Due to the tenfold capacity increase of Ethernet from one generation to the next, 100 Gbps will be the straight forward next step after 10 Gbps. Demand can be predicted for the following years based on increasing internet data traffic and the lack of efficient packet based link aggregation mechanisms in the Ethernet protocol. Solutions have to be found for short haul intra-office and long haul inter-office interconnections of large routers. This contribution focuses on options for physical layer interfaces. Optical component aspects are discussed as well as transmission aspects. The selection of a suitable modulation format in combination with equalizer technologies opens a path towards robust transmission systems for this ultra-high datarate.
A general modeling and simulation strategy suitable for the fast and accurate analysis of a fiber-optical WDM system is presented, that may also include multi-span systems. Noise and fiber dispersion are considered as well as nonlinear effects like four wave mixing, self-phase modulation and cross-phase modulation. Furthermore, amplified spontaneous emission noise of the optical amplifiers and polarization-dependencies (e.g. PMD) are taken into account. Performance evaluation by means of eye patterns, spectral power densities, optical signal-to-noise ratio, the Q-Factor and the bit error rate are addressed. An analysis of the degradation effects against the position within the fiber is shown to get a better overview of the fibers behavior. An improved Split-Step algorithm is outlined as a fast alternative to supplement the FFT calculation within the fiber. A parameter variation, which can also be influenced during the simulation by the user, is presented in order to get an overview of the parameter space. Different modulation formats are taken into account, e.g. return-to-zero, non-return-to-zero and differential phase-shift keying. Both the separated channels and the total field approach are demonstrated. In the separated channels approach the different nonlinear effects can be switched on and off independently for detailed studies of inter-channel effects. Based on this work, a complete design environment (PHOTOSS, The Photonic System Simulator) has been developed. This simulation tool has been tested extensively by several industry partners. Simulation examples are presented here e.g. for PMD simulations.