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    Sharing resource access based on location classes
    24.
    发明专利
    Sharing resource access based on location classes 未知

    公开(公告)号：GB2399991A

    公开(公告)日：2004-09-29

    申请号：GB0307157

    申请日：2003-03-28

    Applicant: MOTOROLA INC

    Inventor： SERFATY SALOMON ,  SHAHAF MARK

    IPC: H04W74/08 ,  H04W84/08 ,  H04Q7/36

    Abstract: Mobile stations are assigned to a location class depending upon their position relative to a fixed terminal. Random access opportunities for resource access are dynamically adjusted based upon the number of attempts made in a given period of time. The resource may be a communications channel for control, speech, text, picture or video information. The fixed termianl may be a base transceiver. The random access opportunities for each location group are provided in given slots or sub-slots of a TDMA system, and may be in neighbouring frequency bands. The location classes may be "near" and "far." The mobiles may determine their own position and assign themselves to the relevant position class, based upon the path loss.

    Radio transceiver unit and a system for control and application of communications
    27.
    发明专利
    Radio transceiver unit and a system for control and application of communications 未知

    公开(公告)号：GB2379361B

    公开(公告)日：2003-11-05

    申请号：GB0121236

    申请日：2001-09-01

    Applicant: MOTOROLA INC

    Inventor： NOCHAM GABI ,  SHAHAF MARK ,  RAFY CARMON

    IPC: H04W12/00 ,  H04L9/08

    Abstract: A radio transceiver unit for use in a radio communications system and operable in a direct mode of operation (DMO), the radio transceiver unit comprising: means for receiving encrypted information including a communication encryption key for use in direct mode communications; means for processing the received encrypted information to derive the encryption key included therein; and means for conducting encrypted direct mode operation using the communication encryption key. A system including a processor and a method of operating the system to provide the encrypted information to enable a user to undertake secure DMO communications is also disclosed.

    Detecting interference in a downlink communication channel
    28.
    发明专利
    Detecting interference in a downlink communication channel 未知

    公开(公告)号：GB2381159A

    公开(公告)日：2003-04-23

    申请号：GB0124888

    申请日：2001-10-17

    Applicant: MOTOROLA INC

    Inventor： SHAHAF MARK ,  CARMON RAFAEL ,  SERFATY SALOMON

    IPC: H04B17/00 ,  H04W24/00 ,  H04M3/26 ,  H04Q7/34

    Abstract: A base transceiver 3 used for radio communication with one or more distant transceiver units 5 (mobile stations) is operable to apply a downlink interference detection mode wherein (i) the base transceiver periodically generates and sends a test signal to the one or more distant transceiver units; (ii) the base transceiver senses whether or not a response signal is sent, possibly within a predetermined time interval, by a distant transceiver in response to receipt of the test signal; and (iii) if no response signal is detected the base transceiver generates an interference detection signal. The base transceiver may further issue an auxiliary control signal to a receiver to initiate identification of the interference level on the downlink channel and possibly distinguish between the following interference conditions: (i) the downlink transmitter has a fault causing noise, (ii) the downlink transmission is subject to interference or (iii) no distant transceiver has received the transmitted test signal. Furthermore the base transceiver may send an interference detection signal to a system controller 7 which may in response change one of its operating parameters to avoid the interference. A method of operation of the base transceiver and a transceiver for use as the distant transceiver are also described.

    Encrypted direct mode operation (DMO) in a radio communication system
    29.
    发明专利
    Encrypted direct mode operation (DMO) in a radio communication system 未知

    公开(公告)号：GB2379361A

    公开(公告)日：2003-03-05

    申请号：GB0121236

    申请日：2001-09-01

    Applicant: MOTOROLA INC

    Inventor： NOCHAM GABI ,  SHAHAF MARK ,  RAFY CARMON

    IPC: H04W12/00 ,  H04L9/08

    Abstract: A user of a mobile station in a radio communications system such as a TETRA (Trans-European Trunked Radio) system purchases and receives encrypted information including an encryption key for use in direct mode communication with another mobile station. The encrypted information may also contain the identity of the mobile station, an amount of purchased direct mode service time and the channel frequency to be used. The user enters the information into the mobile station which processes it to obtain the key and store it in memory. The processing may employ a provisioning key which may be a previously used key to obtain the encryption key. The mobile station may be part of a group of mobile stations authorised to communicate using the encryption key. In order to understand mobile stations using an old key, the previously used encryption key is retained in memory.

    Handover criteria for mobile transceivers
    30.
    发明专利
    Handover criteria for mobile transceivers 未知

    公开(公告)号：GB2377130A

    公开(公告)日：2002-12-31

    申请号：GB0116004

    申请日：2001-06-29

    Applicant: MOTOROLA INC

    Inventor： SHAHAF MARK ,  SERFATY SALOMON ,  GLAZER NIMROD

    IPC: H04W36/32 ,  H04Q7/38

    Abstract: A mobile radio communications transceiver M1, M2, M3, which is operable in a communications system to communicate with one of a plurality of base transceivers B1, B2, B3 etc. in a cellular network, the mobile transceiver operable to receive signals from candidate base transceivers within its range of possible communication and to extract and compare information from the received signals to select one of the base transceivers with which the mobile transceivers is to communicate with, if necessary by handover from the currently selected base transceiver, wherein the mobile transceiver is operable so that the information extracted and compared includes information describing estimates of the distances from the mobile transceiver to the candidate base transceivers. Furthermore the mobile transceiver may use information about both the distance to and quality of service of (for example signal strength) the base transceivers to compile and maintain a preference table of candidate base transceivers. Furthermore the mobile transceiver may calculate a rating value based on signal strength and distance measurements of each of the base transceivers to determine their ranking in the preference table.

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