When OTT launched the Certified Optical Network Engineer (CONE) course back in April 2008 it was already a fairly busy one week course. But ever since, fed by my involvement in International standards committees, attendance at technical conferences such as OFC & ECOC and from my communications with people and companies leading the industry, we have been continuously updating the course to cover all of the developments that are shaping the future of telecoms networks. And, as readers of this blog will already know, there is a vast range of very complex technologies that are now being deployed and developed to meet the challenges of delivering ever more data at ever lower costs. And so the CONE course grew and it grew and it grew. More delegates began to tell me “this should be a two week course” or “maybe a month”…..and also it became apparent that the delegates attending the course had an increasingly different range of training needs. A rethink was definitely in order….

….and so two new courses have been born…

Reorganised and restructured and with new material, we will now be offering two separate one week courses, the new Certified Optical Network Associate (CONA) foundation course and a revised edition of the Certified Optical Network Engineer (CONE) course which will now concentrate on the advanced technologies.

So what’s in CONA?

From our detailed analysis of the technology and the systems being deployed, and taking into account the typical entry levels of candidates, there is a fairly natural break point at 10Gb/s where the most cost effective systems are. So the scope of the introductory level CONA course is set to include all the technologies and the issues involved with the systems that operate at up to 10Gb/s per channel, and may have up to 16 CWDM channels per fibre in metro networks and up to 40 or even 80 DWDM channels per fibre in core networks.

These are the types of systems that are being deployed extensively in metro and regional networks and that are often used for dark fibre connections and for putting fibre to mobile phone base stations (FTTA: Fibre to the Antenna).

Optical Network Planners, Project managers, Operations and Network Managers for these types of networks, need to address issues such as loss and power budgets, chromatic dispersion management and polarisation mode dispersion. They also need to understand the interactions between the way in which the system operates and the infrastructure that it operates over and appreciate what infrastructure test methods and fibre characterisation are needed in order to check the quality of existing infrastructure. The CONA course is designed to cover all of these things.

And what’s in the new CONE?

So the new edition of CONE becomes a more advanced course for those that need to be fully up to speed with all the latest developments in the industry. As data rates go up to 40Gb/s, 100Gb/s and beyond, then things become a lot more complex. Optical Network Architects, Core Network Designers, and Photonic Specialists need to deal with complex systems including those with modulation formats such as DP-QPSK, where two orthogonal polarisation states carry separate channels of information, each of which has the data coded into the phase state of the light wave, rather than just turning the light on and off! These systems need coherent detection at the receive end and extensive digital signal processing to recover the data. Above 100Gb/s then options include n-QAM and OFDM where superchannel transmission and the requirements of increased spectral efficiency are likely to mean a break away from the traditional ITU-T DWDM grid. More issues arise with increased channel count and power levels, with non-linear effects to consider too. And not forgetting that latency issues are important for some applications as well. Networking flexibility and lower operational costs can be achieved using multi-degree ROADM technology to create meshed networks, and the next generation of CDC (&G?) ROADMs are already on the drawing board. The new CONE course is designed to help guide delegates through all of these issues and explain how they relate to and affect each other.

Which one is for me?

If you’d like a quick comparison highlighting the key differences between the CONA and CONE courses you’ll find one here.

More information is available from sales@ott.co.uk or call me or drop me an email if you have any questions on the content of these courses. Dates and venues for public courses are on the website. If you’d like me to run a closed course for your company then call me to discuss it.

ECOC 2011 in Geneva

This year the European Conference on Optical Communications was in Geneva, a city in a stunning setting on the shores of Lake Geneva, with hills around and snow-capped mountains visible in the distance. The water jet in the lake was the inspiration for this year’s ECOC logo.  

The Palexpo centre is visually uninspiring, but the internal arrangement worked well with the conference downstairs and exhibition hall directly above. There were more than 1200 conference delegates. The exhibition was bigger and with more exhibitors than last year, a good sign that things are on the up, despite the expense of doing business in Geneva. Here’s an overview of a few of the presentations in the technical conference that caught my attention.  

FTTH in Switzerland

It was interesting to hear from SwissCom in the opening plenary about the Swiss way of doing Fibre to the Home. Four fibres are being installed to each home to allow SwissCom and another service provider to compete. All the installation has to go underground and so is very expensive. To help share the costs SwissCom is usually installing in partnership with the regional electricity distribution companies of which there are about 800 (!) in Switzerland. The comms links will also facilitate more SmartGrid apllications to run.  

However, this model was considered by the Swiss regulatory authorities as being likely to extend SwissCom’s dominant market position and to be anti-competitive. With rather embarrassing timing for ECOC the entire programme was put on hold, a few days before ECOC started. This is another example of how political FTTH can be, and you’ll be hearing more on this from OTT in the near future…  

635km on OM3 multimode fibre

In the development of standards for 100Gb/s Ethernet and premises cabling we are stuck with a maximum transmission distance of just 100m for 40 & 100Gb/s on OM3 multimode fibre and 150m on OM4 fibre with low loss connectivity. So when I saw the title of this paper from Corning I thought that there was a misprint… but no! In fact the paper reported on the successful transmission of 1.6Tb/s over 635km of Corning ClearCurve OM3 fibre! All of this using technology that is explained on OTT’s Certified Optical Network Engineer (CONE) course.  

Non-intrusive DGD & PMD measurements on live traffic

Vincent Lecoeuche of JDSU

Vincent Lecoeuche of JDSU gave a very good presentation on their new technique for measuring DGD, just by tapping off some of the transmission signal and feeding it into their special coherent detection system with tuneable laser. This has been implemented on their MTS-8000 field test platform and was on display on their exhibition stand. If several wavelength channels are available then PMD can be determined. The system also acts as a very high resolution OSA, which can yield  further information on the signal type and quality. Field trials have already been very successful and will be reported in a paper at OFC2012. Contact richard.ednay@ott.co.uk if you are interested in receiving further information on this system.  

Developments with the “Three ‘M’ technologies”

As described in a previous blog entry, the challenges of providing ever increasing capacity are being addressed using:  

• Multi-level coding schemes
• Multi-core fibre and
• Multi-mode transmission

So, as expected, advances were reported in many papers related to these topics.  

One of the ‘themes’ that I detected at ECOC this year was the expectation that transmission systems based on 16-QAM would become commercially available in the near future.  

One of the post-deadline papers reported on a transmission experiment with a record spectral efficiency per fibre of 60b/s/Hz. This used 32-QAM-OFDM superchannels with 8.6b/s/Hz spectral efficiency, on each of the 7 cores in a multicore fibre that was 76.8km long.  

There was a whole session in the conference dedicated to transmission over few mode and multi-mode fibres.  

Exhibition highlights

The exhibition is a great place to catch up with friends and acquaintances from the world of fibre optics and to try out new products. I also use it as an opportunity to discuss developments in the International Standards that I am involved with producing. This year I conducted a survey of power meter manufacturers, in order to support the revision of ISO/IEC 14763-3. It was also interesting to see a new Optical Modulation Analyser from Southern Photonics being launched at the show. (They also get the prize for the best freebie bag at the show.) In the IEC we are working on a new Technical Report on analysis of complex modulation formats.  

Conec wearable clip on cleaning probe

US Conec have an extended range of cleaning probes for all sorts of connector styles as well as a compact, wearable, cleaning probe with belt clip with retractable cord. 

Social highlights

Alpine Horn welcome

CFCE & CONEs dinner at ECOC 2011

Of course there are also opportunities to socialise. We had a Swiss welcome reception, and also a dinner on board a boat on the lake. And of course a get together for CFCEs, CONEs and supporters.  

Where next?

• ECOC 2012 is in Amsterdam
• ECOC 2013 is in London

See you there!

Optical Fibre Communications (OFC)

• what comes after 100G?
• will DWDM systems break out of the rigid ITU grid?
• will we need Gridless ROADM architectures?
• measurement of complex signal modulation formats

Followers of this blog may recall the three ’M’ technologies to achieve higher throughput per fibre:

• multi-level modulation formats
• multi-core fibre
• multimode fibres using mode division multiplexing

It was interesting to hear about the progress that had been made with these in the Post Deadline Papers where the very latest developments are showcased.
Alcatel Lucent reported 64-QAM transmission over 4x100km spans of fibre.
Two companies presented transmission experiments based on 7-core fibre. In one of these a total of 109Tb/s were sent over 16.8km of fibre. Each of the seven cores carried 97 DWDM channels in each of two polarisation states, each channel carried 86Gb/s using QPSK modulation. Each core had a refractive index ‘trench’ around it – just like bend-tolerant singlemode fibre, this drastically reduced the cross-talk between cores. The fibre loss was as low as 0.18dB/km. There were also a few transmission mode division multiplexing experiments on 2 or few mode fibres. So it seems that the industry is taking steps to help cope with the so-called capacity crunch that is looming as internet data rates continue to grow exponentially.

Exhibition
It’s good to see some British companies exhibiting at the show including Polatis with their very low loss high port count optical switches, Arden Photonics with their world-leading products for encircled flux measurement and control, PE Fiberoptics with their factory and field test equipment for characterising fibres.

I think that, for me, the highlight of the show was the new in-band measurement system from JDSU that made its first public appearance. It can monitor live traffic on the network using a polarisation diverse coherent detection system and polarisation controller. This effectively provides an ultra high resolution polarisation diverse OSA, that can be used to measure in-band OSNR, in-band DGD (and PMD if enough wavelengths are measured). The resolution of the OSA is so good that characteristic features of particular modulation formats and data rates can be identified.

Please get in touch if you would like further information.

San Luis Obispo

“Where is that???” is the most common response when I’ve told anyone that I’ll be attending the IEC working group meetings in San Luis Obispo. Well, it’s a nice little town in California about half way between San Francisco and Los Angeles. The town has a population of about 40,000.

California Polytechnic State University

Fiber Optic Test and Measurement, Editor: Dennis Derickson

CalPoly is also where Jack Dupre, the Secretary of SC86C, did his studies many years ago, and so an invitation was arranged for CalPoly to host the IEC SC86C Working Group meetings in the run up to OFC held in the Los Angeles Convention Centre this year (more on that in my next blog). The emblem of CalPoly is the Mustang, & they get everywhere…

But anyway, on with the business…

In SC86C Working Group 1 (fibre optic systems) we discussed comments on the next edition of 61280-4-2, the standard for testing insertion loss and optical return loss of singlemode fibre optic cabling. I am the project leader for this document. It contains some important new recommendations including the requirement for launch and tail leads when OTDR testing (learn all about it on the CFCE course!). We also discussed PMD measurements on installed cabling; I’m also the project leader for this.
Other interesting items on the agenda included fibre optic sensors and new methods of assessing the signal quality of complex modulation formats such as DP-QPSK using the Error Vector Magnitude (you can learn about this on the CONE course).

Working Group 3 deals with optical amplifiers and there were significant discussions on reliability standards, as well as a joint discussion with WG4 (Active Devices) on Semiconductor Optical Amplifers. In WG4 a new standard for 1310nm VCSELS was proposed and it seems that the long running “wiggle” issue is reaching a conclusion.

Andrzej

Looking back on downtown Seattle, from the boat that took us to the social event at Tillicum Village

As promised (apart from being a little late) here’s an update on what’s going on in the International Standards body for “customer premises cabling”. This group goes under the snappy little title of ISO/IEC JTC1 SC25 WG3, which rolls of the tongue quite readily once you’ve practiced it a few hundred times!

So, what’s it all about this time?
“Customer Premises Cabling” is the cabling that allows computers, and increasingly other ‘connected devices’ to communicate in offices, factories, data centres and homes. Much of this cabling is of course copper, with most desktop connections being made with Cat5E, Cat6 etc. twisted pair. However, for larger premises, the building backbone and campus backbone cabling will all be fibre optic. Fibre optic cabling also has a big part to play in data centres, where enormous amounts of information are moved around. Industrial networks also use fibre extensively to support longer distance communications and to provide immunity to electromagnetic interference.

…and what’s my role?
As mentioned in my last blog, I am the liaison officer from the IEC standards committee that deals with fibre optic systems (SC86C) and this group. This means that I can apply my knowledge of fibre optic systems to help make sure that they will work over the cabling systems that are being standardised upon by this group. In fact, historically there has been a bit of conflict between these two groups, with some overlapping of standards, particularly with respect to testing of installed cabling (regarded as a ‘system’ by IEC). So part of my role is to try and harmonise these different testing standards.
I am also appointed as a UK expert, and so I support the UK’s position, particularly with respect to the fibre optics issues that arise. The UK and its team of experts has been very pro-active in driving through many of the major developments in premises cabling standards.

So, what happened?
It was the first time that this group had met in conjunction with the IEC General Meeting and this meant that several additional fibre optics experts were able to attend, staying on from the previous week’s TC86 meeting, including the chairman of TC86, Umberto Rossi. This gave the group a better balance as it is usually dominated by ‘copperheads’ and so fibre optics issues are often sidelined and given little airtime. But at this meeting some good progress was made on fibre optics issues and interesting decisions made about the future directions of standards…

Key developments in the optical fibre ad-hoc meeting.
At last, a full revision of the standard (14763-3) for testing fibre optic cabling in premises networks is underway – the UK have been pushing for this for several years.
The work done by the UK FIA on Reference Grade Terminations was reviewed.
It was agreed that there was no requirement for the total Optical Return Loss to be specified or tested for optical fibre links and channels in premises cabling (although connector reflectance is specified).
The UK proposal to remove the Optical Fibre channel classification scheme was adopted, although implementation of this decision will take some time.
OM1 grade of multimode fibre performance (usually associated with 62.5/125 multimode fibre) will be removed from the main part of the standards and relegated to history (as an informative annex).

Other issues
There was a poignant moment at the start of the meeting as a minute’s silence was observed in memory of Stuart Reeves of ADC Krone, who was taken by cancer and sadly passed away on August 1st. Stuart had played a very active role in this working group, faithfully recording the minutes and documenting everything, including at times some very heated exchanges. His diplomacy, attention to detail and mastery of the English language were much appreciated by the group. The challenge of recording the minutes of this, often lively, group has been picked up by another Brit – best of luck to James Withey of Nexans!

Any questions?
As ever, if you have any questions or comments on the wonderful world of standards, please leave your comments here or get in touch with me Richard.Ednay@ott.co.uk

Some of the UK delegates at the ‘top table’ of the meeting – from the left, Mike Gilmore, Alan Flatman and James Withey, next to Water von Pattay the working group convenor.

A view of the full meeting.

So, what’s it all about and why am I here?
Well the main bits that I’m involved with are “fibre optic systems” where I’m nominated as the UK’s Principal Expert, although since I also have responsibility for optical amplifiers, active devices (e.g. lasers) and dynamic modules (ROADMs etc). Of course I also have an interest in the discussions of fibres, cables, connectors and passive devices and support other UK experts in these areas.

New Work
In the systems working group there are now many new challenges as fibre optic systems develop to support ever higher data rates and more DWDM channels. Some of the ‘hot topics’ up for discussion are:

• constellation diagram analysis – new ways of measuring quality of transmitted signals, when we are dealing with complex modulation formats where the information is coded into the phase of the lightwave as well as the amplitude
• in-band OSNR measurements, especially with closely spaced DWDM channels in ROADM networks using polarisation multiplexed signals

Maintenance
In addition to these new areas there is also the maintenance and updating of existing standards. I am the project leader for the second edition of the standards for testing insertion loss and return loss on singlemode cabling as well as PMD. New Committee Drafts will be issued on both of these following this meeting.

We are also continuing work on testing multimode fibre, encircled flux is a continuing subject of debate and a new ’round robin’ series of tests is going to be carried out. Contact me if you want to be involved.

Sensors
Another new are of work is on fibre optic sensors. There are many UK companies involved in this area and this also falls in the scope of GEL86/3. The Generic standard for these is being revised and a work programme is being initiated to produce a range of standards covering different ‘measurands’ and ways of measuring them.

Laser safety
The Technical Committee on laser safety (TC76) are also holding their meetings here, and I attended a joint meeting between the two groups, raising the issue of laser safety on fibre optic sensors and powering of remote devices over fibre, neither of which are covered by the current laser safety standards.

Liaisons
Another part of my role in the standards community is that of liaison officer between IEC SC 86C (fibre optic systems) and ISO/IEC JTC1 SC25 WG3 (!) – customer premises cabling. This group are meeting here in Seattle next week – so there will be news from that on “Light Reflections” next week.

As ever – I’m happy to answer any questions on this or hear your views…

Multi-level
Multi-core and
Multi-mode.

Multi-level refers to multi-level coding schemes such as QAM and/or OFDM that may be used to improve the spectral efficiency and therefore the capacity of conventional singlemode fibres.

Multi-core means that we can expect to fibres being constructed with many cores, each of which may be used for transmission. Results were presented on successful manufacturing and even splicing of such fibres. Investigations into cross talk between the cores were also presented.

Multi-mode refers not just to conventional multimode fibre, but the techniques that may be used to implement Mode Division Multiplexing in multimode fibre. This is the process of launching different channels into multimode fibre at different radial positions to increase the total capacity. An array of detectors is used to select different mode groups at the receiver and digital signal processing used to separate the channels and cancel out crosstalk between them. Successful transmission of 8Gb/s over 5km of multimode fibre was demonstrated.