Light Reading
OfCom study shows that LTE can interfere with cable services when the conditions are just right, so take a breather, Chicken Little

Study: LTE Can Knock Out Cable TV

Jeff Baumgartner
LR Cable News Analysis
Jeff Baumgartner
1/12/2011
50%
50%

The circumstances have to be just right, but a new technical report commissioned by U.K. regulatory Ofcom finds that Long Term Evolution (LTE) services operating in the 800MHz frequency band can interfere with -- and possibly punch out -- cable services.

The 83-page report (PDF) details the results of field trials conducted in April 2010 undertaken at Virgin Media Inc. (Nasdaq: VMED)'s RF/optical test facility in Birmingham over a seven-week period, and involving nine set-tops and 12 cable modems. The tests checked the technical and regulatory conditions for fixed and mobile communications networks operating in the 790MHz-862MHz band.

The results showed that interference was present in seven of the STBs tested and in all of the modems (the test didn't name the suppliers). The big caveat: Problems occurred when an LTE handset was operating at the maximum permissible transmit power at a separation distance of one meter. So, it tended to occur when one was practically sitting on top of the cable device.

On top of that, picture failure occurred when the LTE signal and cable-TV signal were operating on the same frequency, meaning there's some cause for concern, but not of the Chicken Little variety as mobile service providers around the globe begin to ramp up deployments of LTE. (See CES 2011: Verizon Takes 10 With LTE, CES 2011: AT&T Accelerates LTE Push, Who's Bagged the Biggest LTE Deals? and Where in the World Is LTE?)

Pixely Wickets

Some of the interference issues were tied to product designs, including those that had high numbers of rectangular holes in the cable device metal sheeting that allow unwanted frequencies to seep in and couple with sensitive circuitry.

Although major interference occurred only in limited scenarios, the report, conducted by U.K.-based Cobham Technical Services, also offered some remedies on how cable gear could be improved to be more resistant to LTE signals. Among the suggestions: Operators could insert a 5MHz-wide band between the cable TV and LTE center frequencies, employ additional filtering to the RF circuitry, or simply not use the 832MHz-862MHz band for cable services.

The latter could require some significant work by the cable operator, and the report does acknowledge that the remedies cited do not examine their commercial feasibility.

Concerns about the potential for interference between cable and wireless broadband services aren't all that new. The U.S. cable industry has previously expressed them over previous studies showing that wireless broadband services that tap unlicensed "white spaces" (vacant airwaves between over-the-air TV channels) can interfere with digital cable services and wireless microphones.

The Federal Communications Commission (FCC) approved the use of white spaces last year, setting aside two channels for wireless mics. However, the FCC removed a suggested requirement that white-spaces devices support automated sensing tech that can detect the signals of TV stations and microphones. (See FCC Opens Up TV White Spaces and Cable Worried About 'White Space' Tech.)

We've asked the National Cable & Telecommunications Association (NCTA) for its reaction to the Ofcom test results and if it has any similar concerns over LTE that it had previously with the use of white spaces.

— Jeff Baumgartner, Site Editor, Light Reading Cable

(3)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View
Jeff Baumgartner
50%
50%
Jeff Baumgartner,
User Rank: Light Beer
12/5/2012 | 5:15:31 PM
re: Study: LTE Can Knock Out Cable TV


Via email, NCTA spokesman Brian Dietz offered this in response to questions regarding whether the organization had any concerns about LTE interference:


"We are aware of the issues that the Ofcom report raises and understand that European cable operators are examining this closely. We will also continue to monitor this situation."


As a reminder, the NCTA did quite a bit of research related to interference caused by white spaces technology.  JB


 

comtech3
50%
50%
comtech3,
User Rank: Light Beer
12/5/2012 | 5:15:26 PM
re: Study: LTE Can Knock Out Cable TV


My take on this is that the cable systems where these test were made do not off-set their carriers.Most US cable system,especially those close to broadcast transmitters, either use HRC ( harmonic related carriers),or IRC ( incremental related carriers ) to mitigate against such interference.Moreover, the problem would affect those MSO who deploy HFC architecture and not those who employ FFTH/FTTP.However, the problem for those MSOs who deploy HFC architecture is interference in the upstream spectrum and not in the downstream, save for ingress and co-channel  on analog for those systems that still support cable-ready TVs without the use of a set-top box.Bottom line is the MSOs in the US has done a good job in ensuring that their plants are free from ingress/egress; no planes have gone down from leaky cable system, knock on wood!


 

pstox
50%
50%
pstox,
User Rank: Light Beer
12/5/2012 | 5:12:28 PM
re: Study: LTE Can Knock Out Cable TV


There was another recent study by a US company on interference between cable TV and LTE

Educational Resources
sponsor supplied content
Educational Resources Archive
Flash Poll
From The Founder
It's clear to me that the communications industry is divided into two types of people, and only one is living in the real world.
LRTV Documentaries
EE: The Road to 5G

12|16|14   |   16:02   |   (1) comment


Andy Sutton, the principal network architect at UK mobile operator EE, explains how his company is using Wembley stadium as a wireless test bed and how that's helping EE to plan the evolution to 5G.
LRTV Huawei Video Resource Center
Highlights of Huawei's NFV Open Cloud Forum 2014

12|16|14   |     |   (0) comments


Huawei hosted its inaugural NFV Open Cloud Forum during the SDN & OpenFlow World Congress 2014 in Düsseldorf, Germany. The Forum brought together technology thought leaders, senior executives and telecom professionals from global carriers, industry associations, as well as other partner companies in the ecosystem, to exchange views on and collectively explore how ...
LRTV Custom TV
Realizing Operators' Digital Vision

12|16|14   |   5:23   |   (0) comments


Leveraging technology is fundamental to digital transformation but understanding customers and serving them really well is at the heart of digital businesses. TM Forum lists the following as the strategic pillars of the digital business: business agility and rapid innovation, operational agility and effectiveness, IT and data centricity, plus customer centricity. ...
LRTV Documentaries
US Cellular Injects Analytics Into LTE

12|16|14   |   2:57   |   (1) comment


US Cellular's Mario Vela explains how the operator uses analytics for network planning and what comes next as the carrier looks to eke more value out of its metrics.
LRTV Interviews
How Cox Biz Plans to Keep Growing

12|15|14   |     |   (1) comment


Steve Rowley, SVP of Cox Business, details how the third-biggest US MSO intends to boost its revenues to $2 billion and beyond over the rest of the decade
LRTV Huawei Video Resource Center
Interview With Bill Zhang, Director of SoftCOM Product Management, Huawei

12|15|14   |   2:50   |   (0) comments


Bill Zhang elaborated on Huawei's open philosophy in NFV solution development and network architecture design at the SDN & OpenFlow World Congress 2014.
LRTV Huawei Video Resource Center
Event Highlights: Huawei at SDN & OpenFlow World Congress 2014

12|15|14   |   3:43   |   (0) comments


Huawei joined the 2014 SDN & OpenFlow Congress as one of the key sponsors and contributors. At the event, Huawei reinforced the openness and flexibility of its network infrastructure strategies, and provided updates on its SDN and NVF innovations. Through participations at the exhibitions, forums and speeches, Huawei encouraged the industry to "think bigger and ...
LRTV Interviews
How Cable Biz Services Hit $10B Mark

12|12|14   |     |   (1) comment


Cable operators reached $10 billion in annual business services revenues by delving deeper into their vertical markets and expanding beyond the smallest firms.
LRTV Documentaries
Mediacom Aims to Test Connected Tractors

12|11|14   |   05:07   |   (3) comments


Cable business service provider is taking its services to the 'agribusiness' sector in partnership with farm equipment specialist John Deere and is getting involved in Gigabit Cities developments.
LRTV Interviews
TWC Business Looks Beyond $3B

12|10|14   |     |   (0) comments


TWC Business Services chief Phil Meeks explains how his unit has reached $3 billion in annual revenues and what its plans are for next year.
LRTV Documentaries
AT&T's New Security Strategy

12|10|14   |   02:36   |   (1) comment


AT&T's Chief Security Officer Ed Amoroso explains how his company is wrapping virtual security layers around micro network domains.
LRTV Documentaries
2020 Vision: A First View

12|9|14   |   02:25   |   (3) comments


At the 2020 Vision Executive Summit in Iceland, unique Heavy Reading research shows that comms service providers are optimistic about the next five or so years.
Upcoming Live Events
February 10, 2015, Atlanta, GA
April 14, 2015, New York City, NY
May 6, 2015, McCormick Convention Center, Chicago, IL
May 13-14, 2015, The Westin Peachtree, Atlanta, GA
June 9-10, 2015, Chicago, IL
Hot Topics
Vodafone to Ride T-Mobile Back Into US
Dan Jones, Mobile Editor, 12/12/2014
1-Gig: Coming to a Small Town Near You
Jason Meyers, Senior Editor, Gigabit Cities/IoT, 12/17/2014
Gardner's Departure a Cautionary Tale
Carol Wilson, Editor-at-large, 12/12/2014
Cisco Makes Big Analytics Push
Mitch Wagner, West Coast Bureau Chief, Light Reading, 12/11/2014
T-Mobile Lights Up 27 Wideband LTE Cities
Sarah Reedy, Senior Editor, 12/15/2014
Like Us on Facebook
Twitter Feed
Upcoming Webinars
Webinar Archive