From your handset, there are three ways you can reach your destination number. They are: (1) Satellite phone handset to another satellite phone handset; (2) satellite phone handset to a cellular phone handset, through cellular network, and (3) satellite phone handset to a landline served phone connected to PSTN.

(1) Satellite phone to satellite phone: This type of call ensures security because the call is never routed through a Landline, or, PSTN - Public Switched Telephone Network, or, for that matter, through cell-network. Let us see graphically how it works:

When you dialed your satellite phone handset the signal is beamed to the satellite from where it is redirected to the Earth-station. The Earth station, then, encodes and sends it back to the satellite which inturn, sends the symbol to the destination hand-set.

(2) Satellite phone to cellular phone served through a cellular network:

Here the call is routed through a cellular network. Let us see, graphically, how it works:

When you dialed your satellite phone handset, the signal is beamed to the satellite from where it is beamed back to the Gateway from where the cellular networks, MTSO -Mobile Telephone switching office, which controls all the cell sites, and, by extension, all cell phones coming under its ambit, sends the signal to the appropriate cell-phone.

(3) Satellite phone handset to land line connected phone set:

Here the call is routed through a PSTN. Let us see, graphically, how it works

As seen as your dialed your handset, the signal is beamed to the nearby Geo-stationery satellite, which, then, transfers the signal to the nearest LES - Land Earth Station. Land Earth station connects the call to the PSTN - Public Switched Telephone Network, which, in turn, sends the signal to the appropriate destination handset.