400G-PSM4: A Proposal for the 500m Objective using 100 Gbps per Lane Signaling

Brian Welch (Luxtera) Gary Nicholl (Cisco)

Keith Conroy (Multi-Phy) Jeff Maki (Juniper Networks)

Beck Mason (JDSU)

IEEE 802.3bs Task Force Nov 2014 1

Supporters

• Tom Palkert (Luxtera)

• Vipul Bhatt (Inphi)

• Chuang Liang (Oplink)

• Alan Tipper (Semtech)

• David Brown (Semtech)

• Bharat Tailor (Semtech)

• Mark Nowell (Cisco)

• Rob Stone (Broadcom)

• Neal Neslusan (Multi-Phy)

• Vasu Parthasarathy (Broadcom)

• Will Bliss (Broadcom)

• Tom Issenhuth (Microsoft)

• Brad Booth (Microsoft)

• RangChen Yu (Oplink)

• Ali Ghiasi (Ghiasi Quantum)

IEEE 802.3bs Task Force Nov 2014 2

400G-PSM4

• Proposal: A 4x100 Gbps parallel SMF interconnect to satisfy the 500m objective.

• Lane Speed: 100 Gbps per lane using 50 Gbaud-PAM4 optical signaling

• Uncorrected BER = 2.1e-5 – Corrected BER < 1e-15

• Single wavelength solution

IEEE 802.3bs Task Force Nov 2014 3

Proposal Objectives

• Enable minimum reach of 500m using a PSM4 fiber plant

• Enable cost/power competitiveness (per Gbps) with 100G solutions

• Enable backward compatibility with 100G-PSM4 solutions – At 100Gbps rate

• Enable breakout potential

IEEE 802.3bs Task Force Nov 2014 4

400G-PSM4 Block Diagram

IEEE 802.3bs Task Force Nov 2014 5

TIA PIN

TX/Encoder

Decoder

TIA PIN Decoder

TIA PIN Decoder

TIA PIN Decoder

TX/Encoder

TX/Encoder

TX/Encoder

4x100 Gbps

Optical PMD PMA (CDAUI16/8/4)

TP2<0:3>

TP3<0:3>

MUX

DEMUX

Spec evolution from 100G-PSM4

• Similar to 100G-PSM4 – http://www.psm4.org/100G-PSM4-

Specification-2.0.pdf

• PSM DL Fiber Plant – 3 dB passive loss budget

• Kolesar_3bs_01_0514.pdf

– Reduced from 3.25 dB for 100G-PSM4

• Approximately 2.2 dB of RX sensitivity relaxation – BW expansion penalty ~ 1.5 – Linearity/AGC penalty ~ 0.5 – BER reduction penalty ~ 0.2 – At wavelength extremes – 1.5 dB mid band relaxation

• PAM4 TX penalties – 4.77 dB modulation penalty – 0.3 dB MPI penalty – 0.25 dB Rin penalty

• 1dB excess margin at min TDP

• Total Margin (min) from OMA11-00 = 9.3 dB

IEEE 802.3bs Task Force Nov 2014 6

400G-PSM4 : Link Parameters 400G-PSM4

Reach (m) > 500

Nominal Signaling Rate (each Lane) † 51.5625 GBd-PAM4

Wavelength(s) 1297 to 1323

Uncorrected BER† < 2.1e-5

Corrected BER† < 1e-15

802.3bs Objective BER < 1e-13

Loss Budget, max (dB) 3

Allocation for Penalties, at max TDP (dB) 5.05

Connector Reflectance, Max (dB) -35

† Assumes Clause91 type FEC. Additional relaxations may be realized with different FEC types.

IEEE 802.3bs Task Force Nov 2014 7

400G-PSM4: Transmitter Specifications (TP2)

400G-PSM4

Nominal Signaling Rate (each Lane) 51.5625 GBd-PAM4

Wavelength(s) 1297 to 1323

OMA11-00, each lane, min (dBm) MAX(-1.9+(λ-1310)2/70,-1.4)+MAX(TDP,0.8)

OMA01-00, each lane, min (dBm) MAX(-6.67+(λ-1310)2/70,-6.17)+MAX(TDP,0.8)

ER11-00, each lane, min (dB) 5

Average launch power, each lane max (dBm) 3.5

Total average launch power per fiber max (dBm) 3.5

Average launch power, each lane min (dBm)‡ -2.7

TDP, each lane, max (dB) 3.5

Transmitter RINave, max (dB/Hz) -142

Transmitter Reflectance, max (dB) -20

‡ Mid band assuming 10 dB extinction ratio

IEEE 802.3bs Task Force Nov 2014 8

400G-PSM4: Receiver Specifications (TP3)

400G-PSM4

Nominal Signaling Rate (each Lane) 51.5625 GBd-PAM4

Wavelength(s) 1297 to 1323

Receiver Sensitivity (OMA), each lane max (dBm)† MAX(-10.4+(λ-1310)2/70,-9.9)

Average received power, each lane max (dBm) 3.5

Average received power, each lane min (dBm) -5.7

Damage Threshold (dBm) 4.5

Receiver Reflectance, max (dB) -26

† Received sensitivity reported in ‘NRZ mode’, equivalent to sensitivity for any sub-eye 01-00,10-01,11-01

IEEE 802.3bs Task Force Nov 2014 9

400G-PSM4

-12

-10

-8

-6

-4

-2

0

2

1295 1300 1305 1310 1315 1320 1325

dB

m

Wavelength (nm)

OMA11-00

OMA01-00

RX Sensitivity

IEEE 802.3bs Task Force Nov 2014 10

Backup

4x25 Gbps PSM4 Chipset Measurements

IEEE 802.3bs Task Force Nov 2014 11

4x25 Gbps PSM4 Chipset Measurements

• There have been questions as to achievable OMA and Sensitivity levels in Silicon Photonics Solutions

• Enclosed are measurements of a PSM4 chipset with four transmitters illuminated from a single light source

• OMA > -0.5 dBm in all cases • Stressed (mildly) sensitivity < -13.9 dBm in all cases

IEEE 802.3bs Task Force Nov 2014 12

4x25 Gbps PSM4 Chipset†

Light Source

† Image used with permission by Luxtera

TX OMA - Channel 0

13

OMA ~ 0 dB

IEEE 802.3bs Task Force Nov 2014

TX OMA - Channel 1

14

OMA ~ -0.1 dB

IEEE 802.3bs Task Force Nov 2014

TX OMA - Channel 2

15

OMA ~ -0.1 dB

IEEE 802.3bs Task Force Nov 2014

TX OMA - Channel 3

16

OMA ~ -0.3 dB

IEEE 802.3bs Task Force Nov 2014

Stressed (mildly) Sensitivity Measurements

-17.0

-16.0

-15.0

-14.0

-13.0

-12.0

-11.0

-10.0

-9.0

-8.0

0 1 2 3

Stre

sse

d S

en

siti

vity

(d

Bm

)

Channel (0-3)

Device A Device B Device C

• RX sensitivity measurements performed on three 4x25 Gbps devices • Using silicon photonics reference transmitter (mildly stressed sensitivity) • Worst case stressed sensitivity @ BER5e-5 = -13.9 dBm

IEEE 802.3bs Task Force Nov 2014 17

Thank You

IEEE 802.3bs Task Force Nov 2014 18