planning - performance - management
Christian Fenger PhD thesis
Author: Christian Fenger Title: Optical Network Solutions planning - performance - management Dansk titel: Optiske netværksløsninger planlægning - effektivitet - styring PhD thesis June 2002 Reseach Center COM Technical University of Denmark DK–2800 Kongens Lyngby Denmark
Front cover: Result of optimization of a 25 node network with biconnectivity requirement. Trafﬁc is uniform, duct prices equal the euclidean distance, ﬁber prices is 1/20th of duct prices. The node cost parameters are: Ccore 100, C port 1, and Cswitching 0 01. The nodes are distributed on a 1000 times 1000 square. The total network cost is 44080, where duct cost is 10718, ﬁber cost is 18037, and node cost is 15325. See Chapter 8. ¡
Optical Network Solutions
planning - performance - management Abstract
It has been a decisive goal in the compilation of this thesis to make us capable of realizing the future national and regional telecommunication networks in an efﬁcient and resource optimal way. By future telecommunication network is assumed an all-optical network where the information in transit are kept optical and not converted into the optical domain. The focus is on the scientiﬁc results achieved throughout the Ph.D. period. Five subjects – all increasing the understanding of optical networks – are studied. Static wavelength routed optical networks are studied. Management on terms of lightpath allocation and design is considered. By using statistical models (simultaneous analysis of many networks) the correspondence between parameters determining the network topology and the performance of the optical network is found. These dependencies are important knowledge in the process of designing a network. It is also seen (statistically) found that the effect of wavelength converters on the performance of static wavelength routed optical networks is negligible. Dynamic wavelength routed optical networks are simulated and analyzed. Manangement of dynamic networks is a more complex task than the static case. Several strategies are considered. The alternative study with reel networks as alternative to computer simulations would have been extremely costly or impossible. Different routing methods have been used and studied. The effect of wavelength conversion has been analyzed and contrary to static optical networks the effect of wavelength converters on dynamic optical networks is signiﬁcant. The effect on
blocking probability of multiple ﬁbers on each link is shown to be signiﬁcant, and it is concluded that neither limited-range nor full wavelength conversion will ﬁnd any signiﬁcant use in all-optical network. Fairness is suggested as a new measure for network performance in line with network blocking probability. Teletrafﬁc is studied for several purposes. Erlang’s ﬁxed point equations have been used verify some results of simulation of dynamic optical networks. An explicit solution for network blocking probability has been derived, and ﬁxed point equations for alternate routing are derived. Secondly is self similar trafﬁc studied and the effect on optical networks considered. The Synchronous Optical Hierarchy is suggested as a new type of network to overcome the technological hurdles of packet switched optical networks and without the capacity granularity problem in wavelength routed optical networks. This new proposal is exactly formulated and experiments are performed to estimate the strengths. In networks, where the typical size of a trafﬁc demand between two nodes is up to two wavelengths, signiﬁcant capacity savings are possible. Network planning in the form of optimal design of national and regional telecommunication networks is thoroughly studied and promising computer programs and methods are developed. In the optimization process are both duct, ﬁber, and switch equipment cost considered. The contribution in network planning are one of the...