Concepts and requirements for the Ethernet-based evolved fronthaul

The use of Ethernet in the fronthaul permits convergence and exploitation of statistical multiplexing gains of the new interfaces, but minimum latency and latency variation requirements may become challenging. The techniques proposed to meet these challenges are summarized

Solutions for 400 Gbit/s inter data center WDM transmission

\u3cp\u3eWe review some currently discussed solutions for 400 Gbit/s inter-data center WDM transmission for up to 100 km. We focus on direct detected solutions, namely PAM4 and DMT, and present two WDM systems based on these formats.\u3c/p\u3

First demonstration of real-time end-to-end 40 Gb/s PAM-4 system using 10-G transmitter for next generation access applications

\u3cp\u3eWe demonstrate the first known experiment of a real-time end-to-end 40-Gb/s PAM-4 system for next generation access applications using 10G class transmitters only. Up to 25-dB upstream link budget for 20 km SMF is achieved.\u3c/p\u3

Performance comparison of 112 Gb/s DMT, Nyquist PAM4 and partial-response PAM4 for future 5G ethernet-based fronthaul architecture

\u3cp\u3eFor a future 5G Ethernet-based fronthaul architecture, 100G trunk lines of a transmission distance up to 10 km over a standard single-mode fiber (SSMF) in combination with cheap gray optics to daisy chain cell site network interfaces are a promising cost- and power-efficient solution. For such a scenario, different intensity modulation and direct detect formats at a data rate of 112 Gb/s, namely Nyquist four-level pulse amplitude modulation (PAM4), discrete multitone transmission (DMT), and partial-response (PR) PAM4, are experimentally investigated, using a low-cost electroabsorption modulated laser, a 25G driver, and current state-of-the-art high-speed 84-GS/s CMOS digital-to-analog converter and analog-to-digital converter test chips. Each modulation format is optimized independently for the desired scenario, and their digital signal processing requirements are investigated. The performance of Nyquist PAM4 and PR PAM4 depends very much on the efficiency of pre- and postequalization. We show the necessity for at least 11 feedforward equalizer (FFE) taps for pre-emphasis and up to 41 FFE coefficients at the receiver side. In addition, PR PAM4 requires a maximum likelihood sequence estimation with four states to decode the signal back to a PAM4 signal. On the contrary, bit loading and power loading are crucial for DMT, and an FFT length of at least 512 is necessary. With optimized parameters, all modulation formats result in a very similar performances, demonstrating a transmission distance of up to 10 km over an SSMF with bit error rates below an FEC threshold of 4.4E-3, allowing error-free transmission.\u3c/p\u3

56 Gb/s DMT transmission with VCSELs in 1.5 um wavelength range over up to 12 km for DWDM intra-data center connects

We demonstrate up to 12 km, 56 Gb/s DMT transmission using high-speed VCSELs in the 1.5 um wavelength range for future 400Gb/s intra-data center connects, enabled by vestigial sideband filtering of the transmit signal. We demonstrate up to 12 km, 56 Gb/s DMT transmission using high-speed VCSELs in the 1.5 um wavelength range for future 400Gb/s intra-data center connects, enabled by vestigial sideband filtering of the transmit signal

First Demonstration of an OpenFlow based Software-Defined Optical Network Employing Packet, Fixed and Flexible DWDM Grid Technologies on an International Multi-Domain Testbed

We demonstrate for the first time an extended OpenFlow based control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet domains. We also demonstrate for the first time multi-domain network slicing and verified results on a global scale trial involving test-beds in UK, Spain and Japan. © 2012 OSA