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Cloud-RAN Workshop 2010.04.231 © Nokia Siemens Networks

Discovery of Cloud-RANHao Guan, Troels Kolding, Peter MerzNokia Siemens NetworksApril 23rd / 2010


Trends & Challenges Cloud RAN &

Benefit

Outline

Summary

3 © Nokia Siemens Networks Cloud-RAN /2010.04.23

Traffic Trends & Challenges“Traffic explodes and is non-homogeneous”• Mobile Internet Traffic is exploding

• Traffic distribution depends heavily on terminal profile:– Laptop => residential areas– Smartphones => urban areas

• 15~20% of the sites carry ~50% of the total traffic

• Data traffic is more Flat over 24h than Voice

• Operators need to further denisfy the macro layer but face the challenge of getting new sites and/or upgardingexisting sites

• Small(er) cells needed to cope with mobile broadband in dense areas

0

5

10

15

20

25

2010 2011 2012 2013 2014 2015

Mobile Internet Traffic [ExaByte/year]

Mobile Laptop

Mobile Handheld

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100Percentile of NB

Traf

fic S

hare

(%)

MeasurementExponential Distribution

Cumulative Distribution Function (CDF) for the Distribution of Traffic over ~10k NB

In most networks ~15-20% of cells carry 50% of traffic

capacity driven coverage driven

Note: Based on measured operator network traffic

Approximation:Tc = (1 – ln (Nc)) Nc

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100Percentile of NB

Traf

fic S

hare

(%)

MeasurementExponential Distribution

Cumulative Distribution Function (CDF) for the Distribution of Traffic over ~10k NB

In most networks ~15-20% of cells carry 50% of traffic

capacity driven coverage driven

Note: Based on measured operator network traffic

Approximation:Tc = (1 – ln (Nc)) Nc


Technology Trends & Challenges“BS moves up and backhaul is decisive”• Base Station moves up the mast:

– Small cell solutions like Micro/Pico– 6 sector solutions, Remote Radio

Heads, Active Antenna Systems, smart antennas (e.g. TD-SCDMA)

• Base Station sites:– Multi-technology (e.g. GSM+TD-SCDMA

soon TD-LTE )– Multi-operator (e.g. site sharing)– Legacy interfaces (CPRI, OBSAI, Ir)

• Backhaul becomes mission critical– Availability (e.g. fiber)– Migration/unification to IP/Ethernet

• RAN TCO is dominated mainly by OPEX and less by BS CAPEX

Antenna integratedAntenna integrated

AntennaAntenna

Tower/mastTower/mast

System moduleSystem moduleBBBB

FiberFiber

RFRF

RRHRRH

AntennaAntenna



RFRFFiberFiber

ConventionalConventional

RFRF

BBBB

AntennaAntenna


BTSBTS

FeederFeeder

ModularModular

AntennaAntenna


RFRFFiberFiber

RooftopRooftop

Mul

ti-m

ode

RF moving towards antenna

Active Antenna (AA)Distributed BTS


AntennaAntenna



FiberFiber

RFRF


AntennaAntenna



FiberFiber

RFRF

RRHRRH

AntennaAntenna



RFRFFiberFiber

RRHRRH

AntennaAntenna



RFRFFiberFiber


RFRF

BBBB

AntennaAntenna


BTSBTS

FeederFeeder


RFRF

BBBB

AntennaAntenna


BTSBTS

FeederFeeder

ModularModular

AntennaAntenna


RFRFFiberFiber

RooftopRooftop

ModularModular

AntennaAntenna


RFRFFiberFiber

RooftopRooftop

Mul

ti-m

ode

Mul

ti-m

ode

RF moving towards antenna

Active Antenna (AA)Distributed BTS


Site Trends & Challenges“Site is a lot more boxes than just the BTS”• Legacy site

– GSM900 site grid opt. for voice opt. – Reusing site, outlook unchanged

• Trend– Multi-Standard upgrades => ”Single

RAN”– Refarming– SON-features

• Site cost– BS minor part of a typical new macro

site!– Construction works, Power

• Breakdown of BTS site OPEX vary a lot depending on the market type:– In mature markets: rental and backhaul– In developing/emerging markets (e.g.

India): Power consumption BTS

Transmissionwireline, fiber, mwrAntenna system

incl. feeders + MHAs

Power systemw/ batteries

Cabinet or shelteroptional

Antenna/BTS supporting stucturetower/pole

BTS

Transmissionwireline, fiber, mwrAntenna system

incl. feeders + MHAs

Power systemw/ batteries

Cabinet or shelteroptional

Antenna/BTS supporting stucturetower/pole

Wide area sites

Medium area sites

Local area

Majority of sites today> 300 m> 5 W output power

Share of sites growing •100-300 m•1-5 W output power

Special cases•10-100 m< 500 mW

Wide area sites

Medium area sites

Local area

Majority of sites today> 300 m> 5 W output power

Share of sites growing •100-300 m•1-5 W output power

Special cases•10-100 m< 500 mW


Cloud RAN & BenefitTrends &

Challenges Summary

Outline


Cloud-RAN“Legacy Systems needs to be taken into account”• How to support legacy systems?

– 2G(GSM), 3G(TDSCDMA) – Variety of site internal interfaces

e.g. Ir• Backhaul vs. Fronthaul?

– How to take advantage of dark fiber– IQ vs. IP requirements e.g. Latency,

Throughput, Synchronization, …– Smart antenna requirements

• What’s right scenario?– Outdoor or Indoor– Site sharing

• Power consumption– PA: 60%~70%

SITE/RRH 1

SITE/RRH 4

SITE/RRH 3

SITE/RRH 2

BTS Cloud, single- or multi-RAN.Multi-cell resource optimization

Single- or multi-RAN/RRH.

Dedicated “dark”fiber or evolved FTTx bundled solution. Ring topology or point to point

(DE)MUX


Cloud-RAN CAPEX/OPEX Savings"TCO saving potential but many screws to tune"

Presentation / Author / Date

CAPEX (40% of TCO)

OPEX (60% of TCO)

Assume 25% cost reduction via C-RAN since battery backup and RRU is needed at each macro site

Assume 25% cost reduction via C-RAN due to load sharing also considering processing needs for radio-over-fiber.

Assume that cost of fiber front-haul is the same as fiber backhaul cost and copper is not used. For some operators/markets this provides negative C-RAN business case.

Assume negligible saving over integrated multi-radio BTS solution requiring power backup. Increased fiber capacity need (and potentially cost) for C-RAN is not considered which may be essential in some markets.Assume 25% reduction of electricity cost (60% of power comes from PA, battery cooling also remains at site).

Assume 50% reduction of O&M costs assuming RRU is robust and upgrades to RF parts (multi-band, multi-radio) are very small compared to BBU.

Calculations depend very much on assumptions and legacy installations.Additional C-RAN savings via multi-operator site sharing not considered.

C-RAN offers 2-5% CAPEX saving

C-RAN offer an OPEX saving up to 10-20%.


Cloud-RAN Capacity Improvements"Approaching Shannon limit, major breakthroughs unlikely"

C-RAN offers opportunity to reduce X2 delay to allow real-time ICIC and CoMP

Real-time ICIC (centralized processing)• Multi-cell RRM gain: ~10-30%

Realtime CoMP (centralized processing)• Joint processing gain: ~10-15%• Possible in LTE 3GPP Release 11/12


SummaryTrends & Challenges

Outline

Cloud RAN & Benefit


Working together for a net positive impact to the industry and environment

and more

Reducing power consumption by up to 70%

Use of renewable energy sources

Over 90% of Flexi BTS recyclable

Life-cycle

Design Suppliers

Own operationsRecycling

ICT can help to save nearly €600 billion in 2020, i.e. 7.8 billion tons CO2

Source: GeSI


Summary

At base of mast or tower

On top of mast or tower

Stacked on floor or shelf

Separated radio units

On wall or pole

Hidden sites BTS or 19”cabinets

Compact FlexiBTS already enables plenty of deployment options

There are plenty of challenges and opportunities which need to be assessed taking specific operator and deployment constraints into account.

Cloud-RAN is a good new fresh idea which needs further study!


Thank you

www.nokiasiemensnetworks.comGuoHua Plaza, 3 DongZhimen South StreetDong Cheng District, 100007Beijing, China

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