Portable wireless communication systems and method

Claim 2

A portable wireless communication system comprising: a plurality of base stations (1-7) each covering a predetermined area (11-17); a subscriber station (51, 52) movable within said predetermined area which can communicate with said base station via radio propagation; and a dedicated line (40-49) provided between adjacent base stations of said plurality of base stations for exchanging control information on channel use; wherein said base station comprises means (1-6) for storing and control information on its own base station and other base stations to be obtained from said dedicated line and means (1-7) for selecting a radio channel and a radio station by and with which said subscriber station performs communication, in accordance with said control information in said storage means.

Claim 3

A portable wireless communication system according to claim 1, wherein said control information includes at least: an identifier number of its own base station; a channel number which channel is presently used by its own base station in communicating with said subscriber station, among a plurality of radio channels assigned for the communication between said own base station and said subscriber station; and a channel number which channel is used by another base station and cannot be used by said own base station due to the interference, among said plurality of assigned radio channels.

Claim 4

A portable and wireless communication system according to claim 1, wherein said dedicated line is a radio channel.

Claim 5

A portable and wireless communication system according to claim 3, wherein said base station receiving said control information sent via said radio channel comprises means for observing the strength of a signal conveying said control information and means for weighting said received control information in accordance with said signal strength.

Claim 6

A portable and wireless communication system according to claim 1, wherein said dedicated line is a wire.

Claim 7

A portable wireless communication system according to claim 1 further comprising: a radio exchange (18) connected to said plurality of base stations; and a private branch exchange (19) connected to said radio exchange and a wire telephone present in said predetermined area.

Claim 8

A portable wireless communication method for performing communication between a portable radio transceiver and a plurality of base stations (1-7) each covering a predetermined area (11-17), via an arbitrary radio channel among a plurality of radio channels assigned to each base station, said method comprising: while each base station of said plurality of base stations does not communicate with said subscriber station, a first step of checking the idle or busy status of radio channels of its own base station to obtain control information; a second step of exchanging said control information obtained at the first step with neighbouring base stations via a dedicated line (40-49); when said portable radio transceiver sends a call initiation signal via a particular radio channel, a third step in which said base station receiving said call initiation signal independently refers to said control information to allocate a base station and a radio channel with and by which said portable radio transceiver performs communication; and a fourth step of performing communication between said portable radio transceiver and said base station via said radio channel allocated at said third step.

Claim 9

A portable wireless communication method for performing communication between a portable radio transceiver and a plurality of base stations (1-7) each covering a predetermined area (11-17), via an arbitrary radio channel among a plurality of radio channels assigned to each base station, said method comprising: while each base station of said plurality of base stations does not communicate with said subscriber station, a first step of checking the idle or busy status of radio channels of its own base station to obtain control information; a second step of exchanging said control information obtained at the first step with neighbouring base stations via a dedicated line (40-49); when said portable radio transceiver sends a call initiation signal via a particular radio channel, a third step in which said base station receiving said call initiation signal independently refers to said control information to allocate a base station and a radio channel with and by which said portable radio transceiver performs communication; and a fourth step of performing communication between said portable radio transceiver and said base station via said radio channel allocated at said third step.

Claim 10

A portable and wireless communication method according to claim 7, wherein said control information at said second step includes an identifier number of a base station and information for discriminating if said radio channel cannot be used because of interference by another base station, can be used because of negligible interference, or is vacant because of no interference, and wherein said channel allocation at said third step allocated a radio channel which can be used by its own base station and cannot be used by neighbouring base stations in priority over the other radio channels, in accordance with said control information.

Claim 11

A portable wireless communication method according to claim 7, wherein said third step further includes: a step in which said base station receiving said call initiation signal sends to said neighbouring base stations a call initiation response signal to the effect that said base station has seized said call initiation signal from said portable radio transceiver; and a step in which said base radio station receiving said call initiation response signal refers to said call initiation response signals of its own base station and neighbouring base stations and judges if said own base station should respond to said call initiation signal.

Claim 12

A portable wireless communication method according to claim 7 further comprising: when the signal strength of said portable radio transceiver lowers to the extent that it becomes necessary to hand off communication with one base station, a step of sending to one or more neighbouring base stations a hand-off request signal including an identifier number and signal strength of said portable radio transceiver and the channel number in use for the communication; a step wherein said neighbouring base stations receiving said hand-off request signal monitor the signal from said portable radio transceiver and return to said one base station a hand-off response signal including the monitor result and other information; and a step wherein said one base station receiving said hand-off response signals from said neighbouring base stations compares data sent from said neighbouring base stations, and sends a hand-off control signal asking for a hand-off of communication to a most suitable base station in accordance with a predetermined comparison criterion.

Claim 13

A portable wireless communication method according to claim 10, wherein when said neighbouring base station cannot afford a hand-off communication, said neighbouring base station returns a signal rejecting the hand-off communication as said hand-off response signal.

Claim 14

A portable wireless communication method according to claim 10 further comprising: when one of said neighbouring base stations returns said hand-off response signal after said one base station sent said hand-off request signal, a step wherein the communication by said portable radio transceiver with said one base station is maintained to continue and after a predetermined time lapse, said one base station sends again said hand-off request signal.