ALICE and LHCb meeting
TTC-PON History & Status
Csaba SOOS, Dimitris KOLOTOUROS, Vidak VUJICIC, Sophie BARON
11/06/2015
S. Baron, CERN PH/ESE
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From TTC …
• Unidirectional
• 1:32 max split ratio
• Low bandwidth
• Very low payload
for Bunch synchronous data
• Obsolete components
11/06/2015
S. Baron, CERN PH/ESE
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…To TTC-PON
•
•
•
•
•
•
•
Bidirectional
High bandwidth
High split ratio
Scalable
Software partitioning
Commercial components
TTC legacy compatible (WDM)
11/06/2015
S. Baron, CERN PH/ESE
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4
PON / FTTx concept
o PON=Passive Optical Network
o
o
o
o
Fiber To The Home (FTTH) technology
1 single fiber, 2 directions
2 wavelengths (λ2 up, λ1 down)
Downstream (OLT -> ONUs) :
o high bandwidth broadcast
o Upstream (ONUs -> OLT) :
o Time Domain Multiplexing
o bandwidth shared between ONUs
o Several PON types (line rates, protocols)
Passive
Splitter
λ1
1
1
OLT
2
1
B
1
λ2
ONU
2
1
2
3
1
1
2
B
2
2 3 3 3
1:32,
64, 128
OLT: Optical Line Terminal
ONU: Optical Network Unit
1
2
3
1
ONU
2
ONU
ONU
ONU
Up to 10km @ 1:128
11/06/2015
S. Baron, CERN PH/ESE
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PON for TTC
o PON devices + FPGAs evaluation boards
o Tuned to TTC needs:
o
o
o
o
Fiber length O(100m)
Fully synchronous with Bunch Clock recovery at ONUs
Both paths freq and phase locked
Custom protocol (get rid of typical PON protocol layers)
ONU
+
ONU
λ1
+
1
OLT
1
2
1
B
1
λ2
2
1
2
3
1
1
2
B
2
2 3 3 3
1:64,128
1
2
3
2
1
ONU
+
ONU
OLT
OLT: Optical Line Terminal
ONU: Optical Network Unit
ONU
A few 100m
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S. Baron, CERN PH/ESE
+
ONU
5
sophie.baron@cern.ch – ACES 2014
PON families of technology
GPON
1G-EPON
XGPON1
10G/1GEPON
NG-PON2
10G/10G-EPON
Specs
ITU-T G.984
IEEE 802.3bk2013
ITU-T G.987
IEEE 802.3bk2013
ITU-T G.989
IEEE 802.3bk-2013
PON Rate
2.488G/
1.244G
Downstream λ
1490
1490
1577
1577
1600
1577
nm
Upstream λ
1310
1310
1270
1310
1530
1270
nm
Split Ratio
1:128
1:64
1:128
1:64
1:256
1:64
Max Reach
60 (C+)
20 (PX40)
40
20 (PRX40)
40
20 (PR40)
OLT Form factor
SFP
SFP
XFP, SFP+
XFP,
XFP
XFP
ONU Form factor
SFP
SFP
SFP+
SFP+
SFP+
SFP+
1
3
1.25G/1.25G 9.953G/2.488G
10.3125G/1.25
9.953G/9.953G 10.3125G/10.3125G
G
units
Gbps
km
2
Source - COMPARING IEEE EPON & FSAN/ITU-T GPON FAMILY OF TECHNOLOGIES – Arris 2014
11/06/2015
S. Baron, CERN PH/ESE
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Project Timeline
Setup A
ML523, 1G-EPON, SFP/SFP
1.6G Down, 0.8up
Proof of Concept
Setup C
KC705, XGPON1, SFP+/SFP+
9.6G Down, 2.4G up
2013
2014
2015
Setup B
KC724, 10G-EPON OE
XFP/SFP+
11.2G down, 2.8Gbps Up
1G-EPON SFF OE
11/06/2015
10G-EPON XFP/SFP OE
10G-EPON & XG-PON full SFP+ Ligent
S. Baron, CERN PH/ESE
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Global features
GENERAL FEATURES
11/06/2015
TTC system
TTC-PON
(2011)
TTC-PON
(2014)
TTC-PON
(2015)
Technology
SONET/SDH OC-3
1G-EPON
10G-EPON
XGPON1
Line Rate (D/U)
80Mbps
1.6/0.8Gbps
11.2/2.8Gbps
9.6/2.4Gbps
Bidirectional
NO
YES
YES
YES
Fiber length
10-300m
10-1000m
10-1000m
10-1000m
Split Ratio
1:32
1:64
1:64
1:128
BC synchronous
YES
YES
YES
YES
Error detection
CH. B ONLY
YES
YES
YES
S. Baron, CERN PH/ESE
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Downstream Principle
25ns
1BC
x bytes / BC
The TTC-PON frame
K28
.5
TT
TT
TT
The TTC frame
A (trigger field, 1bit)
11/06/2015
S. Baron, CERN PH/ESE
B (control channel, 1bit)
9
Downstream features
DOWNSTREAM FEATURES
TTC system
TTC-PON (2011)
TTC-PON (2014)
TTC-PON (2015)
Technology
SONET/SDH OC-3
1G-EPON
10G-EPON
XGPON1
Line Rate
80Mbps
1.6Gbps
11.2Gbps
9.6Gbps
Wavelength
1310nm
1490nm
1577nm
1577nm
Encoding
BPM, Hamming
8b/10b
8b/10b
8b/10b
Payload
~80Mbps(1)
~590Mbps
~8.64Gbps
~8.68Gbps
Payload/BC
2 bits(1)/BC
32 bits/BC
216 bits/BC
192 bits/BC
Trigger Rate
<40MHz
40MHz
40MHz
40MHz
Synchronous
Trigger Type
NO
YES (16 bits)
YES ( >32bits)
YES ( >32bits)
~100ns(2)
~250ns(2)
~80ns(2)
~100ns(2)
Trigger latency
Fixed & deterministic
Actually much less, due to heavy TTC protocol on channel B
Active components only (no fiber, no cable). Delay between flags on K28.5 right before 8b10b encoder
at the OLT and after the 8b10b decoder at the ONU
(1)
(2)
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S. Baron, CERN PH/ESE
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Upstream Principle
o Thanks to:
o
o
o
o
Full synchronization
Light protocol using automatic token
Ranging procedure for gap reduction (the gap has to be as short as possible)
x4 oversampling and complex phase alignment algorithm at the OLT Receiver
o We went from:
o To…
Contiguous Bursts Mode (CBM)
11/06/2015
S. Baron, CERN PH/ESE
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Upstream Features
UPSTREAM FEATURES
TTC system
TTC-PON (2011)
TTC-PON (2014)
TTC-PON (2015)
Technology
x
1G-EPON
10G-EPON
XGPON1
Line Rate
x
0.8Gbps
2.8Gbps
2.4Gbps
Wavelength
x
1310nm
1270nm
1270nm
Encoding
x
8b/10b
8b/10b
8b/10b
Total Payload (All
ONUs)
x
2.2Mbps(2)
640Mbps(1)
640Mbps(1)
Total Payload/BC
x
3.5bits/BC(2)
~16bits/BC(1)
~16bits/BC(1)
ONU Burst length
x
~1.6us(2)
25ns (3)(16 bits)
25ns (3)(16 bits)
Max Latency for 1:64
x
14us
1.6us
1.6us
Max Latency for 1:128
x
x
3.2us
3.2us
(1) Pure
Data: Doesn’t include 8 bits of ONU address field + the possibility of having 3 commas
ratio related – these values are for 1:64
(3) 22ns + 3ns of gap . For the XGPON1 solution, this is at the cost of a significant reduction of
the number of preamble bits
(2) Split
11/06/2015
S. Baron, CERN PH/ESE
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So far …
Technology
Line Rate (D/U)
Bidirectional
Fiber length
Split Ratio
BC synchronous
Error detection
OLT Form Factor
ONU Form Factor
TTC system
SONET/SDH OC-3
80Mbps
NO
10-300m
1:32
YES
CH. B ONLY
SFP
SFP
Wavelength
Encoding
Payload
Payload/BC
Trigger Rate
Synchronous Trigger Type
Trigger latency
1310nm
BPM, Hamming
~80Mbps(1)
2 bits(1)/BC
<40MHz
NO
~100ns
Wavelength
Encoding
Total Payload (All ONUs)
Total Payload/BC
ONU Burst length
Max Latency for 1:64
Max Latency for 1:128
x
x
x
x
x
x
x
GENERAL FEATURES
TTC-PON (2011)
1G-EPON
1.6/0.8Gbps
YES
10-1000m
1:64
YES
YES
SFP
SFP
DOWNSTREAM FEATURES
1490nm
8b/10b
~590Mbps
32 bits/BC
40MHz
YES (16 bits)
~250ns
UPSTREAM FEATURES
1310nm
8b/10b
2.2Mbps
3.5bits/BC
~1.6us
14us
x
TTC-PON (2014)
10G-EPON
11.2/2.8Gbps
YES
10-1000m
1:64
YES
YES
XFP
SFP+
TTC-PON (2015)
XGPON1
9.6/2.4Gbps
YES
10-1000m
1:128
YES
YES
XFP, SFP+*
SFP+
1577nm
8b/10b
~8.64Gbps
216 bits/BC
40MHz
YES ( >32bits)
~80ns
1577nm
8b/10b
~8.68Gbps
192 bits/BC
40MHz
YES ( >32bits)
~100ns
1270nm
8b/10b
640Mbps
~16bits/BC
25ns (16 bits)
1.6us
3.2us
1270nm
8b/10b
640Mbps
~16bits/BC
25ns (16 bits)
1.6us**
3.2us**
* Still very rare
** not fully satisfying, see next slide/presentation
11/06/2015
S. Baron, CERN PH/ESE
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Upstream: some reservations…
o On paper, nice solution
o In real life, not so bad:
o Still, reaching this is not fully painless:
o
o
o
o
Phase Alignment Algorithm complex to optimize
Short Bursts require Fixed bias (APC has to work in Open Loop Mode)
Short Bursts / long gaps induce relaxation oscillations. Likely to be proportional to split ratio
Out of spec solution in term of protocol (and line rate): we can’t expect any help from
manufacturers
 to ensure a steady behaviour, we might have to extend the preamble duration (at the
cost of busy latency)…
 see second presentation focusing on upstream path
11/06/2015
S. Baron, CERN PH/ESE
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Spare slides
11/06/2015
S. Baron, CERN PH/ESE
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Current Setups
Optical: 1G EPON – OE solution
Board: ML605
PLL:
CDCE62000
Optical: 10G - XGPON – Ligent
Board: KC705
PLL:
Si5338
Optical: 10G EPON – OE solution
Board: KC724
PLL:
CDCE
11/06/2015
S. Baron, CERN PH/ESE
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Standard Features
1G-EPON 10G-EPON 2GPON 10GPON
(CURRENT)
IFG (ns)
50
50
16
16
Training (ns)
125
12.5
125
12.5
Payload (ns)
40
4
40
4
Total per frame (ns)
215
66.5
181
32.5
No. of bunch-cycles between transmissions
9
3
8
2
Field
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S. Baron, CERN PH/ESE
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