Feeds

Tiny TV could make billions for FCC

It's a seasonal miracle

The Power of One eBook: Top reasons to choose HP BladeSystem

The CTIA and CES have produced a white paper outlining how to extract 180MHz of TV-broadcast spectrum without impacting TV quality or coverage, and it's worth reading.

The Cellular Telephone Industries Association (CTIA) and Consumer Electronics Association (CES) co-authored the paper (pdf) which proposes replacing centralised TV transmitters with a network of small, low power stations which would work with existing set-top boxes and free up between 100 and 180MHz of spectrum - spectrum which the CTIA's members would love to get their hands on.

Proposals from the CTIA often verge on the hysterical - such as predicting the downfall of American industry if more radio spectrum isn't allocated post haste. Even this one can't help pointing out that only ten per cent of Americans rely (exclusively) on broadcast TV. But after the usual rant, the document sets out a surprisingly reasonable plan for shrinking TV spectrum usage, though a few technical barriers do remain.

Broadcast TV is based around huge transmitters, normally atop massive towers, which pump out enormous signals that can be picked up 40 miles away. Frequencies can be reused, but only for transmitters at least 80 miles apart - actually much further due to variability in signal propagation. So in the USA there are around 1800 towers, which blanket the country with between 15 and 20 6MHz-wide channels (to carry one analogue channel or a digital multiplex) despite the fact that there are 49 slots available.

That disparity is down to the "near-far problem", whereby the strength of signal necessary to reach 40 miles or more, causes the channel to leak into neighbouring channels for users sitting beside the transmitter. That reduces the channels which can be used, and the CTIA reckons it's using a sledgehammer to crack a nut.

The new plan has lots of little transmitters, working on the same frequency to provide the same coverage and with synchronised transmissions. The significant problem here is "ghosting", whereby the TV receives the same signal twice with a tiny time delay between the two based on differing distances to the transmitters. Analogue TV has always had this problem, which literally results in a ghost image appearing slightly offset from the desired picture. But this is generally down to reflected signals bouncing off walls and suchlike, rather than picking up two signals at the same time.

The CTIA argues that modern set-top boxes are so armoured against receiving bounced ghost signals that they can cope with one coming from a different transmitter. Modern boxes accept the strongest signal and are capable of disregarding the others.

That assertion is the weak point, but if the CTIA has its sums right then there's little reason why the system wouldn't work. The group reckons it will cost less than $2bn to built the new transmitter network (based on 15-20 new transmitters for each one currently operating), while it estimates the value of the frequencies released at between $36bn and $65bn. We'd lean towards the lower estimate, but even if it's half that the plan makes economic sense.

Not that access to more spectrum is the only advantage CTIA members would see from the plan. All those new transmitters will need homes, and could easily be bolted onto cellular towers - reducing costs if not providing revenue for the operator. Let's also not forget that that plan would substantially reduce the available White Space which can be used without paying network operators a penny - so it's good news all round.

The technical issues around ghosting need examination, but this proposal certainly merits more attention and not just in America - the same model could equally well apply in the rest of the world too. ®

Maximizing your infrastructure through virtualization

More from The Register

next story
Auntie remains MYSTIFIED by that weekend BBC iPlayer and website outage
Still doing 'forensics' on the caching layer – Beeb digi wonk
Apple orders huge MOUNTAIN of 80 MILLION 'Air' iPhone 6s
Bigger, harder trouser bulges foretold for fanbois
GoTenna: How does this 'magic' work?
An ideal product if you believe the Earth is flat
Telstra to KILL 2G network by end of 2016
GSM now stands for Grave-Seeking-Mobile network
Seeking LTE expert to insert small cells into BT customers' places
Is this the first step to a FON-a-like 4G network?
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
BlackBerry: Toss the server, mate... BES is in the CLOUD now
BlackBerry Enterprise Services takes aim at SMEs - but there's a catch
Bring back error correction, say Danish 'net boffins
We don't need no steenkin' TCP/IP retransmission and the congestion it causes
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.