S. Baron, CERN PH/ESE 1

ALICE and LHCb meeting

TTC-PON History & StatusCsaba SOOS, Dimitris KOLOTOUROS, Vidak VUJICIC, Sophie BARON

11/06/2015

S. Baron, CERN PH/ESE 2

• Unidirectional• 1:32 max split ratio• Low bandwidth• Very low payload for Bunch synchronous data• Obsolete components

From TTC …

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S. Baron, CERN PH/ESE 3

…To TTC-PON

11/06/2015

• Bidirectional• High bandwidth• High split ratio• Scalable• Software partitioning• Commercial components• TTC legacy compatible (WDM)

S. Baron, CERN PH/ESE 4

PON / FTTx concept

11/06/2015

o PON=Passive Optical Networko Fiber To The Home (FTTH) technologyo 1 single fiber, 2 directionso 2 wavelengths (λ2 up, λ1 down)o Downstream (OLT -> ONUs) :

o high bandwidth broadcasto Upstream (ONUs -> OLT) :

o Time Domain Multiplexing o bandwidth shared between ONUs

o Several PON types (line rates, protocols)

OLT: Optical Line TerminalONU: Optical Network Unit

λ1

2 22

11

1

3 33

λ2

2 221 1 1 3 33

1 2 B 1 13 1 2 B 1 13

12

B1

13

12

B1

13

ONU

ONU

ONU

OLTONU

ONU

Passive Splitter

Up to 10km @ 1:128

1:32, 64, 128

4

S. Baron, CERN PH/ESE 5

PON for TTC

11/06/2015

o PON devices + FPGAs evaluation boardso Tuned to TTC needs:

o Fiber length O(100m) o Fully synchronous with Bunch Clock recovery at ONUso Both paths freq and phase lockedo Custom protocol (get rid of typical PON protocol layers)

sophie.baron@cern.ch – ACES 2014

OLT: Optical Line TerminalONU: Optical Network Unit

λ1

2 22

11

1

3 33

λ2

2 221 1 1 3 33

1 2 B 1 13 1 2 B 1 13

12

B1

13

12

B1

13

OLT

ONU

ONU

ONU

1:64,128

OLT

ONU

ONU

ONU

+

+

+

+

A few 100m

S. Baron, CERN PH/ESE 6

PON families of technology

11/06/2015

Source - COMPARING IEEE EPON & FSAN/ITU-T GPON FAMILY OF TECHNOLOGIES – Arris 2014

1 23

GPON 1G-EPON XGPON1 10G/1G-EPON NG-PON2 10G/10G-EPON

Specs ITU-T G.984 IEEE 802.3bk-2013 ITU-T G.987 IEEE 802.3bk-

2013 ITU-T G.989 IEEE 802.3bk-2013 units

PON Rate 2.488G/ 1.244G 1.25G/1.25G 9.953G/2.488G 10.3125G/

1.25G 9.953G/9.953G 10.3125G/10.3125G Gbps

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) km

OLT Form factor SFP SFP XFP, SFP+ XFP, XFP XFP

ONU Form factor SFP SFP SFP+ SFP+ SFP+ SFP+

S. Baron, CERN PH/ESE 7

Project Timeline

11/06/2015

Setup AML523, 1G-EPON, SFP/SFP1.6G Down, 0.8upProof of Concept

2013 2014 2015

Setup BKC724, 10G-EPON OEXFP/SFP+11.2G down, 2.8Gbps Up

Setup CKC705, XGPON1, SFP+/SFP+9.6G Down, 2.4G up

1G-EPON SFF OE 10G-EPON XFP/SFP OE 10G-EPON & XG-PON full SFP+ Ligent

S. Baron, CERN PH/ESE 8

Global features

11/06/2015

GENERAL FEATURES

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 9

Downstream Principle

11/06/2015

The TTC frame

The TTC-PON frame

A (trigger field, 1bit) B (control channel, 1bit)

x bytes / BCK28.5 TT TT TT

1BC

25ns

S. Baron, CERN PH/ESE 10

Downstream features

11/06/2015

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)

Trigger latency~100ns(2) ~250ns(2) ~80ns(2) ~100ns(2)

Fixed & deterministic

(1) Actually much less, due to heavy TTC protocol on channel B(2) 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

S. Baron, CERN PH/ESE 11

Upstream Principle

o Thanks to:o Full synchronizationo Light protocol using automatic tokeno Ranging procedure for gap reduction (the gap has to be as short as

possible)o x4 oversampling and complex phase alignment algorithm at the

OLT Receiver

o We went from:

o To…

11/06/2015

Contiguous Bursts Mode (CBM)

S. Baron, CERN PH/ESE 12

Upstream Features

11/06/2015

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(2) Split 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

S. Baron, CERN PH/ESE 13

So far …

11/06/2015

GENERAL FEATURESTTC system TTC-PON (2011) TTC-PON (2014) TTC-PON (2015)

Technology SONET/SDH OC-3 1G-EPON 10G-EPON XGPON1Line Rate (D/U) 80Mbps 1.6/0.8Gbps 11.2/2.8Gbps 9.6/2.4Gbps

Bidirectional NO YES YES YESFiber length 10-300m 10-1000m 10-1000m 10-1000mSplit Ratio 1:32 1:64 1:64 1:128

BC synchronous YES YES YES YESError detection CH. B ONLY YES YES YES

OLT Form Factor SFP SFP XFP XFP, SFP+*ONU Form Factor SFP SFP SFP+ SFP+

DOWNSTREAM FEATURESWavelength 1310nm 1490nm 1577nm 1577nm

Encoding BPM, Hamming 8b/10b 8b/10b 8b/10bPayload ~80Mbps(1) ~590Mbps ~8.64Gbps ~8.68Gbps

Payload/BC 2 bits(1)/BC 32 bits/BC 216 bits/BC 192 bits/BCTrigger Rate <40MHz 40MHz 40MHz 40MHz

Synchronous Trigger Type NO YES (16 bits) YES ( >32bits) YES ( >32bits)Trigger latency ~100ns ~250ns ~80ns ~100ns

UPSTREAM FEATURESWavelength x 1310nm 1270nm 1270nm

Encoding x 8b/10b 8b/10b 8b/10bTotal Payload (All ONUs) x 2.2Mbps 640Mbps 640Mbps

Total Payload/BC x 3.5bits/BC ~16bits/BC ~16bits/BCONU Burst length x ~1.6us 25ns (16 bits) 25ns (16 bits)

Max Latency for 1:64 x 14us 1.6us 1.6us**Max Latency for 1:128 x x 3.2us 3.2us**

* Still very rare** not fully satisfying, see next slide/presentation

S. Baron, CERN PH/ESE 14

Upstream: some reservations…

o On paper, nice solutiono In real life, not so bad:

o Still, reaching this is not fully painless:o Phase Alignment Algorithm complex to optimizeo Short Bursts require Fixed bias (APC has to work in Open Loop Mode)o Short Bursts / long gaps induce relaxation oscillations. Likely to be proportional to split

ratioo Out of spec solution in term of protocol (and line rate): we can’t expect any help from

manufacturers

Þ to ensure a steady behaviour, we might have to extend the preamble duration (at the cost of busy latency)…

Þ see second presentation focusing on upstream path

11/06/2015

S. Baron, CERN PH/ESE 15

Spare slides

11/06/2015

S. Baron, CERN PH/ESE 16

Current Setups

11/06/2015

Optical: 1G EPON – OE solutionBoard: ML605PLL: CDCE62000

Optical: 10G EPON – OE solutionBoard: KC724PLL: CDCE

Optical: 10G - XGPON – LigentBoard: KC705PLL: Si5338

S. Baron, CERN PH/ESE 17

Standard Features

11/06/2015

Field 1G-EPON(CURRENT)

10G-EPON 2GPON 10GPON

IFG (ns) 50 50 16 16Training (ns) 125 12.5 125 12.5Payload (ns) 40 4 40 4Total per frame (ns) 215 66.5 181 32.5No. of bunch-cycles between transmissions 9 3 8 2