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EP0661893A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

A dual mode cellular modem

Assignee: AT&T Inc
•
Filing: 1994-12-09
•
Granted: —
•
Expires: 2014-12-09
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Abstract

Abstract 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.

Inventors

  • 👤 Robert Earl Scott

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-05 06:09
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04W; H04W76/00; H04W76/10; H04W88/00; H04W88/02; H04W88/06

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 72 words
A method for use in a cellular communications device the method comprising the steps of: establishing a cellular data connection; and switching a modem into and out of the cellular data connection in response to a signal received from a cellular network, where the modem is switched in when the signal represents an analog mode of operation, and the modem is switched out when the signal represents a digital mode of operation.
Claim 2
Dependent Claim 41 words
Cellular communications apparatus comprising: means for establishing a cellular data connection; and means for switching between an analog mode of operation and a digital mode of operation during the existence of the cellular data connection without dropping the cellular data connection.
Claim 3
Dependent Claim 32 words
The apparatus of claim 2 wherein the means for switching detects a predefined signal from a cellular network and then switches to either of the two modes of operation in response thereto.
Claim 4
Dependent Claim 39 words
The apparatus of claim 3 further wherein the means for switching provides a training sequence to a far-end modem-pool modem after detecting the predefined signal from the cellular network, where the predefined signal represents an analog mode of operation.
Claim 5
Dependent Claim 24 words
The apparatus of claim 4 wherein the means for switching receives a training sequence over the cellular data connection from the far-end modem-pool modem.
Claim 6
Dependent Claim 74 words
The apparatus of claim 2 wherein the means for establishing further includes a radio means for modulating data for transmission over the cellular data connection, where the data is provided by the means for switching and where the data is an analog signal if the cellular communications device is in the analog mode of operation and the data is a digital bit stream if the cellular modem is in the digital mode of operation.

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