Why there will never be another GSM
Ofcom squares up to EU over spectrum carve-up
Comment Ofcom is changing the way spectrum is licensed in the UK to remove usage restrictions, but the EU is calling for region-wide harmonisation of use to create economies of scale.
These diverse approaches are going to lead to an unavoidable clash of ideologies that could mean the success of GSM is never repeated.
Great chunks of spectrum are becoming available around the world with the switch off of analogue TV, and traditional licensing mechanisms are increasingly being seen as limiting innovation while protecting incumbents and preventing proper competition. But usage-specific licences are an easy way of minimising interference and ensuring equipment compatibility.
When broadcast radio started in the UK in 1922, it took five months for the 18 companies involved to come up with a proposal for a national broadcaster to manage transmissions, and to decide that both receivers and transmitters would need to be licensed.
Back then, the choice of frequency was just a matter of picking one which offered the greatest range and was able to carry an audio signal. Any potential interference was addressed by switching off transmissions every seven minutes and listening for complaints coming in on the same frequency.
A general rule is that the higher the frequency the greater the data that can be carried, but the shorter the range and the greater the power needed for transmission. So audio broadcasting was quick to grab Medium Wave, around 530 kilohertz to 1.6MHz, allowing the BBC to reach half the UK population with only eight transmitters at limited quality.
TV needs a lot more bandwidth, but still wanted decent range so broadcast TV grabbed the next available chunk, from 474MHz up to 850MHz, leaving later applications such as mobile telephony to camp in higher frequencies starting around 900MHz.
When spectrum was simply being allocated, without charge, governments generally grabbed all they could for their own use. In the UK that amounts to over half of the spectrum below 15GHz, mostly (75 per cent) used by the military, while 12 per cent goes to civil aviation and five per cent to the emergency services. The rest is split between maritime and scientific uses.
Not only is Ofcom planning to auction off great chunks of the spectrum currently used by analogue TV, but it's also set its sights on that 50 per cent owned by the various government agencies, including the military, arguing that such agencies should pay market prices for spectrum or be forced to sell it off to ensure greater utilisation.
Those who buy spectrum in the upcoming auctions won't have to hand them back after a limited time period. These will be perpetual licences which can be sold on or sub-let to other users. And those users won't be limited to a specific technology. They'll be able to deploy whatever they like as long as they don't generate too much interference for their neighbours.
The success of GSM can be attributed to the way a particular technology was mandated, along with the frequencies at which it operated; initially 900MHz, allowing mass production of equipment which drove down the cost of handsets as well as network infrastructure. The use of the same technical standard on neighbouring frequencies (licensed by different operators) also reduces the chance of interference, as the standard incorporates limits on broadcast power as well as interference-avoidance techniques, making life much easier for the regulator.