Intelligent Information Network - KISpalo/Rozne/cisco-expo/2006/...GPON and EPON are two new...

1© 2005 Cisco Systems, Inc. All rights reserved.Session NumberPresentation_ID Cisco Confidential

Intelligent Information Network


FTTX Deployment Considerations

Wolfgang [email protected]


Trends for access bitrates

333© 2003, Cisco Systems, Inc. All rights reserved.Presentation_ID


Trend for access bitrates (1)

• Race between application requirements and technical capabilities(remember evolution of PC capabilities?)

• Bitrate increase usually justified by requirements of video streaming applications (some SDTV and one HDTV stream per household + VoIP + Internet)

• Do we really anticipate future bandwidth requirements?video download rather than streamingvideo e-mailjoint video editing...

• Bursty ultra-high-speed communication vs. real-time streaming• 100 Mbit/s available in a number of networks

in Scandinavia and NL• 1 Gbit/s residential access already available in Hong Kong


Trend for access bitrates (2):exponential growth

1

10

100

1000

10000

100000

1000000

10000000

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

2014

2016

2018

kbit/

s

"High-speed connection," actual Straight line extrapolation

Source: Heavy Reading report “Next-Generation Broadband in Europe: The Need for Speed”


And it grows even faster ...


Topologies



Next Generation Broadband Architecture

DSL Access Node

Distribution Node

BRAS

MPLS PE

SCE

Residential

STB

Aggregation Node

Aggregation Node

Core NetworkIP / MPLS

VoD

Content Network

TV SIPBusiness

Corporate

Business

Corporate

Aggregation Node

SiSi

SiSi

SiSi

SiSi

SiSi

Ethernet Access Node

Aggregation NetworkMPLS, Ethernet, IP

Distribution Node

Access L2/3 Edge

Identity Address Mgmt

Portal Subscriber DatabaseMonitoring

Policy Definition

Billing

Policy Control Plane (per subscriber)

VoD

Content Network

TV SIP

Residential

STBBusiness

Corporate


Topologies

• Tree architecturesPassive Optical Network (PON) technology

• Star architecturesPoint-to-point connection of customers to switches in a star topology

• Ring architectures of Ethernet switchesInterconnection of switches by Gigabit Ethernet in a ring topology

• Topologies can be mixed and matched in a single network, depending on available fiber and service requirements


One fundamental aspect of FTTH in Europe

• In the US there is a clear equivalence FTTH = PON

• In Europe there have been way more POINT TO POINT (or ring) Ethernet deployments than PON

• The market for GPON in Europe may materialize when driven by Incumbents


Passive Optical Networks (PON)



Core Network

Aggregation

Access

Main Point of Presence

Internet

PSTN

ONU in basement

Voice Gateway

SMB and residential

10 Passive Optical Splitter

10 Mbit/s

WiFi

Videosurveillance

1:N split

Video source (VoD / Bcast)

ONT

PCTV Set

Ethernet

RJ-11

RJ-11Ethernet

Set-top Box

AnalogPhones

RF coax

ONT in Appartment or office

ONT in home or business

ONT

ONU

ONT

PON architecture


PON architecture

• Applicable to both MTU and individual subscriber scenarios• Interconnection of aggregation switch (OLT) and

ONU (MTU deployment) orONT (individual subscriber deployment) by a

• Passive Optical Network in a tree topologyPassive splitters used for splitting the feeder fiber into many distribution/drops connecting the end users to central office.Typically uses a single-mode single-fiber for both directions (WDM)

• Up to 32/64 endpoints per tree, depending on specific PON technology

BPON Initial Standard (G.983.1) became available in 1998GPON and EPON are two new standards for PON. GPON has been standardized by ITU-T (G.984) and EPON has been standardized by IEEE (802.3ah).

• Possibility for Analog/Digital TV delivery on a separate wavelength


PON Protocol Overview

OLT

C B A1490 nm

C B A

C B A

C B A

CBA1310 nm

A

C

B

ONT

ONT

ONT

A

CATV overlay

B

CATV overlay

C

CATV overlay

CATV overlay

CATV overlay

CATV overlay

CATV overlay

1550 nm


Reasons for PON deployment vs. star

• Fiber saving between splitter and CO/POPrelevant in scenarios where existing cables or ducts need to be reused towards the splitter, or where fiber deployment is restricted (e.g., aerial cabling)hardly relevant for greenfield scenarios (marginal cost of fiber compared to digging, splicing, ...)

• Analog video overlay for existing broadcast servicesemulates cable TV distribution plant on a separate downstream wavelength delaying introduction of IP TVrequires equivalent of cable headend at each OLT side

• Port saving in the CO/POPneed to terminate thousands of fibers on switch portsPON can reduce this by 1...2 orders of magnitude compared to P2Pport costs on a per-customer base, however, are roughly equivalent

• No deployment of active equipment in the outside plantin Europe typically loops are sufficiently short so that also for P2P there is no need to put active equipment into the outside plant, unless the fiber saving argument becomes relevant

• Religion ...

RF TV


Splitter deployment

Three possibilities to place splitter1. CO/POP

– backhaul of all the fibers to the CO/POP and termination on ODF– no fiber cost saving– port saving in the CO/POP compared to P2P– maximum flexibility to allocate customers to trees and change architecture

in the future to P2P2. Buried in the field

- static allocation of customers to trees- feasible for new-builds where customer acceptance is given- maximum fiber saving towards the CO/POP- no flexibility- splicing in the field required

3. In street cabinet- flexible allocation of customers to trees or even P2P fibers if available- feasible for overbuilds with unpredictable take rate- maximum fiber saving towards the CO/POP- splicing and street cabinet in the field required (expensive!)


Issues with PONs

• Bandwidth is shared among all users on the tree • Every endpoint (OLT, ONT, ...) has to operate at the aggregate bitrate

e.g. a GPON ONT delivering 40 Mbit/s to an end customer has to operate at 2.5 Gbit/s

• Significantly higher optical power required e.g. 20.4 dB (power ratio of 110) for 1:64 split => equivalent to 58 km of fiber at 1300 nm or 102 km at 1500 nm

• Theoretical maximum number of customers per tree is rarely reached due to take-up rates, unless expensive ODFs in the field are used to optimize utilization

• No resilienceOLT optics is single point of failurecorrupt CPE can impact entire PON tree

• In case of technology obsolescence all terminations on a tree need to be replaced


PON deployment (example of splitter in street cabinet)

OLT opt.MDF

ODFwith

splitter

Splice point: pigtails to cable

ONT

ONT

1 fiberper n OLTs

Splitter


Splitter cabinet and splitter

Source: ADC

Splitter cabinet

Splitter


CPE aspects

• CPEs (aka ONUs or ONTs) are an integral part of the PON architecture

• Multi-vendor interoperability left for the future

• Special functionalityMedia Access Control

Burst-mode lasers

Significantly higher optical power

makes PON-CPEs inherently more expensive than native Ethernet CPEs

• Typically deployed and owned by the Service Provider as corrupt CPEs can impact the traffic of other customers and compromise security


ONU/OLT ratio forecast for Japan

166493 663

813 903 953280

1,597

2,947

4,647

5,847

6,647

1.69

3.24

4.44

5.72

6.486.97

-

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

2004 Actual 2005Prospect

2006Forecast

2007Forecast

2008Forecast

2009Forecast

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

OLTONUONU/OLT Ratio

Source: FCR


Star Architecture or Point-to-Point (P2P) orhome run fiber



Core Network

Aggregation

Access

Main Point of Presence

Internet

PSTN

Access switch in basement

Voice Gateway

SMB and residential

10

10 Mbit/s

WiFi

Videosurveillance

Video source (VoD / Bcast)

ONT

PCTV Set

Ethernet

RJ-11

RJ-11Ethernet

Set-top Box

AnalogPhones

ONT in Appartment or office

ONT in home or business

ONT

ONT

Ethernet star architecture


Ethernet star architecture(aka home run)

• Fiber access to individual subscribers (e.g. single family residences)

Access switches in CO or cabinetSingle mode single or dual fibre

• MTU deployments for residential, SMB, and Enterprise customers

Access switches in basement of MTU; last drop via Cat5, MMF, EoVDSL

• Increased resilience can be achieved by dual homing of access switches (second pair of fibers)

• Very flexible and future proof solution as it allows virtually unlimited bandwidth per customer

• No splices in the field needed if, e.g., microduct technology is used


Star deployment

CO switch opt.MDF

Splice point: pigtails to cable

ONT

ONT

n fibersper n ONTs


Typical dimensioning(urban deployment in Europe)

• Loop lengths:average 3.5 km

maximum 5 km

• Size of POP:serving 5 000 – 10 000 homes


CPE aspects

• CPEs can be commodity items purchased at a retail store

• No interoperability issues• No special functionality required

No Media Access ControlNo Burst-mode lasers

CPEs less expensive than PON CPEs• Can be deployed and owned by the customer as

corrupt CPEs can not impact the traffic of other customers or compromise security

just switch off the port in case of insane CPE behaviour


Open Access



Horizontally or vertically integrated?

• Many existing networks are vertically integrated, i.e.,Infrastructure, network, service delivery are owned and operated by a single companyConceptually simplest model, well understoodSignificant Market Players (e.g. incumbent operators) need to open up their networks and offer wholesale services

• Horizontal network structure is being introduced in a number of new networks built by non-classical operators (e.g. municipalities, utilities)

Network structured into layers that can be built, owned and operated independently=> Open Access Network


What is an Open Access Network?

• Wholesale access on equal terms for Service Providers (SPs)ISPsVoice SPsVideo SPsGaming SPs...

• New horizontal business model for utilities and municipalities

Different depreciation cycles and financial models for passive and active infrastructureSkill sets for digging fibre and operating telecommunication networks are complementary

• Owner of physical infrastructure typically does not compete against his SP partners (in contrast to classical wholesale models by incumbents)


Physical Infrastructure Provider

Network Operator(s)

Content Broker(s)

ISP Voice SP Video SP

ISP Voice SP Video SP

Players in Open Access Networks


Open access architecture on the infrastructure and physical layers

• Layer 0 (infrastructure)DuctsMicro ductsCables / Cable elementsFibres

• Layer 1 (physical layer)Wavelength (still hardly used)


Open access architecture on architectural layers

• Layer 2 (Ethernet)Service / provider specific VLANsL2TP over IP infrastructure (hardly used)PPPoE (not used in FTTH deployments, lack of flexibility)

• Layer 3 (IP / MPLS)Standard IP peering agreements between content aggregator and SPMPLS VPN-like


Microduct technology



Microduct technology

• Microducts are small plastic tubes (down to 3mm diameter) which provide a continuous physical channel between endpoints (e.g. CO to customer)

• After installation of the microduct fiber is blown into it as a single strand without any intermediate splices. Up to about 6km of fiber can be inserted in a single blow.

• Microducts are bundled in outer ducts for easy deployment in trenches or sewers

• Routing of individual microducts from one duct to another is typically performed in small underground cabinets, and pieces of microducts are interconnected using muff couplers


Microduct fiber blow technology

Basic concept

Underground microductinterconnection

Blowing equipment

Source: Emtelle


Summary



What has been deployed so far?

• In the US the big incumbents are currently deploying BPON with plans for GPON in the future

Re-use of existing duct and outside cabinet structure

• In Japan NTT are deploying EPONRegulatory situation enforced lowest common denominator

• Virtually anywhere elseDeployment of Point-to-Point/Star Ethernet or Ethernet rings

Only very little traction for PONs


Testimony of largest FTTH project in Europe

Quote from Amsterdam Citynet website

“In accordance with current best practice, Citynet has adopted the home run fiber architecture. It is felt that given the short distances the flexibility and robustness gained by having a dedicated fiber connection from POP to customer premises outweighs by far any cost savings on fiber cablingthat would be possible with multipoint architectures (such as PON).Citynet plans to run standard 2 single mode fibers (1 pair) to each residential customer. This allows for current Ethernet standards using 2 fibers or for 1 fiber for datatransport and 1 fiber for analog TV. It is expected that the miniducts will support some extra fibers. They will be blown and made available on request (i.e. for larger organizations).”


Conclusion

• Fiber deployment to residences is a large investment into the future

• Every deployment scheme for FTTH networks has its own merits

• PONs can optimize deployment cost in the very short term, but do not represent a very future-proof investment as they constitute bottle-necks built into the physical infrastructure

• Star architectures represent the most future-proof solution which can provide virtually unlimited bitrates to subscribers. Individual subscribers can be migrated to more powerful technologies as needed without impacting the service to other subscribers

Intelligent Information Network - KISpalo/Rozne/cisco-expo/2006/...GPON and EPON are two new...

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