Showing papers by "Norbert Hanik published in 2004"
TL;DR: 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, and the impact of nonuniform traffic demands.
Abstract: 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.
74 citations
01 Jan 2004
29 citations
TL;DR: In this article, a link design concept based on erbium-doped fiber amplification is developed and optimized such that originally degrading effects mutually compensate each other, leading to approximately noise-limited transmission.
Abstract: This paper presents a technique that significantly simplifies the design and operation of transparent optical wavelength-division-multiplexing (WDM) networks. Since most of the signal degradations arise due to the interaction of linear and nonlinear physical effects along the fiber links, a link design concept based on erbium-doped fiber amplification is developed and optimized such that originally degrading effects mutually compensate each other, leading to approximately noise-limited transmission. In extensive numerical simulations as well as laboratory experiments, an optimized modular link design is identified. Regenerator-free transmission of a single-channel 10-Gb/s nonreturn-to-zero signal over 4000 km is achieved in a recirculating loop experiment with less than a 3-dB penalty. Reliable WDM transmission is demonstrated over 1600 km, showing the high robustness of this concept. Finally the link design concept is applied in a WDM field trial using deployed standard single-mode fibers (S-SMFs) of the optical network infrastructure of Deutsche Telekom. Between the German cities of Berlin and Darmstadt, 10-Gb/s synchronous digital hierarchy (SDH)-based data, 10-Gb/s duobinary-encoded data, and a native Gigabit Ethernet signal have been transmitted error-free over a maximum distance of 1720 km, thus demonstrating the feasibility of the design concept under realistic field conditions. The presented design approach substantially supports link setup and rerouting procedures by supplying simple rules to identify the maximum number of dispersion-compensated S-SMF amplified spans which can be cascaded for a given tolerable penalty.
28 citations
04 Jul 2004
TL;DR: In this paper, physical models that numerically evaluate system degradation due to XPM, assuming various scenarios of the evolution of light polarisations, are introduced and applied to WDM transmission in an optimised optical link.
Abstract: In optical wavelength-division multiplexed (WDM) transmission, nonlinear coupling of co-propagating modulated light waves due to cross phase modulation (XPM) is one of the main sources of signal degradation. The strength of the XPM effect, in turn, is strongly influenced by the evolution of light-polarisations of the WDM-carriers. In this contribution, physical models that numerically evaluate system degradation due to XPM, assuming various scenarios of the evolution of light polarisations, are introduced and applied to WDM transmission in an optimised optical link. Finally these system simulations are compared to re-circulating loop experiments.
5 citations