Hitachi, Ltd.

Kokusai Electric Co., Ltd.

Hitachi Communication Technologies, Ltd.

Arata Nakagoshi

Hiroshi Kuwahara

Hideya Suzuki

Yoshinobu Yamamoto

Isao Shimbo

Yoshihiro Kondo

Nobuo Tsukamoto

Masayasu Suzuki

Hiroshi Noguchi

Tetsuo Takemura

Tsuneo Furuya

Mitsuhiro Wada

Yoshiaki Hasegawa

Shinichi Iwaki

Yoshihiro Kanomata

Yutaka Fukushima

Yumiko Watanabe

Shinya Oota

Atushi Hoshi

Kouichi Ohta

Hirofumi Udaki

Masao Wanami

Mitsuyoshi Hashida

Takao Inoue

Kazuhiro Suzuki

Toshiro Suzuki

Shiro Mazawa

Manabu Yoshimura

Kazuo Yamakido

Kenzo Urabe

Izumi Horikawa

Jiroh Sakaguchi

Yukinari Fujiwara

Yasuaki Kinoshita

Hideo Aoe

Masahiro Koya

Takafumi Kojima

Michio Iguchi

Tsutomu Sano

Yohichi Ogawa

Naoki Tsubaki

Takakuni Kuki

Noriyuki Sugiura

Michiaki Kurosawa

Isamu Mitomo

Takao Harakawa

Masato Horaguchi

Toshikazu Sasa

Ichiro Kohashi

Hideo Nakasawa

In a case where a cellular phone exists outside a WOS system service area, the cellular phone receives a not-connectable signal and an audio message from a mobile switching controller. The cellular phone conducts disconnection processing with the not-connectable signal as a turning point. Moreover, the cellular phone stores an extension number and converts a dedicated special number into an external number for retransmission, thus establishing connection to a PBX. After the reception of a connection-accepted signal and an automatic exchange answer message from the PBX, the cellular phone automatically transmits the stored extension number.

Cellular phone and mobile switching controller

The normality verification and radio characteristics test of a radio communication system are executed. RF-SWs (radio-frequency coaxial switches) change-over the paths of signals which are transmitted to and received from an access terminal function portion included in an access point. RF-SWs connect the access terminal function portionwith a desired one of radio analog portions. A test function controller controls the changeover operations of the RF-SWs in accordance with information designated by a maintenance apparatus (OMC). An access point controller controls in accordance with received test sort information, one or more of (1) an antenna failure test, (2) a receiver failure test, and (3) a transmitter failure.

Radio access point testing method and testing apparatus

The normality verification and radio characteristics test of a radio communication system are executed. RF-SWs (radio-frequency coaxial switches) change-over the paths of signals which are transmitted to and received from an access terminal function portion included in an access point. RF-SWs connect the access terminal function portion 122 with a desired one of radio analog portions. A test function controller controls the changeover operations of the RF-SWs in accordance with information designated by a maintenance apparatus (OMC). An access point controller controls in accordance with received test soil information, one or more of (1) an antenna failure test in which a voltage surface wave ratio is evaluated on the basis of the transmission power of the access terminal function portion, (2) a receiver failure test in which, after a packet error rate has been adjusted, a reception sensitivity is evaluated based on the transmission power of the access terminal function portion, and (3) a transmitter failure test in which transmission power from any of the radio analog portions is evaluated based on the reception power value of the access terminal function portion.

In data communication using radio communication, an inactivity timer value is changed according to various states, so that an unused time of a communication channel in a non-communication time is decreased, and channel use efficiency is raised. A unit for judging an application of packet data to be transmitted and received by a radio base station/a radio base station controlleris provided, or an inactivity timer value is set through a port number in TCP/UDP header and a traffic pattern and according to a communication content, and the set inactivity timer value is used to control a change from a connected state to a dormant state.

Radio base station/radio base station controller equipped with inactivity timer, mobile station, and state control method

In an interleaver for use in a turbo decoder, a deinterleaver, or an interleaver for use in a turbo encoder, an offset is set based on previously determined thresholds in accordance with symbol numbers generated by a counter. A symbol numbers inputted immediately before generating an address is corrected with the set offset, and the corrected symbol number is converted to generate an interleave read address.

Turbo decoder, turbo encoder and radio base station with turbo decoder and turbo encoder

A radio communication system and a traffic channel assignment method for realizing the assignment of traffic channels capable of improving the efficiency of use of frequency in the case where the traffic density is high and improving a radio link quality in the case where the traffic density is low. A base station judges the traffic density from a carrier to interference power ratio (CIR) on each channel capable of being selected as a traffic channel. In the case where the traffic density is low, a traffic channel assignment mode selecting an available channel having a greater CIR is assigned as a traffic channel to a mobile station. In the case where the traffic density is high, a traffic channel assignment mode selecting an available channel having a smaller CIR is assigned as a traffic channel to the mobile station. Thereby, it is possible to structure a radio communication system which can cope with the condition of the traffic density of the neighborhood.

Traffic channel assignment based on traffic density and signal quality

Duplicate optical fibers connect between a base station controller and a radio base station for each route. The duplicate optical fiber is connected to each of the radio base stations for each route through a star coupler. The radio base stations are arranged in each of areas so that the radio base stations for different routes are arranged adjacent to each other.

Portable telephone system

A radio communication system including a network connecting apparatus for establishing communication between a mobile subscriber terminal and another subscriber terminal and a plurality of radio base stations. At least one wired communication line connects the network connecting apparatus to the plurality of radio base stations, and further control signal communication is enabled at least between the plurality of radio base stations and the network connecting apparatus. The radio communication system enables a wider service area with a smaller number of communication lines.

Radio communication system with plurality of wired lines

In a mobile radio communication system employing a time-division multiple transmission scheme, having a plurality of base stations and a plurality of personal stations, an arbitrary base station, when detecting a pilot signal transmitted from any master base station in the mobile radio communication system, acts as a slave base station which does not transmit its pilot signal but transmits and receives a common control signal to and from a personal station utilizing a frequency channel occupied by the pilot signal. On the other hand, when not receiving the pilot signal, the base station searches for an available frequency channel, and acts as a master base station which transmits its pilot signal on the available frequency channel to occupy the frequency channel, and transmits and receives the common control signal to and from a personal station on that frequency channel.

Mobile radio communication system employing time division multiple

A diversity receiving apparatus includes a plurality of receivers, each of which receives a plurality of signals and includes a detector which selects and outputs a desired signal from the received signals, and a delay circuit which delays the desired signal to produce a delayed signal. A level comparator compares signal levels of the desired signals outputted from the detectors with one another, and produces an output indicating which one of the desired signals has a highest signal level. A selector responsive to the output of the level comparator selects and outputs the delayed signal produced by the delay circuit delaying the desired signal having the highest signal level. A demodulator demodulates the selected delayed signal. A power controller supplies power to the level comparator and all of the receivers at a preset level comparison period, continues to supply power to the receiver including the detector outputting the desired signal having the highest signal level after the level comparator has finished comparing the signal levels of the desired signals with one another until a next level comparison period, and stops supplying power to the level comparator and all of the receivers except the receiver including the detector outputting the desired signal having the highest signal level after the level comparator has finished comparing the signal levels of the desired signals with one another until the next level comparison period.

Diversity receiving apparatus

With respect to a mobile communication system, intelligence learns a cell boundary where the field strength of adjacent base stations becomes equal, by measuring field strength of communications, and from this data determined and stored over a period of time, the intelligence calculates the position and velocity vector of each mobile unit, from which a priority for hand-off can be determined. Hysteresis of the hand-off is determined with respect to hand-off boundaries located a fixed distance from the measured cell boundary, with hand-off preferably being soft hand-off within the narrow hand-off boundaries. Priority is particularly determined using fuzzy logic and calculation of the time estimated for the mobile unit to reach the cell boundary. Battery consumption of the mobile units is improved by prolonging the interval of checking the position of mobile units, when the mobile units are moving slowly or not moving at all. The determination of the cell boundary is updated continuously, to compensate for environment changes affecting field strength.

Mobile communication switching across cell boundaries

A method of controlling the time constant of a filter for use in a radio receiver which receives a signal, transmitted from a transmitting station at a predetermined period, intermittently at the predetermined period and demodulates and delivers the received signal, a filter circuit having the time constant control function based on the method, and a radio receiver having the filter circuit. Preferably, the filter has its time constant switchable stepwise and specifically, parallel connection of capacitors or shortcircuiting of resistors is controlled by turning on/off switches. A controller within the filter circuit or the radio receiver performs control for applying a predetermined periodical signal (or standard pulse signal) to the filter and controlling the time constant of the filter in accordance with an output signal (or triangular pulse) during a first time zone within each operation interval for the intermittent reception and for filtering the signal from the transmitting station and causing a demodulating circuit to demodulate and deliver a filtered signal.

Method of controlling filter time constant and filter circuit having the

A mobile station, operable in a mobil communication system that executes a location registration processing by using the channel quality of a base station and an information concerning a base station the mobile station includes a base station information memory unit for storing therein information concerning a plurality of base stations and an amount in which the channel quality of the base station is changed with time and a location judging unit for judging on the basis of the amount in which the base station information is changed with time and which is stored in the base station information memory unit whether or not location registration processing is to be executed indicating a location in service area. Whether the location registration processing is to be executed or not is determined in accordance with the moving speed of the mobile station, thereby limiting the occurrence of a location registration request which becomes invalid with a large possibility in a short period of time because the mobile station moves to another location registration area or to the calling area in a short period of time.

Mobile communication system and location registration method in mobile

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Kokubunji, Japan

Arata Nakagoshi