What is the next “Next Gen”?
When it comes to the technology of optical networks, we are constantly seeing changes, some of these changes are evolutionary and some are revolutionary. So when does a technology development constitute a new generation and when is it just an extension of an existing generation? This is something I pondered as I developed one of our own ‘next generation’ of optical networking certifications, the Certified Optical Network Engineer (CONE version 2) that will be running for the first time as a public course in September 2013.
As long ago as 2008 the ITU had defined five generations of optical networking, and I was wondering how many we have had since then and what’s next. What do you think have been the most significant developments that might constitute a ‘next generation’, and what do you think will be the defining characteristics of the next next-generation?
To give you a feel for ‘the generation game’ the first five generations as defined in ITU G.Supp42 can be summarised as follows:
1st generation: multimode fibre systems using G.651 (50/125) fibre
2nd generation: the change to G.652 singlemode fibre with single channel systems operating at 1310nm, allowed transmission distances up to 40km.
3rd generation: the move to operating at 1550nm and the development of G.653 dispersion shifted fibre, allowing transmission distances of 80km.
4th generation: the advent of DWDM technology to multiply the fibre capacity, initially by 16 and then 32 and 40 channel systems. The development of G.655, non-zero dispersion shifted fibre, optimised for DWDM transmission, and the complementary technology of the EDFA to multiply the number of fibre spans before regeneration was needed. A move to 10Gb/s data rates and the use of dispersion compensating modules to manage chromatic dispersion.
5th generation: Further increases in capacity with up to 80 DWDM channels and 40Gb/s line speeds, coupled with FEC for error-free transmission. The emergence of Raman amplifiers and G.656 (broadband non-zero dispersion shifted fibre), to extend the useful operational wavelength range of DWDM to include the S-band. The development of OADMs and ROADMs to route wavelength channels independently.
How many generations have we had since then?
So how many generations have we had since then and what are their key characteristics? What is the “next big thing”? Let us know what you think by emailing email@example.com or by posting on the OTT Facebook page.
If you’re stuck for ideas than the syllabus of the ‘next generation’ Certified Optical Network Engineer v2 might give you some food for thought, you’ll find this in the new OTT catalogue that is available from our website. We look forward to hearing your ideas… alternatively you can sign up for the next generation CONE course in September to hear all about my ideas.