Director of RAN development & programmes, EE, UK: “VoLTE cost efficiency has yet to be proven; 3G voice calls are already highly cost efficient”

Mansoor Hanif, Director of RAN development & programmes, EE, UK is speaking in a panel discussion on the evolution of voice services on Day One of the inaugural LTE Voice Summit, taking place on October 1st-2nd at the Hilton Paddington, London. Ahead of the conference we find out more about the recent advances EE has made to its network and find out more about the challenges that implementing VoLTE will bring.

EE has recently moved to offer ‘double speed’. Can you explain technically exactly what you did and what the challenges were?

From launch until June of this year our 4G network was running on 2x10MHz of 1800MHz spectrum. Technically this allows a maximum speed of around 70Mbps per second. Since June we’ve doubled the spectrum used for 4G to 2x20MHz, increasing the maximum theoretical download speed to 150Mbps in 20 of the largest cities across the country. The maximum upload speed was also increased to around 45Mbps. In real-world usage, this translates to average user download speeds of 24-30Mbps, and upload speeds often in excess of 20Mbps.

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This project ran for around six months and involved the efforts of hundreds of our best engineers, project managers and key partners. We had to retune the 2G frequencies to free up the extra 2x10MHz for 4G. This is very tricky to do in a live network without impacting the 2G quality and this was done city-by-city, step-by-step. We applied some parameter settings to shift more traffic to 3G and were able to maintain our network quality, with ample spectrum for our current 2G traffic levels. A lot of testing and optimisation was required on the 4G network to ensure that the boundaries between the “double-speed” areas and the remaining 2x10MHz areas were seamless in terms of user mobility.

This work on the radio network was also accompanied by a massive campaign of transmission capacity upgrades to support these double speeds: this involved hundreds of Microwave upgrades, and Gigabit Ethernet installations. This was a big engineering challenge, and one that the whole team embraced.

The inaugural LTE Voice Summit is taking place on October 1st-2nd at the Hilton Paddington, London. Click here NOW to download a brochure.

You’ve acquired 2 x 5MHz 800MHz spectrum as well in the recent auction. Will this be a national overlay of 1800MHz or only used in certain areas?

We don’t expect to rollout 800MHz everywhere: it is most useful in rural areas to increase our reach into remote spots, and we may also use it in a small number of urban areas to provide extra indoor penetration.

What are the challenges of implementing VoLTE on your network?

We believe that ensuring excellent quality in mobility will be the biggest challenge, especially between different frequency bands – we are pushing our suppliers for intelligent features to help us control this in an efficient way. Battery life will also be a challenge to optimise, and that is something that the ecosystem is working on, and we’re a part of that.

Who will gain most from the transition from CSFB to IMS and VoLTE? Will it offer benefits for users or is it more about lowering the cost per bit?

Hopefully there should be benefit both in terms of user experience and cost-efficiency. However, CSFB when properly optimised has proven to work very well: in independent benchmarks, including those published by RootMetrics for the UK, our CSFB voice has been shown to perform as well as or better than 3G voice, and time lag for call setup is minimal. VoLTE, once fully mature, can offer higher quality audio and extremely fast call setup.

From the network point of view, the simplicity of managing voice and data on a single technology will be appreciated. The cost efficiency has yet to be proven; 3G voice calls are already highly cost efficient and we have yet to see a comprehensive end-to-end cost analysis of a VoLTE call – I hope that this is something I may learn more on at the summit!

To what extent is how VoLTE has been implemented in South Korea an influence on your plans?

We watch closely the development of 4G around the world and South Korea is a tremendously exciting testing ground for VoLTE, and other advanced technologies. We are always interested in sharing experiences with our Korean colleagues – I am pleased that they will be in attendance at the VoLTE summit in London.

Do you have plans to use small cells as fill in coverage?

We will look at all options for infill coverage – we have a very extensive macrocell network which offers excellent indoor and outdoor coverage. There may be some areas where small cells may offer a good solution, and we hope to run some small-scale trials to assess the cost-benefit ratio of small cells later this year.