Passive Optical Network Introduction

Passive Optical Networks Introduction

Aug, 2009

宽带通信 * 点滴生活

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Overview • Why PON (Passive Optical Network) • PON Architecture & Applications • PON Technology • Next Generation



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2009.8

P2

More and More bandwidth for more and more services HDTV with interactive programs, on multiple TV sets or PCs VOD movies and programs streaming or download video games on-line or download video blogs / online photos for digital cameras and camcorders online storage and back-up data security for consumers and SoHo's simultaneous and symmetrical usage multiple equipments

New needs emerging beyond what adsl and cable provide http://fttwho.blog.sohu.com


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2009.8

P3

Bandwidth in Access Network



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2009.8

P4



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2009.8

P5

FTTH is enabling new usage patterns right now fiber access

ADSL access

download and upload at 100mbps

download at 8mbps

upload at 1mbps

30 Gb

40min

>8h

>66h

DVD quality movie

4.8 Gb

6min 30s

1h 20min

>10h

amateur quality video

800 Mb

1min

13 min

1h 40min

20 photos with uncompressed 8M pixels

480 Mb

40s

8 min

> 1h

40Mb

3s

40 sec

5 min

full HD quality movie

10 MP3 music tracks



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2009.8

P6

FTTH modes •

Point-to-Piont (Star) • •

N/2N fibers 2N transceivers

N/2N fiber 2N transceivers

PTP •

Active Optical Network (AON) • • •

•

N subscribers

Minimum fiber 2N ＋ 2 transceivers Electrical Power in the field

Minimum fiber 2N+2 transceivers

PTP Curb

N subscribers

PON-P2MP • • • • • •

Minimum fiber N ＋ 1 transceivers Minimum fibers / space in CO No electrical power in field Uniform management Downstream broadcast (Video)



Minimum fiber N+1 transceivers

PTMP

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N subscribers

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P7

Overview • Why PON • PON Architecture & Applications • PON Technology

• Next Generation



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2009.8

P8

PON Architecture

OLT: Optical Line Terminal


ODN: Optical Distribution Network


ONU: Optical Network Unit

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2009.8

P9

PON Architecture (cont.)

PON system: OLT + ODN + ONU + EMS/NMS http://fttwho.blog.sohu.com


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2009.8

P10

Basic Architecture of PON



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2009.8

P11

PON Application - FTTx



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2009.8

P12

PON Services: Data + Voice + Video



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2009.8

P13

Overview • Why PON • PON Architecture & Applications • PON Technologies • Next Generation



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2009.8

P14

PON Alphabet

TDM-PON

GEPON

APON

BPON

EPON

WDMPON

10GEPON

GPON

DPON

NGPON



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RFPON 2009.8

P15

Passive Optical Network (PON) System Characteristics • Fiber Optic Media – All PON systems are based a point-to-multipoint physical topology where a single feeder fiber from the local exchange office is shared by a group of subscriber optical terminals (typically 32 or more) – A passive optical splitting device (i.e., power splitter or WDM splitter) is used to couple the optical signals from the shared feeder fiber to the individual subscriber (distribution) fibers, and vice-a-versa.

• Active Electronics – A single optical transceiver in the exchange is shared by a group of subscriber optical terminals (typically 32 or more) – For a fiber-to-the-premises (FTTP) systems, there is generally no active electronics in the outside plant. – The various PON technologies make use of different multiplexing techniques to allow shared access to the fiber media • TDM-based PONs and WDM-based PONs are two broad categories • TDM-based PONs are by far the most commonly deployed

– The various PON technologies also differ in available digital capacity, how they dynamically allocate upstream bandwidth to subscribers (for efficient PON bandwidth utilization), and embedded operations capabilities (just to mention a few examples) http://fttwho.blog.sohu.com


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2009.8

P16

TDM PON Example • Downstream – TDM transmission with multiple “listeners” (encryption to insure privacy) • Upstream – TDMA transmission with upstream transmissions (bursts) scheduled to prevent overlap Downstream (single -fiber systems): Upstream: RF video (if present)

E1/DS1/ Telephony

1490 nm 1310 nm 1555 nm

ONT1 Access Node E1/DS1

NB

(and/or) GbE STMn/OCn

TDM TDMA CC NB BB OLT ONT

CC

Data

TDM

VOIP

ONT2 OLT

BB

Time Division Multiplex Time Division Multiple Access Cross Connect Narrow Band Broadband Optical Line Termination Optical Network Termination

E1/T1/ Telephony

1:32 Optical splitter

Video

(or 1:64 for shorter reaches or with Reach Extender)

TDMA

POTS

ONT32

Data

Up to 60 km* physical reach (* with G.984.6 Reach Extender)

PONs are (in some sense) like HFC systems – shared medium http://fttwho.blog.sohu.com


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2009.8

P17

WDM-PON Example



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2009.8

P18

Hybrid WDM-PON Example Hybrid WDM-PON example wavelength splitter TDMA power splitter

Access node SNI

dedicated λ1 pair

ONT (Fixed Optics) ONT Bitrate 1

Feeder Fiber

OLT

1 to N λs on single fiber

dedicated λ2 pair

TDMA Wavelength selection here

* “Fixed” optics might be a cost reduced version of convention DWDM long-haul optics NOTE: Most believe adaptable optics will be required for a practical WDM-PON system


power splitter

ONT Bitrate 2

ONT (Fixed Optics)

Colorless ONTs: Transmitter and Receiver front-end filter characteristics are wavelength adaptable


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2009.8

P19

Today’s PON Systems • TDM-PONs Rule: The vast majority of PON systems deployed today are TDM-based PON systems (i.e., BPON, E-PON, and G-PON) – They almost exclusively operate on a single fiber, with WDM used to provide bi-directional transmission – A third wavelength in the downstream is sometimes used for broadcast video services (e.g., Verizon FiOS)

• WDM-PON: Very limited deploys, mainly in Korea – Costs of WDM-PON in delivering mass market dedicated wavelength services are still higher high relative to TDM-PON – WDM and hybrid WDM-PONs are expected to play a greater role in Next Generation (NG) PON systems (e.g., 5+ years) than today http://fttwho.blog.sohu.com


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2009.8

P20

TDM PON Architecture and Technologies 20 km Maximum Reach 20 km ONU differential range

OLT BPON

TXR

•Typically: 622 Mbps/155 Mbps (down/up)

Max 32 way split (may be cascaded)

B-PON

Fiber splitter

• Typically: 2488/1244 Mbps GPON

• GFP-like transports (Ethernet, and/or TDM)

G-PON

Max 64 way split [constrained by PMD attenuation limits]

Fiber splitter

ITU-T G.984.x

EPON

• 1250 Mbps/1250 Mbps [~850 Mbps effective payload rate])

TXR

ONT

•ATM-based transport ITU-T G.983.x

TXR

LU #1

Max 32 way split (16-way specified in standard)

LU #N, N ≤32

LU #1

ONT LU #N, N ≤64

LU #1

ONT

• Ethernet-based transport

E-PON

Fiber splitter

1000BASE-PX20 per IEEE 802.3ah

LU #N, N ≤32

Network optical transceiver (TXR) shared by “N” subscribers OLT implementations may not necessarily support all PON technologies indicated



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2009.8

P21

x-PON Technology Time Line FSAN GPON CTS

1995

‘98

‘99

FSAN BPON founded (ITU G.983.1)

published

2000

‘01

BPON IEEE OMCI EPON (G.983.2) begins published

‘02

‘03

FSAN BPON begins OMCI GPON (G.983.2) Revised

BPON Completed: April 2000

‘04

‘05

GPON TC (G.984.3) published

FSAN begins NG-PON

GPON OMCI (G.984.4) published

‘06

7th GPON Interop Event

‘09

‘07 ‘08

1st GPON G.984.5 Interop Event published IEEE begins 10GEPON

IEEE 802.3ah (EPON) published

G.984.1, G.984.3 G.984.4 Rev2 published G.984.2 amd2, G.984.6 published

EPON Completed: June 2004

BPON 1st Interop Event: March 2004

EPON 1st Interop Event: Jan 2006

BPON 1 wide-scale deployment: May 2004 st

EPON 1st wide-scale deployment: 2005

GPON Completed: June 2004 GPON 1st Interop Event: Jan 2006 GPON 1st wide-scale deployment: 4Q 2007

10G-EPON Study started: 2007 NG-PON Study started: 2008



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2009.8

P22

EPON - Downsteam



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2009.8

P23

EPON - Upstream



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2009.8

P24

EPON: Ethernet Simple, Fiber Fast •

Standard: IEEE802.3

•

Simple as traditional Ethernet: – – – –

•

EPON Media Access Control (MAC) uses Ethernet framing and line coding. Downstream channel uses true broadcast. Packets extracted by the MAC addresses. Not different from any shared-medium Ethernet LAN.

More concerns – Multiple access for Upstream transmission & Timing sychnization •

MPCP (MultiPoint Control Protocol is introduced)

– QoS on PON •

Dynamical Bandwidth Allocation Algorithm & 802.1d

– Optical power planning – ONU discovery & activiation – Security http://fttwho.blog.sohu.com


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2009.8

P25

BPON Standards • Produced in the Full Services Access Network (FSAN) forum – –

Established by the World’s Telecom operators Requirements driven approach

• Standardized in the ITU-T – G.983.1 R– Basic architecture, PMD and TC for ATM-based B-PON – G.983.2 R2 – Operations Management Communications Interface – G.983.3 – WDM enhancement, for video overlays on B-PON • G.983.3 A1 – Support for higher bit rates • G.983.3 A2 – Optical best practices for B-PON

– G.983.4 – DBA enhancement, for efficient bandwidth distribution – G.983.5 – Survivability enhancement, for protection switching



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2009.8

P26

GPON Standards • GPON is chartered as the ‘next step’ of PON evolution – Address rates greater than 1 Gb/s – To optimize the physical layer for these speeds – More packet-oriented, but still full service

• GPON draws on the B-PON series, but is distinct from it • GPON standards split into four layers – – – – – –

G.984.1: Requirements G.984.2: Physical layer G.984.3: Transmission Convergence layer G.984.3 A1: Refinements to TC layer

G.984.4: Management layer G.984.4 A1: Refinements to Management layer



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2009.8

P27

622/155 BPON Frame Structure

• •

Frames aligned at ATM cell boundaries DS PLOAM cells: – Synchronization – OAM channel – Upstream bandwidth assignment (53 grants)

• •

US PLOAM as needed (VPI=VCI=0) US byte overhead: – Cell synchronization and delineation



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2009.8

P28

GPON Frame Structure • • •

Frame size fixed at 125 µs Supports ATM and GEM payload within the same frame PCBd: – Synchronization – DS OAM channel – Upstream bandwidth map (one byte granularity) – Downstream structure

•

DOWNSTREAM FRAME

UPSTREAM FRAME

PLOu: – Synchronization for the new transmitter

•

PLOAMu: – US OAM channel



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2009.8

P29

Overview • Why PON • PON Architecture & Applications • PON Technologies • Next Generation



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2009.8

P30

Next Generation of PON •

EPON => 10G-EPON – IEEE802.3av – To be finalized in 2009

•

GPON => NG-PON – ITU-T G.984.5: Enhancement Bandwidth – ITU-T G.984.6: Optical Reach Extension

•

WDM-PON – No standard activities

•

RFOG ( RF-PON) – SCTE-IPS910 – Expected to be published in 2009



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2009.8

P31

10G-EPON • Two modes: – 10G downstream, 1G upstream – 10G downstream, 10G upstream

• Back compliant with current EPON standard



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2009.8

P32

NG-PON • •

Still in researching phase Two proposals: – NG-PON1 (2009 – 2012) : ITU G.987 – NG-PON2(2012-2015)

•

Wavelength



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2009.8

P33

WDM-PON •

Advantages: – – –

•

Disadvantages: – – –

•

High bandwidth Protocol/data rate transparency High Scurity Inefficiency in the bandwidth utilization Difficult in the wavelength tuning => colorless ONU Difficult in the cascaded topology

In researching phase



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2009.8

P34

RFoG (RFPON)



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2009.8

P35



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2009.8

P36

Passive Optical Network Introduction

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