  Optical wireless satellite networks (OWSNs) can provide lower latency data
communications compared to optical fiber terrestrial networks (OFTNs). The
crossover function enables to calculate the crossover distance for an OWSN and
an OFTN. If the distance between two points on Earth is greater than the
crossover distance, then switching or crossing over from the OFTN to the OWSN
results in lower latency for data communications between these points. In this
work, we extend the previously proposed crossover function for a scenario such
that intermediate satellites (or hops) are incorporated between ingress and
egress satellites in the OWSN for a more realistic calculation of the crossover
distance in this scenario. We consider different OWSNs with different satellite
altitudes and different OFTNs with different optical fiber refractive indexes,
and we study the effect of the number of hops on the crossover distance and
length of a laser inter-satellite link (LISL). It is observed from the
numerical results that the crossover distance increases with an increase in the
number of hops, and this increase is higher at higher satellite altitudes in
OWSNs and lower refractive indexes in OFTNs. Furthermore, an inverse
relationship between the crossover distance and length of a LISL is observed.
With an increase in the number of hops, the length of a LISL decreases as
opposed to the crossover distance.
