Abstract: Embodiments describe a method and/or system whereby a secret key in a cryptographic system may be replaced without revealing the secret key. One embodiment comprises creating a first private key and corresponding first public key. A second private key associated with the first private key and a second public key corresponding to the second private key are also created. The second private key is output once such that it can be re-created and the second public key is output when outputting the first public key. The first private key is used for authentication. The method further comprises re-creating the second private key; and using the second private key for authentication. Another embodiment comprises creating a private key and corresponding public key with associated system parameter; outputting the system parameter when outputting the public key; and using the private key for authentication. The method may further comprise creating a new private key using the previous key and the system parameter.

Abstract: A system, apparatus and method for a diverse spectrum antenna is disclosed. The diverse spectrum antenna may comprise a circuit board having a ground plane and a chip antenna including a notch, wherein the chip antenna is mounted on the circuit board at a selected distance from the ground plane.

Abstract: Methods and apparatus are presented for providing local authentication of subscribers traveling outside their home systems. A subscriber identification token 230 provides authentication support by generating a signature 370 based upon a key that is held secret from a mobile unit 220. A mobile unit 220 that is programmed to wrongfully retain keys from a subscriber identification token 230 after a subscriber has removed his or her token is prevented from subsequently accessing the subscriber's account.

Abstract: Stream cipher encryption and message authentication. Stream cipher encryption is performed by generating a keystream at the transmitting end from a state value, applying the keystream to plaintext to generate an encrypted message block having at least a portion of the plaintext converted to ciphertext, and updating the state value as a function of said at least a portion of the plaintext. Stream cipher decryption is performed by generating a keystream at the receiving end from the same state value, applying the keystream to the encrypted message block to convert the ciphertext to plaintext, and updating the state value as a function of the plaintext. Message authentication techniques are also described.

Abstract: Apparatus and methods are disclosed for determining a tolerable propagation delay between a repeater and a base station in a communication system. In one embodiment, a tolerable length of fiber optic cable between a repeater and a base station is determined. More particularly, a desired search window size in time is determined. A maximum fiber optic cable delay value is determined based on the desired search window size. Also, a ratio value of fiber optic cable delay value to fiber optic cable length is then determined. The tolerable length of the fiber optic cable is then determined based on the maximum fiber optic cable delay value and the ratio value.

Abstract: A method and apparatus are disclosed for setting total reverse link gain between a repeater and a base station. The method and apparatus generally comprise setting total reverse link gain between a repeater and a base station comprises determining an operating point for the repeater; establishing a reverse communication link between the base station and a transceiver device within a coverage area of the repeater; determining if an increase in a reverse link gain is substantially equal to an increase in a noise figure of the base station, using a transmit power of the transceiver device; and adjusting the reverse link gain by an amount based on the operating point and based on a difference in reverse link gain values, if the increase in the reverse link gain is substantially equal to the increase in the noise figure of the base station, to set the total reverse link gain.

Abstract: A method for reducing the number of required frequency and time hypotheses to acquire an access transmission in a satellite communication system. By reducing the number of required hypotheses, the amount of hardware required to acquire the access transmission is reduced. The method of the present invention reduces the number of required hypotheses by reducing the range of possible frequency and timing values of the access transmission. The range of possible frequency and timing values is reduced by determining the frequency and time uncertainties over individual satellite beams rather than over an entire satellite footprint.

Abstract: Apparatus and method for selecting an appropriate parameter at decompression are disclosed. In particular, when adaptive block size discrete cosine transform compression is used to compress data, different combinations of sub-blocks can be generated. To decompress the different combinations of sub-blocks, the appropriate parameter is selected based on block size assignment information and the address of data in the data block.

Abstract: Embodiments disclosed allow assigning programs for presentation in a digital cinema system. In one embodiment, a scheduler 180 is implemented to generate a schedule in accordance to which decoding modules 140 control playback of data for presentation in the digital cinema systems. The decoding module 140 may operate in an automatic mode and/or manual mode. In automatic mode, the decoding module 140 controls playback based on the schedule, without user intervention. In manual mode, the decoding module 140 cues the user at the appropriate times to control playback based on the schedule.

Abstract: A duplex radio transceiver, coupled to baseband circuitry and to an antenna, includes a receive chain, a transmit chain and a duplexer. The transmit chain includes filter components that attenuate signals originating from the transmit chain in a receive frequency band by a stop-band attenuation that is approximately equal to or greater than the stop-band attenuation of the duplexer in the receive band. Similarly, the receive chain includes filter components filter components that attenuate signals in a transmit frequency band by a stop-band attenuation that is approximately equal to or greater than the stop-band attenuation of the duplexer in the transmit band. A bias control circuit senses a power level associated with radio signals in the transmit chain and adjusts an amplifier in the receive chain responsive to the power level.

Abstract: A method and apparatus for allowing a mobile station in a wireless network to perform network authentication in association with mobile packet data services. The packet data serving node (PDSN) does not authenticate the mobile station with an authentication server prior to sending a CHAP success message. Rather, a mobile station is authenticated via an authentication server after the PDSN receives an IPCP message indicating whether the mobile station desires to use Mobile IP in the current session. If the mobile station desires to use Mobile IP, the PDSN uses authentication techniques in accordance with Mobile IP protocols. In the preferred embodiment, if the mobile station does not desire to use Mobile IP, the PDSN authenticates the mobile station querying an authentication server with the buffered contents of a previously received CHAP challenge response.

Abstract: A method and apparatus for re-synchronizing a stream cipher during soft handoff. Transmitted quasi-secret keying information is used with a secret key to reinitialize a stream cipher generator located in a base station and a stream cipher generator located in a travelling mobile station. Since the quasi-secret keying information is uniquely determined according to each base station in the wireless telephone system, a base station's quasi-secret keying information and a shared secret key can also be used to create a new key. Thus, as the mobile station travels from one base station to another base station, a unique new key is generated for each base station.

Abstract: Method and apparatus for permitting encrypted communications between two stations which are operable with encryption algorithms that accept encryption keys having work factors with different values, by determining the lower one of the values; providing an initial encryption key having a first work factor value; comparing the first work factor value with the lower one of the work factors when the first work factor value is greater than the lower one of the work factor values, performing a first hash function on the initial encryption key to produce a first output, and deriving from the first output a first intermediate key having a work factor value not greater than the lower one of the work factor values; performing the first hash function on the first intermediate key to produce a second output, and deriving from the second output a final encryption key having a work factor value not greater than the lower one of the work factor values; and using the final encryption key to encrypt communications between the

Abstract: An apparatus, system, and method for providing an audio interface between multiple deskset phones and a single radio antenna unit (RAU). The audio interface includes a transmit path and a receive path. The transmit path carries transmit signals from the multiple deskset phones to the RAU. The receive path carries a receive signal from the RAU to the deskset phones. The transmit path and receive path are electrically isolated from each other.

Abstract: A system and method for controlling transmitted output power of outdoor antenna units coupled to hand held wireless devices. When the antenna unit is operating with wireless network technology it may also be referred to as an outdoor unit. Transmit power level of an information signal is controlled in the outdoor unit by obtaining a control voltage from the hand held unit. The control voltage is used by the outdoor unit, to adjust the power level of the transmitted information signal. The transmit power level is adjusted by the outdoor unit performing the following steps: (1) detecting the transmit power level of the antenna unit, (2) determining whether the transmit power level is equal to a control voltage, and (3) adjusting the transmit power level based on the control voltage if the transmit power level is not equal to the control voltage. The adjustment of the transmit power level is accomplished by a closed loop circuit that maintains a constant loop gain.

Abstract: A control interface protocol governs communications in a satellite telephone system. The satellite telephone system comprises a radio antenna unit (RAU) and a plurality of desksets connected to the RAU. An interface bus connects the desksets to the RAU. The RAU and the desksets communicate with each other by packets. Each packet comprises a start of header (SOH) byte, an address number (ADDR) byte, a command (CMD) byte, an argument (ARG) and a block check character (BCC). The ADDR byte comprises a source and a destination address of the packet. All packets, except negative acknowledgment (NAK) packets from the desksets, are acknowledged by the RAU. The packets originating from the desksets are tagged with an address of the desksets. A packet to a specific deskset includes a destination address. A packet originating from the RAU to all desksets includes a first default address. A packet originating from the RAU to a deskset that does not have an address includes a second default address.

Abstract: The present invention represents an integrated antenna assembly comprising a cellular communications antenna and a satellite communications antenna. Such an antenna assembly can, therefore, be used for communications over either frequency range. A wireless telephone using this assembly can, therefore, operate with either a terrestrial cellular communications system or a satellite communications system. In a preferred embodiment of the invention, the satellite communications antenna is a quadrifilar helix antenna and the cellular communications antenna is a sleeve dipole. The whip portion of the sleeve dipole is positioned axially in the center of the quadrifilar helix antenna. This orientation permits operation in both the satellite and cellular frequency ranges without significant electromagnetic coupling.

Abstract: A dielectric-patch resonator antenna having a resonator formed from a dielectric material mounted on a ground plane with a conductive skirt, and a patch element disposed inbetween. The ground plane and patch are formed from conductive materials. First and second probes are electrically coupled to the resonator for providing first and second signals, respectively, to or receiving from the resonator. The first and second probes are spaced apart from each other. The first and second probes are formed of conductive strips that are electrically connected to the perimeter of the resonator and are substantially orthogonal with respect to the ground plane. A dual band antenna can be constructed by positioning and connecting two dielectric resonator antennas together. Each resonator in the dual band configuration resonates at a particular frequency, thereby providing dual band operation. The resonators can be positioned either side by side or vertically.

Abstract: Transmit power of an external antenna unit coupled to a wireless device is controlled by obtaining an output power measurement of the information signal transmitting from an antenna unit, which when operating with wireless network technology may also be referred to as an outdoor unit. The output power measurement is used by a hand held device, to adjust the power of the transmitted information signal. The output power measurement is determined by obtaining an output power measurement, modulating the power measurement onto a carrier, and transmitting the modulated measurement signal to hand held device. The modulated measurement signal is received by a cradle or hand held wireless device and demodulated. The hand held device uses the measurement to adjust the transmit power of the information signal.

Abstract: A mobile telephone user places a call through the communication system to a position call system when they want their geographic position. The call could be initiated in several ways, such as dialing a number, pressing a programmed key, or selecting from a menu. In response to the call, the position call system obtains the geographic position of the mobile telephone from the communication system. The position call system transfers the geographic position to the mobile telephone over the call. The mobile telephone provides the geographic position to the user. The position call system also transfers billing information to the billing system over communication link.