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Entries in Kim Roberts (5)


Kim Roberts: The 2019 John Tyndall Award winner

A Profile

A conceptualiser, mathematician, furniture maker, prolific inventor, sushi lover, creative spirit, team leader and mentor. These are just some of the descriptors applied to Kim Roberts of Ciena by the people that know him. 

Kim Roberts of Ciena. On the wall are some of his 160 patents while on the screen is an image of a 32-point constellation produced by the WaveLogic Ai coherent modem. Source: Ciena.

Roberts has been awarded the 2019 John Tyndall Award by The Optical Society (OSA) and the IEEE Photonics Society in recognition of his “pioneering contributions to the development of practical coherent communication systems”.

“It is well deserved,” says Seb Savory, who first knew Roberts when they both worked at Nortel and who is now an academic at the University of Cambridge working on joint projects with Ciena. Ciena acquired Nortel in 2010.

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Heading off the capacity crunch

Feature - Part 1: Capacity limits and remedies

Improving optical transmission capacity to keep pace with the growth in IP traffic is getting trickier. 

Engineers are being taxed in the design decisions they must make to support a growing list of speeds and data modulation schemes. There is also a fissure emerging in the equipment and components needed to address the diverging needs of long-haul and metro networks. As a result, far greater flexibility is needed, with designers looking to elastic or flexible optical networking where data rates and reach can be adapted as required.

Figure 1: The green line is the non-linear Shannon limit, above which transmission is not possible. The chart shows how more bits can be sent in a 50 GHz channel as the optical signal to noise ratio (OSNR) is increased. The blue dots closest to the green line represent the performance of the WaveLogic 3, Ciena's latest DSP-ASIC family. Source: Ciena.

But perhaps the biggest challenge is only just looming. Because optical networking engineers have been so successful in squeezing information down a fibre, their scope to send additional data in future is diminishing. Simply put, it is becoming harder to put more information on the fibre as the Shannon limit, as defined by information theory, is approached.

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2020 vision

In a panel discussion at the recent Level123 Terabit Optical and Data Networking conference, Kim Roberts, senior director coherent systems at Ciena, shared his thoughts about the future of optical transmission. 

Final part : Optical transmission in 2020


"Four hundred Gigabit and one Terabit are not going to start in long-haul"

Kim Roberts, Ciena 


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Optical transmission's era of rapid capacity growth

Kim Roberts, senior director coherent systems at Ciena, moves from theory to practice with a discussion of practical optical transmission systems supporting 100Gbps, and in future, 400 Gigabit and 1 Terabit line rates. This discussion is based on a talk Roberts gave at the Layer123's Terabit Optical and Data Networking conference held in Cannes recently. 

Part 2: Commercial systems


The industry is experiencing a period of rapid growth in optical transmission capacity. The years 1995 till 2006 were marked by a gradual increase in system capacity with the move to 10 Gigabit-per-second (Gbps) wavelengths.  But the pace picked up with the advent of first 40Gbps direct detection and then coherent transmission, as shown by the red curve in the chart. 

Source: Ciena

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The capacity limits facing optical networking

Ever wondered just how close systems vendors are in approaching the limits of fibre capacity in optical networks? Kim Roberts, senior director coherent systems at Ciena, adds some mathematical rigour with his explanation of Shannon's bound, from a workshop he gave at the recent Layer123's Terabit Optical and Data Networking conference held in Cannes. 

Part 1 Shannon's bound

 Source: Ciena

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