ALICE and LHCb meeting TTC-PON History & Status Csaba SOOS, Dimitris KOLOTOUROS, Vidak VUJICIC, Sophie BARON 11/06/2015S. Baron, CERN PH/ESE1

Unidirectional 1:32 max split ratio Low bandwidth Very low payload for Bunch synchronous data Obsolete components From TTC … 11/06/2015S. Baron, CERN PH/ESE2

…To TTC-PON 11/06/2015S. Baron, CERN PH/ESE3 Bidirectional High bandwidth High split ratio Scalable Software partitioning Commercial components TTC legacy compatible (WDM)

PON / FTTx concept 11/06/2015S. Baron, CERN PH/ESE4 o PON=Passive Optical Network o Fiber To The Home (FTTH) technology o 1 single fiber, 2 directions o 2 wavelengths (λ2 up, λ1 down) o 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) OLT: Optical Line Terminal ONU: Optical Network Unit λ1λ λ2λ B113 12B B B ONU OLT ONU Passive Splitter Up to 1:128 1:32, 64, 128 4

PON for TTC 11/06/2015S. Baron, CERN PH/ESE5 o PON devices + FPGAs evaluation boards o Tuned to TTC needs: o Fiber length O(100m) o Fully synchronous with Bunch Clock recovery at ONUs o Both paths freq and phase locked o Custom protocol (get rid of typical PON protocol layers) – ACES 2014 OLT: Optical Line Terminal ONU: Optical Network Unit λ1λ λ2λ B113 12B B B OLT ONU 1:64,128 OLT ONU A few 100m

PON families of technology 11/06/2015S. Baron, CERN PH/ESE6 Source Source - COMPARING IEEE EPON & FSAN/ITU-T GPON FAMILY OF TECHNOLOGIES – Arris GPON1G-EPONXGPON1 10G/1G- EPON NG-PON210G/10G-EPON Specs ITU-T G.984 IEEE 802.3bk ITU-T G.987 IEEE 802.3bk ITU-T G.989IEEE 802.3bk-2013 units PON Rate 2.488G/ 1.244G 1.25G/1.25G9.953G/2.488G G/1.25 G 9.953G/9.953G G/ G Gbps Downstream λ nm Upstream λ nm Split Ratio1:1281:641:1281:641:2561:64 Max Reach60 (C+)20 (PX40)4020 (PRX40)4020 (PR40)km OLT Form factorSFP XFP, SFP+XFP,XFP ONU Form factorSFP SFP+

Project Timeline 11/06/2015S. Baron, CERN PH/ESE7 Setup A ML523, 1G-EPON, SFP/SFP 1.6G Down, 0.8up Proof of Concept Setup B KC724, 10G-EPON OE XFP/SFP+ 11.2G down, 2.8Gbps Up Setup C KC705, 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

Global features 11/06/2015S. Baron, CERN PH/ESE8 GENERAL FEATURES TTC system TTC-PON (2011) TTC-PON (2014) TTC-PON (2015) TechnologySONET/SDH OC-31G-EPON10G-EPONXGPON1 Line Rate (D/U)80Mbps1.6/0.8Gbps11.2/2.8Gbps9.6/2.4Gbps BidirectionalNOYES Fiber length10-300m m Split Ratio1:321:64 1:128 BC synchronousYES Error detectionCH. B ONLYYES

Downstream Principle 11/06/2015S. Baron, CERN PH/ESE9 The TTC frame The TTC-PON frame A (trigger field, 1bit)B (control channel, 1bit) x bytes / BC K28.5 TT 1BC 25ns

Downstream features 11/06/2015S. Baron, CERN PH/ESE10 DOWNSTREAM FEATURES TTC systemTTC-PON (2011)TTC-PON (2014)TTC-PON (2015) TechnologySONET/SDH OC-31G-EPON10G-EPONXGPON1 Line Rate80Mbps1.6Gbps11.2Gbps9.6Gbps Wavelength1310nm1490nm1577nm EncodingBPM, Hamming8b/10b Payload~80Mbps (1) ~590Mbps~8.64Gbps~8.68Gbps Payload/BC2 bits (1) /BC32 bits/BC216 bits/BC192 bits/BC Trigger Rate<40MHz40MHz Synchronous Trigger Type NOYES (16 bits)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

Upstream Principle o Thanks to: o Full synchronization o Light protocol using automatic token o 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… 11/06/2015S. Baron, CERN PH/ESE11 Contiguous Bursts Mode (CBM)

Upstream Features 11/06/2015S. Baron, CERN PH/ESE12 UPSTREAM FEATURES TTC systemTTC-PON (2011)TTC-PON (2014)TTC-PON (2015) Technologyx1G-EPON10G-EPONXGPON1 Line Ratex0.8Gbps2.8Gbps2.4Gbps Wavelengthx1310nm1270nm Encodingx8b/10b Total Payload (All ONUs) x2.2Mbps (2) 640Mbps (1) Total Payload/BCx3.5bits/BC (2) ~16bits/BC (1) ONU Burst lengthx~1.6us (2) 25ns (3) (16 bits) Max Latency for 1:64x14us1.6us Max Latency for 1:128xx3.2us (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

So far … 11/06/2015S. Baron, CERN PH/ESE13 GENERAL FEATURES TTC systemTTC-PON (2011)TTC-PON (2014)TTC-PON (2015) TechnologySONET/SDH OC-31G-EPON10G-EPONXGPON1 Line Rate (D/U)80Mbps1.6/0.8Gbps11.2/2.8Gbps9.6/2.4Gbps BidirectionalNOYES Fiber length10-300m m Split Ratio1:321:64 1:128 BC synchronousYES Error detectionCH. B ONLYYES OLT Form FactorSFP XFPXFP, SFP+* ONU Form FactorSFP SFP+ DOWNSTREAM FEATURES Wavelength1310nm1490nm1577nm EncodingBPM, Hamming8b/10b Payload~80Mbps (1) ~590Mbps~8.64Gbps~8.68Gbps Payload/BC2 bits (1) /BC32 bits/BC216 bits/BC192 bits/BC Trigger Rate<40MHz40MHz Synchronous Trigger TypeNOYES (16 bits)YES ( >32bits) Trigger latency~100ns~250ns~80ns~100ns UPSTREAM FEATURES Wavelengthx1310nm1270nm Encodingx8b/10b Total Payload (All ONUs)x2.2Mbps640Mbps Total Payload/BCx3.5bits/BC~16bits/BC ONU Burst lengthx~1.6us25ns (16 bits) Max Latency for 1:64x14us1.6us1.6us** Max Latency for 1:128xx3.2us3.2us** * Still very rare ** not fully satisfying, see next slide/presentation

Upstream: some reservations… o On paper, nice solution o In real life, not so bad: o Still, reaching this is not fully painless: o Phase Alignment Algorithm complex to optimize o 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 ratio o 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 11/06/2015S. Baron, CERN PH/ESE14

Spare slides 11/06/2015S. Baron, CERN PH/ESE15

Current Setups 11/06/2015S. Baron, CERN PH/ESE16 Optical: 1G EPON – OE solution Board: ML605 PLL: CDCE62000 Optical: 10G EPON – OE solution Board: KC724 PLL: CDCE Optical: 10G - XGPON – Ligent Board: KC705 PLL: Si5338

Standard Features 11/06/2015S. Baron, CERN PH/ESE17 Field 1G-EPON (C URRENT ) 10G-EPON2GPON10GPON IFG (ns)50 16 Training (ns) Payload (ns)404 4 Total per frame (ns) No. of bunch-cycles between transmissions9382