The UK’s first 4G service has just gone live with others set to follow next spring, but some people are asking whether anyone really needs faster 4G speeds yet.
In addition, the amount of spectrum that can be used for mobile services is more than doubling with the 4G spectrum auctions that have or will soon take place in Europe. So the future’s bright … our mobile and wireless networks should have the capacity to meet the future demands of consumers and businesses for using our smart phones and wireless broadband services?
However, the amount of data we consume through our mobile devices has been growing frenetically and many expect that growth to continue, particularly as smart phones and tablets become more widespread.
The chart below shows a series of market forecasts that vary widely but all show rapid growth – the Mid forecast shows roughly a 100 times increase in demand for mobile data over the next 10 years. NOTE – it’s plotted on a logarithmic scale which gives a compressed view of how fast demand for data is predicted to increase. Going up one notch on the vertical axis represents an ten-fold increase in demand (not a doubling). So is there perhaps a question to answer despite the imminent arrival of 4G and so much new spectrum. And what could we do if there were a risk of a mobile network capacity crunch in the future?
Source: Real Wireless
Does or can government help industry meet soaring demand?
One reason to consider this now is because, if we do need to bring more spectrum on stream in the future, the process is cumbersome to say the least – potentially years of international negotiations and heaps of technical work. In order to get more spectrum in 10 years’ time, we might need to set the wheels in motion quite soon.
The key things to consider are:
- how fast demand for mobile data may grow in the future, taking into account that some of the demand might be carried over Wi-Fi or indoor small cells (i.e. a mini femtocell or picocell base station inside a home or office)
- what spectrum may be available for mobile in the future – it also makes a difference whether other countries are considering doing the same thing
- potential future developments in technologies which could improve mobile network capacity.
My associates, Real Wireless, experts in mobile technologies mapped out the potential future technology enhancements that could increase the capacity of mobile networks in a study for Ofcom. Generally we can identify quite a few techniques now which could be introduced over the next 10 years (despite the uncertainty inherent in technology forecasts):
- deploying more infrastructure – either outdoor small cells (micro / picocells) or full scale base stations (macrocells)
- improvements to 4G technologies e.g. LTE Advanced should enable mobile networks to use spectrum more efficiently and flexibly and increase the top speeds mobile networks can deliver
- techniques to use mobile frequencies more efficiently – e.g. increased sectorisation and use of multiple antenna technologies (MIMO)
- distributed processing and sharing of traffic loads across multiple cell-sites – e.g. Coordinated multi-point and Cloud RAN.
Real Wireless worked out a number of plausible combinations of these techniques and looked at how much additional spectrum Ofcom is currently predicted to make available for mobile use over the next 20 years – up to 350MHz (which compares well to the 200MHz of 4G spectrum currently being released in Europe). This enabled them to make a good forecast (using information on real geographic areas) of how mobile network capacity is likely to increase in the future.
This allowed mobile data demand to be matched against mobile network capacity (once the fluctuations of mobile data demand during the day were taken into account to get a measure of the peak demand).
Spectrum currently earmarked for mobile could be exhausted in just over a decade
The result is that that there may well be a network capacity crunch, in as little as 10 to 12 years’ time in some areas, even given the likely technological improvements and increased spectrum we currently expect to come on stream.
By capacity crunch we mean that the mobile operators will have exhausted all the techniques for increasing capacity we can currently forecast, and the only way to increase capacity would be a significant expansion in base station sites. This would not only be costly, but physical and planning limitation could mean that a major expansion was unlikely to be feasible, particularly in urban areas.
The result was derived by evaluating the costs of the alternatives for increasing mobile network capacity, i.e. using more of the spectrum available for mobile vs. new technologies vs. deploying more base stations. The most cost effective way to increase capacity to meet demand was calculated on a rolling 2-3 year basis. The result is shown in the graph below.
Source: Real Wireless
What could be done to provide more capacity?
The option that is most in the control of governments and regulators is to try to allocate more spectrum for mobile. It’s likely that any suitable candidates are already being used for something else, hence there would be a cost to society in switching over such spectrum to mobile.
The 700MHz band is one possibility. Although currently used for terrestrial TV broadcasting, moves are afoot in Europe and in other regions to consider possible future mobile use. The 700MHz band is attractive because it may gain broad international support. This would make it more likely that leading handsets would work on it. Also, its physical characteristics mean that it can provide more reliable coverage, and hence capacity, compared to the majority of existing mobile spectrum.
700MHz could alleviate the potential capacity crunch
Our research shows that mobile operators could save substantial sums of money by deploying 700MHz spectrum at the key point in the future, instead of deploying more base stations. Consumers should benefit as well through lower prices and more consistent service quality.
However the timing of when 700MHz is available is important, particularly the closer we are to the worst case scenario of when mobile broadband demand is high and the government cannot release as much spectrum for mobile as it currently expects over the next 10 years.
If 700MHz spectrum were available in 2020, the benefits for mobile operators (and consumers) would be much greater than if it were only available when current 700MHz licences expire in 2026.
If 700MHz is not available until 2026, mobile operators would have to start deploying new base station sites when the capacity crunch hit in 2022 to 2024. Deploying new sites would lock the operators into a certain course of action (to exploit the new sites to the full). The potential cost savings from using 700MHz would be much lower than if 700MHz had been available before the new sites were deployed. In other words, there is a risk that the industry could get locked into the wrong technology path.
Despite the exciting changes that 4G is likely to make to our smartphone and tablet experiences, regulators and mobile operators have to keep an eye on the future needs of the mobile networks. Our technological inventiveness may not be enough to avoid a capacity crunch 10 years down the line, hence the mobile sector is likely to need even more spectrum, preferably harmonised on a European or wider basis.
The 700MHz spectrum is potentially a good prospect, but the cost savings it could bring need to be offset against the costs of clearing out the existing broadcasting users.
Full details of the work, including an illustrative video, download of the full report and a link to Ofcom’s use of analysis in their UHF strategy consultation are available at: