& cplSiteName &

Docsis 3.1 Rides the Wireless Wave

Jeff Baumgartner
LR Cable News Analysis
Jeff Baumgartner
1/28/2013
50%
50%

The Docsis 3.1 specs under development at CableLabs won't be published until later this year, but it's already well-established that cable's latest, greatest data platform will make big use of orthogonal frequency division multiplexing (OFDM) as the industry begins to break away from the use of less efficient 6MHz- and 8MHz-wide channels. (See Docsis 3.1 Set for a Spring Fling.) OFDM will provide Docsis with a new order of bandwidth efficiency, but it also offers some sound business reasons for cable to adopt it. OFDM, already used for Wi-Fi and Long Term Evolution (LTE), could lead to better economies of scale and get more vendors interested in the cable market, explained Daniel Howard, the SVP of engineer and CTO at Society of Cable Telecommunications Engineers (SCTE), during a webcast earlier this month on the topic (SCTE is tasked with helping the cable industry get trained up for Docsis 3.1). (See Setting the Stage for Docsis 3.1.) But back to the coming efficiencies. By letting MSOs scrunch small (20KHz-to-50KHz-wide) subcarriers into blocks of spectrum (or "waveforms" up to about 200MHz wide) without interfering with each other, OFDM essentially eliminates the wasteful guard bands required for today's single-channel QAM technology. OFDM also deals well in noisy environments and can handle other impairments such as micro-reflections, meaning cable can be better able to maintain higher forms of modulations and push more bits per hertz on the cable plant even when plant conditions aren't ideal. OFDM's use of adaptive bit loading also allows operators to dial those modulations up and down at the subcarrier level. In the SC-QAM world, the entire 6MHz or 8MHz channel must operate at the same modulation. Howard also pointed out a popular misconception that OFDM alone will help operators achieve higher modulations that can put more bits down the pipe in the same amount of space. (See Docsis 3.1 Targets 10-Gig Downstream.) To hit those anticipated, improved performance levels, OFDM will be paired with low density parity-check (LDPC), a Forward Error Correction (FEC) scheme that will also require less bandwidth than the current Reed-Solomon approach. When used together in Docsis 3.1, they should improve cable's bandwidth efficiency by about 50 percent. So it follows that cable should be able to pump out 5Gbit/s in 500MHz of spectrum with Docsis 3.1, versus 780MHz of spectrum using today's Docsis 3.0 platform. Although Docsis 3.1 will help cable push the limits and extend the life of the hybrid fiber/coax (HFC) plant, the irony is that the industry will owe a debt of gratitude in part to a technology that's helped wireless operators get the most out of their precious spectrum. — Jeff Baumgartner, Site Editor, Light Reading Cable

(2)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
Jeff Baumgartner
50%
50%
Jeff Baumgartner,
User Rank: Light Beer
1/29/2013 | 3:08:41 PM
re: Docsis 3.1 Rides the Wireless Wave
The intro of D3.1-áshouldn't have much of an effect on legacy Docsis CPE.-á Operators will need to light up new spectrum for D3.1, but they'll continue to use the spectrum they're using now for D1.0-D3.0 modems for years to come.-á To help with the transition, vendors are expected to develop hybrid CPE devcies that can handle both Docsis 3.0 and 3.1. JB
Peyton Maynard-Koran
50%
50%
Peyton Maynard-Koran,
User Rank: Light Beer
1/29/2013 | 2:37:18 PM
re: Docsis 3.1 Rides the Wireless Wave
How does all of this affect the millions of 1.0, 2.0, and 3.0 modems that are deployed?
Featured Video
From The Founder
Light Reading is spending much of this year digging into the details of how automation technology will impact the comms market, but let's take a moment to also look at how automation is set to overturn the current world order by the middle of the century.
Flash Poll
Upcoming Live Events
November 1, 2017, The Royal Garden Hotel
November 1, 2017, The Montcalm Marble Arch
November 2, 2017, 8 Northumberland Avenue, London, UK
November 2, 2017, 8 Northumberland Avenue – London
November 10, 2017, The Westin Times Square, New York, NY
November 16, 2017, ExCel Centre, London
November 30, 2017, The Westin Times Square
May 14-17, 2018, Austin Convention Center
All Upcoming Live Events
Infographics
With the mobile ecosystem becoming increasingly vulnerable to security threats, AdaptiveMobile has laid out some of the key considerations for the wireless community.
Hot Topics
Muni Policies Stymie Edge Computing
Carol Wilson, Editor-at-large, 10/17/2017
'Brutal' Automation & the Looming Workforce Cull
Iain Morris, News Editor, 10/18/2017
Is US Lurching Back to Monopoly Status?
Carol Wilson, Editor-at-large, 10/16/2017
Pai's FCC Raises Alarms at Competitive Carriers
Carol Wilson, Editor-at-large, 10/16/2017
Worried About Bandwidth for 4K? Here Comes 8K!
Aditya Kishore, Practice Leader, Video Transformation, Telco Transformation, 10/17/2017
Animals with Phones
Selfie Game Strong Click Here
Latest Comment
Live Digital Audio

Understanding the full experience of women in technology requires starting at the collegiate level (or sooner) and studying the technologies women are involved with, company cultures they're part of and personal experiences of individuals.

During this WiC radio show, we will talk with Nicole Engelbert, the director of Research & Analysis for Ovum Technology and a 23-year telecom industry veteran, about her experiences and perspectives on women in tech. Engelbert covers infrastructure, applications and industries for Ovum, but she is also involved in the research firm's higher education team and has helped colleges and universities globally leverage technology as a strategy for improving recruitment, retention and graduation performance.

She will share her unique insight into the collegiate level, where women pursuing engineering and STEM-related degrees is dwindling. Engelbert will also reveal new, original Ovum research on the topics of artificial intelligence, the Internet of Things, security and augmented reality, as well as discuss what each of those technologies might mean for women in our field. As always, we'll also leave plenty of time to answer all your questions live on the air and chat board.

Like Us on Facebook
Twitter Feed
Partner Perspectives - content from our sponsors
The Mobile Broadband Road Ahead
By Kevin Taylor, for Huawei
All Partner Perspectives