New DOCSIS 1.1 Wave Might Not Speed Rollout


A second wave of Data Over Cable Service Interface Specification 1.1 cable-modem certifications were reported late last month, but it's unclear whether that will speed the technology's progress.

The count now stands at seven certified cable modems and two qualified cable modem termination systems, but many industry observers still expect DOCSIS 1.1 technology will likely remain in test mode through much of 2002.

Vendors Ambit Microsystems Corp., Arris Group Inc., Ericsson Inc., Scientific-Atlanta Inc. and Tellabs Inc. won their first DOCSIS 1.1 certifications in the latest round announced late last month. Toshiba Corp. and Texas Instruments Inc. — which claimed the first DOCSIS 1.1 certified modems in the last round — each added units to their certified lineups.

Toshiba gained certification for a new cable modem and recertified its previously approved unit, while Texas Instruments got the nod for a new modem.

As a side note, Ericsson is in the process of selling its Lynchburg, Va.-based cable-modem business to Canadian firm Aastra Technologies Ltd. of Concord, Ontario.

Though the list of certified modems is now longer, Cable Television Laboratories Inc. did not qualify any new CMTS units. The only two vendors to win DOCSIS 1.1 qualification are Arris and Cadant Inc., and Arris is in the process of acquiring Cadant.

Adding more certified modems doesn't directly translate to more DOCSIS 1.1 service rollouts, according to Kinetic Strategies Inc. president Michael Harris.

"The reality is that no MSOs are deploying 1.1 features in any meaningful way, nor are they likely to for the next six to 12 months," Harris said. "I think you will see cable operators do 1.1 trials in the first half of this year — some have them underway already.

"In the second half of the year they will maybe launch a market or two, and then figure out what the model looks like for them to then launch across their footprints," Harris added.

Toshiba products division marketing communications manager Christopher Boring agreed that deployments were possible late in the year, but was more hopeful about the effect of additional DOCSIS 1.1-certified modems.

"I do think it is going to help accelerate some of these deployments," he said. "Do I think there is going to be a mass deployment by the end of 2002 and everyone is going to be 1.1? No. Definitely not.

"It is going to take a while for everything to filter in. But I think most of the new deployments certainly as you get a little later in the year I think many if not most of the new deployments would certainly have the DOCSIS 1.1 modems."

The existence of just two qualified CMTS units— both of which will be owned by the same company — is not the technology's immediate problem, Harris noted.

"The big issue for a lot of the operators is whether they want to do voice," he said. "And if they don't want to do voice, putting a 1.1 upgrade patch on the Cisco CMTSs they have might be adequate, because voice drives capacity and reliability constraints that potentially exceed that platform."

In the end, it is not the technology but rather the economics of new services that put DOCSIS 1.1 on a slower current in the cable industry.

"The whole issue around DOCSIS 1.1 certification is far less [about] certification, and much more about when operators feel compelled to deploy the technology for new services that can generate new revenue," Harris said. "In reality, I would look at widespread 1.1 deployment as more of a 2003 phenomenon."


As MSOs start testing the DOCSIS 1.1 technology, there are indications that they're also looking at a scheme that has not been associated with cable modems: guaranteed bit-rate service.

Long a competitive plank for cable's data rival — digital subscriber line — fixed-bandwidth services are also viewed as a crucial requirement in developing business connectivity products.

Unlike the variable shared bandwidth, best-efforts features found in DOCSIS 1.0, the 1.1 spec adds data prioritization and quality-of-service tools and can be used to offer guaranteed throughput.

Carlos Oliveira, a principal engineer in Toshiba America Information Systems Inc.'s network products division, said DOCSIS 1.1 modems can provide guaranteed bit rates in two flavors. One fixes the bandwidth over a set time for voice applications; the other guarantees overall bandwidth over a longer period, but allows for bit-rate fluctuations within that window.

The latter is aimed more toward data applications, Oliveira said.

"Some of the MSOs are really interested in providing that," Oliviera said.

Some of operators did try to tinker with earlier modem systems to provide constant bitrate service, "but they did find some problems as far as how they can guarantee some of the applications," he added. "With the 1.1, they believe that will be the way to go."