14.7 Other applications of SOAs in optical communication networks 409 are allowed by the recommendation. A maximum reach of 60 km, with loss budgets of over 27 dB in both the OTL and the ODN are foreseen. The recommendation requires that the PON extension module be fully manageable in terms of its configuration, performance monitoring, and fault reporting. This can be accomplished by including an embedded ONT in the module, which makes the PON extender addressable as one of the ONTs in the PON. 14.7 OTHER APPLICATIONS OF SOAs IN OPTICAL COMMUNICATION NETWORKS Gain compression and recovery at a time scale comparable to the bit rate in on-off keying (OOK) digital transmission leads to inter-symbol interference (ISI) in single channel transmission and inter-channel crosstalk in multichannel wavelength divi- sion multiplexing (WDM) transmission. However, operating the SOAs in the linear regime enables transmission with capacity-distance products that are significant for metro or access network environments. As an example, Figure 14.17 shows eight dense WDM channels (spaced 200 GHz) modulated at 10 Gb/s, transmitted 240 km