[clug] [OT] Optical Fibre reading list & acronym list [LONG]

Mon Aug 26 23:18:13 UTC 2019

Hi Steve

Thanks for the feedback, it was a good talk and I hope was of interest
to everyone.

==

What you've called the PFS is actually a PFE "Power Feed Equipment",
there's a good video on youtube from PIPE networks about PFE's -
https://www.youtube.com/watch?v=Yy165USlmoI

==

Dispersion compensation is indeed a difficult subject to explain, as it
relies on a mix of year 10 physics and advanced photonics to fully
understand, but this video does a reasonable job of explaining it for
people who have a passing interest in what it's all about.
https://www.youtube.com/watch?v=PWaNMjimtP0

regards
On 23/8/19 9:07 pm, steve jenkin via linux wrote:
> Thanks for AARNET for their very generous exposition last night on their new INDIGO fibre.
>
> I know there were acronyms and topics that I needed to read more about, so created notes for anyone playing along at home that wanted to read more or play acronym decoder.
>
> This is ridiculously long so people can scan / search for one term and ignore the rest, not a linear / sequential read.
> It’s not meant to be ‘everything about cables’ or ‘everything AARNET said'
>
> regards
> s
>
> ===========
>
> The most important and least obvious part of the talk was about ‘proper care & feeding’ of the in-line Optical Amplifiers.
> They work best with a constant power signal over the full-spectrum, otherwise their gain vs frequency curve isn’t flat enough to be usable.
>
> Consequently there's a great deal of attention paid by everyone in generating (white?) noise to fill unused channels.
> The cable operator will ‘drop’ a signal source if it is 'out of spec’ and replace it with noise from an internal source to preserve the performance of the whole system.
>
> The 36nm “Spectrum” of each fibre pair  is shared between 4 Consortium partners as 4 x 1075Ghz + guard bands.
> The cable is 2 x pairs for both SYD - PER and PER - Singapore. 4 x pairs around Indonesia.
>
> While these Telco-grade submarine systems are super-fast, “5 nine’s” availability and hence very expensive,
> we’ve seen via the application of Moore’s Law the “trickle down effect” delivering these techniques into ‘’Enterprise” gear even down to commodity servers & “workstations” and maybe desktops.
>
> In 10 years, we might be able to run 600Gbps on affordable Optical transceivers.
> Just how we drive those loads, I’m not sure.
> Server backplanes are stretched by 100Gbps already.
>
> ===========
>
> I worked for most the 1980’s for OTC doing exchange software and other services, including email.
> This was on the cusp of Fibre Optics taking over - the weekly Library Bulletin was full of articles on Fibre & Optical system research.
>
> In 1987, Telecom built it’s first fibre trunk: SYD - CBR - MEL [roughly that route, more complex than this].
> That complemented ISDN or "number 7 signalling”  SS7 - digital common channel signalling. [1988 ISDN introduced]
> I’ve been told they started doing inter-exchange links before then [eg. around SYD & MEL]
>
> From 1986 - 1991, Tasman 2 was designed and built for $160M, 2 pairs at 560Mbps. [link to press release in previous email]
> OTC was merged into Telstra Feb 1992. Tas-2 was their last big build.
>
> ===========
>
> Those 100Gbps end-end tests…. Brought to you by good Open Source.
>
> iPerf - The ultimate speed test tool for TCP, UDP and SCTP
> <https://iperf.fr>
>
> ===========
>
> PFS - electrical "power feed system” 
> 	- or, how do you push 1-Amp DC down copper conductor for 5,000km?
>
> Couldn’t find a good link with those  search terms.
>
> ===========
>
> "Dispersion-Compensation” - it’s complex… 
>
> Tutorial: Submarine Optical Fibre and Cable: Foundation of Undersea Communication Networks
> 2013. PDF
> <https://www.suboptic.org/wp-content/uploads/2014/10/2013-Masterclass-Tutorial-9.pdf>
>
> ===========
>
> Phase / Amplitude encoding of digital bit-streams onto Optical carriers
> [there’s additional layers to this, including layer-1 (link) encryption]
>
> ‘Baud’ is the measure of ’symbols / second’- how fast the carrier is being modulated.
>
> A ’symbol’ can encode multiple bits, there’s many way to do this.
> a 25G-baud signal could carry 100Gbps or much higher, depending
> [Yes, you’ve all seen exactly this before with dial-up modems.]
>
> With single mode optical signals, Polarisation can be maintained, allowing independent QPSK encoding of the different polarisations.
>
> 25Gbaud x 2-bits / symbol x 2 polarisations = 100Gbps [unsure if that’s the standard - looked but search terms failed]
>
> Channel spacing of 25 or 50Ghz is only possible if highly tuned filters can select carrier frequencies before the receiver.
> To get higher bit rates, each baud has to carry more bits, because the carrier frequencies and channel spacing are a given.
>
> The AARNET optical encoders can be configured to a maximum of 600Gbps (QAM-64?), but they’re running at 200Gbps on longer runs and 300Gbps on shorter.
> They’ve a lot of expansion capacity available.
>
> QPSK - Quadrature Phase Shift Keying, 4 phases = 2-bits per ‘baud'
> <https://en.wikipedia.org/wiki/Phase-shift_keying>
>
> QAM - Quadrature amplitude modulation
> <https://en.wikipedia.org/wiki/Quadrature_amplitude_modulation>
>
>  - QAM64 used for 600Gpbs. [not obtained due to limited SNR]
>
> QPSK etc applied to Optical systems
>
> Optical Component Requirements for 400Gbps and 600Gbps Coherent Systems
> 2017 [has eye diagrams]
> <https://www.neophotonics.com/optical-component-requirements-400gbps-600gbps-coherent-systems/>
>
> For example, a single wavelength system operating at 64 Gbaud and 64 QAM can achieve 600Gbps,
>  with allowance for overhead,
>  over distances of 80 km suitable for datacenter interconnects (DCI).  
> A modest premium of 25% in the cost of the high performance components and electronics
>  gives a five-fold reduction in the cost per transmitted bit. 
>
>
> Complex modulation comes to optical fibre
> 2010
> <https://www.edn.com/design/test-and-measurement/4387875/Complex-modulation-comes-to-optical-fiber-4387875>
>
> Because the QPSK signal travels in two polarizations,
> it is called either DP-QPSK (dual-polarization QPSK) or PM-QPSK (polarization-mode QPSK)
> —the terms are interchangeable and both are commonly used.
>
> ===========
>
> ROADM - reconfigurable optical add-drop multiplexer 
> <https://en.wikipedia.org/wiki/Reconfigurable_optical_add-drop_multiplexer>
>
> ===========
>
> OSNR  - Optical Signal to Noise Ratio
> 2005 paper - PDF
> Photonics and Optical Communication Course
> <https://optiwave.com/wp-content/uploads/2015/10/TC-Optical-Signal-to-Noise-Ratio-OSNR.pdf?51da48>
>
> Topics
> • Optical Signal to Noise Ratio (OSNR)
> • Bit Error Rate
> • The Eye Diagram
> • Q Factor
>
> ===========
>
> EDFA = Ebrium Doped Fibre Amplifier
> <https://www.fiberlabs.com/glossary/erbium-doped-fiber-amplifier/>
>  - lasers disguised as optical fibre
>
> Figure 3 illustrates a simplified energy diagram of Er, 
> showing how amplification takes place at 1550 nm.
> Two typical wavelengths to pump an EDFA are 980 or 1480 nm.
>
> Obligatory Wikipedia Link on Optical Amplifiers
> <https://en.wikipedia.org/wiki/Optical_amplifier>
> Types
>  - EDFA
>  - SOA - Semiconductor Optical Amplifier 
>  - Raman amplifier
>
> EDFA:
>
> Gain and lasing in Erbium-doped fibers were first demonstrated in 1986–87 by two groups;
> 	one including David N. Payne, R. Mears, I.M Jauncey and L. Reekie, from the University of Southampton
> 	and one from AT&T Bell Laboratories, consisting of E. Desurvire, P. Becker, and J. Simpson.[
>
> The dual-stage optical amplifier which enabled Dense Wave Division Multiplexing (DWDM,) 
> was invented by Stephen B. Alexander at Ciena Corporation.
>
> ===========
>
> INDIGO Consortium
>
> Sub-partners home page, INDIGO
> <https://subpartners.net/indigo.html>
>
> AARNET & INDIGO CONSORTIUM
> <https://www.aarnet.edu.au/network-and-services/the-network/indigo-project>
>
> Press Release,  APRIL 6, 2017
> <https://news.aarnet.edu.au/new-subsea-cable-to-provide-additional-connectivity-between-australia-and-south-east-asia/>
>
> Indigo subsea cable made ready for use
> 	36Tbps cable linking Australia to Singapore launched slightly over two years from announcement.
> May 30 2019
> <https://www.zdnet.com/article/indigo-subsea-cable-made-ready-for-use/>
> 	- article is useful for list of current cable projects
>
> Indigo subsea cables ready for use
> 30 May, 2019
> <https://www.arnnet.com.au/article/662293/indigo-subsea-cables-ready-use/>
>
> The Indigo subsea cable system is ready to be deployed by
> 	 AARNet, 
> 	Google,
> 	 Indosat Ooredoo, 
> 	Singtel,
> 	 Superloop's SubPartners and 
> 	Telstra,
>  the consortium announced.
>
> ===========
>
> Long distance “Optical Communications” manufacturers
>
> Ciena
> <https://www.ciena.com/partners/list/Southern-Cross-Cable.html>
> <https://en.wikipedia.org/wiki/Ciena>
>
> CISCO & Acacia Communications
> <https://newsroom.cisco.com/press-release-content?type=webcontent&articleId=2000889>
>
> Commentary on ‘Coherent Tech’ and why CISCO wants to buy in
> <https://www.sdxcentral.com/articles/news/why-did-cisco-bet-billions-on-acacia-because-coherent-tech-a-multi-billion-market/2019/07/>
>
> ===========
>
> Cables to Asia off Western Australia were mentioned, acronym used was ’SEA-ME-WE3'
>
> SEA-ME-WE3 or South-East Asia - Middle East - Western Europe
> <https://en.wikipedia.org/wiki/SEA-ME-WE_3>
>
> <http://www.smw3.com/smw3/SignIn/Background.aspx>
>
> In December 1994, a Memorandum of Understanding was signed by 16 Parties for the development
>  of the Sea-Me-We 3 project between Western Europe and Singapore.
>
>  In November 1996, additional MOU(s) were signed to extend the system from Singapore to the Far East and to Australia.
>
>  Finally in January 1997, the Construction and Maintenance Agreement for Sea-Me-We 3 was signed by 92 International Carriers.
>
>  By end-2000 the entire network was completed.
>
> ————————
>
> Comment:
> Australia vs Geography - compare the ‘Ring of File Map and Pacific Optical Cables on TeleGeography’s map [link below]
> You’d think Japan to US would cross ’the ring’ twice… 
>
> Ring of Fire
> <https://en.wikipedia.org/wiki/Ring_of_Fire>
>
> Submarine Cable Map
> <https://www.submarinecablemap.com> 
>
> ===========
>
> SCCX: Important as first Optical Fibre cable from Australia to use “Optical Amplifiers” not ‘digital regenerators’ [fixed capacity]
>
> Southern Cross Cable
> commissioned in 2000
> <https://en.wikipedia.org/wiki/Southern_Cross_Cable>
>  - 320Gbps notional capacity when built
>  - currently around 
>
> Company SCCX
> <https://www.southerncrosscables.com>
>
> ===========
>
> Other Pacific Cables
>
> Coral Sea Cable System - part of Australian Aid budget.
> 	40Tbps submarine fibre optic cable, bringing next-generation connectivity to the people of Papua New Guinea and Solomon Islands.
> <https://www.coralseacablesystem.com.au>
> 	• A 4,700km submarine cable system linking Sydney to Port Moresby and Honiara.
>
> ===========
>
> TGA - Aus to NZ
>
> Tasman-2 entered service in late 1992, 2 x pairs @ 560Mbps PDH to NZ,.
> Phase 2 was NZ to US via ? (Hawaii IIRC) - collectively called PacRim East.
> Phase 3 was ‘PacRim West - cut and relocated to PNG as APNG-2.
>
> <https://www.submarinecablemap.com/#/submarine-cable/tasman-global-access-tga-cable>
> 	• RFS: 2017 March
> 	• Cable Length: 2,288 km
>
> 15 Apr 2016
> Cable Compendium: a guide to the week’s submarine and terrestrial developments
> <https://www.telegeography.com/products/commsupdate/articles/2016/04/15/cable-compendium-a-guide-to-the-weeks-submarine-and-terrestrial-developments/>
>
>
> Construction work on the first section of a new submarine cable link between New Zealand and Australia, named Tasman Global Access
> (TGA), has commenced, with the laying of a 3km fibre-optic cable at Ngarunui Beach in Raglan (New Zealand), newshub.co.nz writes.
>
>  The 2,300km direct link between Raglan and Narrabeen Beach (Australia) will incorporate three fibre pairs with a current design capacity of 20Tbps;
> the system is scheduled to be RFS [Ready for Service] by end-2016. 
>
> As previously reported by TeleGeography’s Cable Compendium, the TGA consortium
>  – comprising Spark New Zealand (formerly Telecom New Zealand), Telstra and Vodafone – 
> awarded the TGAdeployment contract to Paris-based equipment vendor Alcatel-Lucent (now part of Nokia) in January 2015.
>
>  The new system will provide an alternative path for trans-Tasman traffic
>  – currently routed via Tasman-2 and Southern Cross Cable Network (SCCN) –
>  and is expected to significantly improve New Zealand’s international connectivity options.
>
> ===========
>
>
> --
> Steve Jenkin, IT Systems and Design 
> 0412 786 915 (+61 412 786 915)
> PO Box 38, Kippax ACT 2615, AUSTRALIA
>
> mailto:sjenkin at canb.auug.org.au http://members.tip.net.au/~sjenkin
>
>

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