There has been an intensifying battle for spectrum between the broadcasters and cellular industries ever since the advent of the mobile Internet around the mid-noughties. At first there was some consensus between the two camps, since the migration from analogue to digital terrestrial services allowed the same number of channels to be transmitted within a smaller spectral band, yielding the so called digital dividend. But since then the number of TV channels has proliferated which, combined with higher resolutions and now impending Ultra HD services, has put pressure back on terrestrial bandwidth. Now both terrestrial broadcast and mobile services are both generating increasing amount of data which in each case can only be partially mitigated through improvements in compression and spectral efficiency. This has increased tension between the two sectors, particularly in the radio spectrum region that includes Europe.

The ITU (International Telecommunications Union) divides the world into three regions for allocation of spectrum, defined as far as possible to avoid adjacent countries belonging to different zones which could cause interference issues. Region 1 comprises all of Europe, Africa and the Middle East, plus Russia including the part in Asia. Region 2 is all of the Americas and Greenland, while region 3 is all of Asia apart from Russia and all Pacific countries including Australia. The greatest conflict has occurred in region 1 because of disagreement over spectrum allocation between Europe and some of the African as well as Middle Eastern countries. Essentially Europe, with strong backing from the EBU, wants to retain as much spectrum as possible for DTT, while other countries without much terrestrial infrastructure want to reallocate spectrum to mobile services. The conflict flared up particularly during the last WRC conference early in January 2012, when without apparent warning a group of African and Middle Eastern countries effectively staged a coup by pushing for the 700 MHz band (694-790 MHz) to be allocated to mobile. The Europeans managed to buy a little time and also retain shared use of that band, but the WRC-12 conference still decided to allow mobile use on a co-primary basis after this year’s WRC2015 conference. This is in addition to the previously agreed “digital dividend” in the 800 MHz band (790-862 MHz), which had been allocated to mobile services after the earlier WRC2007 conference.

The EBU now wants to shore up the remaining spectrum below 694 MHz and establish adequate regulatory measures to protect against further cellular invasion. "In order to free-up the 700 MHz band, broadcasters and broadcast network operators will have to make substantial investments,” said Simon Fell, Director of Technology & Innovation, referring to the cost of switching to lower frequency transmission. “These investments will only be made if there is certainty that the spectrum below 694 MHz will remain available for DTT for the foreseeable future. This would also enable the broadcast industry to innovate with new technologies and services,” Fell added, citing the generalization of HDTV and introduction of UHDTV as examples.

There is much at stake here for both camps. The UHF band (470-694 MHz) is the only spectrum for terrestrial television that remains globally harmonized. There is growing enthusiasm for unifying all spectrum allocation and also converging to common standards for DTT, which would increase scale economies and avoid duplication of effort. The question then would be whether the UHF band is retained wholly for broadcasting or perhaps shared with mobile services. Cellular operators are keen to get their hands on some of this spectrum not just for the extra capacity this would give, but also because signals at these lower frequencies have higher range, which is particularly valuable in rural locations where cells can be bigger since the subscriber density is lower.

For such reasons co-primary allocation of the sub 694 MHz band so that it is shared between mobile services and broadcasting has been suggested as a possible compromise that may be raised at the forthcoming WRC2015 meeting. But the EBU has pointed out this may not work so well in practice because neighboring countries might then use the band differently, causing problems with cross-border interference. Equally, while demand for mobile spectrum is undoubtedly growing, there are wide disagreements among analysts over future trends.

The EBU therefore argues that there it is premature to reallocate more radio capacity at present, given that in the longer term it is not clear what the preferred configuration of mobile spectrum will be. This points to preserving the status quo in the sub 694 MHz for the foreseeable future, but whether this is what will emerge from WRC2015 is far from certain. There are even calls for a far more radical shakeup of spectrum allocation to yield a more flexible configuration such that mobile and broadcasting can share the whole band, distributed according to demand. But this would require overcoming significant technical challenges to avoid cross border interference for example.