Microtune tunes up DOCSIS 3.0 initiative
Microtune Inc.  has unveiled a new silicon-based tuner designed to handle a key feature of DOCSIS 3.0 - channel bonding - and do so more cheaply than today's pre-3.0 modem implementations.
That component, dubbed the MicroTuner MT2170, will seek a home inside cable modems, set-tops and other DOCSIS 3.0-based devices on the horizon.
The MT2170, according to Microtune Chief Operating Officer Bud Taddiken, will also produce modems that cost much less than pre-3.0 CPEs, which are required to bolt together discreet DOCSIS 2.0 tuners in order to bond multiple (three or four, in most instances) downstream DOCSIS channels. Because Microtune's version for 3.0 bonds those channels (upstream and downstream) via just one tuner, he said, the resulting modem tuner will require 25 percent of the cost, power consumption and physical size of tuners used in today's pre-3.0 Wideband modems.
Microtune said the MT2170 is priced at less than $5 per unit "in volume quantities."
"With this [technology] there's no reason why DOCSIS 3.0 modem tuners can't approach DOCSIS 2.0 tuners in terms of cost," to the cable modem manufacturer, Taddiken said. He acknowledged, however, that Microtune will place a "small premium" on its DOCSIS 3.0 tuners.
Microtune's latest entry can tune in the range of 50 MHz-1 GHz. Although most cable plant is presently built out to 750 MHz or 860 MHz, some operators are considering pushing spectrum beyond that - in greenfields as well as brownfield situations - in order to generate additional capacity for DOCSIS channel bonding. An expansion from 860 MHz to 1 GHz, for example, would provide an operator with more than 20 additional 6 MHz channels for bandwidth-eaters such as channel bonding, IPTV services or a beefier HDTV tier.
Microtune also claims that its implementation goes beyond minimum DOCSIS 3.0 spec requirements. The spec allows for operators to use non-adjacent 6 MHz channels for bonding from a minimum spectrum range of 64 MHz. Microtune said its Wideband tuner can push that range to 100 MHz, allowing operators more flexibility when deciding where to tap slices of spectrum for channel bonding. Because it can combine channels from a spectrum of 100 MHz, the MT2170 can handle the tuning function for 16 bonded 6 MHz channels - provided, of course, that such a digital demodulator was actually available.
"Our tuner can do that, but the limiting factor is what's in the digital electronics," Taddiken said.
Microtune's primary competitor in the silicon tuner arena is Broadcom Corp.  Roughly two-thirds of Microtune's revenue comes from the cable industry, split between set-tops and modems. Scientific Atlanta  is Microtune's largest customer, followed by ARRIS . Motorola Inc.  also uses Microtune tuners inside some of its embedded multimedia terminal adapters. The company recently announced it had shipped its 50-millionth silicon tuner.
Still missing from Microtune's DOCSIS 3.0 silicon tuner picture is a digital demodulator to go with the MT2170.
Microtune has sampled the MT2170 to an undisclosed "developer partner" that also happens to make modulators. Given the litigious history  between Microtune and Broadcom, the most likely candidate is Texas Instruments .
Microtune plans to expand samples to other technology partners in the second quarter of 2007.