Although integrated cable modem termination systems (CMTSs) are expected to retain the bulk of deployments as operators introduce speedier Wideband services, more modular CMTS architectures are showing some signs of life, particularly outside of North America.

The latest case: Hanaro Telecom Inc. of South Korea said yesterday that it's "extensively deployed" an M-CMTS platform that employs NSG 9000 "universal" edge QAMs from Harmonic Inc. (Nasdaq: HLIT). The MSO had already selected Cisco Systems Inc. (Nasdaq: CSCO) as one of its Wideband equipment partners. (See Hanaro Picks Cisco and Hanaro Takes Harmonic to Edge .)

Hanaro is using Docsis channel bonding techniques to deliver shared Internet speeds in excess of 100 Mbit/s. Hanaro has 6 million subs served by a mix of cable and DSL networks.

The M-CMTS allows operators to scale downstream and upstream capacity independently. Typically, the edge QAMs provide the downstream, while the core CMTS supplies the upstream. A Docsis Timing Interface (DTI) – largely developed by Symmetricom Inc. (Nasdaq: SYMM) – ensures that the clocks of the myriad modular components are synched up. (See CableLabs OKs First Modular CMTS Element .)

Early on, most of the M-CMTS activity centered around BigBand Networks Inc. (Nasdaq: BBND). (See BigBand Goes Dutch With M-CMTS and BigBand Trumpets M-CMTS Trials.) Although BigBand still provides the edge QAM element of the M-CMTS architecture, the company exited the core CMTS market last fall. (See BigBand Terminates CMTS.)

Harmonic said it's rolling out M-CMTS-based services to more than 25 operators in Asia, Europe, and North America, for both Docsis 2.0 and newer Docsis 3.0 network environments.

While Cisco appears to be ahead of the modular game from a core CMTS perspective (at least it's shipping product today), the two other major suppliers in this category -- Arris Group Inc. (Nasdaq: ARRS) and Motorola Inc. (NYSE: MOT) -- are fleshing out modular strategies for their respective flagship CMTS platforms. Arris, which makes the C4 CMTS, and Motorola, which markets the BSR 64000 CMTS, also have universal edge QAMs in their product portfolios.

As the M-CMTS market continues to develop, most vendors appear to be concentrating on denser upstream and downstream blades that snap into already-installed integrated-CMTS chassis. (See Moto Wields Upstream CMTS Blade and CMTS Downstream Prices Plummet.)

— Jeff Baumgartner, Site Editor, Cable Digital News