But first a word about QAM (quadrature amplitude modulation) itself. It's a fast (38.8 Mbit/s per 6MHz of spectrum), wideband modulator. It takes in the digital signal and modulates it so it can be passed through the analog portion of the cable network until it reaches the cable set-top box (in the digital video example).
The QAM element of the cable network has been evolving, supporting more services with each generation. Costs, meanwhile, have been tracking downward, heading toward commodity levels.
"We are seeing a lot of pressure... to change from a moderate quantity product to more of a mass market kind of product," says Bill Dawson, vice president of access strategy for C-COR Corp. (Nasdaq: CCBL).
"There's such a demand for narrowcast bandwidth. It's not going away, so this [edge QAM market] is a good place to be," adds Michael Adams, vice president of systems architecture for Tandberg Television .
The first QAMs on the market could support only digital broadcast video services. Video on demand (VOD) was added next. The third generation brought in switched digital video (SDV). The generation after that will support Docsis traffic.
These fourth-generation products are considered "universal" because they can be used for all of those services. They are also considered more efficient because the capacity of each QAM can be distributed flexibly among those services, rather than being stovepiped to just one type of service.
The universal edge QAM (eQAM) will also play a big role in the development of Docsis 3.0 and the modular cable modem termination system (M-CMTS), which allows operators to scale their downstream and upstream capabilities independently.
Docsis-supported eQAMs "won't come into play until the M-CMTS market starts up," Adams predicts.
But vendors agree that the big driver for next-gen eQAMs today is SDV, a bandwidth-saving technique that has already gained favor with Time Warner Cable Inc. (NYSE: TWC) and Cablevision Systems Corp. (NYSE: CVC). Meanwhile, Comcast Corp. (Nasdaq: CMCSA, CMCSK) is starting to test the SDV waters in Denver, Colo. and Cherry Hill, N.J. (See Comcast Puts SDV Vendors to the Test and Comcast Reveals SDV Test Beds.)
Not all MSOs are launching SDV yet. "But if you took a census it would show that they are all at least thinking of it," Dawson says.
Vendors Tee Up eQAMs
If you're a cable technology supplier these days, there's a good chance that you have an edge QAM device in the portfolio somewhere.
Table 1: Vendors Go to the Edge
|Arris||Keystone D5 DMTS|
|BigBand Networks||Broadband Multimedia-Service Edge (BME)|
|Casa Systems Inc.||C2100/C2150 Universal EdgeQAM|
|Cisco Systems/Scientific Atlanta||Universal Edge QAM (U-EQAM)|
|Motorola||MSEN (Modular SEN)|
|RGB Networks||Universal Scalable Modulator (USM)|
|Teleste Corp.||Virtuoso Edge QAM|
|Here's a sampling of companies that have launched or are about to launch next-gen edge QAM products. Many are considered "universal," meaning they can support VOD, switched digital video, broadcast digital video, and Docsis traffic, or can get there through a software upgrade. Source: Cable Digital News research and the companies.|
Motorola Inc. (NYSE: MOT) is coming out with a next-gen eQAM later this year, with shipments expected by the fourth quarter, according to Ray Botempi, director of product management for Motorola's digital video solutions unit.
Motorola's present QAM product can handle broadcast video, VOD, and switched digital video. The new product will incorporate high-speed data and serve as a component of Motorola's M-CMTS.
C-Cor recently introduced its next-gen product, the CHP eQAM, a 1GHz-capable device considered a modular component of the company's CHP Max5000 Headend Platform. Each 2-RU product supports up to 120 QAM channels. It's in lab trials now with two "major" North American MSOs, with commercial availability slated for September. (See C-COR Launches Edge QAM.)
Initially, that product is considered a video edge QAM, but the "hooks" are in place to turn it into a universal edge QAM via a software upgrade, Dawson says.
Cisco Systems Inc. (Nasdaq: CSCO) just unveiled the Universal Edge QAM (U-EQAM). Like C-COR's entrant, Cisco's sports a 1GHz implementation. (See Cisco Unveils Edge QAM .)
Harmonic Inc. (Nasdaq: HLIT), a long-standing QAM vendor, introduced its latest generation product, the NSG9000, at the 2006 Cable-Tec Expo. That product is capable of running M-CMTS apps, according to Nimrod Ben-Natan, the company's vice president of marketing and strategy.
He says the need for QAM resource allocation is being driven by operators as they increase capacity on service groups through node splits. Further down the road, MSOs also could use those QAMs to bypass the CMTS to deliver IP-based unicast or multicast video services.
"We think IPTV is an interesting delivery infrastructure [that is] not unique to the telco," Ben-Natan says.
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