We demonstrate 100Gbit/s DQPSK transmission experiment over 50km SMF. Without resorting OTDM, 100Gbit/s transmission was enabled with DQPSK format and commercially available electronics. Possibility of DQPSK modulation for future 100G Ethernet transport is verified.

100Gbit/s DQPSK Transmission Experiment without OTDM for l00G Ethernet Transport

We propose the coded modulation schemes for ultrahigh-speed transmission (100 Gb/s and above) by using commercially available components operating at 40 gigasymbols/s. The bit-interleaved coded modulation in combination with the low-density parity-check codes that are used as component codes has been applied. The modulation is based on either M-ary quadrature-amplitude modulation or M-ary phase-shift keying. bits are mapped into the corresponding signal constellation point using either Gray or natural mapping. The coherent detection scheme has been found to outperform the direct detection one and to provide an additional margin much needed for longer transmission distances or for application in an all-optical network scenario.

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Using LDPC-Coded Modulation and Coherent Detection for Ultra Highspeed Optical Transmission

This paper investigates the challenges for developing the current local area network (LAN)-based Ethernet protocol into a technology for future network architectures that is capable of satisfying dynamic traffic demands with hard service guarantees using high-bit-rate channels (80...100 Gb/s). The objective is to combine high-speed optical transmission and physical interfaces (PHY) with a medium access control (MAC) protocol, designed to meet the service guarantees in future metropolitan-area networks (MANs). Ethernet is an ideal candidate for the extension into the MAN as it allows seamless compatibility with the majority of existing LANs. The proposed extension of the MAC protocol focuses on backward compatibility as well as on the exploitation of the wavelength domain for routing of variable traffic demands. The high bit rates envisaged will easily exhaust the capacity of a single optical fiber in the C band and will require network algorithms optimizing the reuse of wavelength resources. To investigate this, four different static and dynamic optical architectures were studied that potentially offer advantages over current link-based designs. Both analytical and numerical modeling techniques were applied to quantify and compare the network performance for all architectures in terms of achievable throughput, delay, and the number of required wavelengths and to investigate the impact of nonuniform traffic demands. The results show that significant resource savings can be achieved by using end-to-end dynamic lightpath allocation, but at the expense of high delay.

Next-generation 100-gigabit metro ethernet (100 GbME) using multiwavelength optical rings

This paper reports the first optical transmitter implementations operating at a serial bit rate of 107 Gb/s using solely electronic time-division multiplexing. Two methods to overcome modulator bandwidth limitations are proposed and demonstrated: low-bandwidth optical duobinary modulation and integrated optical equalization. Both transmitters are characterized in terms of bit error ratio and chromatic dispersion tolerance

107-gb/s optical signal generation using electronic time-division multiplexing

It is widely believed that dynamic operation of wavelength-routed optical networks will help overcome the inefficiencies of static allocation in terms of wavelength utilization. In this paper, this hypothesis is reviewed. The wavelength requirements of dynamic wavelength-routed optical networks are quantified and compared to static routing. To do so, new analytical and algorithmic lower bounds for the wavelength requirements of dynamic networks are proposed. They are used to evaluate the optimality of the already proposed algorithms whose wavelength requirements are quantified - by means of simulation- with and without the wavelength continuity constraint, as well as for uniform and nonuniform traffic demand. Results show that, without wavelength conversion capability, the benefit of dynamic wavelength-routed optical networks is not significant: lower wavelengths requirements than static networks are achieved only at low traffic loads (< 0.3 - 0.4). In wavelength convertible networks instead, dynamic operation leads to lower wavelength requirements than static operation over a wide traffic load range (< 0.7 - 0.8), making dynamic operation attractive in this type of network. Under nonuniform traffic it was found that dynamic operation achieves slightly higher wavelength savings than in the uniform traffic case. But the savings were not high enough as to impact on results of the uniform traffic case. These results can aid network operators in the design and optimization of optical WDM networks.

Dynamic Versus Static Wavelength-Routed Optical Networks

Four static and dynamic optical ring network architectures are analysed in terms of end-to-end delay, throughput and wavelength requirements, for implementation in future metropolitan area networks.

Performance comparison of static and dynamic optical metro ring architectures

This paper reports results of a performance comparison for four optical ring network architectures envisaged for future metropolitan area networks (MANs), with particular emphasis on the design of and compatibility to possible 100-Gigabit-Metro-Ethernet (100 GbME) standards. Both analytical and numerical modelling techniques were applied to quantify and compare network performance for all architectures in terms of achievable throughput, delay and the number of required wavelengths. Non-uniform traffic required additional resources and dynamic adaptation of the slotted ring architecture. The study also considered aspects of the physical transmission and interfaces (PHY)for consideration in 100 GbME standards.

Investigation of future optical metro ring networks based on 100-Gigabit Metro Ethernet (100 GbME)

Envisaging the reach of 100-Gigabit Ethernet from LANs to MAN rings, key aspects for the design and deployment of 100GbME are discussed and the implementation of novel physical interface schemes investigated.

J Spencer

Papers

Next-generation 100-gigabit metro ethernet (100 GbME) using multiwavelength optical rings

Performance comparison of static and dynamic optical metro ring architectures

Investigation of future optical metro ring networks based on 100-Gigabit Metro Ethernet (100 GbME)

Design considerations for 100 Gigabit metro Ethernet (100GbME)