1. Insight into EPON & GPON
Sept. 1st, 2007
2017/4/19
Fiberhome Proprietary and Confidential

2. Fiberhome Proprietary and Confidential
Outline
EPON vs. GPON
CTC EPON IOP
Summary
2017/4/19
Fiberhome Proprietary and Confidential

3. Fiberhome Proprietary and Confidential
EPON Vs. GPON
Protocol & Framing
QoS & TDM Support
System Costs
Upgrade Path
Interoperability & service migration
Split ratios, maximum reach, & traffic management
Users Forecast
2017/4/19
Fiberhome Proprietary and Confidential

4. Fiberhome Proprietary and Confidential
PON Framing
ITU-TGPON
125 sec
ATM
GEM
IEEE EPON
OAM & MPCP
No Fixed Frame
GPON is evolving
to look like EPON!
“GPON
Lite”
2017/4/19
Fiberhome Proprietary and Confidential

5. Fiberhome Proprietary and Confidential
GPON Frame Details
Downstream
PCBd n
Payload n
125 us
n+1
Payload n+1
Rate
Frame Size
1.244G
19440
2.488G
38880
PSync
4 Bytes
Ident
PLOAMd
13 Bytes
BIP
1 Byte
PLend
Plend
US BW Map
N*8 Bytes
Coverage of this BIP
(Includes Payload n-1)
Coverage of next BIP
(Includes Payload n)
Upstream
Frame n
125 us
Frame n+1
Rate
Frame Size
1.244G
19440
2.488G
38880
ONT 1
Gap
ONT 2
ONT n
PLOu
Alloc #a
PLOAMu
13 bytes
DBRu 1
Payload 1
Alloc #b
Guard
Time
SStart
2017/4/19
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6. Fiberhome Proprietary and Confidential
Protocol ≠ QoS
OAM
(In-Scope)
Framing
Physical Layer
DBA
(Out-of-Scope)
Neither the EPON nor the GPON specification defines the QoS mechanism
(DBA algorithm); it is out-of-scope, meaning it is up to the system/chip vendor.
EPON and GPON have identical service requirements.
High-performance, QoS-capable systems can be built with either protocol.
Evaluate PON systems on performance and price, not protocol.  
2017/4/19
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7. End-To-End Service Architecture
PSTN
Home
Network
Core
Network
Soft Switch
Triple-Play
FTTH ONT
OLT
Video / IP
STB
PON System: A L2/L3/L4 Ethernet Switch
Connects the Core & Home Networks
Multi-service
Strict enforcement of service contracts
Designed to reduce end-to-end cost
VoD Server
2017/4/19
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8. Fiberhome Proprietary and Confidential
TDM Services over xPON
Cell Site
ONT
Apartment Building
Channel Bank
Ethernet Switch
E GbE
Copper
Telco-grade QoS is required
Jitter, wander, delay, Stratum-traceability
Must be compatible with triple-play networks
EPON & GPON: identical service-layer
requirements for TDM.
TDM
Network
Data
PSTN
Video
Mgmt
Optical
Line
Terminal
Central Office
n x E1
ONT
Business E1
GbE
ONT
ONT
ONT
ONT
Triple-Play Residential Customers
2017/4/19
Fiberhome Proprietary and Confidential

9. GPON Has More Complex Chips and Buffers
GPON uses GEM to Segment and Reassemble Ethernet frames
Each connection (Port-ID) requires a separate SAR buffer
An additional 1MB external buffer memory is required
GPON OLT
100’s to 1000’s of SAR buffers
Frame from ONU must wait until all bytes are received upstream from ONU before it can be processed
GPON ONU
Segmentation buffers for every Port ID
2017/4/19
Fiberhome Proprietary and Confidential

10. EPON Uses Less Expensive Optics – Proven
GPON
1G/2G/10G EPON
Downstream data rate (Mbps)
1244 or 2488
1000, 2500, 10000
Upstream data rate (Mbps)
155, 622, 1244
1000
Payload encapsulation
GPON Encapsulation Method (GEM)
Ethernet framing
Laser on/off
 13 ns *
512 ns
AGC
44 ns *
 400 ns
CDR (Clock Data Recovery)
* Short laser on/off times in GPON require high-speed laser drivers
* Short AGC intervals in GPON require optical power leveling
Additional protocol to negotiate power level
Digital interface to transceiver to set the values
* Relaxed optical specification parameters in EPON  less expensive devices
2017/4/19
Fiberhome Proprietary and Confidential

11. Two Very Different Choices
802.3ah EPON
Continuity of Services & Network Management.
100% Ethernet
Seamless Migration
10 Gb/s
EPON
100% Ethernet
Seamless Migration
2.5 Gb/s
EPON
1.25 Gb/s
EPON
Support for Advanced Services ?
No roadmap beyond
2.5G for GPON. X
2.5 Gb/s
GPON X
Disruption of Services & Network Management.
ATM
BPON
New Protocol -
Forklift Upgrade?
ITU-T GPON
622 Mb/s Gb/s Gb/s Gb/s
Speed
2017/4/19
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12. 1.25 & 2.5 Gb/s EPON: Line Rates & Framing
1.25 Gb/s Downstream
Line Rate: Gb/s (.8 ns per bit)
Data Rate: 1 Gb/s (1 ns per bit)
Line Encoding: 8B/10B
MPCP Timing: Time Quanta (16ns units)
64 bits of
Preamble
1518 Byte Packet
PRE
1518 Byte Packet
PRE
2.5 Gb/s Downstream
Line Rate: 2.5 Gb/s (.4 ns per bit)
Data Rate: 2 Gb/s (.5 ns per bit)
Line Encoding: 8B/10B
MPCP Timing: Time Quanta (16ns units)
64 bits of
Preamble
1518 Byte P
1518 Byte P
1518 Byte P
1518 Byte P
2017/4/19
Fiberhome Proprietary and Confidential

13. Backward & Forward Compatibility
1.25G
2.5G
1.25G
1.25G
1.25G
1.25G
1.25G
1.25G
1.25G
1.25G
1.25G
1.25G
2.5G
1.25G
1.25G
2.5G
2.5G
1.25G
2.5G
2.5G
1.25G
2.5G
2.5G
1.25G
2.5G
2017/4/19
Fiberhome Proprietary and Confidential

14. Progression from 1G to 10G EPON
2017/4/19
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15. Interoperability & Service Migration
“Full” Specification
(ITU-T GPON)
“Open” Specification
(IEEE EPON)
Management Layer
(In-Scope)
Management Layer
(Out-of-Scope)
Management Layer
(Out-of-Scope)
Why are these different?
Services Layer
(In-Scope)
Services Layer
(Out-of-Scope)
System Layer
(Out-of-Scope)
System Layer
(Out-of-Scope)
Allows Telcos & OEMs to differentiate products
“Upper” PON Layer
(Out-of-Scope)
“Upper” PON Layer
(Out-of-Scope)
DBA Algorithm, etc.
“Lower” PON Layer
(In-Scope)
“Lower” PON Layer
(In-Scope)
Different Objectives  Different Scopes
2017/4/19
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16. Scope of the IEEE 802.3 Standard
IEEE covers only the Physical Layer & part of the Data Link Layer
2017/4/19
Fiberhome Proprietary and Confidential

17. Interoperability: Two World Views
World View 1: PON equipment that complies with a complete
specification, such as ITU-T GPON, is mandatory.
Aspiration: A “complete” specification leads to interoperable
equipment from multiple suppliers, leading in turn to lower
cost.
World View 2: PON equipment that allows transparent re-use of existing
IP-based services is mandatory.
Aspiration: Interoperability at the service and management layers with
other access systems (e.g., DSL).
2017/4/19
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18. Fiberhome Proprietary and Confidential
Split-Ratio Myths
Logical vs physical split-ratio limits
Logical
One BPON OLT can address 253 BPON ONUs;
One GPON OLT can address 4k GPON ONUs;
One EPON OLT can address 32k EPON ONUs.
Physical
In real deployments, all technologies are limited to 1x32 or 1x64, depending on reach, condition of the fiber plant, service mix, optical performance.
There is no practical split-ratio limit for any of the PON protocols; all have ample “ONU address space.”
Myth: “EPON is only a 1x16 solution, while GPON supports 1x128”
Statements like this combine willful mis-reading of the EPON spec, which specifies a minimum split-ratio of 1x16, not a maximum split-ratio, with some very simplistic BW utilization calculations.
Myth: “GPON has twice the split-ratio” because it’s downstream is twice as fast as EPON’s
2.5G EPON is here and 10G EPON is coming  soon this issue will disappear.
Latency requirements, bandwidth guarantees, and fairness requirements are more important than raw bandwidth.
Stated another way, if solution A has more raw bandwidth than solution B, but cannot distribute that bandwidth with enough precision and accuracy to meet the SLAs, then solution A, and its higher bandwidth, are useless.
2017/4/19
Fiberhome Proprietary and Confidential

19. Traffic Management & Maximum Reach
Too much emphasis is placed on the PON protocol (EPON vs GPON), and too little
attention is paid to the traffic-management and service-level issues.
The magic of EPON is not so much that it uses Ethernet framing (although that does lead to the lowest costs), but rather that Fiberhome has built in the traffic management functions that are really needed to make the services work properly.
High-performance (or low-performance) systems in principle could be built with either protocol, hence manufacturers and carriers should place highest priority on feature set and performance, not details of the framing.
Comments on maximum reach
Optics performance, split-ratio, and fiber-plant particulars determine the reach, not the PON protocol. Again there is FUD that confuses minimum requirements in the EPON standard with what is actually achievable (and legal) in real systems.
Basically, you can dial up very long-reach PONs using any of the protocols, provided you are willing to choose the right optics, reduce the split ratio, etc.
None of the framing definitions contain any long-distance magic; it’s all about optics and physics.
2017/4/19
Fiberhome Proprietary and Confidential

20. Fiberhome Proprietary and Confidential
EPON in Asia, 2007
Japan: 300k+ lines/month.
NTT, KDDI, Tepco, K-Opticom, Chubu Electric, Energia, Kintetsu, & many others.
Korea: Now in mass deployment, KT and others, 1M+ new subscribers in 2007.
China: 50+ EPON deployments currently underway, 400k+ new subscribers in 2007.
Taiwan, Malaysia, Singapore, Hong Kong, Thailand, Indonesia, Australia, etc.
6 EPON deployments currently underway (including 3 PTTs).
Cost is key.
Since IEEE 802.3ah approval in 2004, EPON equipment costs have decreased by
60+% and optics costs have decreased by 80+%.
2017/4/19
Fiberhome Proprietary and Confidential

21. 2004–2009 PON Subscribers ~ 5M EPON end CY2006
Source: Infonetics Metro Ethernet Equipment, April 2006
With permission: Copyright © 2006 by Infonetics Research, Inc
2017/4/19
Fiberhome Proprietary and Confidential

22. Fiberhome Proprietary and Confidential
2005–2011 FTTH Subscribers
Source: HEAVY READING | VOL. 4, NO. 9, JUNE 2006 | FTTH WORLDWIDE MARKET & TECHNOLOGY FORECAST
2017/4/19
Fiberhome Proprietary and Confidential

23. Connecting two Ethernet networks
Ethernet-over-GEM-over-SDH or Ethernet?
ITU-T GPON or IEEE EPON?
2017/4/19
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24. Fiberhome Proprietary and Confidential
Lessons from History
Ethernet has won every time it has competed with “higher speed” and “higher efficiency” technologies
Ethernet vs. Token Ring
Ethernet vs. FDDI
Ethernet vs. ATM
Ethernet vs. SONET
Ethernet vs. ATM in the DSLAM
Ethernet vs. Multi-service in the Metro
Ethernet is cheap, simple, easy to install & manage
Prediction
Ethernet all the way will win a large fraction of the market.
2017/4/19
Fiberhome Proprietary and Confidential

25. Fiberhome Proprietary and Confidential
Outline
EPON vs. GPON
CTC EPON IOP
Summary
2017/4/19
Fiberhome Proprietary and Confidential

26. Fiberhome Proprietary and Confidential
CTC EPON IOP Key Features
2017/4/19
Fiberhome Proprietary and Confidential

27. Fiberhome Proprietary and Confidential
CTC EPON System Evaluation Test
2017/4/19
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28. Fiberhome Proprietary and Confidential
CTC EPON System Evaluation Test Achievements
2017/4/19
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29. Fiberhome Proprietary and Confidential
CTC View of EPON
EPON is mature and suitable for mass deployment in CTC
–Simple, easy to develop
–Sufficient chip and system vendors
–Large-scale, all-around, chip-level and system-level IOP
–Mass deployment in east Asia
–Stable operation in the field trial of CTC for one and a half years
–Decreasing cost
2017/4/19
Fiberhome Proprietary and Confidential

30. Fiberhome Proprietary and Confidential
CTC View of EPON (Cont.)
After improved by CTC spec, EPON has no distinctive and essential difference in technical capability compared with GPON
-Transport capability
-DBA & QoS
-Operation & Management
-Security
-Multicast
-Fiber protection
-Multi-play support
2017/4/19
Fiberhome Proprietary and Confidential

31. Fiberhome Proprietary and Confidential
NTT View of EPON
“Two types of giga-bit PON systems have been standardized: G-PON by ITU-T and GE-PON by IEEE. Now the question is which one is more promising? ... In Japan, we have seen a drastic price reduction of media converters which could be realized by sharing the technology and products of the LAN market. For services, high quality IP Telephone and IP video are becoming critical basic FTTH services. And for the core network, in NTT we have a full IP backbone network for the FLET’s service. Switches and routers in the network employ Ethernet interfaces. Given these factors, we decided to develop GE-PON as the next-generation FTTH system.”
----Hiromichi Shinohara, Director of NTT Access Labs
(IEEE Communications Magazine, September 2005)
2017/4/19
Fiberhome Proprietary and Confidential

32. Fiberhome Proprietary and Confidential
Outline
EPON vs. GPON
CTC EPON IOP
Summary
2017/4/19
Fiberhome Proprietary and Confidential

33. Fiberhome Proprietary and Confidential
Summary
EPON is more mature & cost-effective than GPON.
Both GPON & EPON will coexist in a long time.
Fiberhome is a FTTH leader in China.
With our effort, Fiberhome FTTH system will be deployed worldwide soon.
2017/4/19
Fiberhome Proprietary and Confidential

34. Fiberhome Proprietary and Confidential
Thank you for attention!
2017/4/19
Fiberhome Proprietary and Confidential