Fujitsu Proprietary and Confidential All Rights Reserved, ©2006 Fujitsu Network Communications

Understanding Mobile Backhaul

Randy Eisenach

Fujitsu Network Communications

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Agenda

Wireless backhaul architecture

Understanding spectrum & transport requirements

Latency / Jitter – they still matter

Multi-protocol solution

Shifting your focus

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Typical 2G/2.5G GSM Network

BTS Base Transceiver Station

BSC Base Station Controller

MSC Mobile Switching Center

SGSN Serving GPRS Support Node

GGSN Gateway GPRS Support Node

BTS

MSC

BSC

GMSC

Abis

BSC

BSC

A

A

MSC

MSC

BSC

BSC

PSTN

SGSN

GGSNInternet

Gb

A

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Physical Interface Requirements

BSC

MSC

SGSN

Abis

A

Gb

2G / 2.5G GSM

RNC

MSC/MGW

3G SGSN

Iub

Iu-cs

Iu-ps

3G UMTS/HSDPA

BTS

BTS

BTS

Node B

Node B

Node B

TS 25.411ATM / TDM – DS1 to OC-12Iu-b, Iu-cs, Iu-psUMTS

TS 48.014TDM - T1/E1Gb

TS 48.004TDM - T1/E1A

TS 48.054TDM - T1/E1AbisGSM

StandardPhysical Layer SpecInterfaceTechnology

Note: Native Ethernet interfaces on NodeB / RNC not expected until mid ‘08

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Wireless Capacity Requirements

Cell tower transport requirementsTypical – copper fed T1s (1 to 4)

2.5G / 3G data requirements – growing but still modest

Spectrum & spectral efficiency determine ultimate capacity

3 sector cell

Spectrum Example

GSM 2G

1.2 Mhz

GSM/Edge 2.75G3.5 Mhz

voice

voice+data

UMTS/HSDPA 3G5 Mhz

data

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Wireless Capacity Requirements (con.)

GSM Spectral Efficiency - example200 KHz carrier frequency channels

• 8 timeslots per channel

• 13 Kb/s voice codec

• = 104 Kb/s voice traffic

0.52 bit/s/Hz

Typical Cell Tower Requirements1 – 4 T1s per cell tower (per carrier) is common

US - Only 15%US - Only 15%

of handsetsof handsets

are 3Gare 3G

capablecapableBusinessweek, June ‘07

iPhone / EDGE

1319.565%3205HSDPA 3G

45.75%310.522.31.2GSM / Edge 2.75G

11.265%30.521.2GSM 2G

# T1s

Total

bandwidth

(Mb/s)Traffic Eng

% Peak

#

sectors

Data

efficiency

(bit/s/Hz)

Voice

Spectral

Efficiency

(bit/s/Hz)

Data

Spectrum

(MHz)

Voice

Spectrum

(MHz)

Wireless Capacity Requirements

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Mobile – Historical reliance on TDM

2G / 3G standards specified TDM physical layer

Modest bandwidth requirements1 – 4 T1s per cell site

Cell tower accesscopper fed T1s widely available to cell tower site

• Conversely, only ~7% cell towers have fiber access

• Hard to justify fiber construction for 1 – 4 T1s

T1s prices have declined from $1500/mo to $300/mo

EthernetLack of carrier grade Ethernet service offerings

• Ethernet over Copper

Latency, Jitter, Availability – They Still Matter

175,000 cell sites in the US

most only need 1 – 4 T1s

approx. 7% have fiber

~ 12,000 towers

Eng

ak

Total

bandwidth

(Mb/s) # T1s

1.2 1

5.7 4

19.5 13

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Latency, Jitter, Availability – They Still Matter!

NoteMany “carrier grade” Ethernet platforms meeting much more stringent performance targets than MEF

Delay

Parameter

<5 ms

Mobile

Target

Jitter 1 ms

Availability 99.999%< 5.3 min/yr

MEF Spec

<25 ms

<10 ms

99.95%< 263 min/yr

TDM /

SONET

<100 us

<3.2 us

99.999%< 5.3 min/yr

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Circuit Emulation Trade-offs

DS1 circuit emulationTrade off between delay & efficiency

• Packetization delay, jitter buffer delay, network delay

- Low delay

- Low efficiency193 bits

T1 Frame

Hdr Data FCSIFG SDPreamble

> 72 Bytes12 bytesworth

125 us - Longer delays

- Improved efficiency

T1 Frames

193 bits 193 bits 193 bits

Hdr Data FCSIFG SDPreamble

> 72 Bytes12 bytesworth

2. 94 Mb/s52%4

BandwidthEfficiencyFrames

6.40 Mb/s24%1

2.37 Mb/s65%8

Circuit Emulation Efficiency (typ)JitterBuffer

51080

Buffer Delay

(ms)

Max Ntwrk

Jitter (ms)

Buffer Size

(frames)

51080

Buffer Delay

(ms)

Max Ntwrk

Jitter (ms)

Buffer Size

(frames)

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Observations

Wireless Backhaul SummaryBandwidth

• increasing, but still modest

• 4G LTE (Yr 2011/12) – bandwidth requirements get interesting

Heavy reliance on T1s

• Multi-protocol world – T1s will be in network for 15 to 20 years

• Many mobile wireless service providers require a TDM transport solution

Ethernet / Circuit Emulation

• Carrier grade Ethernet solutions emerging

• Latency, jitter, availability, protection– these matter to your customers

• Ethernet will grow as native Ethernet interfaces on 3G / 4G base stations are deployed

• T1 circuit emulation best when network is mostly Ethernet with a few T1 ports

Maybe what’s needed ……

• Hybrid TDM/Ethernet platform

• Flexible mix of TDM / Ethernet capacity

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Multi-protocol Solutions

Mobile Wireless Customer ARequires TDM transport – Hybrid TDM/Ethernet solution

BSC/RNC

MSC/MGW

SGSN

GSM

T1

10/100

FW4100ES

UMTS

UMTS / 4G

T1 FW4100

T110/100

FW4100

T1

10/100

Mobile Wireless Customer BComfortable with Ethernet only implementation

BSC/RNC

MSC/MGW

SGSN

GSM

T1 CES

10/100

UMTS

UMTS / 4G

T1

T1 CES10/100

T1 CES

10/100

MPLSOpt. Eth

Opt. EthEth

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Fujitsu Solutions

Fujitsu Experience+3,000 cell sites connected via multi-serviceTDM/Ethernet platforms

None are pure “optical Ethernet”

Fujitsu FLASHWAVE 4100 / 4100 ESTraditional TDM services DS1 to OC-12

Carrier grade Ethernet services

• 10/100BT, 100FX, GigE

• MEF Certified

TDM / Ethernet multi-service hybrid platform

Provisionable bandwidth mix between TDM &Ethernet services – you decide the split

Temperature hardened for OSP applications

Multiple indoor and outdoor cabinet options

Slashes the cost of service delivery to cell sites

FLASHWAVE 4100 LS

FLASHWAVE 4100 ES

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Typical Mobile Backhaul Application

MTSO

FLASHWAVE 4100

FLASHWAVE 4100 ES

FLASHWAVE 4100 ES

FLASHWAVE 4100 ES

Pt - Pt

Microwave

FLASHWAVE

4100 ES

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Shifting your focus…

Core mobile wireless network15 dedicated SONET rings

• OC-48

• OC-12

Need to reduce cost, improveservice flexibility

MSC

Wireline Telco CO

12 R ings OC - 48

3 R ings OC - 12

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Network Design

Overlay ROADM network65% of traffic moved could moveto a single metro DWDM network

• Lower network costs

• Lower operational costs

• Improved service flexibility

• Improved service response

FLASHWAVE 7500

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Summary

Mobile wireless backhaulHistorical reliance on T1 TDM services

Cell tower bandwidths growing, but still modest

Ethernet vs TDMReality - we live in a multi-protocol world

Don’t be surprised if wireless customers require TDM transport services

• Latency, Jitter, Protection Switching, Availability – they still matter

• T1 CES - delay / efficiency issues

• Ethernet will grow, as base stations support native Ethernet interfaces

TDM & Ethernet hybrid provides the optimal solutionFlexible “fusion” of both services

Shift your focusMobile core networks

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