EBU Spectrum usage and requirements - for future terrestrial broadcast applications

The Cush

mrdtv wrote: »

MPEG2 did: used in US And Australia. Not very efficient.

MPEG4: 50% more efficient than MPEG2. used in France etc

DVB-T2: 40 Mb/s in 8Mhz UHF channel vs 24 MB/s for DVB-T1 (irrespective of MPEG encoding).

Therefore total gain of nearly 120% over DVB-T1 MPEG2. Reason for change in UK.

This is a recently published EBU Spectrum Management document. It has a lot of interesting fact and figures regarding DTT spectrum management and future development.

reslfj

The Cush wrote: »

This is a recently published EBU Spectrum Management document. It has a lot of interesting fact and figures regarding DTT spectrum management and future development.

This EBU document is, however, based on outdated information and half truths.

Take as an example Table 3 on page 6. The left part is from an older version - 1.5.1 - of Table A.1 in the DVB-T standard EN 300 744. The new version - 1.6.1 - was published more than 12 month ago by DVB.ORG and the main change was corrections to table A.1.

For the green line for DVB-T
16-QAM 2/3 C/N=14.2 dB should have been 15.3 dB

For the red line for DVB-T
64-QAM 2/3 C/N=19.3 dB should have been 20.3 dB

DVB-T is thus 1-1.1 dB more fragile than the EBU article indicates.

Likewise the right half of EBU Table 3 for DVB-T2 is from Table 43 in the DVB BlueBook A133 . It specifies - e.g in Table 45 - that corrections must added to the C/N values (around 0.5 dB worse C/N in most cases).

While the bitrates for DVB-T is correctly given as 24.1 Mbps the bitrate for DVB-T2 (red line) is given as 36.5 Mbps. But the new DVB-T2 HD mux in the UK will have a bitrate of 40.2 Mbit/sec or 10% higher.

There are a number of other points and articles quoted that one could be critical about - e.g. "[12] Ken McCann: Review of DTT HD Capacity Issues from 2007" - is little more than Mr. McCann's guessing. It would have been far better to use actual 2009 MPRG-2 vs. MPEG-4 figures.

I think the overall conclusion about the need for MPEG-4/DVB-T2 is about right - if anything DVB-T2 is a little better - but using old data is a disgrace to any technical article - IMHO.

But the conclusions about the the WRC07* (channel 61-69 for mobile broadband) is nothing, but a political statement. The DTT spectrum is now (channel 5-12 + 21-69) 56MHz VHF + 392MHz = 448 MHz. Channel 61-69 is 72 MHz or just a 72x100/448% = 16% reduction.

Surely 16% of the total spectrum can be reassigned for other use, when the EBU argues with C/N figures 1 dB off and bitrates 10% off.

Lars

* WRC07 channel 61-69 for mobile broadband relates to this article text:
"For these reasons it is indispensible that the presently-available broadcasting spectrum remains
available for broadcasting. Further reducing the broadcasting spectrum would seriously jeopardize
the competitivenes of the DTT platform"

The Cush

reslfj wrote: »

But the conclusions about the the WRC07* (channel 61-69 for mobile broadband) is nothing, but a political statement. The DTT spectrum is now (channel 5-12 + 21-69) 56MHz VHF + 392MHz = 448 MHz. Channel 61-69 is 72 MHz or just a 72x100/448% = 16% reduction.

Surely 16% of the total spectrum can be reassigned for other use, when the EBU argues with C/N figures 1 dB off and bitrates 10% off.

The EBU is there to represent its members, broadcasters from all over Europe. They are amongst other things a political lobby group within the EU, so when valuable broadcast spectrum is siphoned off for other uses they will react politically.

The GSMA, a lobby group for the mobile industry would like to see a further 40 MHz of UHF spectrum co-allocated to the Digital Dvidend (750-862 MHz), over 25% of UHF spectrum. When you consider some countries will not use VHF spectrum for DTT this is a sizeable chunk of broadcast spectrum to lose.

Of course EU countries do not have to allocate this spectrum to any other use other than broadcasting as it has been allocated on a co-primary basis.

Sam Russell

Why have BAI (and predecessors)and the Dept allocated UHF channels so high up. I would have thought that 3Rock would use ch21 - 30 for their MUXs as they have the largest coverage by population, and would not have any co channel interference with any overspill from NI or Wales. Only Cork has low ch numbers.

Am I missing something?

The Cush

Sam Russell wrote: »

Why have BAI (and predecessors)and the Dept allocated UHF channels so high up. I would have thought that 3Rock would use ch21 - 30 for their MUXs as they have the largest coverage by population, and would not have any co channel interference with any overspill from NI or Wales. Only Cork has low ch numbers.

Am I missing something?

Frequencies are allocated at ITU Regional Radio Conferences (RRC).

Our current analogue VHF/UHF frequencies were allocated at ITU61 in Stockholm in 1961 and the plan is known as the Stockholm Plan (ST61).

In 2006 at Geneva, the ITU RRC-06 Conference revised the ST61 plan and allocated frequencies for Digital broadcasting for ITU Region 1 countries (incl. Ireland), the GE06 Agreement. At this conference we were allocated 8 layers (frequencies) per transmitter in UHF and 1 layer per main transmitter at VHF.

Changes are allowed to the plan in consultation with National Regulators in neighbouring countries i.e. ComReg, Ofcom etc.

Sam Russell

The Cush wrote: »

Frequencies are allocated at ITU Regional Radio Conferences (RRC).

Our current analogue VHF/UHF frequencies were allocated at ITU61 in Stockholm in 1961 and the plan is known as the Stockholm Plan (ST61).

In 2006 at Geneva, the ITU RRC-06 Conference revised the ST61 plan and allocated frequencies for Digital broadcasting for ITU Region 1 countries (incl. Ireland), the GE06 Agreement. At this conference we were allocated 8 layers (frequencies) per transmitter in UHF and 1 layer per main transmitter at VHF.

Changes are allowed to the plan in consultation with National Regulators in neighbouring countries i.e. ComReg, Ofcom etc.

That is as it may be, but when you look at it, why are the channels allocated the way they are.

Cairn Hill 41 44 47 51
Clermont Carn 53 57 60 63
Holywell Hill 25 30 32 35
Dungarvan 55 59 62 65
Kippure 54 58 61 64
Maghera 55 48 67 65
Mt Leinster 39 42 45 49
Mullaghanish 21 24 25 28
Spur Hill 45 49 66 68
Three Rock 54 58 61 64
Truskmore 52 56 53 57
Woodcock Hill 41 44 47 51

Only Mullaghanish and Holywell Hill have allocations below 40. Out of 52 transmitters, only 9 are below 40. That is nearly half the band left empty for the whole country. Given the lower frequencies carry better over terrain, so would be better for our main transmitters.

Now the EU want the band from ch61 up depopulated. That is 11 of the channels currently being readied. Who planned this? Why so much co-channel problems with overspill?

I think given our geographical location, the choice of co-channel frequencies with the few neighbouring transmitters is either incompetence or something else.

One wonders.

mrdtv

Sam Russell wrote: »

That is as it may be, but when you look at it, why are the channels allocated the way they are.

Cairn Hill 41 44 47 51
Clermont Carn 53 57 60 63
Holywell Hill 25 30 32 35
Dungarvan 55 59 62 65
Kippure 54 58 61 64
Maghera 55 48 67 65
Mt Leinster 39 42 45 49
Mullaghanish 21 24 25 28
Spur Hill 45 49 66 68
Three Rock 54 58 61 64
Truskmore 52 56 53 57
Woodcock Hill 41 44 47 51

Only Mullaghanish and Holywell Hill have allocations below 40. Out of 52 transmitters, only 9 are below 40. That is nearly half the band left empty for the whole country. Given the lower frequencies carry better over terrain, so would be better for our main transmitters.

Now the EU want the band from ch61 up depopulated. That is 11 of the channels currently being readied. Who planned this? Why so much co-channel problems with overspill?

I think given our geographical location, the choice of co-channel frequencies with the few neighbouring transmitters is either incompetence or something else.

One wonders.

The full GE-O6 list is in Annex 1 of this document:

http://www.dcenr.gov.ie/NR/rdonlyres/5962FB63-6F77-49F9-BD65-A7B1A76036F2/0/DevelopmentofaNationalPolicyFrameworkforIdentifyingSpectrumfortheDigitalDividend.doc

RTE began by using VHF but the British scrapped VHF and moved to all UHF. In N Ireland Group A is used by Divis and Brougher Mountain and also by Caldbeck in Cumbria. In Wales Group A is used by Blaen-Plwyf and in Cornwall Group A is used by Caradon Hill. The historical commitment of RTE to VHF meant the British were able to scoop the Group A frequencies in bilateral negotiations with Ireland although Group A is in use at Three Rock and Holywell Hill. DTT is more efficient than analogue TV (particularly DVB-T2) in spectrum use but it inherits analogue interlocking relationships. The 800 Mhz band (Ch 62-69) is being cleared EU wide to make way for mobile broadband. This means channel changes in the DTT era are coming at Three Rock, Kippure, Maghera and Limavady in N Ireland so many of these frequencies will be altered. Because DTT has different interference properties it is possible for adjoining stations to have similar allocations eg Preseli COM muxes and 3 of the possible 8 Mount Leinster allotments. It does however mean that without very good shielding the distant station is unwatchable. The retention of VHF by RTE for so long probably has disadvantaged them now. The experience of VHF DTT in the US with a different ATSC system has been disastrous where broadcasters are now clamouring for good UHF channels instead.

reslfj

The Cush wrote: »

The EBU is there to represent its members, broadcasters from all over Europe. They are amongst other things a political lobby group within the EU, so when valuable broadcast spectrum is siphoned off for other uses they will react politically.

And I will call their bluff. Using old data in articles is sloppy work by any standard.

The GSMA, a lobby group for the mobile industry would like to see a further 40 MHz of UHF spectrum co-allocated to the Digital Dvidend (750-862 MHz), over 25% of UHF spectrum. When you consider some countries will not use VHF spectrum for DTT this is a sizeable chunk of broadcast spectrum to lose.

I do not support any industry or lobby group. But the 'all or nothing' spectrum policy of EBU and its members could very easily have resulted in 'nothing'.

VHF band III has been allocated to DTT in ITU region 1. You cannot argue that not enough spectrum is available, when the reason is nothing but your own unwillingness to use some of the spectrum.
In Ireland it is most likely that two VHF SFN muxes can be allocated.

Of course EU countries do not have to allocate this spectrum to any other use other than broadcasting as it has been allocated on a co-primary basis.

The WRC is NOT the EU but ITU. In this case it also involves CEPT - 48 countries in Europe - EU members and non EU members (like Russia).

Lars

Presently Administrations from the following 48 countries are members of CEPT:
Albania, Andorra, Austria, Azerbaijan, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Moldova, Monaco, Montenegro, Netherlands, Norway, Poland, Portugal, Romania, Russian Federation, San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, The former Yugoslav Republic of Macedonia, Turkey, Ukraine, United Kingdom and Vatican.

The Cush

Sam Russell wrote: »

That is as it may be, but when you look at it, why are the channels allocated the way they are.

Where possible DTT frequencies are allocated in the same aerial group as the analogue channels from that transmitter so that consumers would not require an extra aerial or wideband aerial upgrade during the transition from analogue to digital. At the moment 11 of the 13 DTT upgraded transmitters will use the same UHF aerial for both digital and analogue, Mt. Leinster (Gp. A & and Spur Hill (Gp. C/D & E) are the exception.

Sam Russell wrote: »

Now the EU want the band from ch61 up depopulated. That is 11 of the channels currently being readied. Who planned this? Why so much co-channel problems with overspill?

The Digital Dividend sub-band (Ch. 61-69) was co-allocated to mobile services at ITU WRC-07, as I posted earlier countries can continue to use this band for broadcasting.
There isn't enough frequencies available to avoid interference with other transmitter allocations. In Ireland up to 8 frequencies are allocated at each transmitter (4 analogue/4 digital), in the UK up to 11 frequencies can be allocated (5 analogue/6 digital), add to that the numbers of transmitters on the east coast, transmitters in Wales/England/IoM and N Ireland, coordination can be extremely difficult. Coordination is carried out by ComReg, Ofcom, RTE NL and Arqiva.

reslfj

mrdtv wrote: »

The 800 Mhz band (Ch 62-69) is being cleared EU wide to make way for mobile broadband.

Ch 61-69.

The experience of VHF DTT in the US with a different ATSC system has been disastrous where broadcasters are now clamouring for good UHF channels instead.

ATSC is nothing like DVB-T2 (or even like DVB-T). In the US VHF band I is used - In Europe its the 4 time higher frequencies in VHF band III.

VHF DVB-T muxes were (are) working nicely in Germany. VHF band III will be used in Finland from sometime next year for two HDTV DVB-T2 muxes. VHF is courrently tested with DVB-T2 in Uppsala, Sweden.

Lars

Mike 1972

Surely one disavantage of putting DTT on VHF (Band 3) is that DAB/DAB+ is competing for the same frequencies ?

mrdtv

Mike 1972 wrote: »

Surely one disavantage of putting DTT on VHF (Band 3) is that DAB/DAB+ is competing for the same frequencies ?

Exactly. And who wants to go back to giant Band III aerials that come down in the storms? In the States they found out that UHF and VHF just didn't mix for DTT to their cost, and there are significantly worse interference issues. I think we can discount the use of VHF despite Lars theoretical observations which are impractical.

reslfj

mrdtv wrote: »

Exactly. And who wants to go back to giant Band III aerials that come down in the storms?

First
In Ireland (more than) enough UHF spectrum is available for DTT - with or without channel 61-69 - but without analogue.

Second
Band III aerials are not giants. And in Berlin channel 5 and 7 are used for 2 DVB-T muxes:
http://www.mabb.de/digitale-welt/dvb-t/programme.html

A very practical use of the 'my' theory.


Lars

PS! Until DAB was stopped in Germany 4-6 month ago, the DTT VHF mux was to be converted into 4 extra DAB muxes.

The Cush

reslfj wrote: »

In Ireland it is most likely that two VHF SFN muxes can be allocated.

Mike 1972 wrote: »

Surely one disavantage of putting DTT on VHF (Band 3) is that DAB/DAB+ is competing for the same frequencies ?

Ireland's current RRC-06 allocation in the VHF Band - 1 x 7 MHz (DVB-T), 3 x 1.75 MHz (DAB).
From ComReg early 2008

The band 174 – 230 MHz (VHF band III)

Currently, this band is being used for analogue broadcasting as established under a 1961 Regional Agreement (known as Stockholm 1961 or the ST61 Agreement) is based on a fixed channel arrangement of 8 MHz for analogue television. As the Stockholm 1961 Agreement was revised to accommodate the new GE06 Agreement, analogue TV broadcasting in this band is protected until June 2015. As a consequence, this band can now be used for a fixed channel arrangement of 7 MHz bandwidth for digital television and 1.75 MHz for digital sound broadcasting (TDAB), in the absence of analogue television.

The GE-06 Agreement provides each country with a similar amount of spectrum on the basis of frequency allotments and/or assignments, serving different geographical areas, which may be combined to provide layers of national coverage. Ireland’s share is 1 national digital TV layer and three national digital sound layers (each layer is comprised of 1.75 MHz). In order to maintain flexibility to respond to market requirements for TV or sound broadcasting, Ireland has planned for portable indoor reception for both TV and sound broadcasting.

Later in 2008 they said the following in reply to an ECO questionnaire

Currently, Band III in Ireland is used for the transmission of analogue television. Two of Ireland’s public service broadcasting services, RTÉ One and RTÉ Two, use Band III to transmit from twelve sites across Ireland, ranging in power from 32 dBW in excess of 50 dBW. It should be noted that RTÉ One and RTÉ Two transmit on a hybrid network of Band III and UHF Band IV/V and V. It is intended that Band III will not be used as part of Irelands National DTT service, which is due to launch late 2009. Digital Sound Broadcasting Services, e.g. T-DAB, will use Band III. Testing of T-DAB technology in the Irish market has been ongoing in 2007 and 2008. RTÉ has begun a T-DAB service in Band III at the end of 2008 in the North East of the country and in some of the major cities

mrdtv wrote: »

Exactly. And who wants to go back to giant Band III aerials that come down in the storms? ...

I think we can discount the use of VHF despite Lars theoretical observations which are impractical.

I don't think we can discount it, with both Sweden (1 mux DVB-T/MPEG4) and Finland (2 mux DVB-T2) allocating it for HD DTT, in Italy and Germany (will eventually move to UHF) for regular DVB-T. The Ukraine, Hungary, Latvia, Lithuania and Romania plan to use Band III for DTT after ASO, others such as Belgium, Czech Rep, Portugal have not ruled it out.

My LP7 VHF aerial is not that large, no larger than some high gain UHF aerials, you may be mistaking them for Band I aerials, every household receiving RTE1/2 from the five high power VHF transmitters already has a VHF aerial installed.

Countries throughout Europe may decide to use the VHF band for DTT if they regulate for the Digital Dividend in the 790-862 MHz sub-band, which is what happened in Sweden (6 UHF mux, 1 VHF HD mux).

reslfj wrote: »

The Cush wrote: »

Of course EU countries do not have to allocate this spectrum to any other use other than broadcasting as it has been allocated on a co-primary basis.

The WRC is NOT the EU but ITU. In this case it also involves CEPT - 48 countries in Europe - EU members and non EU members (like Russia).

I agree with your statement 100%, but only the EU issue legally binding regulations to its 27 members through Treaties, regulations, directives, decisions, recommendations and opinions.
CEPT Decisions and Recommendations cannot be enforced by law. (A similar situation existed in the European aviation area the non-statutory Europe-wide JAR organisation (a la carte regulation) was replaced within the EU by the statutory EASA so that aviation regulations could be legally binding on its members).

In the case of the Digital Dividend sub-band the EU has stated as follows

The Commission intends to submit to the Radio Spectrum Committee (RSC) pursuant to the
Radio Spectrum Decision a draft EC decision on the technical harmonisation of the 790-862
MHz sub-band for regulatory opinion by the end of 2009. The decision would not oblige a
Member State to open the sub-band for new uses other than broadcasting uses, but if and
when a Member State so decides, it would then have to follow the common technical
parameters.