Abstract: In a mobile telephone that includes an internal voltage controlled crystal oscillator clock, a clock error compensation system is provided that dynamically determines and compensates for clock error during periods in which the mobile telephone is asleep. The system drives the control voltage of the clock to one of the clock's voltage limits, at which limit the sleep error of the clock can be expected to occur. This expected sleep error is then added to the number of clocking pulses which, in the absence of any clock error, would correspond to the length of the desired sleep period, to generate a corrected internal time. At the end of the sleep period as determined by the corrected internal time, the mobile telephone reacquires a system timing signal that represents actual system time, and the corrected internal time is then compared to the system time.

Abstract: A cellular telephone that provides the capability of performing Internet telephone calls without the bulk and expense of Internet telephone computer systems. The cellular telephone uses hardware vocoders and communication circuitry already present in the cellular telephone for normal cellular calls to provide the additional Internet telephone functionality.

Abstract: A portable communications device and accessory system which provides full-duplex asynchronous communications between a portable communication device and external accessories over a synchronous digital interface. The system includes a digital signal processor for generating a first synchronous digital voice signal, a UART for generating a first asynchronous data signal, and a microprocessor for generating a synchronous control command signal. The system further includes a first multiplexer for multiplexing the first synchronous digital voice signal and the first asynchronous data signal and the synchronous control command signal onto an interface line. The interface line couples the communication device to the at least one external accessory.

Abstract: A novel and improved method for implementing a high-transmission-rate over-the-air interface is described. A transmit system provides an in-phase channel set and a quadrature-phase channel set. The in-phase channel set is used to provide a complete set of orthogonal medium rate control and traffic channels. The quadrature-phase channel set is used to provide a high-rate supplemental channel and an extended set of medium rate channels that are orthogonal to each other and the original medium rate channels. The high-rate supplemental channel is generated over a set of medium rate channels using a short channel code. The medium rate channel are generated using a set of long channel codes.

Abstract: The wireless system includes one or more payphones from which users may initiate payphone calls. A mobile switching center connects telephone calls initiated from wireless payphones to external telephone systems such as the public switch telephone network (PSTN). To meter charges incurred during the telephone call within an external system, the external system transmits periodic metering pulses to the mobile switching center. Each pulse is representative of a predetermined amount of money associated with the telephone call. The rate at which the periodic pulses are transmitted to the mobile switching center depends upon the current billing rate and may be affected by, for example, the time of day.

Abstract: The mobile telephone system employs a fleet of satellites and a set of gateway ground stations arranged around the globe for handling communications to and from mobile communication subscriber units such as mobile telephones. Signals are transmitted between a subscriber unit and the nearest gateway via one or more of the satellites. The gateway system is configured to process telephone call connection requests from a mobile subscriber unit based upon the location of the subscriber unit. The location of the subscriber unit is employed, for example, to determine how telephone numbers are to be parsed and how to properly route emergency telephone calls to the nearest appropriate emergency service centers. Multiple location mapping schemes are employed to facilitate a determination of the location of a subscriber unit and to assist in routing emergency calls. In one implementation, each location with the service area of the system is mapped into a set of uniformly sized and shaped information cells.

Abstract: A method for determining the position of a mobile station within a cellular telephone system having a plurality of base stations. A signal is transmitted at a low power level from the mobile station. The strength of the signal is then temporarily increased from the low power level to an increased power level, and the signal is temporarily transmitted from the mobile station at this increased power level. While the signal is being temporarily transmitted from the mobile station at the increased power level, the signal is used to make at least a first positional measurement. The position of the mobile station is determined in accordance with the first positional measurement.

Abstract: An apparatus for providing authentication of a mobile station in a wireless communication system. The present invention takes the number dialed by the mobile station user and computes the 24 bit number (AUTH.sub.-- DATA) for authentication in accordance with a hashing function that has the following characteristics. The hashing function takes as its input at least the entire dialed digit string contained in the request for service and the number of digits. In a preferred embodiment, the ordering of the digits affects the result, as well as, the values of the digits. The preferred embodiment of the hashing function also accepts some or all of the mobile station identifier data. The function provides as output a number of suitable size for input to a second calculation of an authentication signature, such as the 24 bits required for AUTH.sub.-- DATA. The output number is created in such a way that there is a minimum likelihood that other sets of dialed digits may create the same result.

Abstract: A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols.

Abstract: A method and apparatus for determining frequency offsets caused by oscillator error or Doppler effects in a user terminal (for example, a mobile wireless telephone) in a communication system. The system (100) includes at least one user terminal (124, 126) and a base station (112), or gateway (120, 122) for communicating with the user terminal (124, 126) through a satellite (116, 118) with predetermined known orbital positions or patterns. A communication signal (130, 132, 146, 148) is precorrected for known Doppler effects, such as between a gateway and a transferring satellite (146, 148), when used, and transmitted to a user terminal. The user terminal (124, 126) determines the signal frequency relative to a reference oscillator (240), and treats any detected difference as resulting completely from Doppler. The frequency difference is either transferred as data in reverse link transmissions (130, 132, 140, 142), or used as a pre-correction factor for such transmissions.

Abstract: An active phase splitter comprises two or more phase shift circuits. Each phase shift circuit comprises a number of active devices and capacitors. For a single-pole active phase splitter, within each phase shift circuit, two active devices are configured as a cascode amplifier. The first active device is configured as a common source amplifier and the second active device is configured as a common gate amplifier. A capacitor is connected across the gate and drain of the first active device to generates the necessary pole-zero pair for the phase shift circuit. The cascode configuration results in the desired transfer function and provides transconversion of voltage input to current outputs. Active phase splitters with two or more poles can be built using the same inventive concept.

Abstract: A method and apparatus for performing an inter-system soft handoff is described. In accordance with the present invention, when a subscriber unit crosses from a first cellular system to a second cellular system, a base station controller determines if sufficient network resources are available to conduct a inter-system soft handoff. If so, the base station controller generates a set of signaling messages that cause call processing resource to be allocated and for the call to be processed at the second cellular system. The base station controller then perform data-selection and data-broadcast for the call by transmitting data to the subscriber unit by way of the second cellular system as well as via one or more base stations to which the base station controller is directly coupled.

Abstract: A novel and improved method and apparatus for automatically selecting the proper data service based on the data being transmitted is described. Either packet data service or modem emulation data service is selected by a wireless subscriber unit based on the data received from a computer system or other digital data system. If an AT dial command is received, the wireless subscriber unit enters modem emulation mode. If packet initialization sequence is received, the wireless subscriber unit enters packet data service mode. In the preferred embodiment of the invention, a packet data initialization sequence is comprised of a pre-flag byte dead time, followed by a flag byte, followed by the reception of any additional data within a post flag time interval.

Abstract: A method and apparatus for performing inter-system hard handoff between communication systems or inter-frequency hard handoff within a CDMA communication system is disclosed. The purpose of this invention is to reduce the probability of dropped calls during inter-system hard handoff. In the event that a hard handoff attempt is unsuccessful, the mobile station will return to the original system with information which the communication system of the present invention uses to assist in the performance of future handoff attempts. Alternatively, with no handoff attempt made, the mobile station monitors the destination system then returns to the original system with information used to assist in subsequent handoff attempts. The information returned from monitoring a CDMA system consists of results of a search for one or more pilots given at offsets in a specific list provided to the mobile station by the base station or a set of offsets based upon a predetermined search algorithm.

Abstract: In a communications network, a network user communicates through a remote unit via at least one base station. The communications network includes a first mobile switching center for controlling communications through a first set of base stations and a second mobile switching center for controlling communications through a second set of base stations. The network also includes a service providing base station controlled by the first mobile switching center and providing service to a first transition coverage area using a first pseudorandom noise code. The first transition coverage area defines a boundary between a first system controlled by the first mobile switching center and a second system controlled by the second mobile switching center.

Abstract: An antenna interface for a wireless communication device is provided which comprises an outer grounded shell and an inner signal shell, separated by an intermediate dielectric shell. Preferably, the interior surface of the inner signal shell is threaded to accept either an antenna securement member, or a test equipment interface connector. With this interface, an antenna can be driven by the inner signal shell, and two-conductor test equipment can be coupled to the wireless communication device via both the inner signal shell and the outer grounded shell.

Abstract: A signal is transmitted at a transmit power and includes a traffic channel transmitted at a traffic channel transmit power, and a pilot channel transmitting at a pilot channel transmit power. The receive energy of the pilot channel is measured, and a decrease power control command is generating when the receive energy is greater than a receive energy threshold. If the receive energy is less than the receive energy threshold, an increase power control command is generated. The power control command is transmitted to the system generating the signal.

Abstract: A method and apparatus providing softer handoff of a mobile unit between sectors of a common base station. A sectorized base station comprises a set of demodulation elements. Each demodulation element may be assigned to a signal from one of a plurality of sectors. The output of the demodulators are combined before the decoding process independent of the sector from which the data originated. This configuration provides improved output data reliability, more stable power control, and more efficient use of resources at the base station.