Dual mode cellular modem
US5479480A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 30, 1993 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Dec 30, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W88/06
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A mobile phone includes a modem, hereinafter referred to as a cellular radio modem. This cellular radio modem 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, 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 located within the Mobile Telecommunications Switching Office 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.