Interference between DTT & Mobile services in the UHF bands

zg3409

From:

http://www.bbc.co.uk/news/technology-17125468

4G TV interference: Up to a million homes 'need filters'
The 4G signal will be used by the next generation of smartphones and tablets Continue reading the main story
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Almost a million UK homes will need to have filters installed to prevent TV interference from 4G mobile signals - at a cost of £108m.

A smaller number of homes - about 10,000 - will need to switch to satellite or cable TV services in order to avoid degraded picture quality.

Homes that cannot receive these alternative platforms will receive up to £10,000 each to "find a solution".

Costs will be met by the winner of a spectrum auction later this year.

Consultations are currently being held into how spectrum - which is used by analogue television - will be offered to mobile operators once airwaves are freed up by the switch to digital.

These airwaves are crucial to mobile operators to create next-generation mobile services.

The winning bidder, or bidders, will be required to pay for the costs of making sure viewers of digital terrestrial television (DTT) will not be affected by the changes.

Unwanted noise

In a consultation document released in August last year, media regulator Ofcom estimated that about 760,000 homes could be affected.

However, the Department for Culture, Media and Sport (DCMS) told the BBC that further research had suggested that number was likely to be closer to 900,000.

Homes falling within a certain range of transmitter towers will automatically have a filter issued, while a helpline will be set up to deal with interference cases outside of the predicted areas.

The filter, which is fitted to a digital TV box, blocks out unwanted noise from the 4G signal.

Continue reading the main story
“
Start Quote
If you give £10,000 to a lady in Cumbria and say: 'You need to fix it' - I don't think it's enough”
End Quote
Saverio Romeo

Industry analyst
It can be fitted without the help of an engineer - but over-75s and disabled people will be given assistance if needed.

The DCMS said that in a very small number of homes, the filters would not be sufficient. A platform change - to satellite or cable - will be required, the cost of which will also be covered by the mobile operator.

It is estimated that about 10,000 homes may need to take this measure.

It is also predicted that about 500 homes affected by interference will be unable to receive satellite or cable services.

In these cases, expected to be in rural areas, up to £10,000 per household will be provided to fund alternative solutions to receiving television - such as having fibre cabling installed.

The DCMS said it predicted that small groups of affected houses would be able to pool their funding in order to pay for bigger investments like additional relay transmitters.

'Disruptive'

Without the preventative measures, television picture would become unclear and fragmented, warned Saverio Romeo, an industry analyst from Frost & Sullivan.

"The LTE [Long Term Evolution] spectrum, particularly on 800Mhz, overlaps part of the DTT spectrum," he said.


Culture Minister Ed Vaizey said 4G technology would give the UK an economic boost "The closer you are to a base station, the more disruptive the interference."

He said that in addition to the £10,000 fund for the severely disrupted homes, education should be provided in order to help people understand what options were available.

"If you give £10,000 to a lady in Cumbria and say: 'You need to fix it' - I don't think it's enough.

"You need to help people understand new technologies. It's not enough to give subsidies."

A spokesman for the DCMS said additional advice would be given to those receiving the financial help.

Culture Minister Ed Vaizey said adoption of 4G would provide a boost to the UK's digital economy.

"Next-generation mobile services are essential for economic growth. They will bring an estimated benefit of £2-3bn to the UK economy.

"There will be some interference when 4G services are rolled out but we will have the solutions in place to eliminate the disruption to television viewers."

The Cush

The Cush wrote: »

With the top end of the band lost from broadcasting throughout Europe I wonder if aerial manufacturers have plans to revise existing aerial grouping or introduce new aerial groups in the coming years, add to that a potential loss of another slice of spectrum to Digital Dividend 2 in the next 10-13 years.

Article from this month's What Satellite & Digital TV magazine (#315, Summer2012)

At a recent CAI seminar they outlined proposals for new revised aerial groups.

- The 3 main aerial groups A, B, C/D would be reduced to 2 groups L, H.
- Aerial groups K, E would disappear
- The wideband group W would be replaced with a reduced wideband (21-60) group T (Triax has 4 "reduced-band" wideband aerials in its 2012 catalogue)

Existing Aerial Groups
Group|Channels| Bandwidth| Colour| Code
A |21 – 37| 470 – 606 MHz| █ |Red
B| 35 – 53| 582 – 734 MHz| █ |Yellow
C/D| 48 – 68| 686 – 860 MHz| █ | Green
W| 21 – 68| 470 – 860 MHz| █ |Black
K| 21 – 48| 470 – 694 MHz| █ | Silver
E| 35 – 68| 582 – 860 MHz| █ |Brown


Proposed Aerial Groups
Option1 (no broadcast use of channels 31 – 38)
Group|Channels| Bandwidth| Colour| Code
L |21 – 30| 470 – 550 MHz| █ |Orange
H |39 – 60| 614 – 790 MHz| █ |Blue
T| 21 – 60| 470 – 790 MHz| █ |White


Option2 (broadcast use of channels 31 – 38)
Group|Channels| Bandwidth| Colour| Code|
L |21 – 38| 470 – 614 MHz| █ |Orange|Note1
H |31 – 60| 550 – 790 MHz| █ |Blue|
T| 21 – 60| 470 – 790 MHz| █ |White|


Note1 - New Group L not required if Ch 38 isn't used for DTT, Group A (21-37) will remain

reslfj

The Cush wrote: »

....
Option2 (broadcast use of channels 31 – 38)
Group|Channels| Bandwidth| Colour| Code|
L |21 – 38| 470 – 614 MHz| █ |Orange|Note1
H |31 – 60| 550 – 790 MHz| █ |Blue|
T| 21 – 60| 470 – 790 MHz| █ |White|

Note1 - New Group L not required if Ch 38 isn't used for DTT, Group A (21-37) will remain

New group L must include ch39 as the NImux uses ch39+

Lars

The Cush

Now that the spectrum auction is complete and the rollout of 4g services will be happening in the coming months the issue of interference to DTT from 4g will become an issue.

This has been an issue for RTÉ as we can see from the correspondence between them and Comreg/Dept during the consultation process on the multi-band spectrum auction (e.g. in the first post of this thread).

An article in today's Irish Indo says they have just learnt of this potential problem - http://www.independent.ie/business/technology/thousands-may-lose-tv-signal-at-home-in-rollout-of-superfast-4g-mobile-3350762.html

A Dept of Comms working group has been setup with RTÉ and Comreg to look at the issue according to the article.

Existing Dept of Comms/Comreg information on interference - http://www.dcenr.gov.ie/Communications/Business+and+Technology/Digital+Dividend/, http://www.comreg.ie/radio_spectrum/tv_reception_disruption.543.418.html

watty

Comreg are ONLY interested in raising revenue. Not protecting Spectrum or the Consumer.

EU should slap our Government REALLY hard for all the ***** they, DCENR and Comreg have fed EU and Public and failure to meet their mandate. Comreg daily break their own mission statement.

FREETV

watty wrote: »

Comreg are ONLY interested in raising revenue. Not protecting Spectrum or the Consumer.

EU should slap our Government REALLY hard for all the ***** they, DCENR and Comreg have fed EU and Public and failure to meet their mandate. Comreg daily break their own mission statement.

Watty you should contact Irish members of the EU Parliament and inform them of the ***** as you say that Comreg and Co are up to and state your expertise and that you once worked as an Engineer for the BBC. Hopefully they will listen to you?

watty

Various organisations have highlighted the shenanigans here. Such as NBS.

The Cush

The Cush wrote: »

An article in today's Irish Indo says they have just learnt of this potential problem - http://www.independent.ie/business/technology/thousands-may-lose-tv-signal-at-home-in-rollout-of-superfast-4g-mobile-3350762.html

Saorview replied to a comment on this on their facebook page

John Kilbride 15 January at 22:26
Is there any truth in the report in yesterdays newspaper stating that the rollout of 4g will affect Saorview reception

Saorview As things currently stand SAORVIEW are not aware of any planned activity which could affect reception quality. Representatives from RTÉ will be attending a working group, held at the request of the Department of Communications to discuss what television reception implications, if any, may arise from the rollout of the 4G services.
17 January at 16:19

http://www.facebook.com/#!/saorview/posts/445368302199861

They don't appear to be as concerned about potential interference as they were during the consultation process as we saw from the published correspondence between them and Comreg/Dept of Communications.

From: Kehoe, Mick [RTE]
Sent: 23 November 2011 12:28
To: Susan Fleming
Cc: DCENR’s Digital Switchover Group (DSG)
Subject: RE: interference between services in UHF bands

Susan,
I hope ComReg are right. RTÉNL stand by its position and at least if/when a problem does arise we will know where to divert the phone calls.

Regards,
Mick....

winston_1

To_be_confirmed wrote: »

In any case, there's very little that can be done until aerials and amps are finally manufactured to not specifically receive 800MHz broadcasts. I.e. Group C/D aerials and combiners etc. no longer tuned specifically to work from Ch. 61 to 69.

Aerials are not filters and won't sharply cut off at ch 60.

I have a 12 element ch 21 to 60 aerial made by Triax, a reputable manufacturer. It's from the days when German analogue TV only used up to ch 60. But its performance above ch 60 was better than than an 18 element Antiference C/D aerial.

The Cush

The Cush wrote: »

Article from this month's What Satellite & Digital TV magazine (#315, Summer2012)

At a recent CAI seminar they outlined proposals for new revised aerial groups.

- The 3 main aerial groups A, B, C/D would be reduced to 2 groups L, H.
- Aerial groups K, E would disappear
- The wideband group W would be replaced with a reduced wideband (21-60) group T (Triax has 4 "reduced-band" wideband aerials in its 2012 catalogue)

According to a news report in the latest issue of What Sat the CAI has started work on a new post DSO aerial benchmark standard which will reflect changes to broadcast spectrum such as the loss of the 800MHz frequencies.

A large meeting was held at the CAI HQ with the BBC, DTG, aerial manufacturers and distributors present.

"The CAI's executive has now begun a work stream to transform the parameters that define UHF TV aerials for the next few years."

What Satellite Feb 2013

lucernarian

winston_1 wrote: »

Aerials are not filters and won't sharply cut off at ch 60.

I have a 12 element ch 21 to 60 aerial made by Triax, a reputable manufacturer. It's from the days when German analogue TV only used up to ch 60. But its performance above ch 60 was better than than an 18 element Antiference C/D aerial.

That is just one example, its significance is negligible. And why would I or anyone else describe aerials as low-pass filters or anything approximating such?

There is enormous precedent for the merits of higher-gain aerials with narrower bandwidth. The various grouped aerials were produced for a reason. In a worst case scenario, the redefined-bandwidth aerials may offer gain at Ch. 61 of only 3 or 4 dB less than the highest gain the aerial offers, e.g. at Ch. 53. This should still be lower than would be received on Ch. 61 by a current Group C/D aerial and the supplied data with various aerials all show a drop in gain at the upper end of their design bandwidth. This may not make much of a difference but nonetheless an improvement in the "digital dividend" era.

It would be madness to propose making no changes to the bandwidth of UHF aerials when 4G transmission in 800 MHz has been identified as a serious problem.

The Cush

The Cush wrote: »

http://www.independent.ie/business/technology/thousands-may-lose-tv-signal-at-home-in-rollout-of-superfast-4g-mobile-3350762.html

A Dept of Comms working group has been setup with RTÉ and Comreg to look at the issue according to the article.

A Dáil question on this last week

Tuesday, 22 January 2013

418. Deputy Jack Wall
asked the Minister for Communications, Energy and Natural Resources his views regarding ComReg (details supplied); if his attention has been drawn to such problems and the actions to be taken to overcome same; and if he will make a statement on the matter. [2469/13]

Minister for Communications, Energy and Natural Resources (Deputy Pat Rabbitte): I am aware of the press article referred to by the Deputy.

This is an issue that will arise right across the EU as 4G services are rolled out and I can confirm that a group has been established by my Department to examine the degree to which this issue may arise in Ireland when the roll-out of 4G services commences later in 2013.

This group comprises officials from my Department, as well as representatives from ComReg, the Broadcasting Authority of Ireland, RTÉ and the mobile industry and its focus will be on assessing the potential for any interference in regard to households that use “free to air” television and to identify any possible remedial measures that may be required.

ComReg has already confirmed its view that any disruption that may arise to TV signals would be capable of being addressed by filters which are available.

It is my intention that an agreed joint strategy, as necessary, that fully addresses the issue should be put in place in advance of 4G roll-out.

http://oireachtasdebates.oireachtas.ie/debates%20authoring/debateswebpack.nsf/takes/dail2013012200070?opendocument#WRS00525

The Cush

Another Dáil question yesterday on potential interference that may be caused by the new 4G networks.

Thursday, 31 January 2013

33. Deputy Mick Wallace
asked the Minister for Communications, Energy and Natural Resources the outcome of the research initiated by him in relation to potential interference that may be caused by the new 4G network; and if he will make a statement on the matter. [4764/13]

Minister for Communications, Energy and Natural Resources (Deputy Pat Rabbitte): The issue raised in the Deputy’s Question may arise right across the EU as 4G services are rolled out. I can confirm that a group has been established by my Department to examine the degree to which this issue may arise in Ireland when the roll out of 4G services commences later in 2013. The group comprises officials from my Department, as well as representatives from ComReg, the BAI, RTÉ and the mobile industry and its focus will be on assessing the potential for any disruption to TV signals in households that use “free to air” television and to identify any possible remedial measures that may be required. The approaches being developed in other countries, including the UK, will be studied by the group and will help inform the approach that we will take in Ireland. ComReg has already confirmed its view that any disruption that may arise to TV signals would be capable of being addressed by filters which are available. It is my intention that an agreed joint strategy should be put in place in advance of 4G roll-out that fully addresses the issues around any potential disruption to consumers’ television service.

http://oireachtasdebates.oireachtas.ie/debates%20authoring/debateswebpack.nsf/takes/dail2013013100050?opendocument#WRD00750

The Cush

Digital Mobile Spectrum Limited (DMSL), originally called MitCo, the jointly controlled company formed by the 4 UK mobile network operators (EE, Telefónica O2, Three and Vodafone) with responsibility for ensuring that consumers continue to receive clear Freeview TV signals following the roll out of 4G mobile services is now up and running with the appointment of a Chief Executive and a new website.

DMSL website - Let's be clear at 800MHz

http://www.ft.com/cms/s/0/67e3ffdc-7394-11e2-9e92-00144feabdc0.html#ixzz2KjpLZNsV

Simon Beresford-Wylie, a telecoms industry veteran, will this week be named chief executive of Digital Mobile Spectrum Limited, the group charged with ensuring Britain’s terrestrial TV will not be knocked out by 4G mobile services.

“The 4G networks will likely be running from this summer,” Mr Beresford-Wylie said. “We need to be fully operational by March to be in place to mitigate any interference issues.”

The government has raised £180m from the mobile groups who will use 4G spectrum (an amount separate from the £3.5bn the Treasury is expected to raise from auctioning the spectrum) to pay for the filters as well as a nationwide advertising campaign to alert home owners to potential problems.

Engineers will be employed to make home visits to fit the devices where necessary, although the filters are designed to be fitted by home owners in most cases.

Mr Beresford-Wylie said DMSL would work closely with broadcasters and mobile network operators to build a “sophisticated model” to predict where interference might occur, and to provide filters accordingly.

Before the 4G launch, DMSL will conduct pilots to ensure that solutions work and to help find problem areas.

“We expect to be able to identify affected households,” Mr Beresford-Wylie said. “We will need to procure millions [of filters] in the first instance.”

jjf1974

Can we expect the same problems in this country ?

The Cush

jjf1974 wrote: »

Can we expect the same problems in this country ?

Probably.

Households prone to interference from mobile masts will include those close to mobile transmitter sites, aerials with masthead amps, reception from transmitters that use UHF Ch.52 upwards, indoor aerials etc.

Hotblack Desiato

Hmm. We live less than 1km away from a mobile/Digiweb Metro site, which is the highest point in the area, almost exactly in line between our house and Kippure, and we have a wideband aerial. Sounds like the ideal recipe for interference if that site is used for 800MHz and chances are it will be...

The Cush

ninja900 wrote: »

We live less than 1km away from a mobile/Digiweb Metro site, which is the highest point in the area, almost exactly in line between our house and Kippure, and we have a wideband aerial. Sounds like the ideal recipe for interference if that site is used for 800MHz and chances are it will be...

That could be the case, a quote here from the ukfree.tv website

Interpreting the aerial and mast locations

Once the proposed mast locations for 4G services are known, it will then be possible to predict which homes will need to fit the special filters in areas where Freeview uses the higher channel numbers (the C52 to C60 range).

If you then have a rooftop aerial without a signal amplifier, to get an overload you will need the 4G mast to be in the line-of-sight between your Freeview transmitter and the aerial, or possibly "directly behind" the aerial.

If you then have a rooftop aerial and an amplifier, or perhaps have lower-grade cables, you are likely to need to protect from a 4G overload if the phone mast is close to your rooftop aerial.

http://www.ukfree.tv/fullstory.php?storyid=1107052059

Maybe the Dept of Comms or Comreg or RTÉ or the MNOs with 800MHz spectrum will provide the necessary filters to those household affected by LTE interference, then again maybe not :rolleyes:

The Cush

Irish authorities to investigate if 4G will disrupt TV signals in homes - siliconrepublic.com

...

So, will TV in Ireland be affected when 4G goes live?

In response to queries from Siliconrepublic.com, Ireland’s Department of Communications, Energy and Natural Resources confirmed it is evaluating the issue arising in Ireland.

“A group has been established by the department to examine the degree to which this issue may arise in Ireland when the roll out of 4G services commences later in 2013.

“This group comprises officials from the department, as well as representatives from ComReg, the Broadcasting Authority of Ireland, RTÉ and the mobile industry, and its focus is on assessing the potential for any interference in regard to households that use ‘free to air’television and to identify any possible remedial measures that may be required. It is the intention that an agreed strategy, as necessary, that addresses the issue should be put in place in advance of 4G roll out,” the department spokesman said.

When we contacted telecoms regulator ComReg on the issue we were directed to an FAQ that confirmed that homes in weak signal areas that previously had to install a masthead amplifier – a small plastic box – on their rooftop aerials to get a decent signal might be affected.

Homes using the free digital television service Saorview are unlikely to be affected, the FAQ says, because Saorview factored its service in for use without the need for amplifiers.

However, amplifiers are likely to be still in use in homes located in areas of weak signal or coverage blackspots. These homes or homes that use amplifiers to boost a TV signal to a number of other TVs in the household are likely to experience radio frequency (RF) overload when 4G is switched on alongside the new digital terrestrial TV services.

ComReg says: “If you receive off air reception of the national services (RTÉ, TG4, TV3) by means of a roof top aerial which is fitted with a mast head amplifier, you may suffer degradation or even loss of television reception when LTE services come on stream from early 2013 onwards. This loss is likely to be as a result of the amplifier on your roof amplifying an unwanted signal and suffering overload.”

...

Comreg FAQ - What is Radio Frequency (RF) Overload and how might it impact me?

byte

Interestingly, the Johansson wideband amps now have Lte logo on them and only cover E21-60, which is handy. Do other amp brands do similar? Triax don't seem to, though not a fan of their stuff anyway.

hju6

Blake do a selection http://www.blake-uk.com/proobf.aspx

Peter Rhea

That's a separate filter, the amps still cover all of bands IV & V. Triax also do these LTE filters, incidentally.

The Cush

Another Dáil question on potential interference that may be caused by the new 4G networks.

Wednesday, 20 February 2013

163. Deputy Thomas P. Broughan
asked the Minister for Communications, Energy and Natural Resources if there are any issues over potential interference with TV receptions for Saorview viewers here with the roll out of 4G in view of the problems that OfCom in the UK have identified for up to 2.3 million British freeview households; and if he will make a statement on the matter. [9164/13]

Minister for Communications, Energy and Natural Resources (Deputy Pat Rabbitte): This is an issue that will arise right across the EU as 4G services are rolled out. My Department is aware that organisations in several countries including Ofcom have conducted studies on the potential problem.

A group has been established by my Department to examine the degree to which this issue may arise in Ireland when the roll-out of 4G services commences later in 2013.

This group comprises officials from my Department, as well as representatives from ComReg, the Broadcasting Authority of Ireland, RTÉ and the mobile industry and its focus is on assessing the potential for any interference in regard to households that use “free to air” television and to identify any possible remedial measures that may be required.

http://oireachtasdebates.oireachtas.ie/debates%20authoring/debateswebpack.nsf/takes/dail2013022000087?opendocument#WRT00750

watty

So he's doing the same as they do for any other issue. Talking about it.

FREETV

watty wrote: »

So he's doing the same as they do for any other issue. Talking about it.

Yeah, he's all talk like the Lyons ad and no action.

The Cush

The Cush wrote: »

Article from this month's What Satellite & Digital TV magazine (#315, Summer2012)

At a recent CAI seminar they outlined proposals for new revised aerial groups.

- The 3 main aerial groups A, B, C/D would be reduced to 2 groups L, H.
- Aerial groups K, E would disappear
- The wideband group W would be replaced with a reduced wideband (21-60) group T (Triax has 4 "reduced-band" wideband aerials in its 2012 catalogue)

Existing Aerial Groups
Group|Channels| Bandwidth| Colour| Code
A |21 – 37| 470 – 606 MHz| █ |Red
B| 35 – 53| 582 – 734 MHz| █ |Yellow
C/D| 48 – 68| 686 – 860 MHz| █ | Green
W| 21 – 68| 470 – 860 MHz| █ |Black
K| 21 – 48| 470 – 694 MHz| █ | Silver
E| 35 – 68| 582 – 860 MHz| █ |Brown


Proposed Aerial Groups
Option1 (no broadcast use of channels 31 – 38)
Group|Channels| Bandwidth| Colour| Code
L |21 – 30| 470 – 550 MHz| █ |Orange
H |39 – 60| 614 – 790 MHz| █ |Blue
T| 21 – 60| 470 – 790 MHz| █ |White


Option2 (broadcast use of channels 31 – 38)
Group|Channels| Bandwidth| Colour| Code|
L |21 – 38| 470 – 614 MHz| █ |Orange|Note1
H |31 – 60| 550 – 790 MHz| █ |Blue|
T| 21 – 60| 470 – 790 MHz| █ |White|


Note1 - New Group L not required if Ch 38 isn't used for DTT, Group A (21-37) will remain

According to the Blake UK website there will be 2 aerial groups as part of the revised CAI LTE Benchmarked Aerials Scheme. Not yet published that I can see.

Group A - Ch 21-38
Group T - Ch 21-60

Group T (T for Total, according to the ATV website) is the new Group W for the LTE era.

It's being recommeded to fit a Group T aerial instead of Group W to reduce potential future LTE interference problems.



The new Group T may also be replaced in the not too distant future if or when a new Digital Dividend takes place. At that time it could be replaced with the old Group K (Ch 21-48).

Also there will be 2 new LTE aerial benchmark standards under the revised benchmarking scheme from the current Standard 1, 2, 3, 4

- Standard S (Standard / mid gain)
- Standard F (Fringe / high gain)

The Cush

Following on from a discussion in another thread on the new wideband Group T reduced-band aerial group.

The CAI recently published its revised Aerial Benchmarking Procedure and Benchmark Manual - http://www.cai.org.uk/downloadables/finish/37-aerial-benchmarking/519-aerial-benchmarking-cai-dtg-rev-1-iss-15-22-01-2014

Also the latest list of CAI Benchmarked LTE aerials - http://www.cai.org.uk/downloadables/finish/37-aerial-benchmarking/521-cai-aerial-benchmark-list

watty

But in reality
1) you might need a filter and any amplifier is the real issue, the aerial is the least of the worries, though helps.
2) the interference from the phone/modem/gadget in same room is worse and in tests disrupted Cable TV and Cable broadband due to cable ingress.

So high quality connections and decent solid braid and real foil screen coax needed too.

Most people will not
1) Know what is freezing picture
Or
2) know who to complain to
Or
3) even if (1) and (2) sorted they will rather complain in office / pub / Joe Duffy than write a Registered letter. (Emails are easily ignored, deleted and denied).

Because of a false sense of RTE "even handedness" we missed yet another opportunity to have an Irish equivalent body.