Balanced Cabling for 40 Gb/s over less than 100 m
ISO/IEC PDTR 11801-99-1
1
Information technology – Guidance for balanced cabling in
support of at least 40 Gb/s data transmission
Presentation at IEEE 802.3 Interim
J
January
2013,
2013 Phoenix
Ph i AZ
Supporters
2

Authors
Dr. Dieter Schicketanz,
Dr
Schicketanz Reutlingen University
Prof. Albrecht Oehler, Reutlingen University
Hans Lackner, QosCom
Supporters
Yakov Belopolsky, Bel Stewart Connector
Roland Dold, BTR NETCOM
Yvan Engels, Leoni Kerpen
Alan Flatman,, LAN Technologies
g
Habbo Heinze, Telegärtner
Thomas Hüsch, Psiber Data
Martin Rossbach, Nexans
Gerd Weking, Harting
Dirk Wilhelm, GHMT
Content
3



40G cabling & the existing generic cabling model
40G Cabling
g Measurements
Assessment of cabling capacity for 40 Gb/s
ISO/IEC PDTR 11801
11801-99-1
99 1 Annex B
ISO/IEC Generic Cabling
4

In ISO/IEC 11801: 2010 cabling channels are
specified as generic, 100 m with 4 connections.



Channel Approach
Reference implementation (Component Approach)
If the installed length is less then 100 m with fewer
than 4 connections
connections, e.g.
e g 40 m 2 connections
connections, all 100 m
channel limit values hold
ISO/IEC Generic Cabling
5

Insertion Loss
Class F

NEXT
Class FA
Class EA
Class F
Class FA
Class D
100
Class D
500
100
Class EA
500
40G Balanced Cabling Support
6

ISO/IEC Proposed Draft Technical Report 11801-99-1
Information technology – Guidance for balanced cabling in
supportt off att least
l t 40 Gb/s
Gb/ data
d t transmission
t
i i
Nov 12
Feb 13
Apr13
Jun13
Aug13
Okt13
Dec13
PDTR
PDTR
DTR
DTR
TR
TR
TR
published accepted published accepted published accepted published
40G Balanced Cabling Support
7


ISO/IEC PDTR 11801-99-1
11801 99 1 specifies
ifi shorter
h t channels
h
l
and less connectors (2 at each end with 2 m cords)
Use existing specifications with extended frequencies


25 m with Cat. 6A (500 MHz)
25 and 50 m with Cat.
Cat 7A (1000 MHz)
 50m
with improved components (1600 MHz)
Class I with extended and improved Cat.
Cat 6A components
Class II with extended and improved Cat. 7A components
 Clause
Cl
6 explains
l
qualification
lf
off existing channels
h
l
Note:
Channel length is not fixed, PDTR is a Draft.
Formulas to calculate other length are found in Annex A of PDTR.
Comparison of ISO/IEC & TIA
8
Equipment
 Insertion loss is similar ((connectors different))
Cord
50m Cab
bling Chan
nnel
 both use 50 m channel with 2 connectors
C
 TIA Cat. 8 based on Cat. 6A components with
some enhancements
 ISO/IEC Class I & II is based on fictitious
components yet to be standardized.
Permanent
Link
 TIA upper frequency 2 GHz TBD
ISO/IEC 1.6 GHz (values up to 2 GHz ffs)
C
 TIA-568-C.2.1 standard in development
 ISO/IEC 11801-99-1 TR expected in Q4-2013
Cord
Equipment
Comparison of ISO/IEC & TIA
9

Main differences of ISO/IEC Class I and II and
TIA-568-C.2.1 at 1 GHz in dB
Parameter
Class I Class II Diff CI-II
TIA
R
Return
LLoss
6 0 ffs
6.0
ff
8 0 ffs
8.0
ff
2 0 ffs
2.0
ff
6 0 TBD
6.0
Insertion Loss
33.5
31.5
2.0 35.3 TBD
NEXT
22.6
47.9
25.3 16.9 TBD
ACR-F
7.4
37.1
29.7 10.9 TBD
Result:
Less cancellation is needed for Class II
Measurements on prototype channels I and II
10
The measurements were performed with an PSIBER WIREXPERT
up to 1600 MHz in the channel FA setting
2m
•
•
•
•
46 m
2m
46 m horizontal cable S/FTP optimized for 1600 MHz, 8 mm diameter
2 m S/FTP
/
p
patch cords cat6A and Cat. 7A non optimized,
p
, influence can be seen
Class I connecting hardware selected Cat. 6A
Class II connecting hardware selected Cat. 7A
Measurement results Class I and Class II
11
Insertion Loss (non optimized patch cords)

IL class I
50
IL class II
50
45
45
40
40
35
35
30
Limit (dB)
30
Limit (dB)
25
1;2
25
1;2
20
3;6
20
3;6
15
4;5
15
4;5
7;8
10
7;8
10
5
5
0
0
0
400
800
1200
1600
0
400
800
Limits met (influence of patch cords)
1200
1600
Measurement results Class I and Class II
12
Return loss (limits ffs)

RL class I
70
RL class II
80
60
70
50
60
40
30
Limit I (dB)
50
Limit I (dB)
1;2
40
1;2
3;6
20
4;5
10
7;8
3;6
30
4;5
20
7;8
10
0
0
400
800
1200
1600
0
0
Limits met!
400
800
1200
1600
Measurement results Class I and Class II
13

NEXT class II
Near end crosstalk
NEXT class I
100,00
90,00
80,00
70,00
60,00
50,00
40,00
30,00
20,00
10,00
0,00
Limit I (dB)
1;2-3;6
1;2-4;5
1;2-7;8
3;6-4;5
IEC60603-7-71
100,00
90,00
80,00
70,00
60,00
50,00
40,00
30,00
20,00
10,00
0,00
Limit I (dB)
1;2-3;6
1;2-4;5
1;2-7;8
3;6-4;5
3;6-7;8
4;5-7;8
0
400
3;6-7;8
400
800
1200
1600
IEC 60603-7-51
Limits met!
1200
1600
NEXT class II
4;5-7;8
0
800
IEC61076 3 104
IEC61076-3-104
100,00
90,00
80,00
70,00
60,00
50,00
40,00
30,00
20,00
10,00
0,00
Limit I (dB)
1;2-3;6
1;2-4;5
; ;
1;2-7;8
3;6-4;5
3;6-7;8
4;5-7;8
0
400
800
1200
1600
Measurement results Class I and Class II
14
Attenuation to Crosstalk Far End

ACR-F class I
100,00
90,00
80 00
80,00
70,00
60,00
50,00
40,00
30 00
30,00
20,00
10,00
0,00
ACR-F class II
Limit I (dB)
1;2-7;8
3;6-1;2
4;5-1;2
4;5-3;6
7;8-3;6
7;8-4;5
7;8-1;2
0
400
800
1200
1600
1;2-3;6
100,00
90,00
80 00
80,00
70,00
60,00
50,00
40,00
30 00
30,00
20,00
10,00
0,00
Limit I (dB)
1;2-7;8
3;6-1;2
4;5-1;2
4;5-3;6
7;8-3;6
7;8-4;5
7;8-1;2
0
400
800
Limits met (effects of patch cords)
1200
1600
1;2-3;6
Annex B of ISO/IEC PDTR 11801-99-1
Assessment of cabling capacity for 40 Gb/s
15

Assumptions
 155
dBm/Hz PHY background noise
 As
values up to 145 were discussed they will be presented
but outside PDTR
 Transmitter
signal level 3 dBm
 Cabling noise for the moment assumed to be neglected
due to
 Alien
noise by shielding
 NEXT, FEXT and RL by cancellation
Cancellation
16

Compensation of Cable Noise
To compensate the cabling noise below the background noise the following
levels for the proposed classes need to be used. The 2 GHz values were
calculated extrapolating the limits.
For other noise and transmit power values they translate linearly.
Channel Capacity
17



Calculations of channel capacity were performed
similar to the calculation presented by W. Bliss at
the September 2012 meeting (bliss_01_0912.pdf)
As margin
g is a preferred
p
presentation
p
this was
added for 40 Gb/s to the Shannon capacity.
The compensation was assumed flat over frequency
up to the channel bandwidth.
Theoretical Length for 40 Gb/s
18

Theoretical length as
q
y
function of frequency
under the assumption
of 10 dB margin
Theoretical Length
75
70
65
60
55
50
45
40
35
30
0
0,5
1
1,5
145dBm/Hz
Margin 1.0 GHz
1.3 GHz
1.6 GHz
2
2,5
155dBm/Hz
2.0 GHz
10dB
40 m
46 m
48 m
46 m 145dBm/Hz
10dB
66 m
69 m
68 m
64 m 155dBm/Hz
Conclusions
19







Main
M
i purpose off th
the TR is
i tto supportt the
th IEEE 40GBASE-T
40GBASE T
project with a range of possible solutions. Once the IEEE
project has selected an appropriate channel, ISO/IEC will
then consider the development of a formal standard for this.
Publication of the Technical Report is expected in Q4-2013.
50 m channels
h
l are achievable
hi bl under
d the
th PDTR assumptions.
ti
Class II channels require significantly less cancellation
than Class I and EIA/TIA
/
Cat. 8 channels.
Existing ISO/IEC Cat. 7A components specified to their
existing upper frequency are sufficient
Measurements to date suggest that proposed Class I & Class
II channel limits are realistic.
Bandwidth >1.3
>1 3 GHz reduces the maximum length
20
Thanks for your patients with me
Signal to Noise
21
2 theoretical channel length showing the signal and noise over frequency.
frequency As the noise
was not completely compensated some influence can still be seen
At shorter length the theoretical increased FEXT is observed. Shielded pairs used
normallyy in C
Class FA and upwards
p
behave
v differentlyy . The expected
p
influence is much
less.
Channel I figures similar because of assumptions
L 
L  25
Class II
0
0
10
10
20
20
dB
B signal to noisee
dB
B signal to noisee
Class II
30
40
50
60
70
30
40
50
60
70
80
80
90
90
10 0
500
10 00
Fre qu e n cy
Signal
Noise
50
1500
2000
10 0
50 0
10 00
Fre qu e n cy
Signal
Noise
15 00
20 00
Shannon Capacity
22
The Shannon capacity and the corresponding margin for the case shown before
The deviation from a straight line
• below 40 m is because of the increasing FEXT (compensation was kept constant) and
• above 80 m because the S/N gets below 0 dB
Max Frequency 1600 MHz
Margin at 40 Gb/s in dB
Shannon Capacity
Margin in dB
50
140
45
120
40
35
Gbit/s
dB
Gbit/s
100
80
60
30
25
20
15
40
10
20
0
5
10
20
30
40
50
60
70
C h ann e l le n ggth
80
90
100
0
10
20
30
40
50
60
70
C h ann e l le n ggth
80
90
100
Additional Calculations
23
To see different possibilities new calculations were performed (not seen in PDTR)
with different background noise levels. No cabling noise assumed. Therefore margin
results for short length in a straight line.
24
1,3 and 2 GHz figures overlaid
The short lines are for 1.3 GHz
It is therefore of no advantage to go
to 2 GH for the assumptions chosen
25