Long-reach PON was designed with idea of meeting following requirements:

• distance of ~ 100 km;

• combine optical access and metropolitan networking;

• provide high split ratio;

• manage high capacity.

   

As Figure 1 shows, this configuration requires a transporter with optical amplifiers, that will be allocated between the OLT and remote node. PICs integration in large-scale allowed system to benefit from a high degree of optical component integration.

Figure 1. An experimental 135-km DWDM GPON configuration

The long-reach PON isolates high-capacity DWDM optical transport network from the end user. It prevents end user from exposure to laser radiation, which may or may not be dangerous. System shown in Figure 1, was tested and has reached standards of the GPON. In the test, signal round-trip delay for E1 client was 2.25 ms, which is acceptable timing recovery. The long-reach PON is another example of PON that can be used for great capacities of people on further distances.