Editorial: Can LTE Broadcast deliver TV/mobile convergence?

it is possible to support TV services with 84 MHz of spectrum via LTE […], in contrast to the 300 MHz used by today’s ATSC

Nothing generates grandiose, vague and meaningless statements like the discussion of convergence. So when a technology comes along which could actually implement this much-hyped phenomenon, it deserves serious attention. 

LTE has the capacity for one-to-many broadcasting as well as the traditional one-to-one communications we associate with mobile networks. Put crudely, the broadcast mode of LTE might be able to replace traditional terrestrial broadcasting. Would this work technically? We don’t know for sure. Would this move make commercial sense? Again we don’t know. How would merging networks affect national cultural policy? Now we’re really into the realms of speculation.

But it’s necessary because LTE Broadcast has taken something which has been theoretically possible for years and made it – not quite a commercial reality – but something manufacturers are taking very seriously. 

Ericsson sets out the case

An academic paper  by Ericsson scientists argues LTE Broadcast could be used to replace DTT transmissions to standard TVs, offering huge benefits in spectrum efficiency. Their proposal takes the example of the US and says that if cellular towers are reused to create a single frequency network “it is possible to support TV services with 84 MHz of spectrum via LTE… in contrast to the 300 MHz used by today’s ATSC TV broadcast system.”

Ericsson sells LTE transmission equipment so of course it has a vested interest in promoting the technologies, but it is hugely significant that the company’s scientists are prepared to stake their reputation on LTE’s ability to replace existing terrestrial broadcast networks.

Never has there been such pressure for broadcasters to abandon traditional UHF broadcasting or to make greater room for mobile

Independent testing of these claims would be very valuable and let’s hope it will be one of the results to emerge from the European Commission’s recent Green Paper for the audio-visual sector. This asked what further research was needed to facilitate the sharing of frequencies between broadcasting and mobile. The possibilities of using DVB-T2 chips in handsets also deserves further investigation.

It is not just the development of LTE Broadcast which has made broadcast/mobile convergence a real world issue. Governments are desperate to find more spectrum for mobile to satisfy the growing demand for data. The US is trying to free up 500 MHz of spectrum for mobile, and a similar figure is in the European Commission’s sights. Terrestrial broadcasting uses hundreds of MHz in the prime UHF band, which makes it a key target.

Europe is on the verge of making the 700 MHz band not just a broadcasting band but a co-primary band for broadcasting and mobile. There is a Europe-wide consultation on this subject, France and Germany have already decided to do so and the UK is consulting on the same proposal. 

The attraction here is the global nature of mobile in 700 MHz, with few countries wanting to miss out on the possibility of super-cheap handsets generated by the economies of scale in the Asian market, which has already backed mobile in 700 MHz.

This opens up the possibility of doing a similar co-primary allocation for 600 MHz, making the whole UHF band (470 – 862 MHz) available for mobile use. This could be considered during the ITU’s 2015 World Radiocommunication Conference. In Europe the 800 MHz band is being released to mobile as part of digital switchover.

It is hard to see how a move to converged networks could benefit broadcasters commercially 

Never has there been such pressure for broadcasters to abandon traditional UHF broadcasting or to make greater room for mobile by sharing or becoming more efficient. At the very least terrestrial broadcasting is likely to be restricted to the 600 MHz band.
For some countries this would have a huge policy impact but in others the effect would be minimal. To take the European example, DTT is practically unused in Belgium, but vitally important in Spain, Italy and the UK. Some countries like Germany and the Netherlands could easily move to cable, satellite and/or IPTV, but some cannot without an expensive and disruptive re-organisation of their whole approach to TV.

Some countries may therefore conclude it is in their interests to allocate the whole UHF band to mobile, whereas other countries with high DTT penetration will most likely want to continue using at least some of the band for TV.

The fundamental issue is to ensure that frequency planning in UHF is co-ordinated regionally. Unless agreement can be reached between the relevant international stakeholders and ratified through the ITU, there is a real danger of broadcasting use in one country preventing the use of mobiles in its neighbour, and vice versa. 

Will the market provide?

In terms of fulfilling the high level policy goal of increasing spectrum efficiency and finding more bandwidth for mobile, convergence of broadcast and mobile networks could be very effective. The technical case may not be 100 per cent proven yet, but the potential is there and products are nearly ready. 

But will the market deliver of its own accord or is policy intervention needed? It is hard to see how a move to converged networks could benefit broadcasters commercially, although the opposite is true for mobile operators. Many broadcasters in developed countries already have working DTT networks, so why would they want to move to LTE Broadcast?

The situation may be different but in countries which haven’t yet started digital switchover. Why build two networks when broadcasting and mobile may be able to use the same one?

In the countries which have already deployed DTT, there are likely to be long-term commercial benefits for broadcasters in converging networks but are these may be too far in the future to change current behaviour.

Benefits for broadcasters

In most mature markets, online revenues are the fastest growing areas for broadcasters. These new sources of revenue are still minor compared to plain old advertising, but ensuring that content can be accessed on any device at any time requires costly investments. Overall, broadcasters’ moves into the online space have not always been profitable. Partnership with mobile operators offers the chance to deepen the customer relationship and generate greater online revenues. 

If broadcasters were allowed access to data from mobile networks under a cooperative arrangement this would provide the feedback link which is missing from standard TV and would be very valuable in developing advertising sales and planning programming.

Mobile perspective

…converging networks could increase spectrum efficiency, a goal which motivates governments but not usually individual organisations. 

For mobile operators the main advantage of converged networks would be increased access to spectrum. If the US example given by the Ericsson scientists is applicable throughout the world, over 200 MHz of prime UHF spectrum could be freed up for use by mobile.

The failure of mobile TV has taught us that there is little interest in watching traditional linear programming on mobile handsets, and even less appetite for paying for it. This means LTE’s ability to do one-to-many broadcasting is of little direct benefit to mobile operators themselves.

There are limited exceptions, such as the relaying of sports programming around stadiums, but the big issue for mobile operators is coping with the strain imposed by users streaming short bursts of video directly from the network. According to Cisco, video traffic accounted for more than 50 per cent of mobile data usage for the first time in 2012.

Research is underway to use LTE Broadcast to download a package of popular programmes onto handsets which users would be able to watch at leisure. But this is many years away, requiring the development of a new type of handset and currently the main advantage for mobile operators is the increased spectrum access which a converged network could provide. 

In the wider public policy sense converging broadcast and mobile networks could substantially increase spectrum efficiency, a goal which motivates governments but not usually individual organisations. 

This means there are powerful arguments for a government policy intervention. Broadcasters would get a push which would bring a long term advantage, wider public objectives would be served by improving spectrum efficiency and mobile operators would gain the access to extra spectrum which they have so long demanded.

Policy possibilities

What form could this policy intervention take? Step one is independent research into the possibilities of LTE Broadcast and the potential benefits are attractive enough to justify funding by regulators, governments or supra-national bodies like the EU or ITU. 
If LTE Broadcast gets this independent backing, step two would be encouraging broadcasters to merge their networks with mobile operators. What is an attaractive incentive is likely to vary enormously from country to country, and setting out every possibility is beyond the scope of this article.

One alternative which could be adapted for other countries is the incentive auctions due to take place in the US next year. These allow broadcasters to set a price at which they would be prepared to give up their spectrum while mobile operators can put in bids to take it over. 

Another approach in countries which want to continue the tradition of terrestrial TV is to use the state’s perogative to reclaim broadcasters’ spectrum and auction this to mobile operators with the condition that they have to take on television’s universal service obligation. There will clearly be a need to compensate broadcasters for the money spent on DTT neworks but this could be far less than the amount mobile operators would be prepared to pay for the spectrum. Incentivising consumers to put up with the disruption is another issue that needs to be addressed.

Considering the mobile companies’ long term need for more spectrum and the economic development this is likely to generate, the pressure on broadcast spectrum is unlikely to go away. Network convergence is an appealing solution which can meet many objectives for government, broadcasters and the mobile community. The process of finding creative policy solutions which can satisfy all the stakeholders’ needs to start as soon as possible.•