Mbit/s.
"The lab, located at the UNH-IOL's Durham, New Hampshire facility, brings an independent third party to the market that's focused on VDSL2 G.vector testing," Telebyte president Michael Breneisen told us before the announcement. "Combined with expertise of the UNH-IOL. The test lab will be a place for both interoperability and performance testing. Testing services will be available to service providers, network equipment manufacturers, and chipset manufacturers."
The figure below shows a diagram of the G.vector test bed, with Telebyte providing the noise source, noise injectors, and loop simulator. The noise simulator produces noise caused by crosstalk in twisted pairs that come from other twisted pairs.
UNH-IOL senior engineer Lincoln Lavoie, who spoke to us on the same call as Breneisen, said chipset and equipment manufacturers have progressed over the last year to the point where they are getting ready for production or trial deployment around the world. "Unlike other forms of DSL, VDSL2 G.vector testing involves more than just the point-to-point testing of DSL modems and DSLAMs at opposite ends of a DSL subscriber loop. You need to simulate the conditions caused by other DSL lines in a customer's area."
The lab will be able to simulate bundled conditions or, for European locations, unbundled conditions susceptible to outside interference such as radio or impulse noise. Manufacturers can use the UNH-IOL's multitude of DSL modems and DSLAMS for interoperability testing under various noise conditions.
Initially, the UNH-IOL will use the Broadband Forum WT-249: Testing of G.993.5 Self-FEXT Cancellation (Vectoring) for use with VDSL2 Transceivers, test plan as a basis for performance testing. Lavoie called WT-249 a "common testing language" for VDSL G.vector testing, but individual equipment makers and chipset providers often add their own test requirements. The UNH-IOL has held two plugfests in the last year. (See: Plugfest Pulls G.Vector Suppliers Together.)
Will DSL only lose marketshare compared to coax and fiber? I'm writing this using a 3Mbit/s DSL service. It's fast enough for me.
—Martin Rowe, Senior Technical Editor