 in general is a large number. This advantage is all based on the fact that after a sufficient number of cycles (not SO much in a practical network), using LWC means placing only the needed WCs achieving the same OXC dimension in terms of line ports with respect to the case in which PWC is used. On the other hand, the switch matrix of an LWC is much simpler than that of a PWC and the number of deployed converters is much lower. In order to better understand what the number of deployed WCs is in case LWCs are used, in Figure 10.29, the number of WCs deployed into the LWC is represented as a percentage of the number of line ports versus the number of wavelengths per DWDM system in different traffic conditions (total capacity of all the 10 Gbit/s deployed in the wavelength path). Apparently from the figure it could seem that increasing the traffic, the number of WCs decrease, that is clearly false. In the figure, the number of WCs is represented in percent- age with respect to the overall OXC number of ports, that is, a parameter increasing almost linearly with traffic. Thus, even if the percentage decreases increasing traffic, the absolute value increases. For example, passing from 144 to 240 Tbit/s and using DWDM systems Telecommunication Networks Deployed WCs as percentage of the total OXC line ports Traffic (Tbit/s) FIGURE 10.29 Number of WCs deployed into the OXCs as a percentage of the line ports versus the number of wavelengths per DWDM system in different traffic condi- tions (total capacity of all the 10Gbit/s deployed optical GLSPs). Number of wavelength per DWDM system with 128 wavelengths, the WC percentage passes from 8.5% to 5.3%. The number of ports of the OXC increases about a factor 1.8, SO that the average number of WCs in a degree four OXC is about 43 in the first case, and 50 in the second case. Considering the number of wavelength, if it is increased maintaining the traffic con- stant, the partitioning of the network in the wavelength subnetworks is more and more pronounced, causing a greater ne