Abstract: In order to gain access to a secured system, a user must be able to enter valid user identification information and must also have a remote wireless communication device such as a pager or cellular telephone having a number that is substantially unique to that user. When the user requests access to the secured system, the system places a call to the user's remote wireless communication device and sends that device revalidation information such as a random number generated by the secured system. The user must return the revalidation information to the secured system to gain access. In an alternative embodiment, another person (a user-approver) has the remote wireless communication device and must return the revalidation information to the secured system if the user-approver approves the user's request for access.

Abstract: An intelligent wireless communication base station provides communication between individual base stations over an RF radio channel. A control unit in each base station utilizes this communication to facilitate each base station to gather system data regarding the system arrangement of nearby base stations and to facilitate handovers of mobile wireless personal communicators from one base station to a another base station. This control unit is under stored program control and gathers information concerning set up channels of nearby radio ports, a developed list or table of neighbor base stations and signal strength values of nearby channels. Voice channels may be bridged allowing two personal communicators to communicate with each other through a single base station.

Abstract: A highly reliable early warning system that can provide efficient detection of railway activity and early warning of dangerous railway conditions to train operators and to central dispatch control offices. The warning system has an acoustic sensor circuit coupled to the railway for detecting sound waves resulting from physical vibrations thereon, an acoustic analyzer unit for analyzing the sound waves detected on the railway to identify any suspect conditions thereon and to generate an alarm if such a suspect condition is identified, and an acoustic signal processing unit for storing detected sound waves in a sound file for quick retrieval and analysis. The alarm signal may be transmitted over any communications system to the central control office and to trains traveling on the dangerous track.

Abstract: A switching circuit is provided to process a DC voltage and apply a low frequency AC voltage, having a trapezoidal waveform, to a co-axial cable transmitting the low frequency AC voltage to a load which may be powered by the low frequency AC voltage as well as a DC voltage. In one specific embodiment two of the switches are connected as part of buck regulation circuits to serve a dual purpose of polarity switching and regulation.

Abstract: A DC voltage polarity switching circuit includes four switches connected in a bridge configuration. Switches in opposing legs are paired with each other and turned on and off in alternate phases to deliver a low frequency alternating signal having a trapezoidal waveform to a co-axial cable load. Circuitry is included to control the slew rate when the output signal transitions from one polarity to the other. Also, turn on of a switch in one phase is delayed during turn off of a switch in the end of the interval of presently conducting switches in one phase.

Abstract: A plurality of battery/voltage polarity switching circuits are constrained to operate in switching synchronism by a timing circuit associated with each polarity switching circuit that are interrelated to one another such that only the fastest response timing circuit is operative to supply a common synchronizing signal to all the polarity switching circuits.

Abstract: A power plant system architecture includes a plurality of battery polarity switching circuits for providing uninterruptible power/voltage to a plurality of loads, each of which is powered by low frequency AC, and which is also powered by a DC voltage. DC voltage is substituted for the AC voltage applied to the load should the voltage polarity processing circuitry in the power plant fail.

Abstract: Icon indicia are provided on input, output and plug-in power processing units to permit proper matching of plug-in units with each other and with the input and output power processing units in a power distribution system. The indicia are in a co-ordinated matrix format with input icons on a designated chroma background to identify input voltages and output icons on a second designated chroma background to identify output voltages. Icons and background chroma on the plug-in power processing units are coordinated with related icons and background chroma at the same matrix position on other plug-in units and/or the input and output units to assure the compatibility of all the units. A craftsman inserting a plug-in unit onto a shelf of the power chassis need merely compare the unit's icon and chroma background indicia with the input, output, or other unit's icons and associated chroma background indicia to be assured of inserting the correct plug-in unit into the particular shelf.

Abstract: An access director provides a gateway for customer premise based equipment (both wired and wireless) and a wireless port facility to a narrowband/broadband information distribution network. It provides a portable narrowband duplex synchronous and isochronous telephony service and concurrent broad fixed location dodwn link from network to customer isochronous service. The down link broadband service may be combined with narrowband up link service to provide non-symmetric duplex operation or services such as interactive video.

Abstract: An integral transformer/rectifier component includes a lead frame having terminals for connecting to conductors of a circuit substrate. A transformer primary and secondary winding is mounted on the lead frame and a rectifying diode is mounted on the same frame and is directly connected to a winding terminal end of the secondary winding, The transformer windings and diode are encapsulated in a thermoset plastic. A terminal end of the diode is extended beyond the encapsulation and used as an output terminal of the integral transformer/rectifier component.

Abstract: A highly accurate apparatus and method of predicting remaining capacity Q and reserve time t of a discharging battery to a selected end voltage is determined by an arrangement considering the open circuit voltage, battery voltage, battery temperature and its internal resistance. The remaining battery capacity Q is determined from the difference between the battery full charge open circuit voltage Eoc and the voltage loss due to the internal resistance of the battery IRint and the battery voltage on discharge divided by the battery temperature T, which is the temperature-corrected battery overvoltage.

Abstract: A battery charging system controls and modifies the output voltage of the charging rectifier in response to differing temperature ranges of the battery. At a low range of temperatures starting at a low temperature (e.g. within a range of 0 to 25.degree. C. to about 53.degree. C.) the rectifier voltage decreases as the temperature increases to prevent charging current from rising as the battery temperature increases. This change is performed in accord with a linear graphical slope relating the change of charging voltage to temperature. A suitable charging voltage decrease rate may be 3 mV/.degree. C./cell with a range of 1.5 mV/.degree. C./cell to 5 mV/.degree. C./cell being acceptable. Reduction of the charging voltage within this range reduces the aging effect of high temperature operation of the battery. The charging voltage applied to the battery is held at a constant value over a subsequent range of temperatures (e.g. 53.degree. C. to 75.degree. C.

Abstract: A bipolar switching circuit converts an applied DC voltage to a low frequency AC voltage by periodically transmitting and inverting the applied DC voltage. The bipolar circuitry in one embodiment includes four switches which are switched in pairs to alternately provide a direct transmission of the input DC voltage and an inverted version of the DC input voltage.

Abstract: A data transmission system includes a low bandwidth two way transmission network which is employed to arrange access to and use of a wide bandwidth bearer channel to facilitate the transmission of data at a wide bandwidth enhancing the efficiency of data transmission. In one embodiment, a low bandwidth telecommunication service is used to set up a wide band channel connection on a wide band telecommunication service to allow the user to communicate high speed data without the necessity of overhead addressing and accessing communications on that channel.

Abstract: A universal wireless radiotelephone communication apparatus is operative in both a first radiotelephone communication system including a first base station having a wide area of coverage, transmitting radiotelephone signals at a first band of frequencies and in a second radiotelephone communication system including a second base station having a localized area of coverage, transmitting radiotelephone signals at a second band of frequencies higher than said first band of frequencies. The second band of frequencies is optimally selected with an offset of less than twice a frequency contained within said first band.

Abstract: In a battery handle two bands of webbed material are each arranged and threaded to independently engage a plurality of slots at opposing ends of a support housing in which a battery is enclosed. Each end includes six slots arranged in pairs of slots. The longitudinal/major axis of the two uppermost slots are at an angle to the horizontal and the major axis of the remaining four slob are substantially horizontal. In another aspect, the band of webbed material is threaded through two or more slots and the ends are joined together. Another technique loops the ends and expands the loop with a mechanical insert to lock it to the support housing.Many variations of the invention will be readily apparent to those skilled in the art which do not depart form the spirit and scope of the invention.

Abstract: A wireless-enabled host electronic equipment includes a built-in antenna and special plug-in receptacles enabling a plug-in wireless communicator to interact with the host and to connect to the built-in antenna for wireless transmission and reception. In accord with the invention the plug-in arrangement is constructed to conform to a standardized plug-in arrangement, such as a PCMCIA standard and to provide additional plug-in capability in addition to the standardized receptacle which does not conflict with the standardized receptacle. The plug-in arrangement is configured to permit use of a plug-in for other purposes in the same standard receptacle.

Abstract: An information system for automatically providing mobile vehicles with information related to their geographical location and to provide routing control information downloaded from a broadcasting or directed cellular call source includes a GPS receiver and associated data storage unit. A cellular packet data receiver is included to receive data with location markers from a transmission source. The data from the data storage unit and the received data with location markers is coupled to a controller module which includes stored program controls to select data relevant to the present geographical location and to provide centralized alerts and local readout in the mobile vehicle of this information.

Abstract: A boost converter includes a snubber with finite but limited losses to minimize active power switching losses and minimize turn-off losses of the boost diode without generating any additional circulating energy losses. An inductor is connected so as to slow turn off of the boost diode and minimize reverse recovery losses. This inductor additionally minimizes the turn-on switching losses of the active power switch of the converter by providing for zero-current turn-on. A series connection of a finite resistor and a second diode is connected in shunt with the inductor/boost diode connection to prevent excessive voltage ringing across the active power switch by clamping its voltage during turn-off. A third diode is connected to the junction of the inductor and boost diode to prevent the voltage across the boost diode from ringing during the on interval of the active power switch.

Abstract: A microcell unit, in a cellular telephone system using digital signal processing BSs, is digitally connected to a macrocell, via a metallic link, such as a twisted pair. The microcell includes a plurality of radio channel units (RCU), to provide voice connectivity to mobile subscribers (MS), which are under control of a radio control complex (RCC) located in the macrocell. Several time slots of the macrocell TDM bus, through which the RCC exerts control of the RCUs, are remoted to the microcell thereby enabling control of the RCUs at the microcell location by the RCC of the macrocell. This remoting action is achieved, via a remote time division multiplex (TDM) circuit pack which enables the RCC to communicate with the RCUs as if they were located within the macrocell.