Wireless telephone system

• US 4,866,732 A
• Filed: 01/15/1986
• Issued: 09/12/1989
• Est. Priority Date: 02/04/1985
• Status: Expired due to Term

• Current Assignee: Zarlink Semiconductor Inc. (Microchip Technology Incorporated)
• Original Assignee: Mitel Telecom Ltd. (Mitel Networks Corporation)
• Inventors: Carey, Michael J., Anderson, Adrian J.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Chin, Stephen
• Application Number:
  US06/819,044
• Time in Patent Office: 1,336 Days
• Field of Search: 375/1, 375/115, 375/74, 455/53, 455/54, 455/55, 455/33, 179/2 E, 179/2 C, 179/18 AD, 179/18 ES, 370/107, 379/63, 379/93
• US Class Current: 375/141
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 5/28 using the near field of leaky cables, e.g. of leaky coaxial cables
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker

Abstract

A wireless telephone communication system for wireless, voice, data or voice and data terminals comprising apparatus at a central location for receiving one or a plurality of signals for communication with selected ones of wireless communication terminals, apparatus for converting the signals to spread spectrum radio frequency signals, a leaky transmission line located in a communication region, apparatus for applying the spread spectrum radio frequency signals to the transmission line for electromagnetic radiation within the region, at least one wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals and for demodulating it into an intelligible signal.

Claims

1. A wireless system for telephone communication within a building comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one mobile wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals within the building and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signal from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signal to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum modulating the encoded signal and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central RF demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a central synchronization and control circuit connected to all said interface means for receiving supervisory signal from the junctors and/or a bus of the PABX and for formulating polling and supervisory signal of predetermined format received from the wireless communication terminal corresponding thereto and for translating poll messages and supervisory signal of predefined format to supervisory signal and for applying the latter signal to the junctors and/or bus of the PABX, a supervisory channel spread spectrum modulator using a predetermined supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signal, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel demodulator connected to the output of the receive band limiting filter for RF demodulating and despreading a received signal and applying received poll and supervisory signals to the synchronization and control circuit.

2. A system as defined in claim 1 including means for transmitting a supervisory signal on a fixed spread spectrum supervisory channel to said wireless communication terminal, means at said terminal for receiving a predetermined form of said supervisory signal designative of a particular correlation code related to a receive channel, and means for correlating the predetermined one of the spread spectrum signals using the correlation code to effect said demodulation into said intelligible signal.

3. A system as defined in claim 1 including means at the central location for receiving a signal at a particular port designative of a particular junctor or channel of an incoming signal, and means for transmitting said spread spectrum supervisory signal to said wireless terminal containing said predetermined form of said supervisory signal designative of said particular correlation code corresponding to said particular junctor or channel.

4. A system as defined in claim 1 including means at the central location for transmitting said spread spectrum communication signals to the wireless communication terminals using pseudo-random spreading codes which correspond to predetermined fixed correlation codes associated with individual ones of the wireless communication terminals.

5. A system as defined in claim 1, in which each wireless communication terminals is comprised of:

(i) a telephone set,

(ii) means for PCM encoding signals received from the telephone set,

(iii) means for spread spectrum and RF modulating the PCM encoded signals using a first pseudo-random correlation code,

(iv) means for applying the RF modulated signals to an antenna through a first filter for wireless transmission to the leaky transmission line,

(v) means for receiving RF and spread spectrum modulated signals from the antenna via a second filter,

(vi) means for receiving RF and spread spectrum demodulating the received signals using a second pseudo-random correlation code different from the first correlation code,

(vii) means for PCM decoding the spread spectrum demodulated signals,

(viii) means for applying the PCM decoded signals to the telephone,

whereby wireless two-way communication via said leaky transmission line on channels designated by the correlation codes is provided.

6. A system as defined in claim 5 in which the first and second correlation codes are variable, and means for causing variation thereof whereby particular designated send and receive spread spectrum channels are established.

7. A system as defined in claim 6 including a synchronization and control circuit, a second demodulator having its input connected to the output of said second filter for receiving a supervisory signal including synchronization signals, and providing demodulated digital supervisory signals therefrom to the synchronization and control circuit, the second demodulator using a fixed predetermined correlation code for demodulation of the supervisory signals, a second modulator having its input connected to the synchronization and control circuit for receiving supervisory signals and spread spectrum modulating said latter signals using a fixed predetermined pseudo-random code different from that of the correlation code used in the first modulator, RF modulating these signals and applying the signals via the second filter to the antenna, and means in the synchronization and control circuit for receiving supervisory signals from the telephone, generating supervisory data signals of predefined format and applying them to the second modulator, and for receiving supervisory data signals of predefined format from the second demodulator, for translating said latter supervisory signals therefrom and applying said translated signals to the telephone.

8. A system as defined in claim 7 including means at the synchronization and control circuit for deriving designated correlation codes from the received supervisory signals of predefined format and for enabling the first modulator and demodulator to use said latter correlation codes in modulation and demodulation respectively to establish the receive and transmit channels for said signals.

9. A system as defined in claim 8 including means for generating and displaying data at said wireless communication terminal, a data interface circuit connected to said data generating and displaying means, third means for spread spectrum and RF modulating data signals received via said interface circuit and applying the RF modulated signals to the first filter for transmission via the antenna to the leaky transmission line, third demodulation means having its input connected to the antenna via the second filter, and its output connected to the data interface circuit for applying demodulated data signals thereto, and means connecting the third modulator and demodulator to the synchronization and control circuit for carrying signals therefrom designative of the pseudo-random correlation codes to be used by the third modulator and demodulator.

10. A wireless communication system comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signals from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signals to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum modulating the encoded signal and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a central synchronization and control circuit connected to all said interface means for receiving supervisory signals from the junctors and/or a bus of the PABX and for formulating polling and supervisory signals of predefined format corresponding thereto and for translating poll messages and supervisory signals of predefined format to supervisory signals and for applying the latter signals to the junctors and/or bus of a the PABX, a supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signals, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel demodulator connected to the output of the receive band limiting filter for RF demodulating and despreading a received signal and applying received poll and supervisory signals to the synchronization and control circuit, a plurality of unidirectional repeaters connected serially at spaced locations in the leaky transmission line whereby an input and an output to the line are defined, the transmit filter being connected to the input of the transmission line and the receive filter being connected to the output of the transmission line.

11. A system as defined in claim 10, in which each wireless communication terminal is comprised of:

(i) a telephone set,

(ii) means for PCM encoding signals received from the telephone set,

(iii) means for spread spectrum and RF modulating the PCM encoded signals using a first pseudo-random correlation code,

(iv) means for applying the RF modulated signals to an antenna through a first filter for wireless transmission to the leaky transmission line,

(v) means for RF and spread spectrum modulated signals from the antenna via a second filter,

(vi) means for RF and spread spectrum demodulating the received signals using a second pseudo-random correlation code different from the first correlation code,

(vii) means for PCM decoding the spread spectrum demodulated signals,

(viii) means for applying the PCM decoded signals to the telephone,

whereby wireless two-way communication via said leaky transmission line on channels designated by the correlation codes is provided.

12. A system as defined in claim 11 in which the first and second correlation codes are variable, and means for causing variation thereof whereby particular designated send and receive spread spectrum channels are established.

13. A system as defined in claim 12 including a synchronization and control circuit, a second demodulator having its input connected to the output of said second filter for receiving a supervisory signal including synchronization signals, and providing demodulated digital supervisory signals therefrom to the synchronization and control circuit, the second demodulator using a fixed predetermined correlation code for demodulation of the supervisory signals, a second modulator having its input connected to the synchronization and control circuit for receiving supervisory signals and spread spectrum modulating said latter signals using a fixed predetermined pseudo-random code different from that of the correlation code used in the first modulator, RF modulating these signals and applying the signals via the second filter to the antenna, and means in the synchronization and control circuit for receiving supervisory signals from the telephone, generating supervisory data signals of predefined format and applying them to the second modulator, and for receiving supervisory data signals of predefined format from the second demodulator, for translating said latter supervisory signals therefrom and applying said translated signals to the telephone.

14. A system as defined in claim 13 including means at the synchronization and control circuit for deriving designated correleation codes from the received supervisory signals of predefined format and for enabling the first modulator and demodulator to use said latter correlation codes in modulation and demodulation respectively to establish the receive and transmit channels for said signals.

15. A system as defined in claim 14 including means for generating and displaying data at said wireless communication terminal, a data interface circuit connected to said data generating and displaying means, third means for spread spectrum and RF modulating data signals received via said interface circuit and applying the RF modulated signals to the first filter for transmission via the antenna to the leaky transmission line, third demodulation means having its input connected to the antenna via the second filter, and its output connected to the data interface circuit for applying demodulated data signals thereto, and means connected the third modulator and demodulator to the synchronization and control circuit for carrying signals therefrom designative of the pseudo-random correlation codes to be used by the third modulator and demodulator.

16. A wireless communication system comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one mobile wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signals from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signals to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum modulating the encoded signal and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a data interface circuit connected to the former interface circuit for receiving and transmitting data signals from and to the associated junctor and/or data bus of the PABX, a data channel modulator having a fixed correlation code corresponding to the junctor connected to the data interface circuit for spread spectrum and RF modulating a data signal received therefrom and applying the RF modulating signal via the transmit filter to the leaky transmission line, a data channel demodulator having its input connected via the receiver filter to the leaky transmission line, and for applying a data signal to the data interface circuit for transmission to the junctor or PABX data bus, a central synchronization and control circuit connected to all said interface means for receiving supervisory signals from the junctors and/or bus of the PABX and for formulating polling and supervisory signals of predefined format received from the wireless communication terminal corresponding thereto and for translating poll messages and supervisory signals of predefined format to supervisory signals and for applying the latter signals to the junctors and/or bus of the PABX, a supervisory channel modulator using a predetermined supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signals, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel demodulator connected to the output of the receive band limiting filter for RF demodulating and despreading a received signal and applying received poll and supervisory signals to the synchronization and control circuit.

17. A wireless communication system comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signals from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signals to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum modulating the encoded signal and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a central synchronization and control circuit connected to all said interface means for receiving supervisory signals from the junctors and/or a bus of the PABX and for formulating polling and supervisory signals of predetermined format corresponding thereto and for translating poll messages and supervisory signals of predefined format to supervisory signals and for applying the latter signals to the junctors and/or bus of a the PABX, a supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signals, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel RF demodulator connected to the output of the receive band demodulator connected to the output of the receive bank limiting filter for RF demodulating and despreading a received signal and applying received poll and supervisory signals to the synchronization and control circuit, a plurality of unidirectional repeaters connected serially at spaced locations in the leaky transmission line whereby an input and an output to the line are defined, the transmit filter being connected to the input of the transmission line and the receive filter being connected to the output of the transmission line, the frequency of the R.F. modulated signals being between approximately 150 MHz and 1000 MHZ.

18. A wireless communication system comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one mobile wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signals from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signals to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum modulating the encoded signal and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a central synchronization and control circuit connected to all said interface means for receiving supervisory signals from the junctors and/or a bus of the PABX and for formulating polling and supervisory signals of predetermined format corresponding thereto and for translating poll messages and supervisory signals of predefined format to supervisory signals and for applying the latter signals to the junctors and/or bus of a the PABX, a supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signals, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel demodulator connected to the output of the receive band limiting filter for RF demodulating and despreading a received signal and applying received poll and supervisory signals to the synchronization and control circuit, a plurality of unidirectional repeaters connected serially at spaced locations in the leaky transmission line whereby an input and an output to the line are defined, the transmit filter being connected to the input of the transmission line and the receive filter being connected to the output of the transmission line, the frequency of the RF modulated signals being between approximately 150 MHz and 1000 MHZ, the transmission line being coaxial cable having a shield containing gaps sufficient to allow RF energy radiation therefrom.

19. A wireless communication system comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one mobile wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals within the building and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signals from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signals to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum modulating the encoded signal and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a data interface circuit connected to the former interface circuit for receiving and transmitting data signals from and to the associated junctor and/or data bus of the PABX, a data channel spectrum modulator having a fixed correlation code corresponding to the junctor connected to the data interface circuit for spread spectrum and RF modulating a data signal received therefrom and applying the RF modulated signal via the receive band limiting filter to the leaky transmission line, a data channel demodulator having its input connected via the receive band limiting filter to the leaky transmission line and for applying a data signal to the data interface circuit for transmission to the junctor or PABX data bus, a central synchronization and control circuit connected to all said interface means for receiving supervisory signals from the junctors and/or a bus of the PABX and for formulating polling and supervisory signals of predefined format corresponding thereto and for translating poll messages and supervisory signals of predefined format to supervisory signals and for applying the latter signals to the junctors and/or bus of the PABX, a supervisory channel modulator using a predetermined supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signals, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel demodulator connected to the output of the receive band limiting filter for RF demodulating and despreading a received signal, and applying received poll and supervisory signals to the synchronization and control circuit, a plurality of unidirectional repeaters connected serially at spaced locations in the leaky transmission line whereby an input and an output to the line are defined, the output of the transmit band limiting filter being connected to the input of the transmission line and the input to the receive band limiting filter being connected to the output of the transmission line.

20. A system as defined in claim 19, in which each wireless communication terminal is comprised of:

(i) a telephone set,

(ii) means for PCM encoding signals received from the telephone set,

(iii) means for spread spectrum and RF modulating the PCM encoded signals using a first pseudo-random correlation code,

(iv) means for applying the RF modulated signals to an antenna through a first filter for wireless transmission to the leaky transmission line,

(v) means for receiving RF and spread spectrum modulated signals from the antenna via a second filter,

(vi) means for RF and spread spectrum demodulating the received signals using a second pseudo-random correlation code different from the first correlation code,

(vii) means for PCM decoding the spread spectrum demodulated signals,

(viii) means for applying the PCM decoded signals to the telephone,

whereby wireless two-way communication via said leaky transmission line on channels designated by the correlation codes is provided.

21. A system as defined in claim 20 in which the first and second correlation codes are variable, and means for causing variation thereof whereby particular designated send and receive spread spectrum channels are established.

22. A system as defined in claim 21 including a synchronization and control circuit, a second demodulator having its input connected to the output of said second filter for receiving a supervisory signal including synchronization signals, and providing demodulated digital supervisory signals therefrom to the synchronization and control circuit, the second demodulator using a fixed predetermined correlation code for demodulation of the supervisory signals, a second modulator having its input connected to the synchronization and control circuit for receiving supervisory signals and spread spectrum modulating said latter signals using a fixed predetermined pseudo-random code different from that of the correlation code used in the first modulator, RF modulating signals and applying the signals via the second filter to the antenna, and means in the synchronization and control circuit for receiving supervisory signals from the telephone, generating supervisory data signals of predefined format and applying them to the second modulator, and for receiving supervisory data signals of predefined format from the second demodulator, for translating said latter supervisory signals therefrom and applying said translated signals to the telephone.

23. A system as defined in claim 22 including means at the synchronization and control circuit for deriving designated correlation codes from the received supervisory signals of predefined format and for enabling the first modulator and demodulator to use said latter correlation codes in modulation and demodulation respectively to establish the receive and transmit channels for said signals.

24. A system as defined in claim 23 including means for generating and displaying data at said wireless communication terminal, a data interface circuit connected to said data generating and displaying means, third means for spread spectrum and RF modulating data signals received via said interface circuit and applying the RF modulated signals to the first filter for transmission via the antenna to the leaky transmission line, third demodulation means having its input connected to the antenna via the second filter, and its output connected to the data interface circuit for applying demodulated data signals thereto, and means connected the third modulator and demodulator to the synchronization and control circuit for carrying signals therefrom designative of the pseudo-random correlation codes to be used by the third modulator and demodulator.

25. A wireless communication system comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one mobile wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals within the building and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signals from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signals to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum analog and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a data interface circuit connected to the former interface circuit for receiving and transmitting data signals from and to the associated junctor and/or data bus of the PABX, a data channel modulator having a fixed correlation code corresponding to the junctor connected to the data interface circuit for spread spectrum and RF modulating a data signal received therefrom and applying the RF modulated signal via the transmit filter to the leaky transmission line, a data channel demodulator having its input connected via the receive filter to the leaky transmission line and for applying a data signal to the data interface circuit for transmission to the junctor or PABX data bus, a central synchronization and control circuit connected to all said interface means for receiving supervisory signals from the junctors and/or a bus of the PABX and for formulating polling and supervisory signals of predefined format corresponding thereto and for translating poll messages and supervisory signals of predefined format to supervisory signals and for applying the latter signals to the junctors and/or bus of the PABX, a supervisory channel modulator using a predetermined supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signals, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel demodulator connected to the output of the receive band limiting filter for RF demodulating and despreading a received signal, and applying received poll and supervisory signals to the synchronization and control circuit, a plurality of unidirectional repeaters connected serially at spaced locations in the leaky transmission line whereby an input and an output to the line are defined, the output of the transmit band limiting filter being connected to the input of the transmission line and the input to the receive filter being connected to the output of the transmission line, the frequency of the R.F. modulated signals being between approximately 150 MHz and 1000 MHz.

26. A wireless communication system comprising:

(a) means at a central location for receiving a plurality of signals for communication with selected wireless communication terminals,

(b) means at said central location for converting said signals to spread spectrum radio frequency signals using correlation codes corresponding to particular idle channels,

(c) a leaky transmission line located in a communication region within the building,

(d) means for applying said spread spectrum radio frequency signals to said transmission line for electromagnetic radiation within said region,

(e) at least one mobile wireless communication terminal adapted to receive a predetermined one of the spread spectrum radio frequency signals within the building and for demodulating it into an intelligible signal, and

(f) a plurality of similar circuits each comprising an interface means at the central location for connection to an individual junctor of a PABX, for receiving and transmitting communication signals from said junctor and for receiving and transmitting supervisory signals from the PABX relating to a telephone call, a central PCM encoder connected to the interface means for receiving signals to be transmitted to a wireless communication terminal, a modulator using a fixed pseudo-random correlation code associated with the junctor for spread spectrum modulating the encoded signal and generating an RF modulated signal, means for applying the latter RF modulated signal through a transmit band limiting filter to the leaky transmission line, means for receiving an RF modulated signal from the leaky transmission line through a receive band limiting filter, a central demodulator for demodulating and despreading a received RF modulated signal using a fixed pseudo-random correlation code associated with said junctor for demodulating the latter signal, a PCM decoder for receiving a spread spectrum demodulated signal and applying it to the interface means for application to said junctor, a data interface circuit connected to the former interface circuit for receiving and transmitting data signals from and to the associated junctor and/or data bus of the PABX, a data channel spectrum modulator having a fixed correlation code corresponding to the junctor connected to the data interface circuit for spread spectrum and RF modulating a data signal received therefrom and applying the RF modulated signal via the transmit filter to the leaky transmission line, a data channel demodulator having its input connected via the receive filter to the leaky transmission line and for applying a data signal to the data interface circuit for transmission to the junctor or PABX data bus, a central synchronization and control circuit connected to all said interface means for receiving supervisory signals from the junctors and/or a bus of the PABX and for formulating polling and supervisory signals of predefined format corresponding thereto and for translating poll messages and supervisory signals of predefined format to supervisory signals and for applying the latter signals to the junctors and/or bus of the PABX, a supervisory channel modulator using a predetermined supervisory channel correlation code for receiving and spread spectrum modulating said formulated polling and supervisory signals, RF modulating the latter signal and applying the RF modulated signal via the transmit band limiting filter to the leaky transmission line, a supervisory channel demodulator connected to the output of the receive band limiting filter for RF demodulating and despreading a received signal, and applying received poll and supervisory signals to the synchronization and control circuit, a plurality of unidirectional repeaters connected serially at spaced locations in the leaky transmission line whereby an input and an output to the line are defined, the output of the transmit band limiting filter being connected to the input of the transmission line and the input to the receive filter being connected to the output of the transmission line, the transmission line being coaxial cable having a shield containing gaps sufficient to allow RF energy to radiate therefrom.