System and method for providing intercom and multiple voice channels in a private telephone system

• US 6,044,268 A
• Filed: 07/16/1997
• Issued: 03/28/2000
• Est. Priority Date: 07/16/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Haartsen, Jacobus C.
• Primary Examiner(s): Hudspeth, David R.
• Assistant Examiner(s): ABEBE, DANIEL DEMELASH
• Application Number:
  US08/895,138
• Time in Patent Office: 986 Days
• Field of Search: 455/411, 455/426, 455/436, 455/437, 455/438, 455/447, 455/462, 455/464
• US Class Current: 370/294
• CPC Class Codes: H04M 1/72513 On hold, intercom or transfer communication modes
• CPC Class Codes: H04W 84/16 WPBX [Wireless Private Branch Exchange]

Abstract

A system and method for allowing intercom and multiple voice channel communication within a private telephone system employing a private base station and a multiplicity of standard cellular terminals is disclosed. Full duplex intercom communications between two users within the private telephone system may be facilitated by use of two half-rate channels, one channel transceiver on even-numbered TDMA transmission frames and another channel transceiver on odd-numbered transmission frames, both from respective terminals to a private base station, which mediates the communication therebetween. Multiple voice channels are also provided within the private telephone system, allowing two users on two separate channels to communicate with respective remote wireline users simultaneously.

Claims

1. A private base station within a private telephone system, said private base station being in wireless time division multiple access (TDMA) communication with a multiplicity of terminals also within said private telephone system, users of at least two of said terminals being in duplex intercom communication with each other via said private base station, said private base station comprising:

a signal receiving portion for receiving said duplex intercom communications between the users of said at least two terminals over respective half-rate channels;

a signal transmitting portion for transmitting said duplex intercom communications to said users of said at least two terminals over respective half-rate channels;

a signal interconnection means, connected to said signal receiving and signal transmitting portions, whereby a first communication from a first of said terminals is relayed within said private base station through said signal receiving portion, signal interconnection means and signal transmitting portion to at least a second of said terminals, and whereby a second communication from said second terminal is relayed within said private base station through said signal receiving portion, signal interconnection means and signal transmitting portion to at least said first terminal, users of at least said first and second terminals within said private telephone system being in duplex intercom communication with each other via said private base station, and

a multiplicity of intermediate storage devices, connected to said signal interconnection means, for storing signals of said first communication and said second communication from said at least two terminals, each said intermediate storage device being connected to said signal receiving portion.

2. The private base station according to claim 1, wherein said signal interconnection means comprises a first and a second intermediate storage device, said first intermediate storage device for storing signals of said first communication and said second intermediate storage device for storing signals of said second communication.

3. The private base station according to claim 2, wherein said signal interconnection means further comprises a multiplexer, connected to said first and second intermediate storage devices and said signal transmitting portion, for controlling the forwarding of said stored signals from said first and second intermediate storage devices to said signal transmitting portion.

4. The private base station according to claim 3, wherein said multiplexer forwards the stored signals from said first intermediate storage device to said signal transmitting portion during even-numbered TDMA transmission frames and forwards the stored signals from said second intermediate storage device to said signal transmitting portion during odd-numbered TDMA transmission frames.

5. The private base station according to claim 2, wherein said signal interconnection means further comprises a third intermediate storage device for storing signals of a third communication, said third communication being between a third user located at said private base station and said terminals users in said first and second communications, said third intermediate storage device being connected to a microphone at said private base station for receiving said third communication and to said signal transmitting portion.

6. The private base station according to claim 5, wherein said signal interconnection means further comprises a multiplicity of summation devices for summing said communications, a first summation device connected to said first and third intermediate storage devices, a second summation device connected to said second and third intermediate storage devices, said first and second summation devices being connected to said multiplexer for forwarding summed communications of said first and third communications and said second and third communications to said second and first terminals, respectively, and a third summation device connected to said first and second intermediate storage devices, said third summation device also being connected to a speaker for transmitting said summed first and second communications to said third user at said private base station location.

7. The private base station according to claim 6, wherein said multiplexer forwards the stored signals from said first and third intermediate storage devices to said signal transmitting portion during even-numbered TDMA transmission frames and forwards the stored signals from said second and third intermediate storage devices to said signal transmitting portion during odd-numbered TDMA transmission frames, and wherein said third summation device forwards the stored signals from said first and second intermediate storage devices to said speaker.

8. The private base station according to claim 1, wherein said signal receiving portion comprises:

a receiver for receiving the wireless duplex intercom communications from said at least two terminal users;

a demodulator, connected to said receiver, for filtering said communications;

an equalizer, connected to said demodulator, for adjusting said communications; and

a symbol detector, connected to said equalizer, for detecting signals within said communications.

9. The private base station according to claim 8, wherein said interconnection means connects said symbol detector to said signal transmitting means.

10. The private base station according to claim 8, wherein said signal receiving portion further comprises:

a first adder connected to said symbol detector; and

a ciphering unit, connected to said adder, for deciphering said signals, said interconnection means connecting said first adder to said signal transmitting means.

11. The private base station according to claim 10, further comprising a private key device connected to said ciphering unit.

12. The private base station according to claim 10, further comprising at least two private key devices connected to said ciphering unit, a first private key being associated with said first communication and a second private key being associated with said second communication.

13. The private base station according to claim 10, wherein said signal receiving portion further comprises:

a deinterleaver, connected to said first adder, for deinterleaving said signals within said communications; and

a channel decoder, connected to said deinterleaver, for decoding said signals.

14. The private base station according to claim 13, wherein said interconnection means connects said channel decoder to said signal transmitting means.

15. The private base station according to claim 13, wherein said signal receiving portion further comprises:

a speech decoder, connected to said channel decoder, for decoding speech signals within said communications.

16. The private base station according to claim 15, wherein said interconnection means connects said speech decoder to said signal transmitting means.

17. The private base station according to claim 1, wherein said signal transmitting portion comprises:

a burst generator;

a signal modulator, connected to said burst generator, for modulating said communications;

an amplifier, connected to said signal modulator, for amplifying the signals of said communications; and

an antenna, connected to said amplifier, for transmitting said wireless duplex intercom communications to said at least two terminal users.

18. The private base station according to claim 17, wherein said interconnection means connects said signal receiving portion to said burst generator.

19. The private base station according to claim 17, wherein said signal transmitting portion further comprises:

a second adder connected to said burst generator; and

a ciphering unit, connected to said adder, for deciphering said duplex intercom communications, said interconnection means connecting said second adder to said signal receiving means.

20. The private base station according to claim 19, further comprising a private key device connected to said ciphering unit.

21. The private base station according to claim 19, further comprising at least two private key devices connected to said ciphering unit, a first private key being associated with said first communication and a second private key being associated with said second communication.

22. The private base station according to claim 19, wherein said signal transmitting portion further comprises:

an interleaver, connected to said second adder, for interleaving signals within said communications; and

a channel coder, connected to said interleaver, for coding said signals within said communications.

23. The private base station according to claim 22, wherein said interconnection means connects said signal receiving portion to said channel coder.

24. The private base station according to claim 22, wherein said signal transmitting portion further comprises:

a speech coder, connected to said channel coder, for encoding speech signals with said communications.

25. The private base station according to claim 24, wherein said interconnection means connects said signal receiving portion to said speech coder.

26. The private base station according to claim 1, wherein said signal receiving portion receives said first communication in a first TDMA transmission frame and said signal transmitting portion transmits said first communication to said at least a second of said terminals in a subsequent TDMA transmission frame.

27. The private base station according to claim 26, wherein said signal receiving portion receives said first communication in a first timeslot within said first TDMA transmission frame and said signal transmitting portion transmits said first communication in a second timeslot in said subsequent TDMA transmission frame.

28. The private base station according to claim 27, wherein the positions of said first and second timeslots within said first and said subsequent TDMA transmission frames differ.

29. The private base station according to claim 27, wherein the frequencies of said first communication in said first timeslot and of said first communication in said second timeslot differ.

30. The private base station according to claim 1, wherein said second communication from said second terminal is relayed in duplex mode through said signal receiving and signal transmitting portions of said private base station to said first terminal, said first and said second communications each being at half-rate and on alternative TDMA transmission frames.

31. The private base station according to claim 1, wherein said first and second communications are at half-rate and on respective alternate TDMA transmission frames, said private base station receiving signals from said first user in a first timeslot on even-numbered frames and receiving signals from said second user in said first timeslot on odd-numbered frames.

32. The private base station according to claim 31, wherein the frequencies of said first communication in said first timeslot in said even-numbered frames and of said second communication in said first timeslot in said odd-numbered frames differ.

33. The private base station according to claim 31, wherein said private base station transmits signals from said first user in a second timeslot on said odd-numbered frames and transmits signals from said second user in said second timeslot on said even-numbered frames.

34. The private base station according to claim 33, wherein the frequencies of at least two of said first communication in said first timeslot in said even-numbered frames, of said second communication in said first timeslot in said odd-numbered frames, of said first communication in said second timeslot in said odd-numbered frames, and of said second communication in said second timeslot on said even-numbered frames differ.

35. A method for establishing a duplex intercom communication between at least two users within a private telephone system, said private telephone system including a private base station and a multiplicity of terminals in wireless time division multiple access (TDMA) communication therewith, each of said at least two users operating a respective one of said terminals, said method comprising the steps of:

transmitting, from a first of said terminals to said private base station, a communication request from a first user of said first terminal to a second user of a second terminal, said private base station allocating a first communication channel between said first terminal and said private base station;

transmitting, from said private base station to said second terminal, said communication request, said private base station allocating a second communication channel between said second terminal and said private base station, whereby upon communication establishment said duplex intercom communication between said first and second users of said first and second terminals, respectively, are relayed through said private base station across said first and second communication channels; and

receiving, by a third user at a user station at said private base station, said duplex intercom communication between said first and second users.

36. The method according to claim 35, wherein said first terminal transceives signals on said first half-rate communication channel on even-numbered TDMA transmission frames and said second terminal transceives signals on said second half-rate communication channel on odd-numbered TDMA transmission frames.

37. The method according to claim 35, wherein said first and second communication channels are selected by said private base station in accordance with an adaptive channel allocation algorithm.

38. The method according to claim 35, further comprising the step of:

transmitting, by said third user through said private base station, a signal to said first and second users, said first, second and third users having said duplex intercom communication.

39. A private base station within a private telephone system, said private base station being in wireless time division multiple access (TDMA) communication with a multiplicity of terminals also within said private telephone system, users of at least two of said terminals being in remote communication with respective remote parties outside of said private telephone system via said private base station, said private base station comprising:

a signal receiving portion for receiving said wireless communications from said at least two private telephone system terminal users;

wireline communication means, connected to said signal receiving portion, for converting the wireless signals of said TDMA communications from said multiplicity of terminals to corresponding wireline signals, forwarding said converted wireline signals to the respective remote parties and receiving wireline communications from said remote parties to said terminal users over respective half-rate voice channels, and converting the wireline signals of said wireline communications to corresponding TDMA wireless signals;

a multiplicity of intermediate storage devices for storing said wireless communications from said at least two private telephone terminal users, each said intermediate storage device being connected to said signal receiving portion; and

a signal transmitting portion, connected to said wireline communication means, for transmitting said corresponding TDMA wireless signals to said terminal users, thereby establishing at least two wireless-wireline links between said terminal users and said remote parties.

40. The private base station according to claim 39, wherein said wireline communication means converts the wireless signals received from a first terminal user during even-numbered TDMA transmission frames and forwards said corresponding converted wireline signals to a first remote party, and converts the wireless signals received from a second terminal user during odd-numbered TDMA transmission frames and forwards said corresponding converted wireline signals from said second user to a second remote party.

41. The private base station according to claim 40, wherein said wireline communication means converts the wireline signals from said first remote party to corresponding first wireless signals and transmits said corresponding first wireless signals to said first terminal user during said even-numbered TDMA transmission frames at a timeslot therein different from that of said wireless signals received from said first terminal user, and converts the wireline signals from said second remote party to corresponding second wireless signals and transmits said corresponding second wireless signals to said second terminal user during said odd-numbered TDMA transmission frames at a timeslot therein different from that of said wireless signals received from said second terminal user.

42. A method for establishing at least two independent duplex remote communications between at least two users within a private telephone system and respective remote parties outside of said private telephone system, such private telephone system including a private base station and a multiplicity of terminals in wireless time division multiple access (TDMA) communication therewith, each of said at least two users operating a respective one of said terminals, said method comprising the steps of:

transmitting, from a first of said terminals to said private base station, a communication request from a first user of said first terminal to a first remote party, said private base station allocating a first half-rate communication channel between said first user and said first remote party, and establishing a first duplex communication therebetween;

transmitting, from a second of said terminals to said private base station, a second communication request from a second user of said second terminal to a second remote party, said private base station allocating a second half-rate communication channel between said second user and said second remote party, and establishing a second duplex communication therebetween, said first and second duplex communications being independent of each other; and

storing signals from said first duplex communications and said second duplex communications at said private base station.

43. The method according to claim 42, wherein said first and second communication channels are each half-rate channels, said first and second terminals transceiving signals with said first and second remote parties, respectively, through said private base station on said first and second communication channels, respectively, said first communication channel being on even-numbered TDMA transmission frames and said second communication channel being an odd-numbered TDMA transmission frames.

44. The method according to claim 42, wherein said first and second communication channels are selected by said private base station in accordance with an adaptive channel allocation algorithm.

45. A method for establishing at least two independent duplex remote communications between at least two users within a private telephone system and respective remote parties outside of said private telephone system, such private telephone system including a private base station and a multiplicity of terminals in wireless time division multiple access (TDMA) communication therewith, each of said at least two users operating a respective one of said terminals, said method comprising the steps of:

transmitting, from a first of said terminals to said private base station, a communication request from a first user of said first terminal to a first remote party, said private base station allocating a first half-rate communication channel between said first user and said first remote party, and establishing a first duplex communication therebetween;

transmitting, from said private base station, a communication request from a second remote party to said second terminal, said private base station allocating a second half-rate communication channel between said second user and said second remote party, and establishing a second duplex communication therebetween, said first and second duplex communications being independent of each other; and

storing signals from said first duplex communications and said second duplex communications at said private base station.

46. The method according to claim 45, wherein said first and second communication channels are each half-rate channels, said first and second terminals transceiving signals with said first and second remote parties, respectively, through said private base station on said first and second communication channels, respectively, said first communication channel being on even-numbered TDMA transmission frames and said second communication channel being an odd-numbered TDMA transmission frames.

47. The method according to claim 45, wherein said first and second communication channels are selected by said private base station in accordance with an adaptive channel allocation algorithm.

48. A method for establishing at least two independent duplex remote communications between at least two users within a private telephone system and respective remote parties outside of said private telephone system, such private telephone system including a private base station and a multiplicity of terminals in wireless time division multiple access (TDMA) communication therewith, each of said at least two users operating a respective one of said terminals, said method comprising the steps of:

transmitting, from said private base station, a communication request from a first remote party to said first terminal, said private base station allocating a first half-rate communication channel between said first user and said first remote party, and establishing a first duplex communication therebetween;

transmitting, from a second of said terminals to said private base station, a second communication request from a second user of said second terminal to a second remote party, said private base station allocating a second half-rate communication channel between said second user and said second remote party, and establishing a second duplex communication therebetween, said first and second duplex communications being independent of each other; and

storing signals from said first duplex communications and said second duplex communications at said private base station.

49. The method according to claim 48, wherein said first and second communication channels are each half-rate channels, said first and second terminals transceiving signals with said first and second remote parties, respectively, through said private base station on said first and second communication channels, respectively, said first communication channel being on even-numbered TDMA transmission frames and said second communication channel being an odd-numbered TDMA transmission frames.

50. The method according to claim 48, wherein said first and second communication channels are selected by said private base station in accordance with an adaptive channel allocation algorithm.

51. A method for establishing at least two independent duplex remote communications between at least two users within a private telephone system and respective remote parties outside of said private telephone system, such private telephone system including a private base station and a multiplicity of terminals in wireless time division multiple access (TDMA) communication therewith, each of said at least two users operating a respective one of said terminals, said method comprising the steps of:

transmitting, from said private base station, a communication request from a first remote party to said first terminal, said private base station allocating a first half-rate communication channel between said first user and said first remote party, and establishing a first duplex communication therebetween;

transmitting, from said private base station, a communication request from a second remote party to said second terminal, said private base station allocating a second half-rate communication channel between said second user and said second remote party, and establishing a second duplex communication therebetween, said first and second duplex communications being independent of each other; and

storing signals from said first duplex communications and said second duplex communications at said private base station.

52. The method according to claim 51, wherein said first and second communication channels are each half-rate channels, said first and second terminals transceiving signals with said first and second remote parties, respectively, through said private base station on said first and second communication channels, respectively, said first communication channel being on even-numbered TDMA transmission frames and said second communication channel being an odd-numbered TDMA transmission frames.

53. The method according to claim 51, wherein said first and second communication channels are selected by said private base station in accordance with an adaptive channel allocation algorithm.