Electrical Dispersion Compensation (EDC)

Liz WuLinus Chuang

For EE233

Spring 2006

EDC technology

EDC -- compensates for optical dispersion in theelectrical domain by algorithmic methods

Biggest Challenge for 10G -- dispersion management

(Intersymbol interference)ISI

2.48G

10G

Long distance

Long distance

EDC addresses three type of Dispersion

22

2)1( βλπ

λ

λC

VddD

DLT

g

−==

∆=∆

Chromatic dispersion polarization dispersion

Modal dispersion

P. Kirkpatrick et al.Intel Technology Journal 8, 83 (2004)

Brief Review of Dispersion

Existing Solutions of Dispersion

Chromatic dispersion

Modal dispersion

Polarization dispersion

Dispersion compensate fiberDispersive filterFiber Bragg grating

Graded fibers

PMD compensator

Type Solution

Drawbacks – Needs to be engineered for each link-- varies with wavelength

EDC -- deal with the dispersion at the receiver end -- address three different dispersion by different algorithm

Cost-effective & Easy

10G solution on legacy fiber network

Long-haul -OC-48 (2.48G bps)EDC standard-ITU/OIF-ITU-TSG15-10G over OC-48 network for 145-km-2400 psec/nm-chromatic dispersion-near ratification

Short link-1Gb EthernetEDC standard-IEEE-802.3aq (10G-BASE)-10G over OM1 MMF network for 220m-modal dispersion-achieves ratification at mid 2006

10G with/without EDC

2dB2dBN/AN/Apath penalty

1E-121E-121E-121E-12BER

9um9um62.5/125um62.5/125um

SMFSMFMMFMMFfiber type

1550nm1550nm1300nm850nmwavelength

2400ps/nm1600ps/nmN/AN/Adispersion

145km80km220m26mMax distance

ITU-TSG15G.959.1802.3aq802.3aeStandard

long-haul with EDClong-haulwith EDC

10 Gbps SONET10 Git/s SONET10 GbE short-reach

10 GbE short-reach

M. Furlong et al.EDN.com, 85 (March 30, 2006)

EDC equalization algorithms

1. CTF – continuous-time filters

2.FFE– feedforward-equalizerDFE– decision-feedback-equalizer

3. MLSE – maximum-likelihood-sequence-estimator

-simplest, lowest power consumption-compensate for chromatic dispersion

-compensate for ISI that exceed one UI-most common EDC implementation

-best performance-but complicated and large power consumption

Dynamic EDC- self-adaptable algorism

• Fiber degrades over time and introduce new source of interference

• EDC refine compensation algorisms to adapt to these changes

• Close loop feedback mechanism to modify filters and gains

Market

Who entered the market?

Long-haul application- Broadcomm (BCM8105)- SCINTERA (SCN5028) - Civcom (module)- Kodeos Communications- Infinera........

~ US$ 500 per chip(less complicated)

Short link application- SCINTERA (SCN3142)- Vitesse- Infinera- PHYworks (PHY1060)- Intel (?)- Cisco (equipment)- Aeluros........

~US$100 per chip(more complicated)

Who is threatened by EDC?

Long-haul application- Fiber manufacturers- dispersion filter vendors

Short link application- Fiber manufacturers

(Laser optimized 50 µm fiber)- LX4 vendors

Market ForecastShort link application- $400M~$600M of total addressable market revenue opportunity is at

the stake- 1 million 10GbE optical ports to be shipped in 2009 worth $3B

Long-haul application- sub $200M market

0

200

400

600

800

1000(thousand)

2005 2006 2007 2008 2009 2010year

EDC shipment forcast

*Source: OFS (JEG) Estimate Based on CIR 12/04 PR for report titled 10-GIGABIT NETWORKING: A MARKET AND TECHNOLOGY ASSESSMENT

Market Impact

• ITU-TSG15 is nearing ratification• 830.aq is in draft status and it should achieve ratification

by midyear• Interoperability testing between Industry leaders• 40G• LX4• According to ElectroniCast, the worldwide consumption

value of filter-based devices providing variable chromatic dispersion compensation for high-speed telecommunication networks (>=10Gbps) is forecasted to increase from an estimated $580,000 in year 1999 to $30 million in year 2005.

Products of EDC

• Broadcomm announced EDC product BCM8105 at July 2005.

• Applied Micro Circuits Corp launched s19233 Feb. 2005

• Intersymbol Communications , a start up company focus on MLSE development for smartCDR

• Quake Technologies QT1006B1

EDC standardsLong-haulITU-TSG15OIF(Optical Internetworking Forum) ITU(International Telecommunications Union)10G OC-192 over OC-48 network for 145-kmAddress dispersion of 2400 pse/nm(today, OC-192 10G over SMF 80km )

Short-reach applications802.3aqIEEEITU(International Telecommunications Union)10G link over OM1 MMF network to 220mLess complicated module than LX4(today, Ethernet links over legacy OM1 MMF 26m)

G. S. Kanter et al.Optics Express 11, 2019 (2003)

Thank you