Wireline interface for cellular telephone

• US 5,526,403 A
• Filed: 02/24/1995
• Issued: 06/11/1996
• Est. Priority Date: 01/19/1993
• Status: Expired due to Term

• Current Assignee: Novatel Wireless, Inc. (Inseego Corp.)
• Original Assignee: Novatel Communications Incorporated
• Inventors: Tam, Ambrose W.C.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): TROST IV, WILLIAM GEORGE
• Application Number:
  US08/394,068
• Time in Patent Office: 473 Days
• Field of Search: 379/58, 379/59, 379/61, 379/63, 379/127, 379/142, 379/245, 379/246, 379/247, 379/60, 455/33.1, 455/54.1, 455/89, 455/54.2, 455/33.2
• US Class Current: 455/426.1
• CPC Class Codes: H04M 1/725 Cordless telephones user interfaces specially adapted therefor H04M1/724
• CPC Class Codes: H04W 4/16 Communication-related supplementary services, e.g. call-transfer or call-hold
• CPC Class Codes: H04W 88/021 adapted for Wireless Local Loop operation

Abstract

A wireline interface permitting a cellular telephone transceiver to originate and receive calls using both cellular and wireline services. The invention permits a subscriber unit to operate as a standard cellular telephone when it is disconnected from a land-based telephone line, and as both a full-featured telephone and a full-featured cellular telephone when it is connected to a wireline. A wireline interface circuit provides on/off hook, calling identification, and audio signal conversion functions on the wireline signals. A duplexed audio switch permits the audio signals provided to and from a cellular-type handset to be connected either to the cellular transceiver or to the wireline interface adapter, under control of the user. As a result, any handset-provided functions such as speed dialing or hands-free operation are available for use when operating on a wireline circuit as well as when operating on a cellular radio link. Call waiting is implemented between the cellular and wireline interfaces, so that the user may hold a wireline call when a cellular call is incoming, as vice versa. With automatic or semi-automatic call forwarding of the cellular line, permits the user to be accessed through a personal telephone number, regardless of whether the unit is in cellular or wireline mode. In addition, any calling identification information made available during a wireline call may be provided to a display on the handset.

Claims

1. A telephone subscriber unit comprising:

a cellular transceiver for providing cellular audio signals from a wireless telephone network;

a handset for providing handset audio signals;

a wireline interface adapter for providing wireline audio signals from a wireline telephone network;

an audio switch disposed between the cellular transceiver, the handset, and the wireline interface adapter;

means for selectively connecting the cellular audio signals to the handset audio signals during an active cellular telephone call, and for connecting the wireline audio signals to the handset audio signals during an active wireline telephone call;

means for detecting that an active wireline is connected to the wireline interface adapter by detecting the presence of the tip and ring lings of said wireline network; and

means for automatically signalling the wireless telephone network to enable call forwarding of calls intended for the cellular transceiver to the active wireline through the wireline network when an active wireline is detected.

2. A telephone subscriber unit as in claim 1 wherein the cellular transceiver, handset, wireline interface, and processor means are enclosed in the same housing as a hand-held portable unit.

3. A telephone subscriber unit as in claim 1 wherein the cellular transceiver, processor means, and handset are packaged as a transportable unit, and the wireline interface adapter is packaged in a separate housing.

4. A telephone subscriber unit as in claim 1 wherein the handset additionally includes a display having a cellular call indicator, and the subscriber unit additionally comprises:

means for detecting an incoming cellular call; and

means for activating the cellular call indicator when an incoming cellular call is detected.

6. An apparatus comprising:

cellular transceiver means, for processing cellular telephone calls over a cellular radio network, to provide cellular audio input and cellular audio output signals;

wireline interface means, for processing wireline telephone calls over a land-based telephone network, to provide wireline audio input and output signals;

a handset, for providing handset audio input and handset audio output signals, the handset including a line button;

an audio switch, connected to the cellular transceiver means and the wireline interface means;

an active line detector for detecting when an active wireline is connected to the wireline interface adapter by detecting the presence of the tip and ring lines of said land-based telephone network and providing a signal to the cellular radio network to automatically enable call forwarding of calls intended for the cellular transceiver means to the active wireline through the wireline interface means when an active wireline is detected; and

processor means, for operating the audio switch when the line button is operated, to toggle the audio switch to either connect the cellular audio signals to the handset audio signals, or to connect the wireline audio signals to the handset audio signals.

5. A telephone subscriber unit as in claim 6 wherein the handset additionally includes a display having a wireline call indicator, and the subscriber unit additionally comprises:

means for detecting an incoming wireline call; and

means for activating the wireline call indicator when an incoming wireline call is detected.

7. A telephone subscriber unit as in claim 6 wherein the cellular transceiver, handset, wireline interface, and processor means are enclosed in the same housing as a hand-held portable unit.

8. A telephone subscriber unit as in claim 6 wherein the cellular transceiver, processor means, and handset are packaged as a transportable unit, and the wireline interface adapter is packaged in a separate housing.

9. A telephone subscriber unit as in claim 6 additionally comprising:

means for answering a cellular call while a wireline call is in progress.

10. A telephone subscriber unit as in claim 6 additionally comprising:

means for answering a wireline call while a cellular call is in progress.

11. A telephone subscriber unit as in claim 6 wherein the handset additionally includes a display having a cellular call indicator, and the subscriber unit additionally comprises:

means for detecting an incoming cellular call; and

means for activating the cellular call indicator when an incoming cellular call is detected.

12. A telephone subscriber unit as in claim 6 wherein the handset additionally includes a display having a wireline call indicator, and the subscriber unit additionally comprises:

means for detecting an incoming wireline call; and

means for activating the wireline call indicator when an incoming wireline call is detected.

13. A telephone subscriber unit as in claim 6 wherein the handset additionally includes a speaker, and the subscriber unit additionally comprises:

means for detecting an incoming cellular call; and

means for sounding a cellular alert tone on the speaker when an incoming cellular call is detected.

14. A telephone subscriber unit as in claim 6 wherein the handset additionally includes a speaker, and the subscriber unit additionally comprises:

means for detecting an incoming wireline call; and

means for sounding a wireline alert tone on the speaker when an incoming wireline call is detected.

15. A telephone subscriber unit as in claim 6 wherein the handset additionally includes a speaker, and the subscriber unit additionally comprises:

means for detecting an incoming wireline call; and

means for sounding a wireline alert tone on the speaker when an incoming wireline call is detected, the wireline alert tone being different from the cellular alert tone.

16. An apparatus as in claim 6 wherein the wireline interface means additionally comprises a hook switch circuit and hook switch control means, for raising or lower a landline hook switch, and dual tone multi-frequency (DTMF) digit tone generation means, for generating DTMF tones.

17. An apparatus as in claim 6 wherein the handset includes a display having a cellular call indicator and a landline call indicator, additionally comprising:

means for alternately activating the landline call indicator and the cellular call indicator when the line key is alternately depressed; and

means for alternately activating the audio switch to alternately connect the cellular audio signals and landline audio signals to the handset when the line key is alternately depressed.

18. A telephone subscriber unit comprising:

a cellular transceiver for providing cellular audio signals from a wireless telephone network;

a handset for providing audio signals;

a wireline interface adapter for providing wireline audio signals from a wireline telephone network;

an audio switch disposed between the cellular transceiver, the handset, and the wireline interface adapter;

means for selectively connecting the cellular audio signals to the handset audio signals during an active cellular telephone call, and for connecting the wireline audio signals to the handset audio signals during an active wireline telephone call;

means for detecting that an active wireline is connected to the wireline interface adapter by detecting the presence of the tip and ring lines of said wireline network;

means for automatically signalling the wireless telephone network to enable call forwarding of calls intended for the cellular transceiver to the active wireline through the wireline network when an active wireline is detected;

means for detecting calling identification information during an incoming wireline call; and

means for displaying the incoming caller identification information on a display in the handset during the progress of an incoming wireline call.