3:00 PM -- Korean ISP SK Broadband is the latest operator to push the limits of Docsis 3.0 by bonding 16 downstream channels and producing speed bursts of 800 Mbit/s in the lab.

The test featured the Arris Group Inc. (Nasdaq: ARRS) C4 cable modem termination system with the 7.4 software release, and a modem supplied by SK Broadband (a vendor wasn't specified) outfitted with a 16-channel downstream and 4-channel upstream configuration.

However, Broadcom Corp. (Nasdaq: BRCM) and Intel Corp. (Nasdaq: INTC) have yet to release any integrated D3 modem chipsets that can bond any more than eight channels, and there are still questions as to whether the next generation of chips will go with a 16-channel downstream or make the leap to 32.

In light of that, it's likely that the modem involved in this trial ties together two chipsets that are acting in unison. The hope here is to give D3 more legs and produce speeds that can compete with fiber-to-the-premises (FTTP) deployments. (See Broadcom Dips Two Chips in 800M 'Prototype' .)

It also marks the latest attempt to stretch the legs of Docsis 3.0. Late last year, Kabel Deutschland GmbH claimed to hit download speeds of 1.17Gbit/s using a Cisco Systems Inc. (Nasdaq: CSCO) CMTS -- the uBR10012 -- that was capable of bonding 24 downstream channels. Cisco has yet to discuss the modem setup, but it's been speculated that it "duct-taped" together three D3-certified 8x4 modems and linked them to a home-side gigabit router. (See KDG, Cisco Hit 1Gig Cable Modem Speeds .)

But these, again, are trials aimed at testing the current limits of D3 technology, and neither MSO has announced any plans to turn those efforts into deployments.

To date, the fastest commercial D3 deployment belongs to ZON Multimédia of Portugal, which launched a 360Mbit/s (downstream) tier late last year via the bonding of eight 8MHz-wide EuroDocsis channels. (See ZON Turns On 360Mbit/s Internet Service.)

— Jeff Baumgartner, Site Editor, Light Reading Cable