 example of InB crosstalk; the shape of the ideal NRZ pulse and of the pulse response of a typical AWG (a Gaussian filter) are shown in (a), while the information bearing pulse shape is compared with the pulse shape of the InB interfering pulse in (b). Remaining in the area of physical performances, the power consumption per processed wavelength and the real estate are important parameters impacting the OPEX of the car- rier using the OXC. Looking at the switch fabric, the wavelength and the fiber modularity are very useful properties (see Chapter 7) [32,35,36] besides the latching property. Considering the inner connection architecture, the blocking probability in a given con- dition is another OXC important feature, like the connectivity degree (defined in Chapter 7 as the number of all the possible permutations between input and output ports divided by the number of theoretical permutations). Another quality factor related to the inner connectivity is the percentage of the pro- cessed bandwidth that can be dropped in the OXC location. To give a few examples, let us consider from a performance point of view, the three OXC archi- tectures that we have introduced. For the sake of simplicity, let us call them pure wavelength planes (PWPs), pure wavelength conversion (PWC), and limited wavelength conversion (LWC). In order to set up the comparison, let us assume that the LH DWDM line systems have W wavelengths located in the extended C band, SO that every WC can move any channel to any wavelength, and that the OXC is of degree N. In the numerical examples, they will be W = 90, N = 5. Probability density function FIGURE 10.21 Probability distribution of the InB self- interference penalty versus the interference factor, the random nature of the penalty is due to the random phase difference between the Interference factor useful and the interfering channels. Next Generation Networking: Enabling Technologies, Architectures, and Performances 10.3.2.1 PWP Transparent OXC: Example of Performances Since N is rarely greater