Inbuilding telephone communication system

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.

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.