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DOCSIS

MaxLinear Hints at a 1Gbit/s Future

MaxLinear Corp. has introduced two cable receivers that offer Docsis 3.0-like downstream speeds approaching 1 Gbit/s.

Today's state-of-the-art Docsis 3.0 cable modems are configured with the ability to bond eight downstream channels -- enough for 240 Mbit/s using 6MHz channel spacing that is common in North America. MaxLinear's new cable front-end receivers/tuners -- the MxL265 and MxL267 -- support 16-channel and 24-channel downstream configurations, respectively. A modem capable of bonding 24 channels would support theoretical downstream bursts of 960 Mbit/s in North America, and 1.32 Gbit/s using EuroDocsis 3.0's 8MHz channel spacing. [Ed. note: a couple of years ago there seemed to be some interest in a modem that could bond 32 downstream channels -- enough for bursts of 1.2 Gbit/s in North American cable systems.]

MaxLinear's revelation is interesting because Broadcom Corp. (Nasdaq: BRCM) and Intel Corp. (Nasdaq: INTC) -- the cable industry's two D3 chipset makers -- have not announced next-generation chipsets. Entropic Communications Inc. (Nasdaq: ENTR) will soon be in the Docsis modem silicon game via its acquisition of Trident Microsystems Inc. (Nasdaq: TRID), but has not committed to developing any D3 chips. But MaxLinear's new tuner family offers a good sense of where Docsis 3.0 is heading next. (See Entropic Sweetens Pot to Win Trident .)

MaxLinear is basing the new configurations in direct response to its customers, which include makers of stand-alone cable modems and video set-tops and gateways that embed Docsis 3.0 capabilities, says MaxLinear Marketing Director Jim Koutras.

MaxLinear expects volume production on the new tuners to begin in the third quarter of 2012.

Why this matters
Raw capacity aside, the practical use for these enhanced channel bonding capabilities is for the building blocks for cable's IP video migrations, offering enough headroom for MSOs to comfortably deploy IP video simulcasts.

MaxLinear's new tuners also support an important Full-Spectrum Capture (FSC) capability that lets MSOs pluck channels for bonding from from anywhere up to 1GHz, matching a capability that Broadcom introduced last year. Historically, operators have had to bond channels from a dedicated block of 100MHz, which isn't wide enough to support a 24-channel Docsis 3.0 downstream. FSC also gives MSOs more flexibility in how they manage bandwidth for D3 in relation to other cable services.

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— Jeff Baumgartner, Site Editor, Light Reading Cable



Jeff Baumgartner 12/5/2012 | 5:40:35 PM
re: MaxLinear Hints at a 1Gbit/s Future

While not a product roadmap per se, Broadcom did tell us that the architecture they use for the BCM3383 chipset family will let it grow to "16, 24, 32 and beyond" with downstream channel bonding, so 24 may just be in the middle of the next D3 growth curve. JB


 

msilbey 12/5/2012 | 5:40:29 PM
re: MaxLinear Hints at a 1Gbit/s Future

I may be mixing up concepts here, but are there any US cable MSOs that could use that full spectrum other than Cox, which made the upgrade to 1GHz a while back?

Jeff Baumgartner 12/5/2012 | 5:40:28 PM
re: MaxLinear Hints at a 1Gbit/s Future

You're right in that Cox is the only major US MSO that's been very public about 1GHz upgrades, but the majority of  the taps and other plant gear on sale now are 1GHz-capable, and all new STBs and cable modems are likewise capable of tuning to  1GHz whether  or not the operator goes through the process of activating  capacity above 750MHz/860MHz. 


I think the more important part of Full Spectrum Capture isn't whether an operator has activated spectrum between 860MHz and 1GHz, but that operators now have the ability to pluck 6MHz channels from anywhere on the spectrum for downstream  channel bonding rather than having to grab them from a  more limited 100Mhz block of spectrum. It eliminates some spectrum management headaches when you don't have to do that, in addition to the fact that there isn't enough spectrum in a 100Mhz block to bond 24 6MHz channels -- when/if an operator decides to bond that many, which I'd be surprised to see happen all that soon. But the answer is that everyone should be able to use FSC.  JB

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