12 May 2011
New Ofcom research reveals that the next generation of mobile technology will deliver more than 200% of the capacity of existing 3G technologies, using the same amount of spectrum - the airwaves that carry information between customers' mobile handsets and the internet.
This increased capacity is essential in meeting the UK's rapid increase in mobile traffic, fuelled by the growth of smartphones and mobile broadband data services such as video streaming, email, messenger services, mapping services and social networking.
4G mobile technologies will be rolled out in the UK from 2013 and are set to deliver significantly faster mobile broadband services - approaching today's ADSL home broadband speeds.
This will be achieved in part thanks to 4G using spectrum more efficiently.
Dr Stephen Unger, Chief Technology Officer at Ofcom said: "4G mobile technologies will be able to send more information than 3G, for a given amount of spectrum. This increased efficiency means that 4G networks will be able to support increased data rates and more users.
"The research that we commissioned indicates that early 4G mobile networks with standard configurations will be 3.3 times (230%) more spectrally efficient than today's standard 3G networks. To put this in context, a user on an early 4G network will be able to download a video in around a third of the time it takes today on a 3G network. It is anticipated that this efficiency will increase to approximately 5.5 times (450%) by 2020."
The research was conducted to understand the likely spectrum efficiency improvements that will be gained from 4G technologies, based on a review and analysis of both existing theoretical predictions and real-world trials in realistic deployments. This information provides a vital input into Ofcom's strategic spectrum management work.
The research looked at a number of 4G technologies including Long Term Evolution (LTE) and later generations of LTE, which are still in development, such as LTE Advanced. It also considered emerging and later generations of WiMAX - a wireless technology, similar to Wi-Fi, but with a longer range which can cover many kilometres.
The research revealed that the capacity gain from the increased spectral efficiency of 4G technologies will not on its own be sufficient to meet the expected growth in demand for mobile data. As well as using existing spectrum more efficiently, more spectrum itself is also needed, some of which will be gained from the auction of new spectrum at 800 MHz and 2.6 GHz in 2012 - the largest ever single auction of additional spectrum for mobile services in the UK, equivalent to three quarters of the mobile spectrum in use today.
Finally, mobile networks will also need to be designed intelligently to ensure the best use of spectrum. In particular, the research anticipates a greater use of small cells to meet demand in specific areas.
The research is available here: http://stakeholders.ofcom.org.uk/market-data-research/technology-research/2011/4G-Capacity-Gains/
 Alternatively, an early 4G network will be able to support more than three times the number of users for a given data rate compared to current 3G networks.