A system for interfacing an alarm reporting unit with a cellular radio transceiver so that the data which is produced by the alarm reporting unit is effectively matched to the radio transceiver, irrespective of its initial format, includes circuitry for matching the format of the alarm reporting unit to that of the cellular radio transceiver, and circuitry for matching the format of the cellular radio transceiver to that of the alarm reporting unit, to permit interactive communications which assure the reliable transmission of data while allowing suitable acknowledgement signals to be returned to the alarm reporting unit to regulate the effective transmission of data within the system, and isolation circuitry to effectively separate the alarm reporting unit from the cellular radio transceiver so that the alarm reporting unit can communicate with a monitoring facility via the cellular radio transceiver, as well as the wired telephone network. This further enables the data being produced to be simultaneously applied to the cellular radio transceiver as well as other communicating media which may be employed for purposes of redundancy.
This application is a continuation of application Ser. No. 07/183,045, filed Apr. 19, 1988, now abandoned which is a continuation-in-part of prior co-pending U.S. patent application Ser. No. 129,644, filed Dec. 7, 1987 and entitled "System for Interfacing an Alarm Reporting Device With a Cellular Radio Transceiver", now abandoned, which is itself a continuation-in-part of prior co-pending U.S. patent application Ser. No. 062,174, filed Jun. 12, 1987 and entitled "Supervised, Interactive Alarm Reporting System" now U.S. Pat. No. 4,868,859. The subject matter of each of these patent applications is incorporated by reference as if fully set forth herein.
Tone detection may be accomplished by receiving an in-phase signal component 203 and a quadrature signal component 204. These components are then sampled to produce a plurality of sampled in-phase signal components 207 and a plurality of sampled quadrature signal components 208. The sampled in-phase signal components 207, or the sampled quadrature signal components 208, are then shifted by a pre-determined phase angle to produce a plurality of shifted components. Having shifted these signals, the shifted signals, or at least a set of them, are compared with the opposite non-shifted sampled signals, or a set thereof. When each of the shifted signal components substantially match the opposite non-shifted signal components, a tone signal is being received.
An emulator circuit is provided for allowing a data/fax/voice modem, a host computer, and a telephone headset to emulate the functions of a telephone. For voice communication, the emulator circuit connects the telephone headset to the telephone line. For automated data/fax/voice communications, the emulator circuit connects the modem to the telephone line. Two specific embodiments of the emulator circuit are described. In one, the emulator circuit is configured from analog circuit components connected to the modem. In the other, the emulator circuit is an integrated circuit component of the modem. In both embodiments, the provision of the emulator circuit obviates the need to provide a separate telephone for handling voice telephone conversations.
When an alarm panel needs to transmit alarm data, it seizes the PSTN and disconnects the premises-wiring. If in a call, the user is cut off immediately and it appears to the user that the connection to the PSTN has been lost. If trying to place a call, the user also perceives that the connection to the PSTN is lost. The present invention provides tonal signals to the user to indicate that the PSTN line is in use by the alarm panel and also notifies the user when the PSTN connection is available for use.
When an alarm panel needs to transmit alarm data, it seizes the PSTN and disconnects the premises-wiring. If in a call, the user is cut off immediately and it appears to the user that the connection to the PSTN has been lost. If trying to place a call, the user also perceives that the connection to the PSTN is lost. The present invention provides tonal signals to the user to indicate that the PSTN line is in use by the alarm panel and also notifies the user when the PSTN connection is available for use.
A method and devices for dialling services in a mobile telecommunication network include a set of stored character strings used for comparison with character strings entered by a subscriber to call a service is modified, if a mobile user equipment switches from or to a visited telecommunication network.
