What Does Universal Service Bus Modem Mean?
A universal service bus modem (USB modem) is a modem that interfaces with a computer using a USB connector. Typically, the term is used in the context of a V.92 (the last dial-up standard) analog modem or a DSL modem.
Techopedia Explains Universal Service Bus Modem
A USB modem can be any type of data/fax/voice modem if not a complex cable one. Commonly, a USB modem is a small portable USB device, usually the size of a USB flash drive, that functions as a modem and plugs into a laptop or desktop computer. One end has a USB interface while the opposite end has an RJ-11 port for connecting to a telephone line.