A dual mode cellular modem.

A mobile phone (400) includes a modem, hereinafter referred to as a cellular radio modem. This cellular radio modem (400) supports two modes of operation - an analog mode, where the cellular radio modem provides an analog signal for transmission; and a digital mode, where the cellular radio modem provides a digital bit stream for transmission. During operation, i.e., the existence of a data connection to a far-end modem (280), the cellular radio modem is alerted by the cellular network to switch to the appropriate mode―analog or digital. The cellular radio modem then switches and continues transmission in the new mode. In this embodiment, the far-end modem is part of a modem-pool (280) located within the Mobile Telecommunications Switching Office (270) of the cellular network. The far-end modem automatically detects this switch by the cellular radio modem and itself switches to the appropriate mode. This allows a mobile data user to transparently move between the analog mode and the digital mode without disconnecting a preexisting data connection.