INSIGHT REPORT

Small cellS 2012 integration and optimisation

EUROPEMOBILE

REPORT SPONSOR REPORT CONTRIBUTORS

Richard Webb, Infonetics Research

Thomas Wehmeier, Informa Telecoms &Media

Keith Dyer, Mobile Europe

| mobile europe insight report

Keith Dyer: Parker, why do you think the

industry is seeing so much buzz around small

cells right now?

ParKer Moss: The chief reason is the

ramping demand for mobile broadband

capacity. We think 25 times growth in

demand in the next five years is a

conservative estimate in some dense urban

areas and operators all over the world are

faced with an unprecedented need to add

capacity to their networks.

There are only three ways to do that: add

more spectrum, improve the spectral

efficiency of the network, or reuse that

spectrum you have by sectorising the

network. The traditional way to do that is to

split the macro cell, but that's a very

expensive thing to do because macros cost a

lot of money, and sites and permissions are in

short supply.

That's why we think the way to further

densify 3G networks right now is with 3G

metrocells that sit underneath the metro

layer. In 4G lTe networks, metro cells will

bear the bulk of urban data capacity and

need to be built into HetNet coverage and

capacity site plan from the start. metrocells

are a lot less expensive and have a much

smaller footprint, waste less energy by

putting the antenna closer to the user, and

lead to increased spatial efficiency.

Keith Dyer: You mention demand growth

over the next five years. are solutions

available now in the metrocell environment?

ParKer Moss: We announced lightRadio in

February 2011at mobile World congress and

then demonstrated that concept with a live

metro network in Barcelona in 2012, using

the award winning lightRadio cube to

provide a very small, flexible and directional

antenna element for metro cells.. It enables

flexible deployment models with either a

local or remote baseband and is ideally

positioned to deliver very high capacity

with very high energy efficiency and a near

invisible footprint.

We expect metros to be all over the

urban landscape so we put a lot of efforts

into the aesthetics and into reliability: We

worked with Frog Design to get a great

looking metro, and our metro cells are

passively cooled, with no cooling fans,

which significantly improves reliability and

meantime between failure between devices.

Keith Dyer: What are the challenges of

moving to this dense, underlay, metrocell

network?

ParKer Moss: Our insight from trials and

deployments around the world is that the

real cost and complexity of metro is in the

operational layer. In fact we calculate that

80% of the cost and complexity of the

metro layer is unrelated to the radio.

Operators have to rethink the way that

networks are planned, deployed and

maintained in the metro cell world

because new considerations come into

play: access to backhaul and power, site

acquisition, and the deployment and

operation of a much larger number of

network elements than ever had to deal

with. allied to that are new regulatory and

municipal concerns.

Keith Dyer: Do you think operators are

ready to make that shift in planning,

deployment and operation?

ParKer Moss: I think that a lot of

operators have started thinking about

these challenges. The real complexity for

them is that metro cell deployment and

operation draws upon a very wide scope

of skill sets, and it is typically difficult for

an operator, or for a vendor that doesn't

have a full service capability, to optimise

all these new elements at the same time.

To make these decisions you have to

involve the backhaul, site acquisition,

field service and power teams and really

get them to think about the network in a

new way.

metro cells are driving operators to

rethink the orthodox view of network

planning where site locations are optimised

for best possible radio performance, and

instead take a more holistic view of RF,

power, backhaul and site availability.

The good news, that I can announce

exclusively to mobile europe, is that

alcatel-lucent is launching a turnkey

service to aid operators in the planning,

deployment and operation of metrocell

networks. That service leverages our

leading positions in backhaul, wireless and

IP, along with our full service capability to

offer the complete range of skill sets that

operators require.

lightRadio metro cell express will

provide operators with the capability to

respond efficiently and quickly to the

growing demand for mobile broadband

capacity.

SPONSOR'S FOREWORD

RETHINKING SMALL CELL DEPLOYMENT

PARKER MOSS, VICE PRESIDENT, WIRELESS STRATEGY ANDMARKETING, ALCATEL-LUCENT, ANNOUNCES THE LAUNCH OF A NEW

SERVICE THAT WILL SUPPORT OPERATORS IN THEIR DEPLOYMENTOF DENSE SMALL CELL NETWORKS. HE TELLS KEITH DYER HOW

LIGHTRADIO METRO CELL EXPRESS PROVIDES OPERATORS WITH THECAPABILITY TO RESPOND EFFICIENTLY AND QUICKLY TO THE

GROWING DEMAND FOR MOBILE BROADBAND CAPACITY. Parker Moss

mobile europe insight report |

he small cell market is as old as

the mobile industry, and

involves this decade’s big

league of RaN vendors: alcatel-lucent,

ericsson, Huawei, Nokia Siemens

Networks and ZTe, as well as a few small

cell specialists such as airvana, ip.access,

contela and Ubiquisys.

In the mid-nineties, augmenting the

macrocellular network with low power

nodes (e.g., typical output power less

than 4W) such as microcell and picocell

base stations, was considered an option to

increase capacity — for voice coverage —

for GSm and cDma systems.

From the late nineties throughout the

first decade of this century, microcells and

picocells were primarily used as the

anchor of distributed antenna systems

(DaS); again, this was to address voice

coverage issues but deployments were

modest at best, because GSm and cDma

networks were well designed to cope with

large coverage areas.

Until HSPa rollouts took off in 2007, we

hadn’t heard much debate about small

cells. Now, data rather than voice is the

key driver of mobile infrastructure and

with new and better devices such as

smartphones and tablets available every

quarter, mobile operators have to go

deeper in fixing capacity-crunched zones

to support data traffic growth; not only

does data growth put capacity (and

spectrum) at more of a premium, but 3G

signals suffer from attenuation as they go

from outside to in-building much more

than 2G signals do.

all of this has driven renewed interest in

denser cell deployment, and the industry

is expecting widespread utilisation of

various types small cells as a means of

handling the rapidly rising mobile data

volume.

But how much small cell activity is

there right now, and what scale of

deployment should we expect? What are

the challenges to be overcome and what

impact will small cells have on the mobile

network of the future?

MarKet ConfusionThe term 'small cells' seems to mean

many things to many different people and

there is no industry consensus as to the

exact definition. Vendors have been quick

to seize the opportunity to drive new

streams of RaN-based revenues but have

different ideas about the right products,

architectures and terminology. One folk's

'public access femtocell' is another

person's 'indoor pico cell' and someone

else's 'mini-BTS' and so on. So, before we

consider the dynamics of the market, let's

try and clear up some of the confusion

regarding what exactly we mean by 'small

cell.' The chart below is Infonetics' take on

the various flavours of small cell:

T

INSIGHT REPORT

SMALL CELL MARKETREALITY CHECK

BY RICHARD WEBB, DIRECTING ANALYST, INFONETICS RESEARCH

Specifications Microcells Picocells PS Femtocells

Cell radius 2 km maximum 200 meters max 10-100 meters

Output Power 33—36 dBm/2—5 W 250 mW—1 W 1 mW—250 mW

Number of users More than 100 30 to 100 Less than 20

Controller signaling protocol Iub Iub Iub

RRH/RRU option Yes Yes No

DAS usage Yes Yes No

Applications Microcells Picocells PS Femtocells

Low power outdoor sites Yes Yes No

Villages and road sites Yes Yes No

City centers Yes Yes No

Rooftop sites Yes Yes No

Stadiums Yes Yes No

Tunnel sites (e.g., subway) Yes Yes No

In-building sites (e.g., buildings} Yes Yes Yes

Shopping centers, malls Yes Yes Yes

Table 1: Small Cell Specifications Comparison: Microcells, Picocells, and Public Space Femtocells

PiCoCells will Prevail in MaCronetworK DensifiCation

In a picocell, the shorter transmission

distance coupled with lower transmit

power, enhances both capacity as well as

the signal to interference noise ratio

(SINR) achievable within the cell. Put

another way, from a pure radio

architecture standpoint, dividing a large

macrocell into a certain number of small

cells to enable efficient frequency reuse is

one of the most effective ways to increase

the overall system capacity — on top of

advanced signal processing techniques,

expanded use of spectrum, and improved

modulation and coding techniques. While

improving the overall throughput

achievable in the macrocell, this also

brings down deployment costs.

However, dividing a large macrocell

into a certain number of microcells does

not bring enough granularity; a microcell

still requires relatively high power and

covers hundreds of users but from what

we understand from operators, the goal

of cell densification is to provide ad hoc

capacity to areas that typically have less

than a hundred users. In addition, the

new generation of picocells integrates

collapsed RNc and standardized backhaul

interfaces, which also helps the

densification model.

In addition, we are seeing indications

that picocells are likely to have integrated

WiFi. Both technologies have similar range

and power requirements, and this may be

another advantage for picocells over

microcells, as the dense cell option could

have its own in-built offload option e.g.,

alcatel-lucent’s lightRadio now integrates

WiFi; Nokia Siemens Networks' Flexi Zone

and ericsson’s mRBS and pRBS small cell

series integrate Belair’s WiFi features.

PiCoCell-baseD DensifiCationDesign reMains CoMPliCateD

even though there are some benefits to

the pico-orientated small cell architecture,

it is by no means simple to design, deploy

and manage; there are complexities

inherent in small cell networks which are

holding the market back so far. Infonetics

has been discussing these issues over the

past two years with both vendors and

mobile operators and the following

questions pop up the most:

z What is the optimum picocell to

macrocell ratio?

z What is the optimum cell size that

maximizes the picocell throughput?

z Does the receiver configuration matter?

z What happens if the picocell BTS is

within the building or located outside?

z What is the implication of frequency

reuse on the throughput achievable?

z What is the optimum antenna size?

z What are the restraints on small cell

deployment, in terms of size,

appearance, location?

z What are the backhaul options?

no Consensus on sMall CellarChiteCture

When interviewing operators about

small cell strategies, we found more

questions than answers, and little

consensus. Strategies vary widely: some

operators are planning a dense use of

outdoor small cells, especially in urban

areas; others plan only comparatively

moderate use currently, with a few

deployments in urban areas; some have

no plans for outdoor small cells at all,

saying they see no need for the next few

years.

Taking all these perspectives into

account we have established the following

rules of thumb that allowed us to build a

forecast model:

z most operators are planning small cells

only in the urban core in the next three

or so years; some will have none (the

Russian operators), some will have a lot

more (e.g. some of the Nordic

operators).

z Some operators will have none at all due

to their country's regulatory classification

of small cells as potentially carcinogenic

(France, Israel); we do not currently

expect this to become a prevailing

viewpoint but will nonetheless be a

major inhibitor in some places.

z Urban core cell sites are about 5% of

cell sites; each of these urban core sites

will have three to five small cells per

macrocell for most operators we

surveyed; one plans three to eight per

macro, another plans 13-20 (typically

pico cells); several national-scale mobile

operators are planning three to five

microcells per macrocell in dense urban

areas only and none elsewhere.

z asia could have different ratios, due to

widespread RRH usage in china and

Japan, and WiFi hotspots; But Softbank

mobile told Infonetics its next wave of

investment will be in small cells. It will

only start when the TDD lTe macro

network is complete in 2014: 160,000

sites — and with new spectrum.

| mobile europe insight report

INSIGHT REPORT

Though there are some benefits to thepico-orientated small cell architecture, thereare complexities inherent in small cellnetworks which are holding the market back so far.

Table 2: Worldwide Small Cell Units and Revenue

mobile europe insight report |

z Small cells are commonly expected to

be a key characteristic of lTe networks,

yet there is a growing acceptance that

they will also play a vital role in late-

stage HSPa networks, where they have

so far played only a minor role.

z It is unclear how small cells can be fully

embedded in the whole macro network,

because so far, microcells and picocells

have been deployed only to improve

coverage in metro areas and buildings.

z Today, outdoor small cells are deployed

by only a few operators and mostly on a

small scale; therefore, there are few

deployments from which operators can

draw operational data to develop

common practices, common

dimensioning plans, and common

strategies.

So, bearing in mind the inhibitors and

complexity in small cell networks,

Infonetics expects the market to grow

modestly in the short-to-medium term,

with shipment volumes only starting to

ramp up from 2015 onwards; even then,

the scale we foresee (3m units in cY16) is

nothing near as dramatic as other more

bullish projections — admittedly some of

these generated by vendors.

The forecast model we built depicts a

three-phase type of rollout:

z Phase 1: 3G rollouts (2008–2011)

z Phase 2: 3G expansion and upgrades

(2012–2016)

z Phase 3: 4G capacity upgrades

(2013–2016)

Until early lTe adopters start capacity

upgrades, 3G small cells — mostly W-

cDma/HSPa — will be predominant; by

2014, 4G femtocells will become the main

growth engine:

z 2012: 100% of small cells will be 3G

only as we believe early 4G deployments

will only be field trials.

z 2013: Kick-off year for more notable

growth with 37% 4G small cells versus

63% for 3G.

z 2015: Ramp-up with 4G small cells

accounting for 57% of total, overtaking

3G.

rrh/rru, relay, rePeaters, Das anDwifi are also Part of the Mix

The unabated demand for mobile

broadband and the resulting traffic surge

in radio access networks is challenging the

conventional wisdom of just improving

and densifying the macro layer. Put

another way, simply adding new macro

sites and BTS is not enough and no longer

works. But also, the addition of micro,

pico and public access femto small cells,

as discussed above, may not be sufficient

on its own.

There is likely to be a need to also

augment and enhance the existing macro

layer with various low power nodes such

as remote radio heads/units (RRH/RRU),

relays, repeaters, distributed antenna

systems (DaS) and WiFi access points. as

all low power nodes are integrated in the

whole mobile network with the macro

layer, the ensemble creates a

heterogeneous network.

carrier WiFi is seeing a renewed boom,

driven for the most part by mobile

operators eager to leverage the availability

of a 'free' technology (ie. using unlicensed

spectrum) to augment their existing

mobile data services in public spaces;

often, WiFi is already available, but mobile

operators are keen to build out their own

WiFi access points based on newer

versions of the technology: not only will

802.11ac be widely deployed once this

faster protocol is fully ratified, but mobile

operators will also want to integrate WiFi

more closely with the mobile network

using WiFi 2.0 capabilities.

From our discussions with mobile

operators that are strong DaS proponents,

we know that today's active DaS

topologies are bringing enormous

functionality and benefits to the in-

building domain by the shaped and

sculptured RF coverage patterns they

offer, which minimizes spillage and

maximizes in-building signal strength. In

addition, the systems are driven from a

central BTS or NodeB, overcoming

handover issues. also, advanced active

DaS systems are capable of efficiently

extending network coverage far from the

BTS or NodeB, using technologies such as

RF-over-fiber and other transport

mechanisms, which make this an optimal

option to spread an existing cellular signal

in venues such as stadiums, where small

cell solutions are not sufficient to cover

terraces and standing areas.

sMall Cells: not so big just yetIn units, small cell numbers can be big,

and much bigger than those of

macrocells, provided interference and

backhaul issues are under control. But

don’t get too excited. There is no

question that there is a small cell market

and a heterogeneous network market, but

given the magnitude of the annual macro

RaN market, standing at $50B, small cells

are not likely to generate anything too

close to this in terms of new revenues.

also, a clash between the BIG 5 RaN

vendors and the small cell pure-plays that

started with consumer femtocells is

looming. Take for instance the public

space femtocell segment: we currently

count over 20 vendors, more than a third

of which are trying to move upstream and

expand into the picocell segment, which

will lead them to cross paths with the

RaN giants. clearly, it remains to be seen

how sustainable this market is for so many

vendors.

all in all, the small cell market is still

early in the game: the currently available

products are not the ones that will be

purchased by the hundreds of thousands

in several years' time, and a raft of

operational issues persists for operators to

sort out. There are still no widespread

deployments from which the industry can

learn the best practice and form common

strategies, and operators continue to face

challenges regarding the implementation

of QoS, SON and HetNet whilst trying to

build a new-look network from the range

of indoor and outdoor small cells, WiFi

hotpots, DaS and home femtos.

INSIGHT REPORT

| mobile europe insight report

INSIGHT REPORT

WIFI REQUIRES CO-ORDINATIONOPERATOR WIFI STRATEGIES NEED TO BE CO-ORDINATED, TECHNICALLY AND INBUSINESS MODEL TERMS, OR OPERATORS FACE VALUE REDUCTION, SAYSTHOMAS WEHMEIER, PRINCIPAL ANALYST AT INFORMA TELECOMS & MEDIA.

need to open this comment

with a brief confession. ever

since immersing myself in the

topic of Wi-Fi and, more specifically, in

understanding and analysing operator

strategies and business models for Wi-Fi,

I have argued that all operators will

need to integrate Wi-Fi into a holistic

traffic-management strategy focused on

sustainable and profitable mobile data

growth. although I believe we have

clearly explained how Wi-Fi can and

should play a complementary role for

operators, I don’t believe we have

sufficiently outlined the risks and threats

to future operator business models. I

would add, though, that this is not

about scare-mongering but about

presenting a balanced perspective on

future carrier Wi-Fi strategy.

I have spent a large part of the past

year speaking with industry players

(operators, vendors, regulators, OTT

players) about a range of issues related

to both Wi-Fi and the future evolution of

mobile data pricing. These discussions

have brought me to a new set of

conclusions that I am starting

to articulate to our customers. although I

stand by the statement that ensuring

that executives “get” Wi-Fi will be crucial

to the success of operators globally, I feel

that I need to contribute new insights to

the arguments for and against large-scale

public Wi-Fi deployment.

One of the most important

conclusions I have come to is that

although Wi-Fi is indeed going to play an

important role in the development of the

provision of Internet access and other

services, it is not clear that the

widespread deployment of Wi-Fi outside

of the home is going to deliver to

operators the sustainable and profitable

future their shareholders and investors

demand. This is especially true if the

investment in Wi-Fi is not backed up by a

clearly articulated and joined-up strategy

that evaluates the overall impact of a

greater migration of smartphone-, tablet-

or laptop-originated data-traffic share to

Wi-Fi and away from the operators’ core

cellular networks.

One of the principal conclusions I

have made is that many operators are

seemingly “blindly” deploying Wi-Fi

without a clear understanding of the

overall impact of their investments on

their business in the future, especially

regarding the effect on mobile data

usage from their 3G/4G networks.

I

Although I believe we have clearlyexplained how Wi-Fi can and should play acomplementary role for operators, I don’tbelieve we have sufficiently outlined the risksand threats to future operator business models.

mobile europe insight report |

INSIGHT REPORT

I am increasingly of the opinion that

much of today’s operator investment in

public Wi-Fi is led by apparent short-term

thinking about the role that Wi-Fi can

play in alleviating traffic bottlenecks on

their networks. But although Wi-Fi can

obviously play a role in a comprehensive

and holistic traffic-management strategy,

operators are placing too much emphasis

on Wi-Fi without really investing in

demand-side measures (i.e. pricing) that

can enable them to build sustainable and

profitable propositions to increase data

traffic in line with customer demand in a

way that delivers maximum value to the

bottom line. There is still far too much

industry rhetoric around the “challenge”

of data-traffic growth when the reality is

that this level of demand for their service

should be seen as a major opportunity to

monetise huge investments made in 3G

and 4G networks.

The real crux of this discussion should

focus on the fact that mobile network

operators make a lot more money for

every megabyte/gigabyte/terabyte of

data that goes over their cellular

networks (i.e. 3G/4G) than they do

when the traffic goes over Wi-Fi,

especially when it is private, in-the-home

Wi-Fi, where they effectively make zero

revenue. Show me a single operator that

can today claim that it is really

extracting comparable value (i.e.

bottom-line profits) from its customers’

Wi-Fi usage vs. usage on its own cellular

networks.

For some operators that have perhaps

underinvested in their cellular networks,

Wi-Fi has a definite role to play to help

alleviate traffic concerns in certain

locations or at certain times of the day

and because it is the preferred, primary

form of data connection used by many

of their customers. But it’s important

that operators realise the long-term

impact that a strong migration to Wi-Fi

could have on their own opportunities

to make money out of their customers.

The more customers end up using Wi-Fi,

the harder it will be for operators to

persuade them to shell out hard-earned

cash to pay for access to their 3G/4G

networks.

In the short term, the impact is likely

to be that operators that have set up

tiered volume-based pricing will miss out

on “overage” charges when users

exceed their bundled data allowance or

customers deliberately choose to stay on

cheaper plans with smaller data

allowances because Wi-Fi is so freely

available in the home and on the move

that they feel confident enough not to

purchase bigger bundles on more

expensive plans.

In the longer term, the risk is that

there will be a strong migration of

smartphone usage away from cellular

networks and onto Wi-Fi, which would

ultimately dilute operators’ revenue-

generation opportunities from demand

for data access.

I think there’s no question that

customers will still need access to 3G/4G

networks for data connectivity for all

those occasions where Wi-Fi is not

available, the connection is not secure or

the experience is poor. But the real

concern for operators has to be that

these situations are becoming less and

less frequent the more that high-quality,

secure and “free” Wi-Fi is made available

to them.

That being said, I do recognise that

some operators, including O2 UK, have

developed a clearly articulated and

comprehensive view of the role that Wi-

Fi can play in expanding their other new

business lines (O2 media, O2 Wallet, O2

money, Priority moments, etc.) and as a

result have a much clearer and stronger

strategy to underpin their investments in

Wi-Fi rollouts without fearing revenue

“cannibalisation.” I also recognise that in

some specific scenarios, such as data

roaming, Wi-Fi could actually generate

incremental revenues that have not

successfully been captured on cellular

networks because of exorbitant data-

roaming prices.

But I don’t think the rest of the

industry has caught up with the leading

thinkers in this space. We believe more

operators will need to follow O2 UK’s

lead if they are going down the path of

investment in Wi-Fi. This means building

a business case from the bottom up that

covers all areas of Wi-Fi that have an

impact on the operator business and is

not simply focused on isolated aspects of

the Wi-Fi value proposition, such as

network-capex alleviation. We also think

operators will have to develop much

better insights into the future impact of

major Wi-Fi adoption and usage on the

profitability of their own (cellular)

mobile data businesses.

I do recognise that someoperators, including O2 UK,have developed a clearlyarticulated and comprehensiveview of the role that Wi-Fi canplay in expanding their othernew business lines.

Home and enterprise (below left): carrier WiFi may threaten the businesscase of mobile operators if not thought through, warns Wehmeier.

A TECHNOLOGY WHOSE TIME HAS COMEJim Tavares is a Director for Strategy & Business Development in Cisco Services. Keith Dyer

| Mobile Europe

Caption CaptionCaption

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ADVERTORIAL

It is not news that mobile data is growing at an

unprecedented rate and will continue to do so in the near

future. Alcatel-Lucent Bell Labs predicts that mobile data

will increase twenty-five times by 2016. It is also not news

that a macro-only approach cannot provide the capacity

needed to satisfy the demand. Recently, it has become

widely accepted that the solution for providing massive

capacity is the densification of the network with metro cells,

in essence creating a heterogeneous network or HetNet.

Metro cells are appealing to operators for a number of

reasons. They are cost efficient and may be quickly placed

just about anywhere where coverage and capacity is

needed. Additionally, metro cells are spectrally efficient,

enabling operators to squeeze more capacity from their

scarce spectrum than by using macro cells alone.

However, what will be news to some is that large

deployments of metro cells pose a number of challenges

that require operators to rethink their operational and, in

some cases, business models.

CELL LOCATIONOptimised placement of metro cells necessitates the

development and use of new models, tools, and

methodologies. Unlike macros, metro cells provide

coverage and capacity to much smaller areas or hotspots

within the larger macro network. A hotspot usually ranges

from 70 to 100 metres in diameter and occupies only

about eight percent of a typical macro cell’s coverage area.

Because of this, the established models and tools used in

the planning and design of macro networks are not

effective in determining where to place metro cells. Not

only are they inaccurate for small areas, but they also do

not consider other factors important in placing metro cells.

The first step in determining where to place metro cells is

to pinpoint the exact location of the hotspots. This can be

accomplished by creating a heat map. The process involves

collecting subscriber call records over a period of time, geo-

locating the calls on a map and then extracting the packet

data volumes to determine the amount of data being used

by location.

Using the heat map, the operator can then identify the

macro cells that are the best candidates for offloading. For

each of these cells, the operator must determine the

number of metro cells, along with their placement within

the macro’s coverage sphere, needed for optimal

offloading. This requires several calculations for each of the

macro offload candidates. The

offload potential is, however, not

the only factor that is important

to the selection of the metro cell

sites. To ensure easy

deployments and low site

rentals, the MSP must also

consider shared carrier exclusion

zones when applicable, friendly

landlord sites, as well as sites

offering power and backhaul.

SITE ACQUISITION Operators know how to

acquire sites for macro cells,

from locating the best sites

within search rings, to

negotiating site rental leases and

management agreements. Many

operators also have long-

standing relationships with

tower companies. Metro cells,

however, are not placed on towers or rooftops, but rather

in new locations, such as lampposts, utility poles, and on

the interior and exterior walls of buildings. Another

difference is that metro cells are deployed in mass,

requiring the acquisition of many sites all at once.

To deploy metro cells quickly and keep costs low, the

MSP has to find many suitable sites with low rental fees,

readily available power, and access to backhaul. Forming

GUARANTEE A SUCCESSFUL METRO CELL DEPLOYMENT

Metro cells present operators with a number of deployment challenges that must be addressedbefore their full benefits may be realised. That means operators must not only rethink how theyplan, design and implement their networks, but also their business relationships andpartnerships, says James Seymour, Senior Director of RAN Strategy, Alcatel-Lucent.

Adoption barriers to the

deployment of metro cells.

Ease of installation and

turn up will be critical in

metrocell deployments.

Mobile Europe |

ADVERTORIAL

strategic relationships or partnerships with municipalities,

utilities and other companies that own or have access to

infrastructure suitable for the deployment of metro cells

offers an effective means of doing this. Municipalities own

lampposts, traffic lights, and other structures. Utilities

possess thousands of power poles and wireline service

providers have telephone poles as well as other

infrastructure, such as Digital Subscriber Line (DSL) and

Gigabit Passive Optical Network (GPON) that not only offer

a place to mount metro cells, but also easy access to

backhaul. There are also cable companies with miles of

above the ground cable strands and companies with

thousands of Wi-Fi locations that can provide mounting

locations for metro cells and the necessary power and

backhaul.

By forming strategic relationships and partnerships,

operators can negotiate right-to-use agreements with

municipalities and companies that have infrastructure

within those targeted locations. This facilitates the

availability of highly suitable sites when metro cells need to

be deployed. Additionally, by negotiating right-to-use

agreements for many sites at one time, the MSP is able to

keep rental fees for individual sites low.

THE RIGHT BACKHAULMetro cell backhaul demands a number of questions of

operators. Does the backhaul network have to provide the

same level of performance for metro cells as it does for

macro cells? What other factors must be taken into

consideration to ensure the quick and cost-effective

deployment of metro cells? What is the best way to keep

the operational costs of the backhaul network low? Does

the selection of metro cell sites have any impact on the

backhaul network?

First, the design of the metro cell backhaul network must

deliver the appropriate level performance. Will metro cells

primarily be used for filling in coverage holes or for

offloading capacity? The answer to this question

determines the level of performance that needs to be

supported. Coverage requires that the metro cell backhaul

network meets the sa me level of reliability, availability, and

quality of service (QoS) as that provided by the macro

backhaul network. Basic capacity offload, on the other

hand, has performance requirements that are more

relaxed. Metro cells used for coverage will typically require

a higher performing, higher cost backhaul network than

that needed for capacity offload.

It is also essential that the backhaul network be designed

for easy scalability and maintainability as well as for the

easy installation and turn up of metro cells. Building in

scalability ensures that the backhaul network can grow

quickly and cost-effectively to keep pace with the

deployment of metro cells, while designing in

maintainability reduces the number of required site visits,

keeping operational costs low. Designing the backhaul

network for the simplified installation and turn up of metro

cells also guarantees quick deployments and fast time to

market.

The selection of certain sites for the deployment of

metro cells may adversely impact the cost of

backhaul. Some sites may offer optimal locations of

coverage and capacity, friendly landlords, low rental

costs, available power, and easy accessibility for

installation and maintenance. However, if these sites

do not have readily accessible wireline backhaul or a

clear line of sight (LOS) back to a backhaul

aggregation point, then the cost of providing

backhaul may be too high, outweighing the other

advantages these sites have to offer.

This combination of backhaul availability and site

performance means that to keep backhaul costs as low

as possible, operators must do the backhaul and metro

cell radio design at the same time to ensure a selection

of sites that optimizes backhaul costs.

CONCLUSIONTo realise the full benefits of metro cell deployments,

operators must rethink their approaches to site

acquisition, RF planning and backhaul to take account of

the greatly increased need for scale, flexibility and low

operational cost. Only by treating the deployment of

metro cells in a holistic, whole-life manner, can operators

fully unlock the business benefits of metro cells.

More InformationTo learn how Alcatel-Lucent’s lightRadio™ Metro Cell

Express comprehensive solution can help you guarantee

the successful deployment of metro cells, please visit

www.alcatel-lucent.com/lightradio-metro-cell-express/.

ABOUT THEAUTHOR:James P. Seymour isSenior Director ofRAN Strategy in theWireless CTOorganisation, Alcatel-Lucent. He is therecipient of a BellLabs Fellowshipaward for hisoutstandingcontributions towireless technologyand first joined AT&TBell Laboratories in1994.

Optimal site acquisition

requires a rich ecosystem

of partnerships and

relationships.

mobile europe insight report |

INSIGHT REPORT

SON & MANAGED INTERFERENCETe is predicted by many to bring

with it the advance of the true

Het Net, as operators deploy

small cells that are intended to relieve

capacity-stressed sites in zones across dense

urban areas, at lower costs than by rolling

out an equivalent macro cell expansion.

But the challenge of integrating a small

cell layer into the macro layer brings with it

a major concern for mobile operators —

that of interference management.

compared to traditional single macro

layer networks, small cell devices will be

deployed in very high numbers. even if it is

at just three cells per macro cell (and many

people think it will be many more), across

just a fifth of the network, that would be

an additional 12,000 cells in a network like

Vodafone’s in the UK. If they were to be

deployed in an uncoordinated way, this

would present significant challenges

around interference management and

mobility management (how devices are

attached to, and moved between, network

layers).

Interference is a particularly difficult

conundrum to be solved, explaining its

continued presence, along with backhaul,

as one of the key deployment challenges in

the small cell model. This includes

interference between both the macrocell

layer and the small cell layer, as well as

interference between the small cells

themselves, between neighouring pico

cells. In fact, this topic is as relevant in 3G

as in lTe networks, and brings with it

many similar concerns.

at the lTe World Summit, held in may

2012, Jaime lluch, Radio access

Technology manager, Telefonica,

confirmed that interference issues are still a

current concern for operators. Outlining a

situation where an operator is considering

deploying a small cell layer within an

existing network, he highlighted the fact

that differing vendors still have differing

opinions on whether he can technically

deploy in a multi-vendor manner, or stick

with his existing vendor.

For example, you can read an ericsson

interview within this report in which the

company states quite clearly that if

operators want to benefit from small cell

deployments, they must use cells from the

same supplier as the macro vendor. Yet, of

course, that’s not the story new entrants

tell, or even competing “incumbents” such

as NSN and alcatel-lucent.

alcatel-lucent’s view is that by handling

hand-off between the macro and micro

layers on the S1 interface, operators will

achieve a satisfactory level of performance.

That means that operators don’t have to

wait to deploy hand-off on the X2

interface. NSN insists its Flexi Zone

architecture, which sees clusters of small

cells managed in an aggregated manner

by a local controller node, can be deployed

in a non-NSN macro cell and still have

beneficial effects on the overall capacity of

the macro.

competing messages can create

confusion. “When I ask the incumbent

vendors if interoperability can happen, they

say it can't be done. If I ask the new

entrants, they say it's not a problem…”

lluch said, indicating that the industry itself

is not necessarily helping with the clearest

possible view of how interference can be

mitigated.

another operator we spoke to said that

there is still a lot of due diligence to do on

interference on small cells interference

planning, even though the macro

environment is well understood.

The industry, of course, does have tools

at its disposal to meet the demands of

handing mobility and interference issues

between cells operating at differing power

levels and layers in the network.

The Small cell Forum claims in a recent

white paper, “W-cDma Open access Small

cells: architecture, Requirements and

Dependencies”, that interference

management techniques allow small cells

and macrocells to coexist in the same

frequencies without causing undue

interference.

You can derive a very good idea of how

the “small cell industry” itself recommends

operators deal with the issues of

interference, from an article written by

Simon Saunders, chair of the Small cell

Forum, in may 2012 for industry blog

Wilson Street (funded by alcatel lucent for

the discussion of small cell matters).

Saunders argues that interference “sounds

bad” but “can actually be a good thing”.

His take on the interference issue is that,

managed carefully, the use of controlled

interference could improve mobile network

performance 100 fold.

He outlined a few of the likely causes of

interference between small cells and the

macro layer, tests that the Small cell Forum

L

mobile europe insight report |

INSIGHT REPORT

carried out, and steps that can be taken to

mitigate that. Saunders wrote (all extracts

reproduced with permission of the Small Cell

Forum and Wilson Street) that the Forum

has spent a lot of time looking at the

potential impact of interference and how

to mitigate it. Its testing has included the

following scenarios:

z co-channel deployments where the small

cell and macro are on exactly the same

frequency

z closed access nodes and what happens

when a mobile user, who is not registered

for that small cell, gets close to it and

generates and receives interference

z low frequency bands where signals go

further

z and small cells and interference in lTe as

well as 3G.

“When small cells and macrocells are on

exactly the same frequency (co-channel)

there are some areas of interference

between the macrocell and the small cell,”

Saunders says. “This happens because

transmit power is turned up when a

handset is at the furthest distance from a

cell, and because a handset might hear a

small cell better than a macrocell but not

be registered to use it. In our studies on

interference, we looked at three scenarios

for interference:

z a macro-connected handset that is in

close proximity to a small cell that it is

not registered to use, causing a

deadzone.

z a small cell-connected handset that is at

the furthest range of the small cell.

z a small cell-connected handset that is

closer to a small cell in the house next

door, but is not registered to use it.

“clearly we’re most concerned with how

a small cell interferes with a macro network

because it can impact the most users.

“These are all worst case scenarios. If

you were able to arrange your small cells

on a slightly different frequency or

straddling two macrocell channels, you get

zero or much-reduced interference. also, if

you only had open small cells, it would also

be avoided because the handset would

roam between the strongest signals.

“But many operators will need to deal

with a co-channel interference caused by

open and closed cells. Some have a hybrid

model where closed small cells are opened

up to unregistered users if they are

experiencing or causing a lot of

interference to the neighboring macrocell.

“So even before we go into complicated

interference management techniques,

there is a host of ways of obviating

interference.

1) You get dead zones because there is too

much small cell power in relation to

macrocell power. If the small cell was

aware of that the neighbouring

macrocell had a weak signal, the small

cell would scale back its own power.

2) If a small cell-connected device is very

powerful and drowning out a macrocell

in close proximity, we recommend that

the small cell has the ability to tell the

handset what the maximum power it

can transmit at so as not to impact the

neighboring macro and to adjust its

own sensitivity to avoid its own receiver

being ‘deafened’ by the strong signal.

3) If a macrocell is interfering with a small

cell, unfortunately you can’t really

tamper with the macrocell output. It has

been manually configured to give a

certain coverage level and you don’t

want to change that every time a new

femto is turned on. But the small cell

can adjust its power to give the

optimum balance between good

coverage over its designated area and

interference beyond its reach.”

interferenCe Can be a gooD thingFinally, Saunders concluded that those

worried about small cell interference need

to consider the opposite scenario where

there are no femtocells at all.

“The average 3G throughput in a

metropolitan district (and these are the

results of a real test) is just 50kbps.

Interference impacts so much that there is

less that 1mbps of shared capacity in the

entire macrocell.

“If you introduce femtocells into this

area, macrocell performance improves

substantially. average user throughput

jumps to 8 mbps each, while the shared

capacity increases to 88 mbps – 100 times

greater than when there is managed

interference.”

Saunders’ summary: to get 100x

throughput compared to macro-only

networks, the following techniques may be

applied:

z adaptive Pilot Power control

z extended Tests for Dynamic Range

z Uplink power capping

z Dynamic receiver gain management.

the sonas well as taking these kinds of steps, the

hope of the industry has been that Self

Organising and Self Optimising Networks

would enable operators to achieve lower

costs of deployment and operation by

automating many processes that are

currently labour-intensive, and also deal in

a dynamic fashion with some of the

interference and mobility management

issues that the Het Net could introduce.

at one level, well-understood by

operators, SON can be about auto-

configuration, where an eNodeB can

autofeed to and from a configuration

server, download its configuration, and in

future carry out aNR (automatic

Neighbour Relations) on X2 interfaces.

“That’s about as far as SON goes today,”

one operator told us.

“There’s a lot more we could see. I think

in terms of the self optimising part of SON,

generally operators are a bit sceptical at

the moment as to how much you let this

run. They are happy with auto

configuration, but there are so many

parameters to adjust, and dynamics, that it

takes fairly large optimisaiton teams do this

work. clearly there will be financial benefts

if you can then automate this but that’s

not there at the moment. For operators it’s

‘steady as she goes’.”

If you’re wondering what exactly is

meant by SON, the following specfications

are a useful primer.

Firstly, SON is about the automatic

collection of data from nearby and

neighbour cells. each small cell gathers

data from neighboring cells through a

combination of:

z measurement reports generated by

the mobile users, which include a list

of their serving cell’s neighboring cells;

z Network monitoring mode detection

of downlink signals from neighboring

cells, which is performed by small cells

that behave as simple user equipment

(Ue) devices.

z exchange of information directly

between cells.

This last point brings us back to the

discussion about which interfaces to do this

upon, as the industry is waiting for the X2

interface to enable cell to cell

communication. (That is why a vendor

such as alcatel-lucent argues that handoff

on the S1 interface is sufficient, for now)

after the Organising, comes the

Optimising part. Once data has been

collected, parameters are then inputted

either in a centralised server that then

optimises a group of small cells, or it can

be done in a distributed way, whereby

each small cell optimises along its own

parameters.

The hope the small cell industry has is

that SON technology will unlock some of

the business case for HetNets. The

challenge though, is matching existing

SON architectures, which tend to be

centrally implemented, and limited in

scope (configuration, rather than

optimisation) to the need for SON software

that can act in a more distributed manner,

to enable the deployment of interoperable,

multi-vendor networks. That requires what

is termed a hybrid approach, blending

centralised SON coordination with more

distributed models.

Due to its promise of reduced cost,

increased automation, and increased

distributed intelligence, SON technology is

seen by many as key to the success of small

cells. even in dedicated-carrier residential

femtocell deployments, where cells are

behind walls and very low powered

indeed, small cells must have plug-and-

play simplicity, and they must be capable

of automatically adapting their parameters

depending on conditions. In outdoor

environments, where output higher may

well be higher, SON will be even more

crtitical.

Some small cell vendors are hoping that

their existing knowledge of SON, gained

through the deployment on femtocells so

far, can be integrated with operators’

existing centralised SON systems, to allow

an overall management capability across

the macro and small cell layers.

at the moment, as we have seen, the

centralised SON servers are not designed

to receive parameters, either manually or

automatically from a separate layer of a

large numbers of small cells. This could

lead to a class of SON that ties the

experience gained through the

management systems of femtocells to the

macro layer management systems.

If this works, it would give small cell

entrants, regarded as standalone solutions

providers, the ability to present themselves

as being able to be deployed in an end to

end fashion in the network. It is another

brick removed from the wall that

incumbent vendors are building out of

coordinated mobility management,

interference management, and SON.

Finally, it should be noted that SON and

interference management specifications

change with the industry srtandards. as the

industry moves to lTe Release10 and

beyond, 3GPP is exploring new

technologies that would incorporate more

sophisticated interference management

techniques into operator networks,

techniques such as Range expansion, and

eIcIc (enhanced Inter cell Interference

coordination). Range expansion is the term

given to a technique that would allow a

user on a capacity-constrained cell to

connect to a nearby small cell, even if it is

at lower power than the macro cell. This

relies on advanced receivers that can

operate at lower signal to noise ratios.

For those who can wait, these are issues

that can be sorted in time. But for those

who must deploy now to meet demand,

the situation is still unclear.

| mobile europe insight report

INSIGHT REPORT

Capacity/Mbps

Femto + macro Macro-only

Expected available throughput per UE 7.87 0.08

Number of UEs per cell (34 UEs across three macro cells) 11.3 11.3

Expected available throughput per macro cell (= network capacity) 88.9 0.9

Increasing the available throuput with the use of femto plus macro cells (Small Cell Forum).

Mobile Europe Insight Report |

INSIGHT REPORT ROUND TABLE

THE PARTICIPANTS

An exclusive Mobile Europe debate

Held in association with Avren Events, organiser of theSmall Cells World Summit

SMALL CELLSthe network ofthe future

JULIAN BRIGHTSenior Analyst,

Networks, InformaTelecoms & Media

KEITH DYEREditor,

Mobile Europe

RICHARD WEBBDirecting Analyst,Infonetics Research

VIRAJ ABHAYAWARDHANASpecialist Strategy, BT Wholesale

ALEJANDRO PINEROSmall Cells Director,Avren Events

ANDY SUTTONPrincipal NetworkArchitect, EverythingEverywhere

MATT YARDLEYPartner,

Analysys Mason

| Mobile Europe Insight Report

INTRODUCTIONSKeith Dyer:

Let’s have a traditional start – cards on

the table. What’s your current

involvement with small cells?

Andy Sutton: I work in the area of RAN architecture

evolution and mobile backhaul and I’m

responsible for a rolling five year evolution

plan for the network, looking at the

evolution of the RAN and at how it will

impact backhaul requirements. The small

cell area is an interesting challenge in

itself; we need to find a new economic

price point for small cells, generally one

tenth the price of macro cells, and that

impacts the overall budget for acquisition,

the infrastrucure itself and backhaul. I’m

also heavily involved in the NGMN

Alliance work on small cells and on small

cell backhaul.

Julian Bright:The InformaTM networks team focuses

on all aspects of network technology, so

we encompass RAN, all aspects of small

cell technology and produce various

forecasts, research and analysis.

Alejandor Pinero:At Avren the portfolio I run works with

the Small Cell Forum to deliver a series of

small cell events around the world. I am

in ongoing conversation with vendors,

analysts and operators to come up with

events that are attractive to everyone.

Matt Yardley:I'm working with operators to

understand external business cases in

fixed and mobile, and with other

stakeholders who are becoming

increasingly interested in the space.

Governments are pushing to get

ubiquitous coverage at high speed, and

that’s deriving a lot of interest. For me,

understanding how fixed and wireless will

work together in the future is really

interesting.

Viraj Abhayawardhana:At BT Wholesale we have worked on

strategy around small cells for a number

of years, in terms of innovation and

research. I also chair the Backhaul SIG in

the Small Cell Forum.

BT is rolling out a lot of fibre,

particularly in urban areas, so my role is to

ensure that infrastructure can be used for

the backhaul of carriers’ small cells. We’ve

also done a lot on wireless cities, so have

gone through the pain of deploying the

WiFi flavour of small cells in a number of

cities.

Richard Webb: I focus on a number of different

wireless markets, macro and small cell and

mobile architecture. We include micro,

pico and all flavours of small cells in the

public network and consumer space.

We’re also looking at carrier WiFi and the

impact of RAN base architecture

development, to look at the whole piece

of mobile operator CAPEX to try and

figure out the options for different

strategic deployments and the choices

the operators are faced with at the

moment.

INSIGHT REPORT

SMALL CELLSbig debate

Mobile Europe brought together operators and analysts to discuss the directionsoperators and carriers are taking to plan, deploy and support small cells. Thediscussion roamed over the rationale for small cells, how and when operatorswill deploy, the backhaul challenge, and how WiFi fits in.

Mobile Europe Insight Report |

SMALL CELLS NOWKeith Dyer:

Where are we now with operator

deployments of small cells?

Richard Webb: It would be hard to point to a very

strong example of an operator

pioneering in Europe with a widespread

small cell deployment. Operators require

a long runway to explore this technology

and still have a lot of concerns around

interference and how small cell networks

play with the macro network. There are

also cost-related or model issues related

to the small cell form factor, and real

challenges in terms of scaling this up.

So there is a set of technical changes

to overcome, and after that some

commercial challenges as well. That

means we are seeing a very low, modest

market in terms of actual shipments for

RAN infrastructure vendors. They’d all

like it to be a much bigger market and

many of them are counting on that.

Julian Bright:The consumer femtocell market has

been quite fragmented: we’ve seen

quite successful adoption of the

technology by some operators, whilst

others have elected not to go down

that route. But overall that market has

not developed as quickly or seen as

broad an uptake as anticipated 18

months ago.

Our expectations are that we will see

growth in small cell, but that requires

definitions. In pico cells there are

deployments. If you look to new sectors

like metro cells, operating like a shrunk

down micro cell or a single sector

macro cell, currently that’s very much

in the early phase of moving into trials

with operators and vendors. There’s still

a lot to prove in terms of the

technology. From the vendor side the

major vendors are pinning a lot on the

uptake of small cells. There is a

reasonably compelling case to move in

this direction but we still need to see

operators convinced that the

technology works, that they can

backhaul it effectively... so there's that

learning phase before moving to any

significant deployment.

Andy Sutton: Everything Everywhere is in the fairly

unique situation of currently integrating

two large macrocellar networks. We

started with a combined site base of

27,000 T-Mobile and Orange sites, but

we’re cutting that down to around

18,000. Although the new network will be

a lot larger than either previous network

was, we are still looking at some capacity

issues. Given the site base we have to

start with we've done a lot of work

looking at what level of densification we

will require and at what point it becomes

cost effective to start targeting specific

traffic hotspots.

There's a lot of capacity in the macro

network still but there's only so far you

can go in terms of some practical aspects:

how much spectrum you have, the

constraints on how much power you can

emit from a cell site, and how densely

packed a macro grid can become in terms

of managing interference and the user

experience. So we are starting to see

some practical constraints in the macro

network, however there’s still some

additional densification that can be

realised if we have to.

What we need now is the most cost

effective way of addressing capacity. And

actually that capacity often comes from

fairly small hotspot areas or hot zones.

Getting the capacity where it's required

and removing that traffic at source will

reduce overall interference in the macro

network to produce capacity gains in the

macro space. It should also give you a

lower cost point, which is where I came

up with this figure that we really shouldn’t

be paying any more than a 10th of the

price of a macro cell for a small cell on a

like for like basis.

So it is still something to come in the

main. We have small cells deployed in

special projects at the moment, in-

building etc. Operator owned, operator

backhauled public access pico cells—

these kind of cells are just starting to be

realised now and we are seeing products

come to market. We have plans to roll out

LTE: our LTE capacity will be delivered by

the macro network initially, and as that

becomes constrained we are looking at

small cells some way down the road for

LTE. The real driver at the moment is 3G

small cells. We are now starting to see a

real requirement for 3G small cells with

features such as HSPA+ Dual Carrier

operation and 64QAM, so there is a

significant amount of capacity with

20MBps backhaul requirement downlink

and 5Mbps, initially, on the uplink.

ROUND TABLE

Left: The panelassemble at The RoyalExchange, London.

| Mobile Europe Insight Report

INSIGHT REPORT

????????

Alejandro Pinero:I think we are seeing operators

building up a portfolio of solutions. We

will talk about WiFi, and I know that in

the USA there’s widespread use of DAS,

for sporting venues for example. It’s

worth considering that as well, within

the overall small cell discussion.

SMALL CELL REQUIREMENTSKeith Dyer:

Can we size the likely scale of small cell

deployments, so we could understand

what requirements small cell deployments

might place on the wider network?

Richard Webb:There’s quite a range in terms of scale.

Three to six per cell is typical, but we’ve

heard operators say they will only add

small cells to 20% of macro sites where

they might be looking at somewhere like

to 5-10 added incrementally over time.

I’ve even heard 20 to a macro cell, which

seems a bit of a stretch to the model.

Andy Sutton:Today we would consider deploying a

single small cell to a hotspot to relieve

capacity, clearly over time that would

grow. Our thinking is somewhere in the

region of three to six small cells per

macro. I hear people say up to 10, and

people often think that maybe ten would

replicate the coverage of a macrocell. I

think it is impossible to replicate the

coverage of a macrocell with small cells;

they are fundamentally different and you

have to plan accordingly. One of the

things we are trying to understand from

our trials is even though we’ve got the

coverage we require, what additional

coverage does a small cell bring? When

you put small cells down at street level,

you’re going to get 10 yards into the back

of a restaurant or shop, where you often

lose that macro cell coverage. So in that

environment you get additional coverage

that was certainly not the primary

objective for small cells. But if we

introduce additional coverage and our

subscriber sees coverage on his handset

he’ll want to make a voice call as well as a

data session so therefore we end up

supporting voice and data…

Viraj Abhayawardhana:What I'm hearing from the Small Cells

Forum SIG for backhaul is that for small

cells to work there are two key challenges.

One is sites, and the other is backhaul.

How do you obtain these sites in a

painless way and then manage the sites.

Andy is saying 18,000 macro cells but if

he deploys small cells at scale it will be an

order of magnitude bigger than that, so

how do you manage this kind of site

portfolio? That’s one of the key problems.

The second is that backhaul is a significant

portion of cost: if you want to bring that

down to 1/10th how do you get that cost

per site down to a level that can work? As

a backhaul provider we don't care what

goes on the end of it but we like to

understand what performance that will

place on the backhaul products that we

like to provide. So the key issue is about

how reliable should small cells be? Do you

see these having as 99.999% reliabilitity

or something lower than that, because

that drives the cost.

Where are the compromise that need

to be made in an economic sense? Will an

operator be willing to carry voice as well

as data? Could you carry the voice on the

macro cell and only carry data on the

small cell — is that possible because again

that drives a different requirement on

timing and the availability of timing. I

think operators are going through trials,

and the trials are meant to understand

these scopes and where these

compromises can be made and what kind

of use cases can be made, the services

you can delver effectively over small cells.

So that’s really a crucial juncture for me. I

personally think if there’s no economic or

cost-effective way of doing this it won’t

happen at the scale we want it to happen.

Matt Yardley:If the sites and backhaul are the two

fundamental restraints, which I think

they are, then you look at FT in Europe

and KDDI in Japan, who are both doing

indoor WiFi based strategies. Is that

because sites and backhaul externally are

more complicated? Or is it that they are

making that choice because it's the lower

hanging fruit and they might be trading

off to some extent the quality part? It

seems to me at the moment there's more

of a momentum towards WiFi and it is

probably for the very simple reason that

the installed base is there and the

economics are so good.

It doesn't mean it's going to win out in

the end but that seems to be where the

experimentation is. Now when you got

to an external small-cell based approach

the interesting question is to what extent

that addresses the in-home demand. I

think that’s the really interesting switch

point because it may be in the long term

Mobile Europe Insight Report |

ROUND TABLE

that the WiFi thing switches over to

external, but at the moment it's really

hard to call.

Richard Webb: I think in the long term there will be a

very compelling case for both, but I agree

that WiFi has been an available

technology that operators and users are

comfortable with. Right now it’s about

getting a proportion of traffic off the

network to ease data congestion. In time

we will see WiFi integrated into small cells

and see dual infrastructure, as there are

very compelling reasons to have both. For

example WiFi does not handle video

streaming as well as LTE networks that are

more applicable to that kind of content.

And then there’s the ability to have data

sessions simultaneously on the same

device, with a video stream on LTE and

files over WiFi at the same time, to give a

dual WiFi-LTE experience.

Matt Yardley:Standardisation will come around the

things that WiFi does well, and that small

cells do well. We hear about WiFi not

being able to deal with encryption,

authentication, policy control, and if that

were resolved would you see a femto and

WiFi strategy start to become more

common in the next five years?

Andy Sutton: Even if we have carrier grade WiFi,

again what does that mean for backhaul?

If we want low latency in our macrocell

network, then surely we want to match

that user experience.

Richard Webb: Yet one of the things I’m hearing from

the vendors now is kind of the reverse of

what Andy was saying, that there is less

focus on making WiFi carrier grade and

more focus on making small cells more

WiFi grade, more best-effort rather than

the macro model of due diligence that

operators would put towards the

deployment of a macro cell. Just

proliferate small cells, throw them out

there, with the mindset that 20% would

be exactly where you want them, 60%

more or less where you want, and maybe

20% won’t really do a great deal in terms

of benefitting that area, but the overall

benefit in terms of cost and speed of

deployment is there. So they are trying to

put the smarts into the small cells to allow

operators to just throw them out, almost,

wherever they have a specific set of

challenges, without necessarily the same

analytics and criteria that you would get

for macro cell sites. So I think we might

see a little bit more of that, and that

impacts on backhaul, and that’s why I

think we’re seeing things like unlicensed

millimetre wave radio get consideration,

which is something that would never have

been on the table for macro. There seems

to be a gradually lowering set of

parameters in terms of the reliability of

that backhaul, a gradual shift of

philosophy in deployment of small cells

being driven by the vendors.

Andy Sutton: It’s potentially a huge gamble and

you’d certainly have to see the acquisition

and backhaul price low enough to justify

doing that, and also in the future the likes

of eICIC and more advanced features like

CoMP find their way down into the small

cell layer, we’re not really seeing that at

the moment. Those are advanced features

that require very tight company between

the small cell layer and macro network in

terms of coordination and radio resource

management.

This really leads into a discussion of

what the small cell architecture will look

like. Is a small cell with traditional

backhaul a long term solution, or actually

if you want to build a small cell layer

should it be subtended from the macro

layer which then changes the dynamics of

those coordination issues, but again

you’ve still got the acquisition issues and

need to get fibre out there. To my mind

that’s more of a Het Net discussion, an

advanced discussion for the future, than

where we are today with small cells.

OPERATIONAL CHALLENGEKeith Dyer:

I wonder what challenges small cells

will place on the way operators install and

manage the network? Their network

teams are geared for macro installations

up towers, for instance, rather than a

single person on a ladder.

Julian Bright:Vendors do seem to be putting a lot of

effort into that element of the small cell

offering, so that installation is a very

simple process. It all sounds good in

theory and if it works that well in practice

then it will ease the process considerably.

Richard Webb:Some operators are saying they see a two-

man team for micro cells installing two to

three of those sites per day. For small cells

a one man team would be deploying

four to six in a day. What’s interesting is

that this is a metric that has not really

been a part of their macro thinking.

Matt Yardley:Looking at it from a radio perspective, in

small cells the traffic is where the traffic is,

you’re not necessarily going to have the

flexibility to say, “Stick the site 200m

down the road, and we’ll change the

parameters of the grid to adapt.”

Viraj Abhayawardhana:The devil is in detail on sites. I think it will

all come down to those three to six sites

per macro, then working out where you

want to go. Then the backhaul portfolio

should be wide enough to select these

different options. There’s not going to be

one solution for all.