Browse Prior Art Database

Modem Interface to Cellular Telephones

IP.com Disclosure Number: IPCOM000114017D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Wulf, JC: AUTHOR

Abstract

Disclosed is a modem which includes a digital signal processor programmed to emulate the control interface of a cellular telephone. Digital control signals are provided to the cellular telephone transceiver through a pluggable interface.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Modem Interface to Cellular Telephones

      Disclosed is a modem which includes a digital signal processor
programmed to emulate the control interface of a cellular telephone.
Digital control signals are provided to the cellular telephone
transceiver through a pluggable interface.

      As shown in the Figure, a typical cellular telephone
transceiver 10 includes a pluggable interface for attachment to
analog signal lines 12 and to digital control lines 14, which may be
used, for example, to carry indications of incoming calls, display
data, and data representing keypad usage.

      A modem 16, connected to a computer system 17, includes a
digital signal processor 18 and associated memory 20.  Digital signal
processor 18 is programmed to emulate the control interface of
transceiver 10.  Four programmable DI/DO registers 22 within modem 16
are connected to digital control lines 14 to provide this control
interface.

      Modem 16 also includes provides analog input and output through
lines 23, and through a digital to analog and analog to digital
convertor 24.  Lines 23 are tied to lines 12 through amplifiers 26,
which are provided for signal shaping and level shifting.

      Lines 23 may alternately be connected to telephone lines 28
through a direct attachment arrangement 30, which provides standard
signalling recognized by telephone circuits, such as for outbound
signalling through audio tone combinations, allowing the direct
attachment of modem...