Inbuilding telephone communication system

• US 5,349,631 A
• Filed: 11/21/1991
• Issued: 09/20/1994
• Est. Priority Date: 11/21/1991
• Status: Expired due to Term

• Current Assignee: Cellco Partnership, Inc. (Verizon Communications Inc.)
• Original Assignee: AirTouch Communications (Vodafone Group PLC)
• Inventors: Lee, William C.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Shankar, Vijay
• Application Number:
  US07/795,782
• Time in Patent Office: 1,034 Days
• Field of Search: 379/56, 379/58, 379/59, 379/60, 455/33.1, 455/33.3, 455/34.1, 455/15, 455/17
• US Class Current: 455/463
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/0802 using antenna selection H04B7/0868 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures

Abstract

An Inbuilding Communications System for providing telephone communication to a first set of portable telephones located in a first area and to a second set of portable telephones located in a second area; the first set of portable telephones transmit and receive a first set of radio signals having a set of assigned frequencies; the second set of portable telephones transmit and receive a second set of signals having the same set of assigned frequencies; the first and second areas are separated by a structure which attenuates radio signals. A first set of at least two antennas is located inside the first area for communicating with the first set of portable telephones. The number of antennas and the position of each antenna in the first set of antennas are chosen such that the first set of radio signals is attenuated below a pre-determined level after passing through the structure. A second set of at least two antennas is located inside the second area for communicating with the second set of portable telephones. The number of antennas and the position of each antenna in the second set of antennas are chosen such that tile second set of radio signals is attenuated below a pre-determined level after passing through the structure.

Claims

1. An inbuilding communication system for providing telephone communication to a first set of portable telephones located in a first area and to a second set of portable telephones located in a second area, the first set of portable telephones transmitting and receiving a first set of radio signals having a set of assigned frequencies, the second set of portable telephones transmitting and receiving a second set of radio signals having the same set of assigned frequencies used by the first set of portable telephones, the first and the second areas being separated by a structure which attenuates radio signals, said inbuilding communication system comprising:

a first set of at least two antennas located inside the first area communicating with the first set of portable telephones over the first set of radio signals, the number of antennas and the position of each antenna in said first set of antennas being chosen such that said first set of antennas is able to communicate with the first set of telephones at all locations in the first area above predefined minimum signal levels and such that the first set of radio signals is attenuated below a predetermined level after passing through the structure so as to reduce interference between the first and second set of radio signals;

a second set of at least two antennas located inside the second area for communicating with the second set of portable telephones over the second set of radio signals, the number of antennas and the position of each antenna in said second set of antennas being chosen such that said second set of antennas is able to communicate with the second set of telephones at all locations in the second area above predefined minimum signal levels and such that the second set of radio signals is attenuated below a predetermined level after passing through the structure so as to reduce interference between the first and second set of radio signals;

first selection means for selecting an antenna of said first set of antennas for transmitting a first selected radio signal of the first set of radio signals to a corresponding one of the first set of portable telephones, said selected antenna of said first set of antennas requiring the lowest signal intensity for transmitting said first selected radio signal of the first set of radio signals to said corresponding one of the first set of portable telephones; and

second selection means for selecting an antenna of said second set of antennas for transmitting a first selected radio signal of the second set of radio signals to a corresponding one of the second set of portable telephones, said selected antenna of said second set of antennas requiring the lowest signal intensity for transmitting said first selected radio signal of the second set of radio signals to said corresponding one of the second set of portable telephones.

2. The inbuilding communication system of claim 1 wherein said first selection means comprises:

first scanning means coupled to said first set of antennas for generating a first selection signal, said first selection signal indicating said selected antenna of said first set of antennas being the antenna which receives the highest signal strength of the radio signal transmitted by said corresponding one of the first set of portable telephones; and

first zone selection means responsive to said first selection signal for directing said first selected radio signal of the first set of radio signals for transmission to said selected antenna of said first set of antennas.

3. The inbuilding communication system of claim 2 wherein said second selection means comprises:

second scanning means coupled to said second set of antennas for generating a second selection signal, said second selection signal indicating said selected antenna of said second set of antennas being the antenna which receives the highest signal strength of the radio signal transmitted by said corresponding one of the second set of portable telephones; and

second zone selection means responsive to said second selection signal for directing said first selected radio signal of the second set of radio signals for transmission to said selected antenna of said second set of antennas.

4. The inbuilding communication system of claim 1 further comprising means for providing at least one telephone communication channel and means for coupling at least one said telephone channel to said first and said second selection means.

5. The inbuilding communication system of claim 4 wherein said means for coupling comprises:

first conversion means coupled to said means for providing for converting a first signal of at least one said telephone communication channel to a first carrier signal having a first carrier frequency;

second conversion means coupled to said means for providing for converting a second signal of said at least one telephone channel to a second carrier signal having a second carrier frequency;

third conversion means coupled to said first selection means for convening said first carrier signal to said first selected radio signal of the first set of radio signals; and

fourth conversion means coupled to said second selection means for convening said second carrier signal to said first selected radio signal of the second set of radio signals.

6. The inbuilding communication system of claim 5 wherein said first selection means further includes a first adder for generating a first combined signal by adding a second selected radio signal of the first set of radio signals received by said first set of antennas and wherein said second selection means further includes a second adder for generating a second combined signal by adding a second selected radio signal of the second set of radio signals received by said second set of antennas.

7. The inbuilding communication system of claim 6 wherein said means of coupling further comprises:

fifth conversion means coupled to said first adder of said first selection means for convening said first combined signal to a third carrier signal having a third carrier frequency;

sixth conversion means coupled to said second adder of said second selection means for converting said second combined signal to a fourth carrier signal having a fourth carrier frequency;

seventh conversion means coupled to said means for providing for converting said third carrier signal to said at least one communication channel; and

eighth conversion means coupled to said means for providing for converting said fourth carrier signal to said at least one communication channel.

8. The inbuilding communication system of claim 7 wherein said first, said second, said third, and said fourth carrier signals are microwave signals.

9. The inbuilding communication system of claim 7 wherein said first, said second, said third, and said fourth carrier signals are optical signals.

10. The inbuilding communication system of claim 4 wherein said means for providing comprises a cell site coupled to a mobile telephone switch office.

11. The inbuilding communication system of claim 4 wherein said means for providing comprises a private branch exchange.

12. The inbuilding communication system of claim 7 wherein said first set of antennas further includes a first set of diversity antennas and wherein said first selection means further includes a third adder for generating a third combined signal by adding the signal received by said first set of diversity antennas.

13. The inbuilding communication system of claim 12 wherein said second set of antennas further includes a second set of diversity antennas and wherein said first selection means further includes a fourth adder for generating a fourth combined signal by adding the signal received by said second set of diversity antennas.

14. The inbuilding communication system of claim 13 wherein said means of coupling further comprises:

ninth conversion means coupled to said third adder of said first selection means for convening said third combined signal to a fifth carrier signal having a fifth carrier frequency;

tenth conversion means coupled to said fourth adder of said second selection means for convening said fourth combined signal to a sixth carrier signal having a sixth carrier frequency;

eleventh conversion means coupled to said means for providing for convening said fifth carrier signal to said at least one communication channel; and

twelfth conversion means coupled to said means for providing for convening said sixth carrier signal to said at least one communication channel.

15. The inbuilding communication system of claim 1 further comprising means for allowing a member of the first set of portable telephones to continue its telephone communication as it moves from the first area to a connecting area and from the connecting area to the second area.

16. The inbuilding communication system of claim 15 wherein said means for allowing comprises:

means for assigning a third set of radio signals having a set of assigned frequencies different from said set of assigned frequencies of said first and said second sets;

at least one antenna located in the connecting area for transmitting and receiving signals; and

switching means for switching said member of the first set of portable telephones from using said first set of radio signals to using said third set of radio signals as said member moves from the first area to the connecting area and for switching said member from using said third set of radio signals to using said second set of radio signals as said member moves from the connecting area to the second area.

17. The inbuilding communication system of claim 16 wherein said switching means comprises:

a first scanning receiver associated with the first area for detecting the signal strength of radio signals;

a second scanning receiver associated with the second area for detecting the signal strength radio signals;

a third scanning receiver associated with the connecting area for detecting the signal strength of radio signals;

means for switching said member of the first set of portable telephones from using said first set of radio signals to using said third set of radio signals when said first scanning receiver detects a sharp drop in the signal strength of the radio signal transmitted by said member and when the signal strength of the radio signal transmitted by said member and detected by said third scanning receiver is above a first predetermined value; and

means for switching said member of the first set of portable telephones from using said third set of radio signals to using said second set of radio signals when the signal strength of the radio signal transmitted by said member and detected by said second scanning receiver is above a second predetermined value.

18. An inbuilding communication system for providing telephone communication to a first set of portable telephones located in a first floor of a building and to a second set of portable telephones located in a second floor of the building, the first set of portable telephones transmitting and receiving a first set of radio signals having a set of assigned frequencies, the second set of portable telephones transmitting and receiving a second set of radio signals having the same set of assigned frequencies used by the first set of portable telephones, the first and the second floor being separated by a structure which attenuates radio signals, said inbuilding communication system comprising:

means for providing a plurality of telephone communication channels;

first conversion means coupled to said means for providing for converting a first signal of said plurality of telephone communication channels to a first carrier signal having a first carrier frequency;

second conversion means coupled to said means for providing for converting a second signal of said plurality of telephone channels to a second carrier signal having a second carder frequency;

third conversion means for convening said first carrier signal to a first selected radio signal of the first set of radio signals; and

fourth conversion means for converting said second carrier signal to a first selected radio signal of the second set of radio signals;

a first set of at least two antennas located inside the first floor for communicating with the first set of portable telephones, the number of antennas and the position of each antenna in said first set of antennas being chosen such that the first set of radio signals is attenuated below a predetermined level after passing through the structure;

a second set of at least two antennas located inside the second floor for communicating with the second set of portable telephones, the number of antennas and the position of each antenna in said second set of antennas being chosen such that the second set of radio signals is attenuated below a predetermined level after passing through the structure;

first scanning means coupled to said first set of antennas for generating a first selection signal indicative of the antenna of said first set of antennas which receives the highest signal strength of the radio signal transmitted by said corresponding one of the first set of portable telephones;

first zone selection means responsive to said first selection signal for directing said first selected radio signal of the first set of radio signals for transmission to said antenna of said first set of antennas indicated by said first selection signal;

second scanning means coupled to said second set of antennas for generating a second selection signal indicative of the antenna of said second set of antennas which receives the highest signal strength of the radio signal transmitted by said corresponding one of the second set of portable telephones;

second zone selection means responsive to said second selection signal for directing said first selected radio signal of the second set of radio signals for transmission to said antenna of said second set of antennas indicated by said second selection signal;

a first adder for generating a first combined signal by adding a second selected radio signal of the first set of radio signals received by said first set of antennas;

a second adder for generating a second combined signal by adding a second selected radio signal of the second set of radio signals received by said second set of antennas;

fifth conversion means coupled to said first adder for converting said first combined signal to a third carrier signal having a third carrier frequency;

sixth conversion means coupled to said second adder for converting said second combined signal to a fourth carrier signal having a fourth carrier frequency;

seventh conversion means coupled to said means for providing for converting said third carder signal to a third signal of said plurality of communication channels; and

eighth conversion means coupled to said means for providing for converting said fourth carrier signal to a fourth signal of said plurality of communication channels.

19. The inbuilding communication system of claim 18 wherein said means of providing comprises a cell site coupled to a mobile telephone switch office.

20. The inbuilding communication system of claim 18 wherein said means of providing comprises a private branch exchange.

21. An inbuilding communication system for providing telephone communication to a set of portable telephones located in a location having a first area, a second area, and a connecting area connecting the first and the second areas, the set of portable telephones transmitting and receiving a first set of radio signals having a set of assigned frequencies in the first and the second areas, said inbuilding communication system including means for allowing a member of the set of portable telephones to continue its telephone communication as it moves from the first area to the connecting area and from the connecting area to the second area, said means for allowing comprising:

means for assigning a second set of radio signals having a set of assigned frequencies different from the set of assigned frequencies of the set;

at least one antenna located in the connecting area for transmitting and receiving signals; and

switching means for switching said member of the set of portable telephones from using said first set of radio signals to using said second set of radio signals as said member of the set of portable telephones moves from the first area to the connecting area and for switching said member of the set of portable telephones from using said second set of radio signals to using said first set of radio signals as said member of the set of portable telephones moves from the connecting area to the second area.

22. The inbuilding communication system of claim 21 wherein said switching means comprises:

a first scanning receiver associated with the first area for detecting the signal strength of radio signals;

a second scanning receiver associated with the second area for detecting the signal strength of radio signals;

a third scanning receiver associated with the connecting area for detecting the signal strength radio signals;

means for switching said member of the set of portable telephones from using the first set of radio signals to using the second set of radio signals when said first scanning receiver detects a sharp drop in the signal strength of the radio signal transmitted by said member and when the signal strength of the radio signal transmitted by said member and detected by said third scanning receiver is above a first predetermined value; and

means for switching said member of the set of portable telephones from using said second set of radio signals to using said first set of radio signals when the signal strength of the radio signal transmitted by said member and detected by said second scanning receiver is above a second predetermined value.