Peter M. Krummrich

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A novel constraint-based routing (CBR) algorithm taking into account the dominant linear and nonlinear fiber optical transmission impairments has been analyzed. It is shown that CBR and intelligent regenerator placement decrease the blocking probability significantly. 1. Introduction In future transparent optical transmission systems automatic wavelength(More)
Coherent optical OFDM (CO-OFDM) has recently been proposed and the proof-of-concept transmission experiments have shown its extreme robustness against chromatic dispersion and polarization mode dispersion. In this paper, we first review the theoretical fundamentals for CO-OFDM and its channel model in a 2x2 MIMO-OFDM representation. We then present various(More)
An energy efficiency comparison of conventional path protection schemes for fixed-grid WDM and flexible-grid OFDM-based networks has been carried out. The survivable elastic network with SP scheme was found to offer the best energy efficiency per GHz at any traffic load value. Introduction Telecommunications operators are continuously exploring new(More)
In linear communication channels, spectral components (modes) defined by the Fourier transform of the signal propagate without interactions with each other. In certain nonlinear channels, such as the one modelled by the classical nonlinear Schrödinger equation, there are nonlinear modes (nonlinear signal spectrum) that also propagate without interacting(More)
A differentiated quality of protection scheme is evaluated in terms of energy efficiency for fixed-grid WDM and flexible-grid OFDM-based networks. Significant energy savings can be achieved by exploiting the heterogeneous protection requirements. 1. Introduction Telecommunication networks are becoming more and more indispensable for the availability of many(More)
—Currently, the need for " greener " telecommuni-cation networks is stimulating research efforts to find new solutions to cope with power consumption and sustainability issues. Exploiting the potential of optical Wavelength Division Multiplexed (WDM) networks for this purpose has been identified as an attractive approach. However, the traditional WDM(More)
Keywords: Cost evaluation Elastic optical networks Energy efficiency Flexible-grid networks Flexible rate transponders Optical OFDM Protection schemes Routing and wavelength assignment Routing Modulation level and spectrum allocation a b s t r a c t The ever-increasing Internet traffic demand introduces new challenges for telecommunications carriers.(More)
In this paper, the concept of supermode is introduced for long-distance optical transmission systems. The supermodes exploit coupling between the cores of a multi-core fiber, in which the core-to-core distance is much shorter than that in conventional multi-core fiber. The use of supermodes leads to a larger mode effective area and higher mode density than(More)
— We have compared the total cost of an innovative elastic network with respect to the conventional WDM ones operating in realistic network scenarios. The results give an insight of the cost benefits that can be obtained with an elastic OFDM-based network for the operation of future optical transport networks with different protection schemes.
We propose a novel online physical-layer impairment-aware routing algorithm taking into account a minimum quality of transmission (QoT) constraint, which must be satisfied in all cases, even if the network load is changing, and new channels are activated. Our online constraint-based routing (CBR) algorithm considers the actual network load to get a more(More)