Wireless Waffle - A whole spectrum of radio related rubbish
What A Waste Of (White) Space!signal strength
Friday 17 October, 2014, 09:14 - Broadcasting, Spectrum Management
Posted by Administrator
There can be no doubt that there is increasing pressure to find radio spectrum for a growing number of applications and uses. At the same time, there is a diminishing amount of spectrum that can be relatively easily re-purposed. It is against this backdrop that various organisations are seeking to find new ways to access the spectrum for new services without unduly upsetting the existing ones. One of these methods is the use of what has been termed 'white-space' spectrum.

So called white-space is comprised of the little 'off-cuts' that are left lying around after big holes have been punched into the radio spectrum by existing users. television white spaceFor example, high powered television transmitters punch great big holes into the spectrum, occupying big pieces of spectrum over very large areas. But the nature of such high powered broadcast services is that transmitters on the same frequency have to be separated by large physical distances so as to avoid neighbouring transmitters interfering with each other. At points roughly half-way between two such transmitters, neither transmitter will provide a signal that is strong enough to deliver a useful service, but the frequency can not be re-used for more broadcasting as doing so would cause interference to viewers in the coverage area of the two transmitters. But a different service (in particular one with much lower power) could be squeezed in without causing such interference. These small off-cuts can, in theory, be sewn together to form a patchwork quilt of spectrum that might just be useable.

For many years, organisations including Google and Microsoft have poured large amounts of money into finding the right thread to stitch the pieces together to make a piece of spectrum big enough to be useful. Thousands of man-hours of research have been poured into radio spectrum white-space and millions of pounds of investment into technology and standards (including Huawei's recent purchase of white-space gurus Neul) have been made, but so far, other than a few technology trials, no 'killer app' for white-space has been found.

ofcom zoocam 1Kudos then, to Ofcom and Google, who have launched 'ZooCam' in which live pictures of animals at London Zoo are being transmitted from their cages directly to somewhere or other using white-space technology and then streamed onto the internet. When Wireless Waffle popped by to share in the excitement, the Otters were asleep, the Meercats were nowhere to be seen and the Galapagos Tortoise was moving so slowly that a daily photo update would have been just as informative as a live feed.

Philip Marnick, group director of Ofcom's Spectrum Policy Group is quoted as saying:
In a world where consumers' demand for data services¹ is experiencing huge growth, it is essential we find the most efficient ways to share the airwaves. White space technology could be one way of meeting this demand.

¹For 'data services' read 'pictures of furry animals on the internet' (which are known to account for over 85% of all internet traffic).

Might we be so bold as to suggest some other uses for this high-cost, leading-edge technology:wales download
  • 'BergCam' - participate in a thrilling, spill-a-minute live stream of global warming in action as the ice caps slowly melt.
  • 'DecorCam' - in which a group of decorators position a camera somewhere different each day after painting a wall so can you watch it dry.
  • 'HerbiCam' - a live-action feed from Lords Cricket ground focussing on a few blades of grass so that you can watch them grow.
  • 'CymruCam' - share the excitement as someone in rural Wales tries to perform Windows updates using their dial-up internet connection.
Whilst programme makers, machine-to-machine communication proponents, smart-everything activists and public safety organisations the world over are screaming for access to more spectrum, it is clear that Ofcom believe that there are far more economically valuable uses for this colourful patchwork of frequencies. Is it just us, or does this new initiative appear to be a complete waste of (white) space?
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PMSE Industry Calls For More Domed Citiessignal strength
Tuesday 9 September, 2014, 04:36 - Broadcasting, Spectrum Management
Posted by Administrator
european commission logoThe European Commission has finally made a ruling on harmonising spectrum for programme making and special events (PMSE) use. PMSE includes things such as radiomicrophones and in-ear monitors that allow performers to hear themselves think whilst on a noisy stage.

You would think that the PMSE community would be cock-a-hoop about the fact that their needs had been recognised at a European level and that spectrum had been safeguarded for their specific use, but it appears that many in the industry believe it is too little. A spokesperson for the Association of Learned Engineers of Sound (Asso.LES) told Wireless Waffle:
All video and audio broadcasts use wireless devices in their production. The paltry and squalid spectrum being offered by the Commission will cause many thousands of creative, cultural and media industry workers to suffer harmful interference leading to infection and death. Add to this the many churches, schools and hotels who use wireless microphones and this ruling could cause a catastrophic failure of society. We could see plagues, widespread rioting and a failure of social cohesion resulting in a cataclysmic new world-order, not to mention the need to put up new antennas in some theatres.

No one from the Commission was available to comment, however Jörg Van Beaulieu who has a name that sounds like they could work for the Commission, was heard to comment:
Asso.LES couldn't see a gift horse if it kicked them in the face. The Commission has done its calculations and as far as we can see, the only events that will require more spectrum than we are offering are the Eurovision Song Contest and one or two occasions when sporting events occur on the same date as One Direction concerts - interruptions to which we believe the socio-economic impact would be low.

eurovision logoThe impact on the Eurovision Song Contest will come as a blow to its millions of fans both in Europe and across the world. Next year's organisers, ORF have already been in crisis discussions with the Austrian government and the European Commission and have issued this statement:
On advice of the Bundesministerium für Verkehr, Innvation und Technologie (BMVIT) we have decided to move the location of the competition next year from Vienna to Attnang-Puchheim. The town's railway marshalling yard will be flattened and a metal cage will be erected around the area to seal in the radio spectrum so it can be used for the Contest. We are sure that this will allow this critical European cultural event to go ahead without problems of interference from mobile phones or potentially dangerous inter-galactic laser beam weapons.

dome home cone

Meanwhile it is understood that the Council of Westminster are considering similarly drastic steps and that plans to demolish the majority of the West End to allow a protective metal dome to be built around London's infamous theatre district are well developed. The spokesperson for Asso.LES said that this move was welcome and rightly recognised the economic importance of radio microphone users above all other members of society.
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Is it time for a 'Digital Switch-Off'?signal strength
Wednesday 21 May, 2014, 20:02 - Broadcasting, Spectrum Management
Posted by Administrator
poor cousinIt could be argued that before the switch-over from analogue to digital television broadcasting, the value of terrestrial broadcasting was on the decline. Faced with fierce competition from cable and satellite, each offering 10 or more times the number of programmes, terrestrial television was a poor cousin whose main use was often to deliver public service broadcasting and, through general interest obligations imposed by national governments, to provide an accessible (free-to-air) service to 95% or more of a country's population (measured both geographically and demographically).

As digital switch-over has taken hold, terrestrial broadcasting has had a repreive and is now able to offer true multi-channel television. Where previously it was only possible to broadcast a single television station on a single frequency, that frequency can now hold 10 or more standard definition (SD) channels, or 4 or 5 HD channels. Where there may have been 6 analogue stations on air, there can now be upwards of 60 stations. In many cases, 60 stations is enough for the average viewer and the bouquets of channels offered on cable or satellite may now begin to seem expensive compared to free-to-air DTT. In many countries the draw of cable and satellite TV is no longer the sheer variety of channels available, but the premium content that is on offer. Pay-TV services offering sport and movies continue to be popular, but such premium content is not usually available on DTT. Nonetheless, for many viewers DTT is perfectly sufficient.

biting at the heelsBut just as digital terrestrial TV (DTT) has had a new lease of life, the other broadcasting platforms are once again biting at its heels with new service offerings. Whilst 3D television seems to have taken a back seat for the time being, new, even higher definition television, is stepping to the fore. Ultra-High Definition (UHD) has twice the resolution of standard HD and large UHD televisions are already on show and on sale in many retailers. At present there is minimal UHD content, however a hand full of new UHD channels are being launched and, for example, the World Cup football in Brazil will be broadcast in UHD.

To be able to see the difference that UHD makes compared to standard HD, a very large television set is needed (42 inches or greater) and it could therefore be argued that UHD will always be a niche product. Then again, many broadcasters believed that HD would be a niche, but it is becoming the de facto standard and average television sizes are on the increase.

Technically speaking, UHD requires a bit-rate of around 20 Mbps. Whilst such bit rates are relatively easy for cable and satellite networks to deliver, broadcasting UHD over DTT would require at least half of a DVB-T2 multiplex, and the most advanced video (HEVC) codecs. In practice this means that were a terrestrial frequency currently carries 10 or more SD, or 4 or 5 HD channels, it might, at best, be able to offer 2 UHD channels.


uhd samsung tvBut that is not the end of the story. Just around the corner is super-high vision (SHV), sometimes called 8K, which once again doubles the resolution of the picture compared to UHV. SHV will require around 75 Mbps to be broadcast and at this point, whilst cable and satellite are still in the game, DTT is no longer able to broadcast even a single programme on a single frequency (without very complex transmitter and receiver arrangements that would require, for example, householders to install new, and potentially more than one, antenna). Of course to benefit from SHV, an even larger TV screen will be necessary, but with the growth in home cinema, it is can perhaps be expected that in time, a goodly proportion of homes will want access to material in this super high resolution.

So where does that leave DTT? Arguably, within a few years, it will once again be unable to compete with the sheer girth of the bandwidth pipe that will be provided by cable and satellite networks. It's probably worth noting at this point that most IP-based video services (with the possible exception of those delivered by fiber-to-the-home) will also be unable to deliver live SHV content. This time there will be no reprieve for DTT as it simply does not have the capacity to deliver these higher definition services.

What is therefore to be done with DTT? Is it necessary to provide continued public service, universal access, free-to-air services that were the drivers for the original terrestrial television networks? Is its role to provide increased local content which might be uneconomic to broadcast over wide areas? Should it be used to deliver broadcast content to mobile devices where it has more than sufficient capacity to provide the resolution needed for smaller screens? Or, should it be turned off completely, and the spectrum it occupies be given over to something or someone else?

In countries where cable and satellite penetration is already high, there is arguably nothing much to lose by switching DTT off. In Germany, for example, RTL have already withdrawn from the DTT platform and there is talk of turning off the service completely. In countries that have not yet made the switch-over, it might be more cost effective to make the digital switch-over one that migrates to satellite (and cable where available) than to invest in soon-to-be-obsolete DTT transmitters.

tv service goneBroadcasters should be largely agnostic to the closure of DTT. After all, their business is producing content and as long as it reaches the audiences, they ought not to care what the delivery mechanism is. Other radio spectrum users (e.g. mobile phones, governments) would surely welcome the additional spectrum that would become available. So who loses? Those companies who currently provide and operate the DTT transmitter networks, such as Arqiva in the UK, Teracom in Sweden and Digitenne in the Netherlands, who stand to lose multi-million pound (or Euro) contracts. For these organisations the stakes are high, but even the most humble economist would surely admit that the benefits elsewhere outweigh the costs. So let's turn off DTT - not necessarily today - but isn't it time to plan for a 'digital switch-off' to follow the 'digital switch-over'?
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90 years of the 'time pips'signal strength
Friday 7 February, 2014, 13:43 - Broadcasting, Licensed, Much Ado About Nothing
Posted by Administrator
What a disappointment it was to find a recording called 90 years of the time pips, to discover that it is a special version of the pips¹ designed to celebrate their 90th birthday.

Wouldn't it have been more fun to have calculated how many pips there have been in 90 years and then created audio that just pipped (or beeped continuously) through all 90 years? How many pips would that be?

90 years × 365.25 days × 24 hours = 788,940 hours²

The first 5 pips have a duration of a tenth of a second, and the final pip has a duration of half a second, so the total duration of the pips each hour is exactly 1 second (5 × 0.1 + 0.5). A constant tone of duration 788,940 seconds (which is 9 days, 3 hours and 9 minutes precisely) would therefore represent '90 years of the time pips' much more accurately.

So here for your listening pleasure, is the Wireless Waffle tribute to the pips... 90 years of pips compressed into 9 days, 3 hours and 9 minutes.

play 90 years of the pips
Just click the play button, sit back and enjoy!

gladys knight and the pips¹ Not to be confused with Gladys Knight's backing group who, whilst also played on the BBC from time-to-time, are not the pips in question here.

² Of course the pips have not been broadcast every hour over that period. Other time signals (such as the chimes of Big Ben) are used on some hours. Equally the BBC has not always been a 24 hour service, so this figure is probably a significant over-estimate.
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