Matsushita Electric Industrial Co., Ltd.

Jun Nagamatsu

Jun Yamada

Masaki Terashima

A microcellular communication system which broadcasts its local channel block, including the control channels allotted from a total channel block to the microcellular system, on all control channels being used by the system. A mobile unit seeking access to the microcellular system initially searches the total channel block in an effort to receive the local channel block information broadcast by the microcellular system. The mobile unit compares received local channel block information with stored total channel block information and replaces its memory content with the newly received information. Periodic searching of stored channel block information is conducted to verify that the mobile unit has the relevant channel block information for the local microcellular system.

Method of use of a control channel in a cellular communications system

In a micro cellular system (MCS) which co-exists with a cellular system (CMTS) in a frequency band, fraudulent use of the MCS when it is moved from the CMTS to the location of another CMTS is prevented by providing a control unit 2 in the MCS which controls the overall operation of the MCS and a system ID receiving and judging unit which is capable of receiving all the downward control channels used in the CMTS. When the system ID receiving and judging unit receives a system ID transmitted from the CMTS which matches a system ID stored in the MTS, the control unit is allowed to start the operations of the MCS. Otherwise, the MCS is disabled. Therefore, if the MCS moves to another CMTS zone where the system ID is different, it is impossible to operate the MCS.

System and method for preventing unauthorized use of a micro cellular

A microcellular communication system which broadcasts its local channel block, comprising the control channels allotted from a total channel block to the microcellular system, on all control channels being used by the said system. A mobile unit seeking access to the microcellular system initially searches the total channel block in an effort to receive the local channel block information broadcast by the microcellular system. The mobile unit compares received local channel block information with stored total channel block information and replaces its memory content with the newly received information. Periodic searching of stored channel block information is conducted to verify that the mobile unit has the relevant channel block information for the local microcellular system.

A method and system for preventing fraudulent use in a cellular system whereby upon establishment of communication with said micro cellular system, a maintenance console transmits an identifier to the control unit of said micro cellular system. The control unit compares the transmitted identifier to a stored value and controls the operation of the micro cellular system based upon said comparison. Operations of the micro cellular system are terminated if said transmitted value does not match said stored value and maintained if a match is found. The control unit additionally includes a time limit timer which is set upon activation of the control unit and is adapted to be reset upon command from the maintenance console, which command accompanies each communication for which access is maintained. Operation of the micro cellular system is terminated when said time limit expires without resetting.

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Kawasaki, Japan

Jun Nagamatsu