Investigation of the technical feasibility for

200G/400G beyond 10km optical PHYs using

high-power TOSA and APD-ROSA

Shuto Yamamoto, Toshihide Yoshimatsu,

NTT Corporation

IEEE802.3 Interim meeting, Geneva, Jan. 2018

2

Overview

Feasibility investigation for 200G/400G beyond 10km optical PMD

� 53-Gb/s and 56-Gb/s PAM4 transmission experiments with high-

power TOSA and APD-ROSA

� Receiver sensitivity and dispersion penalty are evaluated

assuming 8-lane LAN-WDM 40-km transmission.

In Orlando meeting, …

investigation using normal EML + APD was reported. (sone_b10k_01a_1117)

In this meeting, …

investigation using high-power EML + APD is reported.

3

Assumed link budget for 50G/200G/400G 40km

50G 40km 200G 40km 400G 40km

Optical fiber 18 18 18

MUX 0 2 (4-ch MUX) 3 (8-ch MUX)

DEMUX 0 2 (4-ch DEMUX) 3 (8-ch DEMUX)

Dispersion penalty 0.5 0.5 (Worst CH) 1 (Worst CH)

MPI penalty 0.5 0.5 0.5

Other 1 1 1

Total 20 dB 24 dB 26.5 dB

4:1

mux

TOSA L0

TOSA L1

TOSA L2

TOSA L3

2:1

mux

4:1

mux

TOSA L4

TOSA L5

TOSA L6

TOSA L7

DEMUX loss

1:2

dem

ux 1:4

dem

ux

1:4

dem

ux

ROSA L0

ROSA L1

ROSA L2

ROSA L3

ROSA L4

ROSA L5

ROSA L6

ROSA L7

Optical-fiber loss (18dB)

MUX lossConfiguration of 8-lane LAN-WDM

* Engineered link

40-km

Single-mode fiber

(Engineered link)

2dB 1dB 2dB1dB

4

Experimental setup

VOA1ch TOSA

(L5)4ch ROSA

Optical fiber w/ dispersion

(40-km SMF equivalent)

Setup

High-power TOSA

APD-ROSA

(Including 4-ch DEMUX)

Link budget:

22 dB for 200G

24.5 dB for 400G

� PAM4 signal is transmitted using 1-ch high-power TOSA and 4-ch APD-ROSA.

� Receiver sensitivity and dispersion penalty are evaluated assuming 8-lane

LAN-WDM 40-km transmission.

� In the case with 4-ch ROSA including 4-ch DEMUX, the link budget is below;

- 200G: 24 dB → 22 dB

- 400G: 26.5 dB → 24.5 dB

Tx power measurement point Rx power measurement point

4:1

mu

x

TOSA L0

TOSA L1

TOSA L2

TOSA L3

2:1

mux

4:1

mu

x

TOSA L4

TOSA L5

TOSA L6

TOSA L7

DEMUX loss

(none for 200G/ 1dB for 400G)

4-ch ROSA

1:2

dem

ux

1:4

de

mu

x

1:4

de

mu

x

ROSA L0

ROSA L1

ROSA L2

ROSA L3

ROSA L4

ROSA L5

ROSA L6

ROSA L7

• Optical-fiber loss (18dB)

• Dispersion penalty

(0.5 dB for 200G/ 1dB for 400G)

• MPI penalty (0.5dB)

• Other (1dB)

MUX loss

(2dB for 200G/ 3dB for 400G)

22 dB (for 200G)

24.5 dB (for 400G)

5

Experimental result (53-Gb/s PAM4)

-18.00 dBm (BtoB)

BER=2E-4 (KP4-FEC)

Tx OMAouter = +7.23 dBm

4ch APD-ROSA performance1ch TOSA performance

CD Penalty=0.7dB

Link budget

= 25.2dB

200G

40 km

400G

40 km

Required 22 dB 24.5 dB

Measured 25.2 dB

Margin 3.2 dB 0.7 dB

*Tx eyediagram w/o FFE

In 8-lane LAN-WDM 40-km transmission, the range of

chromatic dispersion is from -203.3 to +37.5 ps/nm.

PRBS31, 1299.187nm, ER=7dB, TEC=45degC

6

Experimental result (56-Gb/s PAM4)

Tx OMAouter = +7.15 dBm

1ch TOSA performance

Link budget

= 26.2dB

200G

40 km

400G

40 km

Required 22 dB 24.5 dB

Measured 26.2 dB

Margin 4.2 dB 1.7 dB

*Tx eyediagram w/o FFE

-19.08 dBm (BtoB)

BER=1E-3 (Stronger FEC)

CD Penalty=0.7dB

4ch APD-ROSA performance

In 8-lane LAN-WDM 40-km transmission, the range of

chromatic dispersion is from -203.3 to +37.5 ps/nm.

PRBS31, 1299.187nm, ER=7dB, TEC=45degC

7

Stronger FEC

Ref.) wang_x_3bs_01a_0115

8

Conclusion

� We investigate the feasibility of 200G/400G 40km optical PMD

through the experiment using high-power TOSA & APD-ROSA.

� 200G/400G 40km transmissions have some margins.

OMA margin

53 Gb/s

(KP4-FEC)

56 Gb/s

(Stronger FEC)

200G 40km 3.2 dB 4.2 dB

400G 40km 0.7 dB 1.7 dB

1-dB improvement

9

Backup

10

Required link budget in this investigation

200G 40km 400G 40km

Optical fiber 18 18

MUX 2 (4:1 MUX) 3 (4:1 MUX & 2:1 MUX)

DEMUX - 1 (1:2 DEMUX)

Dispersion penalty 0.5 (Worst CH) 1 (Worst CH)

MPI penalty 0.5 0.5

Other 1 1

Total 22 dB 24.5 dB

* Engineered link

4:1

mu

x

TOSA L0

TOSA L1

TOSA L2

TOSA L3

2:1

mux

4:1

mu

x

TOSA L4

TOSA L5

TOSA L6

TOSA L7

DEMUX loss

(1dB)

4-ch ROSA

1:2

dem

ux

1:4

de

mu

x

1:4

de

mu

x

ROSA L0

ROSA L1

ROSA L2

ROSA L3

ROSA L4

ROSA L5

ROSA L6

ROSA L7

• Optical-fiber loss (18dB)

• Dispersion penalty (1dB)

• MPI penalty (0.5dB)

• Other (1dB)

MUX loss

(2dB + 1dB)

24.5 dB (for 400G)

400G

4:1

mu

x

TOSA L4

TOSA L5

TOSA L6

TOSA L7

4-ch ROSA

1:4

de

mu

x

ROSA L4

ROSA L5

ROSA L6

ROSA L7

• Optical-fiber loss (18dB)

• Dispersion penalty (0.5dB)

• MPI penalty (0.5dB)

• Other (1dB)

MUX loss

(2dB)

22.0 dB (for 200G)

200G

11

Block diagram

Link budget is defined from optical transmitter to optical receiver in our investigation.

12

Chromatic-dispersion penalty

-18.00

-20

-19

-18

-17

-16

-15

-14

-13

-12

-250 -200 -150 -100 -50 0 50

OM

Ao

ute

r (d

Bm

)

D (ps/nm)

Rx Sens. at BER=2E-4

LAN-WDM 8λ 40km:-203.3 ～ +37.5ps/nm

-0.5

0

0.5

1

1.5

-250 -200 -150 -100 -50 0 50Po

we

r P

en

alt

y (

dB

)

D (ps/nm)

CD Penalty

0.56 0.22

CD penalty ≦ 0.56dB (-203.3～+37.5ps/nm)

26GBd

-19.08

-20

-19

-18

-17

-16

-15

-14

-13

-12

-250 -200 -150 -100 -50 0 50

OM

Ao

ute

r (d

Bm

)

D (ps/nm)

Rx Sens. at BER=1E-3

LAN-WDM 8λ 40km:-203.3 ～ +37.5ps/nm

-0.5

0

0.5

1

1.5

-250 -200 -150 -100 -50 0 50Po

we

r P

en

alt

y (

dB

)

D (ps/nm)

CD Penalty

0.51 0.21

CD penalty ≦ 0.51dB (-203.3～+37.5ps/nm)

28GBd

13

Worst-case dispersion for 40-km SMF transmission

14

Beyond 10km: stronger FEC

� Several potential hard-decision FEC with 8-9 dB NGC can help to

achieve beyond 10km 400GbE.- RS-FEC, BCH-FEC, or Staircase FEC…

Ref.) B. P. Smith, et al., JLT, no. 1, vol. 30 (2012) Ref.) wang_ecdc_01_0316

◆

KP4

15

400GbE 40km application

Extended reach interface is essential for inter-building connections

in service providers network.

Single-mode fiber

Reach 2 km 10 km 40 km

Application

802.3bsobjectives ✔ ✔ -

L2-SW

TransportSystem

Inter-building usage #12 km and 10 km

Inter-building usage #210 km and 40 km

L2-SW

TransportSystem

100GE 100GE

Intra-building usage2 km and 10 km

Long haul NW L2-SW L2-SW

100GE

L2-SW

TransportSystem

L2-SW

TransportSystem

Long haul NW L2-SW

100GE 100GE

Intra-building

Inter-building usage #1

Inter-building usage #2

Direct connection without long-haul transmission system

10-km reach:Covers 50% of inter-building links

40-km reach (for example):Covers almost 100% of inter-building links

10-km reach:Covers 50% of inter-building links

40-km reach (for example):Covers almost 100% of inter-building links

L2SW/ Router to long-haul transport system

L2SW/ Router to long-haul transport system

• Low-cost solution for some metro areas