Ntt Docomo, Inc.

Takeshi Terayama

Hiroyuki Hosono

Takeshi Okamoto

Takaaki Sato

Takahiro Hayashi

Masafumi Masuda

Rie Nagato

Takayuki Tsuneda

A radio network controller includes an acquisition unit configured to acquire a radio communication state of a neighboring cell located around a cell formed by a base station which the mobile station camps on among base stations, and a level determination unit configured to determine the in-out reception level based on an acquisition result of the radio communication state by the acquisition unit. The level determination unit calculates an estimated reception level of the radio channel in a reception level tie point P in which the reception level of the radio channel transmitted by a base stationand the reception of the radio channel transmitted by a target base stationbecome substantially equal to each other, and determines the in-out reception level based on the calculated estimated reception level &#x3b1;.

Mobile communication system, base station, and mobile communication method

A mobile communication systemincludes a selection unitconfigured to select a transition target frequency from the plurality of frequencies when a condition under which a mobile communication terminal not utilize a transition source frequency being any of the plurality of frequencies is fulfilled, and an instruction unitconfigured to instruct the mobile communication terminal to perform a transition to the transition target frequency selected by the selection unit. The selection unitexcludes the transition source frequency from a frequency candidate to be utilized by the mobile communication terminal until an elapsed time after the instruction of the transition to the transition target frequency exceeds a predetermined time.

Mobile communication system, network apparatus, and mobile communication method

A radio controllerincludes a transmission power acquisition unitconfigured to acquire a neighboring cell transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the neighboring cell, an offset determination unitconfigured to determine a power offset of the neighboring cell to be added to the predetermined transmission power value, based on a difference between the predetermined transmission power value and the neighboring cell transmission power value acquired by the transmission power acquisition unit, and an offset notification unitconfigured to notify the power offset determined by the offset determination unit to the mobile station.

Mobile communication system, radio controller, base station, and mobility control method

A radio controllerincludes an acquisition unit configured to acquire a radio communication state of a neighboring cell around the cell formed by a base station, and a threshold determination unit configured to determine an in-out threshold based on an acquisition result of the radio communication state by the acquisition unit. The threshold determination unit calculates an estimated overall reception level within a frequency band at a point at which the reception level of the common control channel transmitted by the base stationbecomes the highest in the cell formed by the base station, based on the reception level of the common control channel and the overall reception level, and determines the in-out threshold based on the calculated estimated overall reception level.

A base station outputs annunciation information which corresponds to a plurality of radio cells established by a 3G public base station and an LTE public base station and which is different from annunciation information output from the 3G public base station and the LTE public base station into a target region X and forms a radio cell. A mobile station that enters the radio cell receives the annunciation information of the radio cell and executes a position registration process. An information administration device can thereby find the mobile station based on the position registration process even in the environment where a plurality of radio cells to which different frequencies are assigned are established geographically overlapping with one another.

User information administration system and user information administration method

A transmission power determination system configured to control a transmission power of a radio signal transmitted by a small base station in a mobile communication network including a general base station forming a predetermined cell and the small base station forming a small cell smaller in size than the predetermined cell, the transmission power determination system comprising: a reception power acquisition unit configured to acquire a reception power of a radio signal from one of a different small base station or the general base station, which can be received by the small base station; a determination unit configured to determine one of the different small base station and the general base station which transmits the radio signal acquired by the reception power acquisition unit; a pathloss value calculation unit configured to calculate, when it is determined by the determination unit that the radio signal is transmitted from the different small base station, pathloss value between the different small base station and the small base station based on a difference between a transmission power of the radio signal from the different small base station and the reception power of the radio signal from the different small base station acquired by the reception power acquisition unit; and a transmission power determination unit configured to determine the transmission power of the radio signal transmitted by the small base station, based on the pathloss value calculated by the pathloss value calculation unit.

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Tokyo, Japan

Takeshi Terayama