In FiWi networks, for peer-to-peer communication between wireless client a and b, its traffic routing has two choices: either through the available shortest path between clients within the wireless subnetwork or through the wireless-opticalwireless mode.
For the latter choice, traffic will be first routed from a to its nearest ONU through the shortest path within the wireless subnetwork.
Then in the PON subnetwork, traffic will be sent to the OLT which then broadcasts traffic back to all ONUs.
The ONU closest to b then sends traffic to b through the shortest path within the wireless subnetwork again.
By comparison of the respective total wireless hop counts in above two choices, we choose the one with smaller hop counts for the traffic routing since the wireless network throughput generally decreases as the hop counts increases [17].