Combined fixed and mobile radio communication system and method

• US 5,633,873 A
• Filed: 09/13/1995
• Issued: 05/27/1997
• Est. Priority Date: 12/06/1990
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Kay, Stanley E., Corrigan, John E. III, Avis, Graham, Parr, Michael I., Mehta, Ashok D., Kaul, Pradeep, Wendling, Daniel
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US08/528,182
• Time in Patent Office: 622 Days
• Field of Search: 370/80, 370/95.3, 370/95.1, 370/94.1, 370/109, 379/57, 379/59, 379/60, 379/61, 455/33.1, 455/33.2, 455/33.3, 455/33.4
• US Class Current: 370/336
• CPC Class Codes: G10L 19/012 Comfort noise or silence coding
• CPC Class Codes: H04J 3/172 Digital speech interpolation, i.e. DSI
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]
• CPC Class Codes: H04W 88/021 adapted for Wireless Local Loop operation

Abstract

A digital cellular communication system in which fixed subscribers and mobile subscribers share base transceiver stations, base station controllers and mobile switching centers to communicate with the switched telephone network. Mobile subscribers communicate using any cellular radio protocol, while the fixed subscribers communicate via a multi-subscriber unit (MSU) using the inventive air interface. The MSU system uses digital speech interpolation to transmit speech spurts between subscribers and the switched telephone network. Preferably, time division multiple access channels in a digital speech interpolation pool are allocated and deallocated on a speech spurt basis.

Claims

1. A combined system for communication of individual fixed and mobile telephone subscribers with a remotely located base station of a radio communication system, comprising:

a base station having a transceiver for receiving and transmitting signals including digital signals corresponding to speech spurts from and to subscriber locations;

a base station controller connected between the transceiver and a mobile switching center for performing speech coding and digital speech interpolation;

at least one mobile subscriber telephone having an antenna for radiating and collecting signals corresponding to speech spurts to and from the base station transceiver;

a multi-subscriber unit in a fixed location remote from the base station having an antenna for radiating and collecting digital signals corresponding to speech spurts for a plurality of different individual subscribers to and from the base station transceiver; and

a telephone for each of said plurality of different individual subscribers, said telephones being at fixed locations and wired electrically to the multi-subscriber unit.

2. The system of claim 1 wherein the multi-subscriber unit comprises means responsive to a speech spurt for transmitting a request for assignment of a traffic channel;

means for detecting voice activity;

means for speech encoding to reduce transmission bit rate requirement;

means for speech synthesizing to reconstruct a compressed signal; and

a controller for managing call processing, speech compression and transmission of the plurality of different fixed telephone.

3. The system of claim 1 wherein the base station includes means for establishing a pool of available traffic transmission channels, each traffic transmission channel having a time slot in a repeating time division multiple access frame at a predetermined carrier frequency.

4. The system of claim 2 wherein the base station includes means for establishing a pool of available traffic transmission channels, each traffic transmission channel having a time slot in a repeating time division multiple access frame at a predetermined carrier frequency.

5. The system of claim 3 wherein the multi-subscriber unit includes means responsive to detection of a speech spurt for transmitting a request for assignment of a traffic transmission channel.

6. A system for telephony communication of subscriber telephones through a radio link with a remotely located base station comprising:

a plurality of subscriber telephones at fixed locations;

a base station having a link to a telephone network and a transceiver for receiving signals from and transmitting signals to the plurality of subscriber telephones;

at least one mobile subscriber telephone having an antenna for receiving signals from and transmitting signals to the base station transceiver;

a multi-subscriber unit in a fixed location wired electrically to the plurality of fixed subscriber telephones, having a subscriber interface for detecting an off-hook condition at each of the fixed subscriber telephones, a subscriber activity detector for detecting the presence of data to be transmitted at each fixed subscriber telephone at which an off-hook condition is detected, and a transceiver for transmitting the data from each fixed subscriber telephone at which data is detected to the base station and for receiving data from the base station for transmission to the fixed subscriber telephones;

means coupled to the subscriber activity detector for requesting the allocation of a traffic transmission channel from the base station upon the detection of the presence of data at any one of the fixed subscriber telephones.

7. The invention of claim 6 wherein the multisubscriber unit further comprises:

a plurality of connectors for providing electrical communication with the plurality of subscriber telephones;

a processor for modulating data from the telephones for transmission over the radio link;

a processor for demodulating data from the transceiver for transmission through the connectors to the telephones.

8. The invention of claim 6 wherein the data to be transmitted comprises speech, the subscriber activity detector comprises a speech spurt detector, the processor for modulating data comprises a speech spurt encoder for converting spurts of speech into a compressed digital form, and the processor for demodulating comprises a decoder for converting compressed digital bit sequences into speech spurts.

9. The invention of claim 6 further comprising means coupled to the subscriber activity detector for requesting the deallocation of a traffic transmission channel from the base station upon the detection of the end of data presence at any one of the fixed subscriber telephones.

10. The invention of claim 6 wherein the transceiver comprises means for transmitting and receiving frames of digital information in a time division multiple access format, each frame including a plurality of time slots for channel allocation and deallocation information.

11. The invention of claim 6 wherein the subscriber interface comprises means for generating a dial tone in response to the detection of an off-hook condition for communication to each fixed subscriber telephone for which the off-hook condition was detected.

12. The invention of claim 6 wherein the subscriber interface comprises means for generating a ringing signal in response to an indication of an incoming call from the base station for communication to any one of the fixed subscriber telephones for which the incoming call is intended.

13. The invention of claim 6 further comprising:

a bus interconnecting the subscriber interfaces and the processors; and

a multilink pad connected to the bus having an input port for a high speed data subscriber for allowing data to be transmitted between the base station and the high speed data subscriber through the transceiver.