metro cells the bigger picture - tmcnet

METRO CELLS THE BIGGER PICTURE ADDRESSING THE KEY CHALLENGES OF BUILDING A METRO CELL NETWORK

EXECUTIVE SUMMARY

Mobile network operators (MNOs) need cost-effective solutions to deal with the predicted exponential

growth in mobile data traffic on their networks, in order to maintain their subscribers’ quality of experience

(QoE). Metro cells, which are less costly macro cells, are widely seen as a leading solution to enable MNOs

to build a heterogeneous network, or HetNet, to overcome capacity and coverage constraints. However,

MNOs have many questions concerning deployment of metro cells, which by their nature must be deployed

in far greater numbers than traditional macro cells. To help MNOs successfully introduce metro cells into their

networks, Alcatel-Lucent offers two papers that address both the radio planning challenges and those beyond

the radio. This executive summary presents a brief overview of both papers.

TABLE OF CONTENTS

1. Introduction / 3

2. Overview / 3

3. Why consider metro cells? / 4

4. When to deploy metro cells? / 5

5. Where to use metro cells? / 5

6. Dedicated or shared carrier? / 6

7. Overcoming metro cell deployment challenges / 7

8. Conclusion / 9

9. Alcatel-lucent lightradio™ metro cell express solution / 9

10. Acronyms / 10

Metro Cells – The Bigger Picture ALCATEL-LUCENT BROCHURE

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1. INTRODUCTIONMobile data is growing at an unprecedented rate. Alcatel-Lucent Bell Labs predicts that mobile data will increase 25 times by 2016. It is widely understood that a traditional macro-only solution cannot provide the capacity needed to satisfy demand in the long term, either economically or operationally. This is because spectrum is limited; spectral efficiency improvements are close to exhaustion, as we get closer to the theoretical limits predicted by Claude Shannon; and it will be impossible to put macro cells everywhere capacity is needed due to regulatory and cost constraints. Rather, the solution for provid-ing massive capacity is the effective segmentation of radio frequency (RF) into smaller geographical “sectors” or coverage areas. There are a number of ways to do this, from deploying active array antennas (AAA) to small cells, with one of the main solutions being the densification of the mobile network with metro cells, small cells that are owned and managed by the MNO, to create a heterogeneous network or HetNet.

2. OVERVIEWMetro cells, a vital component of any HetNet, appeal to MNOs for a number of reasons. They enable MNOs to strategically and cost-effectively add capacity to traffic hotspots to improve the quality of experience (QoE) for end users. In addition, they extend network coverage to indoor locations that have traditionally been challenging to cover with a macro-only solution (see Figure 1).

Figure 1. Metro Cells places capacity and coverage wherever needed

However, MNOs have many questions concerning the deployment of metro cells, both within existing 3G networks and within LTE networks:

• Whyandwhenshouldmetrocellsbedeployed?

• Wheredometrocellsmakethemostsense?

• Shoulddedicatedorsharedcarrierbeusedformetrocells?

Furthermore, a large deployment of metro cells poses a number of challenges that must be addressed to keep costs low.


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To help MNOs successfully introduce metro cells into their networks, Alcatel-Lucent offers two papers on this topic. The first, Metro Cells Part I – Why, When, Where and How to Deploy Them, describes the challenges of building a metro cell network underlay. The second, Metro Cells Part II – How to Guarantee a Successful Deployment, looks at the challenges beyond the radio, including power, backhaul, installation, commissioning, provisioning, configuration, network optimization, site selection and acquisition — and regulatory and policy compliance. This executive summary presents a brief overview of both papers.

3. WHY CONSIDER METRO CELLS?Metro cells, small cells deployed by operators in public or open access areas, provide more capacity at a lower cost, place capacity and coverage directly where they are needed and improve the QoE for subscribers.

“ I think people expect to be on the grid all the time…If it was a known

fact that this venue didn’t have reception, I don’t think that we’d

keep them on our list of options.”

Sarah-Jane Semrad

Events Director, KXT 91.7 FM, Dallas

As small, low-power access points, metro cells offer a lower total cost of ownership (TCO) than a macro-only solution. To determine the savings metro cells can provide, Alcatel-Lucent Bell Labs compared the TCO of a macro-only solution to that of a macro and metro cell solution, with and without the early introduction of LTE. The Bell Labs studyshowedthataW-CMDAmacroandmetrocellsolutionprovidesa38percentTCOsavingscomparedtoaW-CDMAmacro-onlysolution(seeFigure2).WhenLTEmacrocellsaredeployedwithW-CDMAandLTEmetrocells,thefive-yearTCOisreducedby45percent,comparedtodeployingW-CDMAmacrocellsonly(seeFigure3).

Figure 2. Five-year TCO for W-CDMA macro-only and W-CDMA macro + metro cells capacity upgrade

W-CDMAMacro-only

W-CDMA Macroand Metro Cells

100

120

80

60

40

20

0

38% TCO Savings

Eu

ros

(in

mil

lio

ns)

69

112

Figure 3. Five-year TCO for W-CDMA macro-only and LTE macro + W-CDMA and LTE metro cells capacity upgrade

W-CDMAMacro-only

W-CDMA Macroand Metro Cells

100

120

80

60

40

20

0

45% TCO Savings

Eu

ros

(in

mil

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ns)

62

112


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4. WHEN TO DEPLOY METRO CELLS?Whentodeploymetrocellsdependsonwhethermetrocellswillbeusedforcapacity or coverage.

As a capacity solution, metro cells are usually deployed in high-traffic locations to offload traffic from heavily loaded or saturated macro sites. To better understand when high-densityW-CDMAnetworkswillbecomesaturated,withandwithoutthelaunch of LTE, Alcatel-Lucent Bell Labs conducted a five-year network simulation with a tier 1 MNOinWesternEurope.ThesimulationshowedthatapproximatelytwopercentofallW-CDMAmacrocellsitesarealreadysaturated.Therefore,MNOswithhigh-densitynetworks who are planning on launching LTE late would benefit from deploying W-CDMAmetrocellsasacapacityoffloadsolutionrightnow.IfLTEistobelaunchedearly, the MNO can start to deploy metro cells now, on a more selective basis, then increase the volume of deployment in 2013 or 2014, as the macro sites begin to saturate. LTE metro cells, on the other hand, should be incorporated into the LTE network design from the onset, especially for high traffic-density zones that are expected to saturate quickly after service launch.

As a coverage solution, metro cells are usually deployed in areas with poor or non-existent macro coverage. These include both in-building locations and outdoor locations, such as the edge of suburban (coverage-limited) cells or small rural towns. Such coverage holes are very expensive to fill using conventional macro sites. Therefore thetimetodeployW-CDMAmetrocellsforcoverageandcost-effectiveQoEisnow.

5. WHERE TO USE METRO CELLS?Metro cells are used to provide capacity for urban hotspots, improve coverage in indoor locationsandextendnetworkcoverageandcapacitytorurallocations.Whenusedtoprovide capacity to urban hotspots, metro cells are deployed in selected high-traffic locations, such as city centers, train stations or shopping malls.

Whenusedtoimprovecoverageforindoorlocations,metrocellsaredeployedwithinindoor locations, such as event and convention centers, hotel lobbies or office buildings, to deliver superior voice and packet data services to areas with poor or non-existent macro coverage. In summary, metro cells can be deployed where they offer a lower TCO than other methods of extending coverage to in-building locations.

“ The problem with introducing more and more mobile masts is mainly

the vision impact. London is a protected skyline and we’re governed

by a lot of restrictions”

Andy Sherrin

Building Services Director


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For coverage and capacity extension to rural areas, metro cells are deployed in villages and other rural areas to deliver cost-effective voice and packet data services to locations with poor or non-existent macro coverage.

6. DEDICATED OR SHARED CARRIER?The economic return of a metro network is driven by the percentage of traffic that it offloads from the macro network — and this percentage is heavily influenced by which frequency is allocated to the metro layer. Metro cells can be deployed using a dedicated frequency or by sharing a frequency with the macro network (see Figure 4).

Figure 4. Coverage area of metro cell deployed with dedicated and shared carrier

Withdedicatedcarrier,theMNOreservesacarrierfortheexclusiveuseofmetrocellsin geographies that have been specifically targeted as needing extra capacity. In all otherareas,macrocellscanusethissamecarrier.Withshared-carrierdeployments,metro cells use one of the same carriers assigned to the macro layer, which would nor-mally have one or more additional dedicated carriers. The coverage range and offload effectiveness of metro cells deployed with shared carrier are lower than those using dedicated carriers. Also, with this type of deployment, metro cells cannot be placed too close to high-power macro cells. Alcatel-Lucent Bell Labs simulations provide guidance on the approach to take here, as described in Metro Cells Part I – Why, When, Where and How to Deploy Them.

Coverage area of metro cells deployedwith dedicated carrier

Coverage area of metro cells deployedwith shared carrier

Lowefficiency zone

Mocerateefficiency zone

Exclusion zone

High efficiency zone


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7. OVERCOMING METRO CELL DEPLOYMENT CHALLENGESMetro cells cover much smaller areas than macro cells, and they need to be deployed in much larger numbers in non-traditional locations, including at street level. Because of these differences, metro cell deployment poses a number of challenges that the MNO must address to ensure a quick and cost-effective deployment. Top challenges include site selection and acquisition and backhaul. For information on others, refer to Metro Cells Part II – How to Guarantee a Successful Deployment.

“ The complication comes in with site acquisition, power, and backhaul.

Those three are the key elements of putting in small cells and a

heterogeneous network”

Frank Favichia

Field Services

Bell Labs, Alcatel-Lucent

The selection of sites is a familiar process for MNOs, but the established models and tools used to plan and design macro networks are not effective in determining where to place metro cells. This is because metro cells provide coverage and capacity in much smaller areas or hotspots within the larger macro network. Optimal placement of metro cells necessitates the development and use of new models, tools and methodologies.

Operators know how to acquire sites for macro cells, and many also have long-standing relationships with tower companies. Metro cells, however, are not placed on towers or rooftops. Rather, they are deployed in large numbers in non-traditional locations, such as lampposts, utility poles and on the interior and exterior walls of buildings. To deploy metro cells quickly, while keeping costs low, the MNO has to find many suitable sites with low rental fees, readily available power and access to backhaul. Forming 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 meeting these objectives (see Figure 5).


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Figure 5. Optimal site acquisition requires a rich ecosystem of partnerships

Metro cell backhaul presents a number of challenges to mobile operators. Metro cells will substantially increase the number of sites, and the cost of backhaul can make or break the business case. Therefore, it is essential for the backhaul network to take important planning factors into consideration, such as the required availability, through-put and latency of the network, while also enabling fast, efficient installation and turn up of metro cells. In addition, it must be scalable for quick, cost-effective growth that keeps pace with the deployment of metro cells — and it must be easy to maintain to reduce the number of required site visits and keep operational costs low. The combina-tion of backhaul performance, availability, maintainability and scalability all factor into the overall metro cell backhaul TCO, which must be kept to a minimum to support the successful deployment of a HetNet.

Operators face a potentially daunting implementation burden when deploying new metro cell networks. To help MNOs deploy these new networks to reduce deployment and operational risks and speed time to market, Alcatel-Lucent is pooling all it’s capa-bilities across competencies, including site selection and acquisition, backhaul, power, regulatorycompliance,andothersintoasinglecomprehensiveservice.WiththeBuild,Operations Assist and Transfer service, Alcatel-Lucent provides consulting on business, operations and systems infrastructures, — and designs, integrates, tests, and assists with operations and knowledge transfer of the metro cell network to the operator, eliminating all the complexities of launching a new network and ensuring an optimized metro cell network.

Many sites aquired at one time

Optimal locations formetro cell deployment

Guarenteed availability of sites for quick deployment

Low site rental fees

WI-FISERVICE

PROVIDERSCABLE COMPANIES

MUNICIPALITIES

RETAILCOMPANIES

WIRELINESERVICE

PROVIDERS

ALTERNATIVEFIELD FORCES

UTILITIES

BILLBOARDCOMPANIES


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8. CONCLUSION Metro cells provide capacity and coverage at a lower TCO than macro-only solutions and enable MNOs to meet subscribers’ increasing expectations for a high QoE, no matter where they are. As a capacity solution, metro cells should be deployed in traffic hotspots todaytooffloadW-CDMAsitesthatarealreadysaturated.Metrocellsshouldalsobeincorporated into LTE networks from day one, especially in extreme traffic-density zones, such as sports stadiums, as these locations are expected to saturate quickly after service launch. MNOs would also benefit from deploying metro cells today for coverage, particularly for in-building locations that, traditionally, have been challenging to cover with a macro-only network and for rural areas where macro cells are cost prohibitive. For LTE networks, especially those being deployed in the higher bands, metro cells should be deployed for in-building coverage from the onset.

Because metro cells are quite different from macro cells, a large deployment of metro cells presents the MNO with a number of new deployment challenges that must be addressed before their full benefits can be realized. To accomplish this, MNOs must not only rethink how they plan, design and implement their network, but must also rede-fine existing business relationships and partnerships, as well as form new ones. Only by treating the deployment of metro cells in a holistic manner can operators fully unlock the business benefits that metro cells offer.

9. ALCATEL-LUCENT LIGHTRADIO™ METRO CELL EXPRESS SOLUTIONAlcatel-Lucent continues to drive the evolution of small cells. Initially envisioned for improving cellular performance at home and work, this technology is now well-suited for delivering increased mobile data capacity in public places. As the need to reuse spectrum intensifies, small cells, specifically metro cells, are becoming the optimal means of delivering higher capacity at a lower cost per bit to help operators rise above the mobile data storm. To fully realize the benefits that metro cells have to offer, MNOs require more than just a box. They need products and services specifically designed to simplify the deployment, operations and maintenance of metro cells. Alcatel-Lucent lightRadio Metro Cell Express offers a comprehensive solution. It includes superior products and services, such as a broad portfolio of metro cells designed for easy instal-lation and commissioning within a multi-vendor environment; business and economic modeling; hotspot geo-location services for optimal site selection; many pre-established partnerships and relationships for fast site acquisition; a full range of backhaul and design capabilities; and more. As a result, this end-to-end solution enables quick deployments, fast time to market, simplified operations and maintenance, and high scalability for future growth.

www.alcatel-lucent.com Alcatel, Lucent, Alcatel-Lucent and the Alcatel-Lucent logo are trademarks of Alcatel-Lucent. All other trademarks are the property of their respective owners. The information presented is subject to change without notice. Alcatel-Lucent assumes no responsibility for inaccuracies contained herein. Copyright © 2012 Alcatel-Lucent. All rights reserved. M2012063510 (June)

To date, Alcatel-Lucent has 39 commercial deployment agreements and over 20 ongoing trials of its end-to-end small cells solution. Publicly announced customers include: Telefonica in Spain, Etisalat and du in the United Arab Emirates (UAE), MegaFon and VimpelCom in Russia, Optus in Australia, and the Vodafone Group, which selected Alcatel-Lucent as its preferred vendor for nationwide “Sure Signal” femtocell services in the United Kingdom and New Zealand, “Booster” in Italy and “Private 3G Zone” in the Czech Republic.

To learn how Alcatel-Lucent lightRadio Metro Cell Express can help you in the successful deployment of metro cells, please visit www.alcatel-lucent.com/lightradio-metro-cell-express/ .

10. ACRONYMS 3G Third Generation

HetNet heterogeneous network

LTE Long Term Evolution

MNO Mobile Network Operator

QoE Quality of Experience

TCO Total Cost of Ownership

UAE United Kingdom

UK United Arab Emirates

W-CDMA Wideband Code Division Multiple Access

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

metro cells the bigger picture - tmcnet

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