POTS has "no mobile capabilities" and is strictly "analog signal transmission over copper loops" [0] so I suspect that's the source of confusion in this case.

POTS has "no mobile capabilities" and is strictly "analog signal transmission over copper loops" [0] so I suspect that's the source of confusion in this case. PSTN is probably the acronym you meant, which refers to "Originally a network of fixed-line analog telephone systems, the PSTN is almost entirely digital in its core network and includes mobile and wireless networks" [1]. [0] https://en.wikipedia.org/wiki/Plain_old_telephone_service https://en.wikipedia.org/wiki/Plain_old_telephone_service [1] https://en.wikipedia.org/wiki/Public_switched_telephone_network https://en.wikipedia.org/wiki/Public_switched_telephone_netw...