Abstract: In a mobile radio communication system, a mobile station has a field level decision section which outputs a decision signal when the electric field level of a received signal exceeds a threshold level. A controller sequentially sets a plurality of different threshold levels. In response to the decision signal from the decision section, synchronization to the received control signal begins. When the mobile station receives down-going control signals from a plurality of base stations, it selects the one having the highest field level, and then sets up synchronization to the signal selected.

Abstract: In each radio base station of a cellular mobile communication network in which a mobile station is communicative with the radio base stations through a time division multiplex radio link, a transmitter/receiver serves as a synchronization system in cooperation with a base station control unit (35) to synchronize a down-link radio signal generated from a transmission frame generator at a transmission time with a like down-link radio signal transmitted from a different one of the radio base stations. The synchronization system has a received frame regenerator for detecting a reception time of one of frames of an up-link radio signal directed from the mobile station to the different station. A timing controller calculates a time difference between the transmission and the reception time. Controlled by the control unit in accordance with the time difference, the timing controller controls, in turn, the transmission time.

Abstract: A method and arrangement of locating cordless units in a wide area cordless telephone system is disclosed. A service area is previously divided into a plurality of small service zones and, a plurality of cordless units are provided for establishing communications with a system controller via a plurality of access stations. The system controller locates the cordless units and stores therein location data thereof. Each of the cordless units also stores the location data thereof applied from the system controller. A cordless unit issues a request signal which includes cordless unit location data. The request signal is received at an access station which in turn checks to determine if the request signal applied thereto is issued from a cordless unit whose location data indicates a service zone belonging to a predetermined service zone group.

Abstract: In a cellular communications system, the quality of a signal transmitted over a first two-way connection from a mobile station via a first base station is compared with a threshold to determine whether a handoff is to be performed to a second, adjacent base station. When the quality of the transmitted signal becomes lower than the threshold, a second two-way connection is established from the mobile station to the second base station, and a switching request signal and an information-bearing signal are sent from the mobile station over both connections to a switching exchange. In response to the request signal, one directional path of the first connection is cleared to prevent a version of the signal passing through the first connection from reaching the destination station, and a first switching complete signal is sent through the other path of the first connection to the mobile station to allow it to clear the first connection and return a second switching complete signal.

Abstract: In a wide area cordless telephone system, an individual-call signal is generated if an incoming call from the telephone network is an individual call to one of cordless stations of a group and a group-call signal is generated if it is directed to all cordless stations of the group. A group of access units are associated with the cordless station of each group to establish a control channel and speech channels with the cordless stations. The access units respond to the individual-call signal by transmitting a speech channel identifier to one of the cordless stations through the control channel and transmitting a ringing signal through a speech channel specified by the speech-channel identifier. In response to the group-call signal, speech-channel identifiers are successively transmitted from the access units to the cordless stations through the control channel and group ringing signals are respectively sent to the cordless stations through speech channels specified by the speech-channel identifiers.

Abstract: In a radio communication network system for use in carrying out communication with a plurality of radio telephone sets in a service zone by the use of a control channel and a plurality of speech channels, a connecting equipment unit (CE) is selectively operable in cooperation with a radio control unit (RCU) in a speech mode of forming a speech path through a selected one of the speech channels and an additional mode of selectively monitoring the control and the speech channels. The additional mode may be divided into first and second control modes for allowing and rejecting reception of a call with the control channel monitored, respectively. Alternatively, either a rest mode or a combination of rest and initial program loading modes may be added to the additional mode. A plurality of the connecting equipment units may be located in a single service zone and selectively put into the speech and the additional modes with only one of the connecting equipment units kept in the first control mode.

Abstract: A vibrating transducer for detecting the resonant frequency of a vibrating diaphragm and using that frequency to determine the pressure or density of a fluid contacting the diaphragm. The device includes a container having a diaphragm separating the cavity in the container into two chambers with the diaphragm preventing flow communication between the two chambers. A first fluid inlet in flow communication with the first chamber introduces fluid to the first chamber with that first chamber having an acoustic compliance less than the mechanical compliance of the diaphragm. The second fluid input is in flow communication with the second chamber and introduces fluid into the second chamber. By controlling the acoustic compliance of the chamber with respect to the diaphragm accurate measurements of the density or pressure of the fluid can be obtained.