Fujitsu Corporation

Tsuyoshi Yoneta

Tetsuo Tachibana

Tetsuo Nishino

Osamu Isono

Ryuji Hyodo

Katsumi Oomuro

Naoyuki Miyamoto

A cellular mobile communication system employs frequency multiplexing as a multiplexing system and adopts a sector configuration for cells. The cellular mobile communication system includes: a device for determining a scheduling turn of a local sector for a downlink scheduler of a base station apparatus; a device for acquiring assigned frequency information about adjacent sectors; a device for assigning a frequency to the local sector while considering the frequencies not used in the adjacent sectors; and a device for notifying about the result of the frequency assignment for the local sector. Thus, the interference between the sectors can be reduced and the frequencies can be effectively used.

Method for reducing interference between adjacent sectors, and base station apparatus

A mobile terminal is connected to both first and second base station devices when handover is performed. Each of the first and second base station devices is connected to an upper level device. The first base station device is authorized to request retransmission of data to the mobile terminal when there is a bit error in an up-link for transmitting data from the mobile terminal to the first base station device. When a bit error is detected in the up-link from the mobile terminal to the first base station device, and no bit error is detected in the up-link from the mobile terminal to the second base station device, the first base station device does not perform retransmission control, and the second base station device transfers the received data to the upper level device.

Communication method used in mobile communication system

A synchronization circuit for ATM cells transferred in an ATM communication system, wherein the synchronization circuit receives and holds in a bit serial manner the input bit trains constituting the received ATM cells by a shift register unit, performs a CRC operation in a bit serial manner on the held input bit trains by a continuous CRC arithmetic unit in accordance with a simplified CRC operation process different from the usual CRC operation process, and performs the necessary synchronization control upon receiving the CRC arithmetic operation result at a synchronization control unit, thereby enabling CRC arithmetic operations to be performed continuously and by simple hardware on the headers in the ATM cells.

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Kawasaki, Japan

Tsuyoshi Yoneta