Telephonic communications – Having light wave or ultrasonic link for speech or paging... – Including fiber optic link within telephone network
Patent
1989-12-12
1992-08-04
Dwyer, James L.
Telephonic communications
Having light wave or ultrasonic link for speech or paging...
Including fiber optic link within telephone network
379 61, H04M 1100
Patent
active
051366290
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a radio communication system of a multi-channel access type in which an idle one of a plurality of radio channels is detected to perform transmission and reception of voice signals, data signals or the like, and also a method of controlling the radio communication system.
2. Background Art
FIG. 3 is a block diagram showing an arrangement of a prior art radio communication system of the type referred to above. In the drawing, a base unit 1 is to be coupled, at its one side, through a radio communication circuit to a radio telephone set 2 as a radio terminal apparatus; while the base unit is also connected, at the other side, to a wired telephone line 3.
A signal sent from the wired telephone line 3 is supplied through a line relay 10 and a hybrid circuit 11 to a transmitter 12 as its modulation input. Electromagnetic waves subjected to a modulation at the transmitter 12 are transmitted from an antenna 14 to the radio telephone set 2 through antenna duplexer 13.
Electromagnetic waves transmitted from the radio telephone set 2, on the other hand, are received at the antenna 14 and sent through the antenna duplexer 13 to a receiver 15 to be demodulated thereat. A signal subjected to demodulation at the receiver 15 is send through the hybrid circuit 11 onto the wired telephone circuit 3.
A synthesizer 16 applies to the transmitter 12 and the receiver 15 a signal of a frequency corresponding to radio channels, that is, speech and control channels.
The receiver 15 has a function of demodulatiing a data signal included in the received demodulation wave signal, that is, demodulating an identification signal determined by a combination of the base unit 1 and the radio telephone set 2, and the receiver 15 applies the demodulated identification signal (ID code) to a controller 17. The controller 17 per se is used to control the synthesizer 16 in such a manner that the switching of the radio channels is controlled and a transmission data signal is applied to the transmitter 12 as its modulation input. A ringing-signal detecting circuit 18 detects a ringing signal of 16 Hz received from the wired telephone line 3. The identification signal of the radio telephone set 2 is previously stored in a ROM 19.
As in the base unit 1, the radio telephone set 2 also has an antenna 20, a receiver 21, an antenna duplexer 22, a transmitter 23 and a synthesizer 24, a demodulated output of the receiver 21 being output to a speaker 30. A voice input through a microphone 25 is applied to the transmitter 23 as its modulation input, sent to the antenna duplexer 22 and further transmitted from the antenna 20.
The synthesizer 24 and a ROM 26 are substantially the same as those in the base unit 1. A controller 27 performs the entire control over the radio telephone set 2. A loudspeaker 28 is a sounder which generates a ringing tone at the time of receiving an incoming signal.
The control of this prior art in its incoming signal mode is schematically carried out in accordance with such a flowchart as shown in FIG. 4. The base unit 1, when detecting at the ringing-signal detecting circuit 18 an incoming signal received from the wired telephone line 3 in its wait mode (step 30), sets the oscillation frequency of the synthesizer 16 at a control channel frequency, turns ON the receiver 15 to receive electromagnetic waves on a control channel (C-CH), and in the absence of the received electromagnetic waves, judges that the control channel is idle and transmits the incoming signal from the transmitter 12 (steps 31 and 32). In this case, the incoming signal contains a speech channel (S-CH) designation signal.
In the radio telephone set 2 during the wait mode, on the other hand, the synthesizer 24 is turned ON, the oscillation frequency of the synthesizer is set at the control channel frequency, and the receiver 21 is intermittently turned ON. When the receiver 21 is turned ON (step 50), the transmitter 23 is turned ON under a condition that the ID code contained in the in
REFERENCES:
patent: 5014295 (1991-05-01), Kunihiro
Fuse Shoji
Ohta Yuji
Ono Koji
Saegusa Noboru
Shimura Yukihiro
Bost Dwayne D.
Dwyer James L.
Kabushiki Kaisha Toshiba
NEC Corporation
Nippon Telegraph and Telephone Corporation
LandOfFree
Radio communication system having control method for shortening does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Radio communication system having control method for shortening , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radio communication system having control method for shortening will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-785449