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

[Bob Edwards]

On 27/8/19 9:18 am, Steve Walsh via linux wrote:
> Hi Steve
> 
> Thanks for the feedback, it was a good talk and I hope was of interest
> to everyone.
>+1 (or +1000, if I was allowed to...)

Bob Edwards.

> ==
> 
> 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
>>
>>
> 
> 
>