Next Generation FTTH Chris Pfistner ECOC 2011

Transcription

1 Next Generation FTTH Chris Pfistner ECOC 2011

2 Table of Content NG FTTH - What do we need? Bandwidth vs Reach vs Cost per Bit How did we get here? The Pioneers APON & BPON The Volume Leaders - GPON & GEPON The latest Generation - 10G PON Going beyond 10G ODN The biggest investment Multiplexing Techniques Photons vs Electrons Other Options to consider How do the different options compare? 2

3 Global PON Market Forecast India ramps GPON deployment KT starts GEPON deployment Verizon GPON slows down NTT slows GEPON (20M Users) China continues GEPON NTT starts B-PON AT&T & VZ start BPON NTT starts GEPON AT&T & VZ start GPON China starts GPON deployment 10G PON deployments start in China for FTTB/C NG PON: 40G+ downstream 10G+ upstream 3

4 The Technology Perspective The network The biggest Investment by Carriers Power Splitters (PS) Wavelength Filters (WS) Hybrid Power Splitters & Wavelength Filters Multiplexing Techniques The usual Suspects Time Division Multiplexing (TDM) Wavelength Division Multiplexing (WDM) Frequency Division Multiplexing (FDM) How about higher split ratios in existing PON architectures? Concept of the Mode Coupling Receiver (MCR) 4

5 The Optical Distribution Network (ODN) MDU Central Office OLT Wavelength Division Multiplexing Single Family Homes AAWG Business Loss Budgets as defined in FSAN/ITU GPON XG PON B+ C C+ N1 N2 E1 E2 Min (db) Max (db)

6 Historical Performance Curve: Photonics vs Electronics Electronics: Photonics: Global Optical Transceiver Industry 2010: Global Semiconductor Industry: > $250B Annual Revenue: > $25B in Development per year (10%) > $3-5B in Research Efficient Manufacturing Eco System ~ $2.5B Annual Revenue: $250M in Development per year $25 - $50M in Research per year Mostly inhouse Manufacturing Performance Increases often come in spikes, e.g. WDM introduction in 1990 s. 6

7 TDM - Time Division Multiplexing TDM offers full flexibility in agile shifting and sharing of bandwidth resources across all N users at the core of today s PON networks: DBA - Dynamic Bandwidth Allocation At the conceptual level, TDM solves many energy dilemmas N customers share a single OLT transceiver resource energy savings in the OLT. It is possible to use the TDMA upstream to reduce power when the ONU is not transmitting. (An average ONU has a transmission duty cycle of 1/N) TDM s weak link is that it requires all ONU transceivers to operate at the overall PON data rate. Do customers that use a maximum bandwidth of 10 Mb/s really need an ONU with 10G bidirectional transceivers? 7

8 WDM Wavelength Division Multiplexing Concept: WDM PON provides secure virtual point-to-point connections over a shared ODN to each user. Advantages: Optically transparent Service and protocol independent No intrinsic loss from power splitters, just excess loss in the AWG What is holding up the ubiquitous deployment of WDM PON: WDM PON is ideal for high bandwidth applications: e.g. Business & LTE Backhaul. Majority of today s ODN use power splitters. WDM PON consumes valuable resources (energy, capacity) to support idle frames. Cost effective WDM Transceivers for the ONU remain a challenge, both for colorless (tunable) and colored (fixed wavelength) type. The concept of Self- Seeding RSOA ONU is getting attention lately. 8

9 WDM PON Athermal AWGs are field proven!! Athermal AWG s have been field deployed for a decade and represent a mature technology. Two compensation mechanisms exist: Mechanical compensation without any intrusion on optical path Refractive index compensation through material insertion into optical path NeoPhotonics AAWG devices are approaching a cumulative 200M hours in the field, often under extreme conditions with zero failures to date. 9

10 Stacked TDM: A pragmatic combination of TDM & WDM PON Concept: Stack 4 8 TDM PON networks on the same ODN using WDM wavelengths in existing ODN transmission windows. ONU OLT λ 12 OLT λ 34 external Mux/DeMux Power Splitter ONU ONU ONU Advantages: Compatible with existing ODN Leveraging existing technology Accommodating different split ratios/data rates for different user groups Challenges: OLT λ ij OLTλ nm WDM Transceivers remain higher cost than Standard Transceivers Tunable filters at ONU still in trial stage ONU ONU ONU ONU 10

11 FDM Frequency Division Multiplexing In FDM multiple electrical RF carriers are transported jointly over a single optical carrier: Downstream: one or more RF carriers are dedicated to each ONU Upstream: each ONU emits one or more RF carriers RF carrier allocation can be static or dynamic At a conceptual level, FDM solves many energy dilemmas: N customers share a single OLT transmit and receive resource energy savings in the OLT. Advantage over TDM: Each ONU only processes the allocated RF carriers at a fraction of the combined data rate. However, further advances in DAC/ADC, and DSP, as well as PIC technology are needed for a cost effective implementation of FDM in NG Access Networks. Leverage advances in electronics!! 11

12 Challenge in current Access Networks - small ONU count during initial deployment Fiber Distribution Panel 1-port OLT SPF C+ 1-port OLT SPF C+ 1-port OLT SPF C+ Individual PON Networks GPON OLT LINE-CARD 1-port OLT SPF C+ serves 4 C+ PONs CENTRAL OFFICE w C+ outside plant 12

13 Mode Coupling Receiver (MCR) Increasing Split Ratios in existing PON architectures Work by Alcatel-Lucent, Huawei, France Telecom, and NeoPhotonics has resurrected an old idea, - use of a mode coupling receiver to eliminate upstream splitter loss. 1. F. Fredricx, B. De Vos, C. Bouchat, J. Watté, P. Van Overmeir, J. Vandewege, X.Z. Qiu and K. Noldus, Solutions for Extended Split PON, IEEE / IEICE OHAN Workshop Proceedings, Yokohama, April 2001, F. N. Raharimanitra, P. Chanclou, G. Perrin and M. Thual, Demonstration Of The Use Of An Optical Fibre Combiner With Low Loss To Connect Four Single Mode Fibres To One Photoreceiver, Access Networks and In-house Communications 2010, paper AThC3 3. N. Cheng, Z. Liao and F. Effenberger, Large Splitting and Long Reach Passive Optical Networks with Mode Coupling Receivers, 36th European Conference on Optical Communications (2010), paper Tu.5.B.3 4. N. Cheng, Z. Liao, F. Effenberger and P. Chanclou, Pay-as-You-Grow Approach for Large Scale PON Deployment, ECOC Market Focus, Torino, 21 September D. Piehler, Implementing High [> 2048] Split Ratios in any PON, Optical Fiber Communication Conference , paper NThF4 13

14 Extending Passive Optical Networks Mode Coupling Receiver (MCR) The upstream loss of a PON optical splitter can be eliminated by an optical mode coupling receiver (MCR) coupling all fiber modes to a large photodetector: A mode coupling receiver is incurs no noise penalty for a TDMA upstream active area 62.5 μm 9.2 μm MFD 5.3 μm MFD signal: An APD presents a large target, accommodating high-efficiency coupling from many upstream waveguide modes. 2.5 Gb/s APD SMF 28 fiber high-δn PIC waveguide 14

15 Challenge in current Access Networks - small ONU count during initial deployment Fiber Distribution Panel 1-port OLT SPF C+ 1-port OLT SPF C+ 1-port OLT SPF C+ Individual PON Networks GPON OLT LINE-CARD 1-port OLT SPF C+ serves 4 C+ PONs CENTRAL OFFICE w C+ outside plant 15

16 4-port MCR OLT transceiver allows GPON line-card to serve 4 ONUs Fiber Distribution Panel 4-port OLT SPF C+ 4-port OLT SPF C+ 4-port OLT SPF C+ Individual PON Networks GPON OLT LINE-CARD serves 16 C+ PONs 4-port OLT SPF C+ 4F-Ribbon Cable CENTRAL OFFICE w C+ outside plant 16

17 4-port MCR OLT transceiver allows GPON line-card to serve 4 ONUs - enabled through PIC technology Fiber Distribution Panel 4-port OLT SPF C+ 4-port OLT SPF C+ 4-port OLT SPF C+ Individual PON Networks GPON OLT LINE-CARD serves 16 C+ PONs 4-port OLT SPF C+ 4F-Ribbon Cable CENTRAL OFFICE w C+ outside plant 17

18 Summary NG PON Architectures should protect the investment in the existing ODN as much as possible. The known Multiplexing Techniques of TDM, WDM and FDM all show advantages and disadvantages. Leverage advances in DSP, ADC, DAC as well as PIC technologies as much as possible. Consider intermediate steps that address limitations in current networks like MCR for increased split ratios. 18