Abstract: In a mobile communication apparatus having a codec which codes first voice data into second voice data and decodes the second voice data into the first voice data, a memory in which the second voice data should be recorded and a silent data generating unit which generates silent data, the second voice data is successively recorded in the memory. While the second data is being recorded, the silent data is recorded in the memory as a substitute for the second voice data which is in a first state. The first state is a state in which the second voice data may be noise data.

Abstract: Conventional portable telephones have a problem that their space factor is bad and the size thereof is increased because a transmitter/receiver unit and a battery are disposed in parallel with each other in a case formed of a lower cover and an upper cover. In a portable telephone of the present invention, the frame member of a transmitter/receiver unit is attached to a mother substrate in the state that the frame member is partly interposed between the mother substrate and a battery. With this arrangement, the space between the mother substrate and the battery can be effectively used, whereby there can be provided a small portable telephone having a good space factor.

Abstract: A garment having at least one layer providing bullet-proof protection for the wearer. One or more additional layers incorporate sensors to detect the magnitude of an impact to generate a signal activating a wireless transmitter to send distress signals and/or positional and other information to a remote base location. Additional sensors may be provided to indicate physical characteristics of the wearer.

Abstract: A roaming decision is made and roaming channel selected in a wireless communications system based upon an evaluation of the operability of a data link layer interconnection, In a connection based protocol, the peer to peer data link layer interconnection is implemented through use of a unique connection identifier known in each peer functional layer of the data link interconnection. If the connection identifier has a value outside of a valid range, the interconnection is presumed nonoperational and the system makes a decision to roam.

Abstract: An automatic gain control apparatus (106) and method for a radiotelephone receiver employs stored inverse transfer function data (400) of the radiotelephone receiver and a gain estimation circuit (200). The gain estimation circuit (200) estimates the input power of received signal (103) and determines a required gain based on a nonlinear portion of the inverse transfer function data (400) of the radiotelephone receiver to provide an improved dynamic range of the receiver. The apparatus and method performs convergence within one iteration to perform fast gain control. In addition, if desired, a DC offset compensation circuit, such as a feedforward DC offset compensation circuit (202), compensates the digital representation of the input signal for use by the gain estimation circuit (200).

Abstract: The first frame of a paging slot (405) contains a portion of every page's (401-404) address. Likewise, the second, third, and fourth frames of the slot (405) contain a second, third, and fourth portion from each of the paging addresses. Address information is organized in the atomic frames of the slot (405) in such a way that the information in the earliest frame gives the mobile a high probability that it can determine that no messages directed to it are present in the slot. After receiving a first frame, a mobile station uses known partial address comparison techniques to determine if the mobile station has a page pending.

Abstract: Radio interface apparatus in combination with a lapel mounted microphone and speaker and a radio and with or without a head-protective helmet, radio interface apparatus in combination with a lapel-mounted radio and with or without a head-protective helmet, and radio interface apparatus for being mounted to the nape device of a head-protective helmet.

Abstract: The invention relates to a power control method and a cellular radio system used for power control, comprises at least one subscriber terminal, one base station and means for changing the step size to be used for power control. The means receive information on the speed of the subscriber terminal and the cellular radio system uses a fading channel. The means change the step size to be used for power control on the basis of the information on hte speed of the subscriber terminal for diminishing fading in the channel.

Abstract: A system is provided for detecting the presence of an FM-modulated audio signal from an auxiliary source, and operating a switch to provide that audio signal to a tuner in lieu of the radio frequency signal received at the tuner antenna. The tuner can be a vehicle tuner. The system also comprises a modulator unit for modulating the audio signal and an output plug for insertion into a cigarette lighter receptacle or power receptacle of a vehicle. A radio frequency transmission line, such as a coaxial cable, connects the cigarette lighter receptacle or power receptacle to the vehicle battery and to an antenna switch unit and transports both DC power and the FM-modulated audio signal. The antenna switch unit comprises switched inputs for the vehicle antenna and the output from the modulator unit, and a radio frequency signal detection device for detecting when the FM-modulated audio signal is present. The antenna switch unit provides the output from the modulator unit to the tuner whenever it is detected.

Abstract: To provide an analog mixer circuit operating with low power consumption and without needing any BEF for isolating two input signals, an LO signal and an IF signal are supplied to bases of a first transistor (Q1) and a second transistor (Q2) serially connected. A signal of a node (17) where the emitter of the first transistor (Q1) and the collector of the second transistor (Q2) is amplified nonlinearly by a third transistor (Q3) to be output to an output terminal (11), wherefrom an RF signal is extracted by a HPF (18).

Abstract: The following description regards a frequency converter (1) for applications on millimetric radio waves. The circuit structure comprises a diplexer filter realized in thin film on an alumina layer connected to a balun set up by a quartz plate on which two mixing diodes in GaAs have been mounted, placed in the center of a rectangular cavity (2) closed on one side by a short circuit plate and on the opposite side communicating with a rectangular waveguide (4) transporting a radio frequency signal (RF). On the upper side of the plate three parallel metallic bands have been put in the sense of the width of the cavity, between the bands the diodes are connected in series. The most external bands are welded to the walls of the cavity (2), the central one on the other hand is connected to the point common to both sections of the diplexing filter by means of a metallic strap in the air welded to a microstrip.

Abstract: A communication system includes mobile units, a network switching center, and service centers to provide a variety of enhanced services to the mobile units. In one embodiment, a service center communicates menu data to a mobile unit using a voice network. The mobile unit displays at a user interface menu options generated in response to the menu data communicated by the service center. Selecting a menu option at the user interface enables a function associated with traditional or enhanced services.

Abstract: An analog cellular voice telephone system and subscriber stations associated therewith are controlled to conserve power and to provide alternate service carriers. Acquisition of all of the service carriers is facilitated through the use of system identification numbers (SIDs) associated with each service carrier. A roaming subscriber will tune to a cellular digital packet data (CDPD) frequency to obtain a list of service carriers operating within that geographical area. Based upon a comparison with a preferred SID list stored in the subscriber station, an available service carrier will be selected by the subscriber station, and registration with the selected service carrier will take place. Usually, analog voice communication is suspended until the selection process takes place.

Abstract: At least one ground station (120) and at least one subscriber unit (SU) (130) allow users to perform user-aided registration procedures in satellite communications system (100). Ground station (120) and SU (130) communicate with each other using at least one communications satellite (110). The user-aided registration procedures (400, 500, and 600) enable border crossings to more accurately be processed by the system (100). Registration region information is presented to a user using a display device. A user response is processed by the SU and the ground station during registration procedures.

Abstract: Group communications between subscribers (20, 22) affiliated with a terrestrial communication system (12, 14) and subscribers (46, 48) affiliated with a satellite communication system (10) is begun when a subscriber has initiated a group communication request. The request is provided, via a controller (i.e., a terrestrial system controller or satellite system controller depending on which communication system the requesting subscriber is affiliated with), to a systems interface (36). Upon receiving the request, the systems interface determines whether subscribers that are identified to participate in the group communication are located in the terrestrial system and/or the satellite system. If the group of subscribers have members in both communication systems, the systems interface establishes satellite communication links for each subscriber affiliated with the satellite communication system and establishes a terrestrial communication link for subscribers affiliated with a terrestrial communication system.