10g | 5g | 2.5g | 1g | 100m physical layer phy · 2015-08-25 · • self near end (next) and far...

© 2015 AQUANTIA CORP. CONFIDENTIAL & PROPRIETARY

10G | 5G | 2.5G | 1G |

100M PHYSICAL LAYER

PHY

HOT CHIPS 2015 CONFERENCE

RAMIN SHIRANI

RAMIN FARJAD-RAD

| HOT CHIPS © 2015 AQUANTIA CORP. CONFIDENTIAL & PROPRIETARY

MEGATRENDS DRIVING NEED FOR NEXT GENERATION

CONNECTIVITY

• Transition to Next Generation Ethernet Solution Required

• Must Alleviate Critical Bandwidth Constraints in Global IT

Infrastructure

Source: Cisco VNI Report, 2015

2014A 2019E

CAGR:

57%

2.5Exabytes / m

24.3Exabytes / m

2 | HOT CHIPS © 2015 AQUANTIA CORP. CONFIDENTIAL & PROPRIETARY

| HOT CHIPS © 2015 AQUANTIA CORP. CONFIDENTIAL & PROPRIETARY| HOT CHIPS © 2015 AQUANTIA CORP. CONFIDENTIAL & PROPRIETARY

ENTERPRISE NETWORK STRUCTURE

• Enterprise networks follow:

Three Tier Design Approach• Proven

• Widespread

• Stable topology

• More than 70% of enterprise

campus wiring = Cat5e/Cat6

• Aquantia ICs increase speeds

on Cat5e/Cat6 links:

• Enterprise access switches

• Wireless APs

Core

Distribution

Access

AP AP AP APAps &

End Devices

cat 5e 46%

cat 6 28%

cat 6A 16%

cat 7 5%cat 7A 4%

3


WLAN UPGRADE CREATING BOTTLENECK IN ENTERPRISE

NETWORKS

• Legacy wireless access connections dominated by 1000Base-T - 30W PoE

• Wireless transition to 802.11ac (Wave 1 & Wave 2) needs:

• Multi-Gigabit speeds + 60W UPoE

• Aquantia’s 28nm ICs were designed for 5 speeds on 100 meters:

• 10G Cat6A and Cat7

• 5G/2.5G/1G/100M on Cat6A, Cat6, and Cat5e

New AP

Deployments

Require >

1G

802.11ac: 6.9Gbps

802.11n: 600Mbps

802.11a/g:

54Mbps

802.11b: 11Mbps

802.11: 2Mbps

CAT 5e: 5 Gbps

Wiring Closet

Enterprise

Switch

4x1.25G

WIFI Small Cell

>> 1GE

802.11ac Wave 2:

Creating bottlenecks on the AP and

switch

Aquantia: founding

member

• 2.5G/5G electrical &

interoperability

specifications

4


MULTI-GIGABIT APPLICATION SPACE

5 | HOT CHIPS © 2015 AQUANTIA CORP. CONFIDENTIAL & PROPRIETARY


1000BASE-T | 2.5G | 5.0G | 10GBASE-T SIGNALING

• Duplex transmission Echo power >> Received power

• Self Near End (NEXT) and Far End (FEXT) Crosstalk

• Alien crosstalk noise from adjacent cables

• Environment specific interferences (e.g. Enterprise)

Local Transceiver Remote

Transceiver

NEXT FEXT

2500 Mb/s Full Duplex for 10G

Return Loss

EMI

Alien crosstalk

ANEXT AFEXT

SignalSignal

Near End Far End

6


ESD IMPULSE NOISE IN ENTERPRISE

• ESD events are generally band pass (80MHz to 200 MHz)

• Low duration, frequent in enterprise that interferes with the operation of data rates above 1000BASE-T

• Such interference events increases the bit error rate of an otherwise properly operating data link

• Example enterprise space: Visitors taking a seat & getting up in a public library

Example of ESD Differential noise in

enterprise

Am

plit

ud

e(m

V)

Time (nsec)

0 200 400 600 800 1000 1200 1400 1600 1800 2000

80

60

40

20

0

-20

-40

-60

-80

Impulse Noise from Mesh Desk Chair Internal ESD at

2m (Cat 5e UTP)

Vptp = 63 mV, Span (90%) power) = 81 nsec, 220 MHz LP Filter

Applied

7


CABLING QUALITY: DATA CENTERS VS. ENTERPRISE

• Goal in Enterprise is to extend the life of

existing cabling to the next generation

• Many enterprise cabling setups are qualified

only up to 1000BASE-T (<62MHz)

• Poor cable return loss leads to large impulse

reflections in full-duplex links

• Next generation Data Centers are built

cleanly from scratch with new cabling

8


NON-LINEARITY IN TRANSMIT SIGNAL & RETURN

LOSS

9

Tx

Hyb

rid

Rx Linear Echo

Nonlinear Echo

Ma

gn

eti

c

Cn

tr

Cn

tr

Echo Canceller


10GBASE-T CODING

• 10GBase-T DSQ128 allows 128

combinations

• There are 7 bits/DSQ128 symbol– 3MSBs are uncoded

– 4LSBs are FEC coded through LDPC

• These 3 uncoded bits are most

vulnerable to large impulse noise– Dominant in Enterprise

128 DSQ

3 uncoded bits per coset

4 coded bits per coset

0010 0110 1110 1010

0011 0111 1111 1011

0001 0101 1101 1001

0000 0100 1100 1000

10


HOW TO PROTECT ALL TRANSMIT BITS WITH LDPC?

• Gray-coded PAM16 signaling

• PAM 16 = 4 bits per symbol

• 8bits vs 7bits per 2 symbols

• Additional bits per frame used to protect uncoded bits by same

LDPC machinery

• Combination of LSB & MSB bits in the LDPC Frame

• Higher number of encoding bits improves FEC gain by over 1dB

• Robust to non-stationary impulse noise & AFE

imperfections

• Otherwise, a scaled version of 10BASE-T

1111111100000000

0000111111110000

0011110000111100

0110011001100110

b3 b2 b1 b0

1513110907050301-01-03-05-07-09-11-13-15

Gray Coded

11


DATA MAPPING• 5Gb/s via fully LDPC coded PAM 16

running at 400Ms/s

• 2.5Gb/s via fully LDPC coded PAM 16

running at 200Ms/s

• Fully Encoded PAM16 An FEC

extended to uncoded bits

• Removes errors caused by noise

spikes

• Provides additional margin for ESD

events

• Relaxes the PHY transmit linearity

spec significantly

• Relaxes the magnetic RL

requirementReceive Mapping

CT

R

L D00 7

D18 16

D217 23

D324 31

XGMII Block 0 (First)

CT

R

L D00 7

D18 16

D217 23

D324 31

XGMII Block 1 (Second)

CT

R

L D00 7

D18 16

D217 23

D324 31

D432 39

D140 47

D248 55

D356 63

65B Block

x58 Scrambler 25x 65B FIFO

65B

#1

65B

#2

65B

#3

65B

#4

65B

#5

65B

#6

65B

#24

65B

#25

97

Zeroes

LDPC

(1723,2048)

Encoder1723 bits

65B

#1

65B

#2

65B

#3

65B

#4

65B

#5

65B

#6

65B

#24

65B

#25

97 Random

Bits 325 Check Bits

2048 bits

Nibble

#1

Nibble

#2

Nibble

#3

Nibble

#4

Nibble

#5

Nibble

#6

Nibble

#6

Nibble

#7

Nibble

#510

Nibble

#511

Nibble

#512

PAM-16

Encoder

PAM16

#1

PAM16

#2

PAM16

#3

PAM16

#4

PAM16

#5

PAM16

#6

PAM16

#6

PAM16

#7

PAM

#510

PAM16

#511

PAM16

#512

PAM16

#1

PAM16

#5

PAM16

#505

PAM16

#509PAM16

#2

PAM16

#6

PAM16

#506

PAM16

#510PAM16

#3

PAM16

#7

PAM16

#507

PAM16

#511PAM16

#4

PAM16

#8

PAM16

#508

PAM16

#512

Pair A

Pair B

Pair C

Pair D

12


AQUANTIA PHY BLOCK DIAGRAM

• PHY analog & digital blocks

architected to power scale

proportional to data rates

10G/5.0G/2.5G

• Analog power saving

achieved by modifying

performance requirement

• USXGMII SerDes runs at

fixed 10Gbps at all PHY

data rates to simplify

system interface

USXGMII

Line

DSQ128PAM16

XFI 2 XFI

Pass-thru

MAC

I/F

PCS Encoder

PCS Decoder

Scrambler

Descram

LDPCEncoder

LDPCDecoder Framer

FIFO

FramerFIFO

FramerFIFO

FramerFIFO

THPPrecoder

Echo Cancellation

NEXT Cancellation

FEXT Cancellation

DAC /Driver

Hybrid

EQVGAFilter

Line

13

FIFOFramer


AQUANTIA PHY CHIP (28nm)

• Analog frontend with 5 receive channels and 4 transmit

channels

• 5th receive to sense/cancel in band RFI

• Combination of LC & ring PLLs to cover all required

speeds

• High-Gain LDPC FEC 128DSQ: ~8dB, PAM16: >9dB

• Modular FIR filters combined with convergence engines

• Supporting:

• 1588 & PTP Features, Energy Efficient Ethernet (EEE),

MACSEC

• Chip Area: 40mm^2

• Power: 1W, 2W, 3W for 2.5G, 5G, 10G

Receive / Transmit Interface

FIR1 & Update

Engine

FIR2 & Update

Engine

FIR3 & Update

Engine

FIR4 & Update

Engine

FEC

(LDPC)

Physical

Coding

Sublayer

MSACSEC

1588, PTP, and system interface

10G KR

100M &

Gigabit

Engine

ADC2 ADC3 ADC4 ADC5ADC1

DAC

Driver1DAC

Driver2

DAC

Driver3

DAC

Driver4

PLL1

PLL2

XAUI

PLL

VGA4VGA1 VGA3VGA2 VGA5

14


IEEE PERFORMANCE SPECIFICATION FOR 2.5G | 5.0G

• 2.5 Gb/s PHY specified for operation over

• Up to at least 100m on four-pair Class D (Cat5e) balanced copper

cabling on defined use cases and deployment configurations

• 5 Gb/s PHY specified for operation over

• Up to at least 100m on Class E (Cat6) balanced copper cabling on

defined use cases and deployment configurations

• Up to 100m on Class D (Cat5e) balanced copper cabling on defined

use cases and deployment configurations

15


2.5Gbps ALIEN X-TALK LIMIT LINES (BER<1E-12)

16

20

30

40

50

60

70

80

-15 5 25 45 65 85 105 125

2.5GBASE-T 10GBASE-T

2.5Gbps

18dB

10GBASE-T

ANEXT AELFEXT

10

20

30

40

50

60

70

80

-15 5 25 45 65 85 105 125

2.5GBASE-T 10GBASE-T

2.5Gbps

18 dB

10GBASE-T


5.0Gbps ALIEN X-TALK LIMIT LINES (BER<1E-12)

30.00

35.00

40.00

45.00

50.00

55.00

60.00

65.00

70.00

0 50 100 150 200 250

5GBASE-T 10GBASE-T

5Gbps

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

0 50 100 150 200 250

5GBASE-T 10GBASE-T

5Gbps

12dB

12 dB

10GBASE-T

10GBASE-T

AELFEXTANEXT

17


Cat5e & Cat6 SIGNLE-CABLE PERFORMANCE SETUP

18


2.5Gbps | 5.0Gbps PERFORMANCE OVER SINGLE CABLE

• 2.5Gbps reach for BER<1E-12

• Over ~195m of Cat5e

• Cable IL = ~42dB@100MHz 18dB exceeding Cat5e limit line


• Over ~125m of Cat5e

• Over ~135m of Cat6

• Cable IL = ~43dB@250MHz 9dB exceeding Cat6 limit line

19


6around1 CABLE COMPLIANCE RACKS (Cat6A/Cat6/Cat5e)

20


2.5Gbps/5.0Gbps PERFORMANCE On 6around1 CABLE


• Over ~135m of Cat5e (Full length 6@1)

• Cable IL = ~29dB@100MHz Margin to CAT5e Limit= -5dB


• Over ~100m of Cat6 (Full length 6@1)

• Cable IL = ~32dB@250MHz Margin to Cat6 Limit= 2dB

21


ALIEN X-TALK OF FULL 100M 6around1 CABLE SETUPS

0

20

40

60

80

100

0 25 50 75 100 125 150 175 200 225 250

dB

ANEXT AELFEXT

0

20

40

60

80

100

0 25 50 75 100 125 150 175 200 225 250

100m Cat6A 6around1

100m Cat6 6around1

100m Cat6 6around1

100m Cat6A 6around1

22

5Gbps10Gbps

10Gbps

5Gbps


IEEE DEFINED WAP ENTERPRISE USE CASE

http://www.ieee802.org/3/NGBASET/email/pdfy0VqAHwlWI.pdf

WA

PLmax = 13m (42ft)

R = 13m (42ft)

X = 18.3m (60ft)TO

TO TO

Hmax = 80m (262ft)

max 6m (20ft)

equipment cord

Active equipment

TO

TR

Typical Uniform Cell Size

Cell sizing (wireless access points placed

anywhere inside the cell)

23

http://www.ieee802.org/3/NGBASET/email/pdfy0VqAHwlWI.pdf


6around1 CABLE BUNDLED CONFIGURATIONS

http://www.ieee802.org/3/10GBT/public/mar03/vanderlaan_1_0303.pdf

•6@1 Bound by Binders Across

the Cable

•6@1 Tied by Straps every 4ft

(Most Common)

~9dB improvement of alien xtalk

•Unbound Cables

(e.g. Conduits)

20dB improvement in alien xtalk

24

http://www.ieee802.org/3/10GBT/public/mar03/vanderlaan_1_0303.pdf


Cat6 ALIEN X-TALK: TYPICAL ENTERPRISE INSTALLATIONS

• Configuration:

• 24 Cat6 Cables

• Tied every 5 feet

• Tied length <80m

• Victim at center of bundle

• Routed to the ceiling

• X-Talk Measurement meets the

target 5Gbps alien xtalk limit

lines!

Category 6 “Alien” Power Sum NEXT

(plenum bound)

25

35

45

55

65

75

1 10 100 250

dB

MHz

1 10 100 250

25

http://grouper.ieee.org/groups/802/3/tutorial/nov02/tutorial_2_1102.pdf

5Gbps


CONCLUSION• The ever growing data requirements in the

cloud and mobility are creating a bandwidth

constraint in global IT infrastructure

• In 2012, Aquantia focused on adding

2.5G/5G speeds on Cat5e/Cat6 Links to

address the next generation wireless access

bottleneck

• Aquantia’s five speed ICs (single, dual, and

quad) are the only commercially available

NBASE-T compliant ICs since 2013

• Five speed ICs from Aquantia has been

shipping in large volumes in all major switch

and AP platforms since 2014

26

10g | 5g | 2.5g | 1g | 100m physical layer phy · 2015-08-25 · • self near end (next) and far...

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