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'Every European Digital': The Challenge of Bridging the Broadband Gap � Brussels, 31 May 2011

Can spectrum provide the answer?

Presentation by Richard Womersley, Helios

We all know that spectrum is an increasingly 'hot' topic. It is a limited resource

facing rapidly growing demand. Over the past 20 year that I have been involved in

spectrum management, introducing new wireless services has gone from being a

technology first, spectrum second approach, to being a spectrum first, technology

second approach, recognising the higher value and importance of spectrum in

technology implementation.

The question I have been asked to address is "Can spectrum provide the answer?"

But in order to be able to decide whether spectrum can provide the answer, we

first need to know what the question is!

I think the question we are trying to answer is "Can spectrum be used to achieve

broadband for all using terrestrial wireless broadband networks?" Commissioner

Kroes said that opening up spectrum reduces the number of sites needed. This is

unquestionably true, but "Can spectrum provide the answer?" My answer is a firm

'no'.

Let me explain.

Wireless broadband networks, whether fixed or mobile, have to trade off three

economic and technical factors: low cost, high coverage and high capacity (that is

the ability to provide high speed connections to large numbers of users).

A network can achieve any two of these, but not all three. For example, it is

possible to have a network with high coverage at low cost but not one which also

provides high capacity. So a rural network providing connections for remote users

is possible at low cost, but it will not provide high speed connections to every user.

Equally it is possible to have a high capacity network at low cost, but it will not

cover large areas. Such a network might be found in a densely populated city

centre.

So these are the trade-offs that all operators have to juggle in order to deliver a

commercially viable service. But what are the challenges they face and what are

the tools they can used to deal with them?

According to various sources (such as the much cited Cisco white paper), demand

for data on wireless networks is approximately doubling every year. Some network

operators are already claiming that some of their 3G cells are at full to capacity at

the busiest times of the day. Others are already offloading data onto WiFi where

hotspots are available to reduce the load on their networks.

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Wireless network operators have therefore to decide how to tackle this increasing

demand, whilst at the same time trying to roll-out additional coverage to provide

broadband to new customers and to innovate in service provision in order to remain

competitive.

To grow their network, operators have access to three fundamental choices: Firstly

they can use more efficient technology, moving from 2G to 3G or 3G to 4G.

Secondly they could roll-out additional infrastructure using new sites to provide

more coverage or capacity. Or alternatively they could use more spectrum.

First let’s consider technology. A recent study for Ofcom has demonstrated that

the next generation mobile broadband technology (LTE) is just over 3 times more

spectrally efficient than current 3G (UMTS) networks. This represents just over 18

months growth based on current data traffic expectations. Does new technology

help solve the cost, capacity, coverage problem? Slightly. But to implement the

new technology on an existing site is costly, and whilst this might improve

capacity, it does little for coverage. Further, the costs of using new technology are

exacerbated by the need to replace user equipment as well as network

infrastructure. Thus there is a growth in capacity but a growth in cost and the

trade off between cost, coverage and capacity remains.

What about additional infrastructure? Any new sites will obviously incur new costs.

This is acutely the case for sites in remote areas where the economic and

environmental cost of developing sites, including supplying power and providing a

backhaul connection into the rest of the network, are particularly high. New sites

do provide additional coverage and can provide additional capacity but this comes

at a high cost and so does nothing make juggling cost, coverage and capacity any

easier.

And so to spectrum. Wireless operators in most European countries share around

500 MHz of spectrum between them. The digital dividend will add another 60 MHz

to this pot. This is 12% more, and would deal with about 6 weeks growth in data.

Even if the amount of spectrum available were doubled, a move which is being

proposed by several European regulators, this would only provide space for a 12

months growth in data. Worse still, to use spectrum in a new band requires new

infrastructure to be installed, and new user equipment, much the same as using a

new technology does, and thus the juggling act continues.

Let's re-cap:

• Any commercially viable terrestrial wireless broadband network has to trade

off high coverage and high capacity against low cost.

• Data is estimated to be doubling each year.

• New technology is approximately three times more efficient, accounting for

18 months growth of data, but this requires new (and expensive) re-fits of

sites.

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• The digital dividend will only provide spectrum to deal with 6 weeks growth

of data.

• Even doubling the current amount of spectrum only deals with 12 months

growth of data.

• Using new technology or new spectrum also requires new user equipment

and new network infrastructure.

To the question of "Can spectrum provide the answer?" the fundamental fact is that

there is simply not enough spectrum to deal with the growth in data. Nor will

technology offer a solution which deals with long-term growth. The only solution

for operators is to roll-out new sites both in inner cities and slowly pushing out into

more scarcely populated areas. And this is expensive to the extent that public

subsidy may be necessary to make such sites commercially viable.

This does not mean that objective to provide broadband for every European is not

feasible, nor that it requires public subsidy. We should not forget that there are

other technologies which are much better suited to providing cost-effective

broadband coverage, together with a host of other services, in remote areas, in

particular satellite. Satellite does not suffer the same coverage issues that

terrestrial networks do, one satellite could cover the whole of Europe, but still has

to trade off capacity and cost. What is therefore essential is the use of a mix of

technologies, with each playing to their strengths: Fibre in cities, terrestrial

wireless in the suburbs and satellite in rural areas.

If the question we are trying to answer is 'can spectrum be used to achieve

broadband for all using satellite broadband networks?' my answer would still remain

a 'no' for many of the same reasons I have already given. But as with terrestrial

networks, satellite spectrum (such as Ka-Band) remains an important input to

delivering commercially viable services.

Taking spectrum away from one broadband technology to give it to another (such

as is being proposed for the 3.4 to 3.8 GHz band) is like diverting water supplies

from agricultural to domestic or industrial use. It may provide short-term benefit,

but may have devastating long-term economic and environmental implications.

In conclusion, "Can spectrum provide the answer?" No. But as Commissioner Kroes

said, “we have to use all the tools available to us”, and I strongly agree. All

wireless technologies, whether terrestrial or satellite need sufficient, secure

access to spectrum to allow them to play their roles in achieving Europe's

broadband ambitions.

For more information, contact Richard Womersley

richard.womersley@askhelios.com

Tel: +44 1252 451 651

www.askhelios.com