Patents Represented by Attorney, Agent or Law Firm Raymond J. Warren
  • Patent number: 6393127
    Abstract: Encryption keys are transferred by obtaining a public and private key pair (42, 65) from a source device (21, 61). The public key is transmitted (42, 65) from the source device (43, 66) to a target device (23, 62). The target (23, 62) obtains a traffic key (44, 67) stored within the target device (23, 62). The traffic key is encrypted (45, 68) within the target device using the public key. The encrypted traffic key is transmitted to the source device (46, 69) where it is decrypted (47, 70) using the private key. The replacement encryption key(s) is(are) encrypted using the traffic key by the source device (48, 71) forming an encrypted replacement key message which contains a target slot identification for each of the replacement encryption keys. The encrypted replacement key message is transmitted to the target device (49, 72) where the replacement encryption key(s) is(are) recovered (50, 73). The replacement encryption key(s) is(are) then stored at the target device in an identified target slot (51).
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: May 21, 2002
    Assignee: Motorola, Inc.
    Inventor: Dean H. Vogler
  • Patent number: 6212382
    Abstract: A method of performing a handover as shown in FIGS. 2-3 for a mobile station in a multicellular environment including the steps of determining to handover from one of the plurality of microcells to the macrocell, performing handover from the one of the plurality of microcells to the macrocell; and sending a false neighbor list to the mobile station.
    Type: Grant
    Filed: July 14, 1997
    Date of Patent: April 3, 2001
    Assignee: Motorola, Inc.
    Inventors: Andrew Watson, Jonathan Hopkinson
  • Patent number: 5884159
    Abstract: A method of spawning a communication service comprises the steps of detecting (201) a failed call attempt initiated by a first communication unit (101) and directed to a second communication unit (109), and determining (207) if a code associated with the first communication unit (101) is an authorized code associated with the second communication unit (109), wherein the first communication unit (101) is associated with a first user and the second communication unit (109) is associated with a second user. If the code is an authorized code, a communication service is spawned (209), resulting in a message directed at a user other than the second user, such as the first user or a third user, or a communication unit other than the second communication unit (109), such as the first communication unit (101) or a third communication unit (109), which may be associated with a third user other than the first user or the second user.
    Type: Grant
    Filed: November 27, 1995
    Date of Patent: March 16, 1999
    Assignee: Motorola, Inc.
    Inventors: Stuart W. Thro, David E. Morgan, Gary W. Grube
  • Patent number: 5818883
    Abstract: A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).
    Type: Grant
    Filed: July 23, 1996
    Date of Patent: October 6, 1998
    Assignee: Motorola, Inc.
    Inventors: Paul Fielding Smith, John M. Smith, Alan P. Rottinghaus, Shelia Marie Rader, Danny Thomas Pinckley, Yuda Yehuda Luz, Daniel Morris Lurey, Kevin Michael Laird, Tony Kobrinetz, Robert C. Elder, Donald E. Bailey
  • Patent number: 5781857
    Abstract: A user, after accessing (41) the communication system (10), selects (42) a paged email service option. In response, the communication system (10) dispatches (43) a service logic block to a service node proxy (110) of an email system (101-105). The service logic block is deposited (44) in a site-specific service logic block repository (112) of the email system (101-105). An email monitor is established (45) for the email system (101-105). Once established, the email system sends (46) an acknowledgment to the communication system (10). The user is then notified (47) of receipt of the acknowledgment.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: July 14, 1998
    Assignee: Motorola, Inc.
    Inventors: Yeou H. Hwang, Jonathan R. Engelsma
  • Patent number: 5740526
    Abstract: A base site (100) employs a method and apparatus for selecting two of a plurality of antennas (101-106) from which to receive a communication signal. A first signal quality metric is measured for a communication signal received from a first antenna (102) and a second signal quality metric is measured for the communication signal received from a second antenna (103). When the first signal quality metric differs from the second signal quality metric by a threshold, a signal receiver (113) is coupled to a third antenna (e.g., 101) and a third signal quality metric is measured for the communication signal received from the third antenna (101). Based on the three signal quality metrics, a primary antenna and a secondary antenna are selected from which to receive the communication signal.
    Type: Grant
    Filed: June 1, 1994
    Date of Patent: April 14, 1998
    Inventors: Jeffrey D. Bonta, Dennis Ray Schaeffer
  • Patent number: 5732352
    Abstract: A method including the steps of performing a synchronization measurement of a received signal (102), and performing a handoff (110) between a first communication channel and a second communication channel in response to the synchronization measurement. An apparatus including a receiver (50) detecting a received signal over a first communication channel, a receive signal processor (44) responsive to the receiver (50), and a handover controller (40) responsive to the receive signal processor (44). The receive signal processor performs a synchronization measurement of the received signal. The handover controller (40) initiates a handoff between the first communication channel and a second communication channel in response to the synchronization measurement.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: March 24, 1998
    Assignee: Motorola, Inc.
    Inventors: Gerald J. Gutowski, Jeffrey D. Bonta
  • Patent number: 5687189
    Abstract: Noise in an ADPCM signal is muted or suppressed by modifying the magnitude of the ADPCM information during noisy conditions. In one method, the ADPCM data is changed to a predetermined magnitude value. In another method, the magnitude is reduced by a predetermined amount.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: November 11, 1997
    Assignee: Motorola, Inc.
    Inventors: Sybren D. Smith, Paul D. Marko, Craig P. Wadin
  • Patent number: 5678208
    Abstract: A remote power measuring device (1) is used to measure the power output of the transmission system (20). The measured power is then transmitted to a controller (5) and used by the controller (5), along with preset calibration data (41) for each power amplifier (3), to determine power output adjustment factors (22). The adjustment factors (22) are then communicated to the appropriate power amplifier (3) to adjust its output.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: October 14, 1997
    Assignee: Motorola, Inc.
    Inventors: Rolf Ernst Kowalewski, Steven James Fillingim, David Thomas Tennant, Kirby Eric Kirchhoff
  • Patent number: 5678187
    Abstract: A method and apparatus is provided for reducing interference in a radio communication link from a central site (230) to a mobile unit (228) in a cellular communication system. The central site (230) includes a first (202) and a second (216) antenna which serve the geographic region (214) in which the mobile unit (228) is located. The radio communication link may be provided by communicating a signal in a first radio communication channel between the first central site antenna (202) and the mobile unit (228). Similarly, the radio communication link may be provided by communicating a signal in a second radio communication channel between the second central site antenna (216) and the mobile unit (228). A measure of interference in the first radio communication channel providing the radio communication link is determined. The radio communication link is switched, in response to the measure of interference being above a predetermined threshold, from the first to the second radio communication channel.
    Type: Grant
    Filed: June 16, 1995
    Date of Patent: October 14, 1997
    Assignee: Motorola, Inc.
    Inventors: Reuven Meidan, Noam Livneh, Giora Silbershatz, Mordechai Ritz
  • Patent number: 5668875
    Abstract: A method and apparatus for authenticating a roaming subscriber. In a preferred embodiment, a subscriber receives a challenge that is in a format of a local authentication protocol, and determines whether the local authentication protocol is the subseriber's home system authentication protocol. If it is not, the subscriber converts the challenge into a format (e.g., bit length) compatible with its home system authentication protocol, and processes the converted challenge with the subscriber's secret key and authentication algorithm into an authentication response. The authentication response is converted to be compatible with the local authentication protocol, and transmitted to a local system communication unit. The challenge and response is then forwarded to the subscriber's home system for similar conversion and processing, and subscriber's response is compared against a home system generated response.
    Type: Grant
    Filed: July 15, 1996
    Date of Patent: September 16, 1997
    Assignee: Motorola, Inc.
    Inventors: Daniel Peter Brown, Louis David Finkelstein
  • Patent number: 5649299
    Abstract: A digital radiotelephone system employs vocoders to convert between analog speech and a digital format suitable for transmission via radio. Under most circumstances, the highest data rate is selected for optimum audio quality. When the system occupancy exceeds a particular threshold, as detected at the fixed site of the system, some or all of the vocoders are instructed to switch to a lower data rate to provide for an increase in the number of communication channels. Further, a portable subscriber unit may autonomously change its vocoder data rate depending upon the charge state of its battery.
    Type: Grant
    Filed: October 27, 1993
    Date of Patent: July 15, 1997
    Assignee: Motorola, Inc.
    Inventors: John W. Battin, Charles N. Lynk, Jr., Kevin M. Laird
  • Patent number: 5640676
    Abstract: In a cellular communication system (40) a handoff candidate list is generated for a source sector (51) by eliminating (12) from a list of potential handoff candidates (52-56) any sectors having an interference parameter exceeding a threshold value. The list is further reduced by determining (21) a handoff radius (60) and eliminating any candidate sectors (52-56) that fall outside the handoff radius (60). Candidate sectors (52-56) that do not have overlapping coverage areas are also eliminated (23). In addition, candidate sectors (52-56) having a relative angle of sight to the source sector (51) that exceeds a maximum angle are also eliminated (24). Finally, the list is reduced (15) to a preset number of candidates dependent upon the interference parameter.
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: June 17, 1997
    Assignee: Motorola, Inc.
    Inventors: Jeffrey Robert Garncarz, Timothy J. Gallagher, Brent Lane Goldstein
  • Patent number: 5629934
    Abstract: A transmitter transmits the desired signal using a continuous duty cycle at transmission rates of less than full rate (FIG. 6 ). The energy used in each power control group is related to the transmission rate. By repeating the power control groups, time division diversity (FIG. 6 ) is provided. In the receiver, the received power control groups are analyzed and compared to several levels of energy thresholds (73, 75, 77, 79). The results of the comparisons are converted into a power control signal (74, 76, 78, 80, 81) and returned to the mobile. The mobiles are capable of selecting the appropriate bit (93) and adjusting their power (94). Alternatively, an indicator of the transmission rate can be forwarded (155) in advance of the frame. The receiver compares a power estimate with the threshold for the transmission rate indicated (166).
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: May 13, 1997
    Assignee: Motorola, Inc.
    Inventors: Amitava Ghosh, Kamyar Rohani
  • Patent number: 5627880
    Abstract: In a frequency hopping cellular communication system (40) having a number of base sites (41-48) and using mobile assisted handoff, a method is offered of providing base site identification signals. The method includes the steps of assigning each base site of the number of base sites to a slot of a intersite control frame; and, periodically transmitting, in the assigned slot of the intersite control frame, the identification signal of the base site.
    Type: Grant
    Filed: April 19, 1995
    Date of Patent: May 6, 1997
    Assignee: Motorola, Inc.
    Inventors: Walter Rozanski, Kamyar Rohani
  • Patent number: 5594757
    Abstract: A method and apparatus for digital automatic frequency control includes circuitry for frequency controlling a first information portion of a digital input signal, correlating the output with a known characteristic of the first information portion, and outputting a timing signal and channel estimation signal. The digital input signal is also decimated using the timing signal and frequency controlled into a frequency controlled output signal. This signal is used, along with a signal quality estimate derived from the channel estimation signal and first information portion, to determine an estimated frequency correction signal. The estimated frequency correction signal is used to control the frequency correction steps.
    Type: Grant
    Filed: July 28, 1994
    Date of Patent: January 14, 1997
    Assignee: Motorola, Inc.
    Inventor: Kamyar Rohani
  • Patent number: 5583886
    Abstract: Each of a plurality of transmitters (31-37) transmits (62) one of a plurality of known signals. The known signals being known to a receiver (40). The receiver (40) then measures the known signals (63); and using those measurements, estimates the plurality of channel responses (64). The channel responses are then used to determine a power ratio parameter (65) and a phase correction parameter (66).
    Type: Grant
    Filed: December 3, 1992
    Date of Patent: December 10, 1996
    Assignee: Motorola, Inc.
    Inventors: Kamyar Rohani, Amitava Ghosh, R. Mark Harrison
  • Patent number: 5570343
    Abstract: In order to mitigate problems caused by total or partial failure of a number of sectorised radio channel unit transceivers (RCU) in a base station of a particular cell (16) of a radio communications system, base stations (26, 32) in adjacent cells (14, 20) increase the power transmitted from RCUs controlling sectors adjacent to that particular cell 16, thereby filling the gap in coverage left by the failure of that cell (16).
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: October 29, 1996
    Assignee: Motorola, Inc.
    Inventors: Peter W. D. Bishop, Ian M. Bartlett
  • Patent number: 5559832
    Abstract: An information gap in an ADPCM signal is detected in one or both of a transmitter or receiver. This detection can be accomplished using a voice activity detector. When an information gap is detected, a clock signal to the encoder and/or decoder is interrupted. Alternatively, null frames can be inserted into the encoder and/or decoder. When null frames are used, it is preferable to insert comfort noise into the signal output from the decoder.
    Type: Grant
    Filed: March 16, 1995
    Date of Patent: September 24, 1996
    Assignee: Motorola, Inc.
    Inventor: Kevin M. Laird
  • Patent number: D383116
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: September 2, 1997
    Assignee: Motorola, Inc.
    Inventors: Jeffrey Gerard Hoss, Jeffrey Alan Walter, Jeffrey Apgar