Ntt Docomo, Inc.

Shogo Yabuki

Kazunori Obata

Seigo Harano

Mikio Iwamura

Wuri Andarmawanti Hapsari

Tadashi Uchiyama

Hideaki Takahashi

Tooru Uchino

Kenichiro Aoyagi

Akihito Hanaki

Alf Zugenmaier

Ryouichi Shimizu

Minami Ishii

Hiroyuki Hosono

Takao Someya

Atsushi Fukuda

Yusuke Sasaki

Kosuke Fujino

Hirotsugu Miura

In a state where a mobile station UE is communicating with a radio base station S-eNB supporting 'extended PDCP-SN,' the mobile terminal continues communications even if it performs a reconnection procedure with a radio base station T-eNB not supporting 'extended PDCP-SN.' A mobile communication method according to the invention includes the steps of, when detecting RLF in the bearer in the above-described state, the mobile station UE resetting setting of &#x201c;extended PDCP-SN&#x201d; and establishing a bearer using &#x201c;conventional PDCP-SN&#x201d; by performing a reconnection procedure with a radio base station T-eNB not supporting &#x201c;extended PDCP-SN.&#x201d;

Mobile communication method and mobile station

A radio base station apparatus including a function for determining a transmission power, including: a neighbor cell detection unit configured to detect a neighbor cell that interferes with a target cell that the radio base station apparatus can form; a received power measurement unit configured to measure, for each neighbor cell detected by the neighbor cell detection unit, a received power from the neighbor cell; and a transmission power determination unit configured to calculate, for each band part that overlaps with a transmission band of the radio base station apparatus in transmission bands of each neighbor cell, a sum of received powers for neighbor cells having transmission bands each including the band part, and to determine an interference amount in the target cell based on the sum of received powers so as to determine the transmission power by using the interference amount.

Radio base station apparatus, and transmission power determination method

Even when handover processing to a radio base station T-eNB not supporting 'extended PDCP-SN' is performed on a mobile station UE communicating with a radio base station S-eNB supporting 'extended PDCP-SN,' the communications are continued. A mobile communication method according to the invention includes the steps of: causing a radio base station S-eNB to determine to perform handover processing of a mobile station UE to a radio base station T-eNB not supporting &#x201c;extended PDCP-SN&#x201d; in a state where a first bearer using &#x201c;extended PDCP-SN&#x201d; is established with the mobile station UE, and causing the radio base station S-eNB to create &#x201c;RRC connection reconfiguration&#x201d; which instructs deletion of the first bearer and addition of a second bearer using &#x201c;conventional PDCP-SN&#x201d; and to transmit &#x201c;RRC connection reconfiguration&#x201d; to the mobile station UE.

Mobile communication method

A radio control base station connected to a plurality of switching centers includes a capacity information receiving unit configured to receive capacity information from at least one of the plurality of switching centers, a load information receiving unit configured to receive load information from at least one of the plurality of switching centers, a selection ratio calculating unit configured to calculate a selection ratio for selecting a connection-target switching center to which a call from a mobile station is to be connected based on the received capacity information and the received load information, and a connection-target switching center determining unit configured to determine the connection-target switching center based on the calculated selection ratio.

Radio control base station and method of determining connection-target switching center

A radio communication system includes at least one user equipment, base stations, and a control station. After expiration of the timer started after establishment of the data bearer, the base station selects the access point base station for the user equipment on the basis of the voice congestion levels and indicates the access point base station to the user equipment if the voice bearer has been established, and selects the access point base station for the user equipment on the basis of the data congestion levels and indicates the access point base station to the user equipment if the voice bearer has not been established.

Radio communication system and base station

A radio base station determines at least any one type of subframe constituted of multiple system information subframes for sending system information to a mobile station, paging subframes for sending paging messages for the mobile station in idle mode, or on-duration subframes corresponding to on-durations at which the mobile station receives downlink control channel signals in discontinuous reception mode for the downlink control channel signals. The radio base station allocates, to the mobile station, inter-frequency measurement periods for inter-frequency measurement at the mobile station, while avoiding simultaneous occurrence of inter-frequency measurement periods and the subframes determined by the subframe determiner.

Radio base station

A base station is disclosed. The base station includes: a reconnection setting information generation unit configured, in a case where handover is requested from a first base station, after a reconnection request signal is received from a mobile apparatus, to generate reconnection setting information to be used for specifying the mobile apparatus; a transmission unit configured to transmit a reconnection request signal to the first base station; a receiving unit configured to receive reconnection setting information to be used for specifying the mobile apparatus from a second base station that is a destination of handover of the mobile apparatus after the second base station receives a reconnection request signal from the mobile apparatus; a reconnection setting information holding unit configured to hold the reconnection setting information; and a connection processing unit configured to perform reconnection processing with the mobile apparatus by using the reconnection setting information held in the reconnection setting information holding unit in accordance with a reconnection request signal from the mobile apparatus after initial connection processing between the second base station and the mobile apparatus.

Base station and method

A base station includes a radio communication unit () configured to wirelessly communicate with a mobile apparatus capable of communicating in both a first mobile communication system and a second mobile communication system and a network communication unit () configured to communicate with a switching station in the first mobile communication system, and if a line setup instruction signal (Initial Context Setup Request) received at the network communication unit from the switching station is not due to initial access to the switching station by the mobile apparatus, the radio communication unit receives mobile apparatus capability information in the second mobile communication system (UE-UTRA-Capability) from the mobile apparatus after transmitting a line setup response signal (Initial Context Setup Response) to the switching station.

Base station and method to acquire capability of mobile apparatus in mobile communication system

A mobile communication method according to the present invention including the steps of: generating, at a mobile station (UE), first verification information by use of a first key, a first parameter and an algorithm for 'Integrity Protection'; generating, at the mobile station (UE), second verification information by extracting predetermined bits of the first verification information; and performing, at the mobile station (UE), cell selection processing, and transmitting, from the mobile station to a radio base station that manages the selected cell, an RRC-PDU for RRC connection re-establishment request through a common control channel, upon detection of a radio link failure in an RRC connection, the second verification information being set in the RRC-PDU for RRC connection re-establishment request.

Mobile communication method, mobile station and radio base station

A base station apparatus including a reconnection request signal receiving unit configured to receive a reconnection request signal transmitted from a mobile apparatus, the reconnection request signal being for the mobile apparatus requesting reconnection to the base station apparatus, a status detection unit configured to detect whether a status of the mobile apparatus immediately before transmitting the reconnection request signal corresponds to a status where a frequency band measurement period is activated, the frequency band measurement period causing the mobile apparatus to measure a frequency band different from a frequency band for a radio access technology for use in radio communication between the mobile apparatus and the base station apparatus, a response signal generation unit configured to generate a response signal to the reconnection request signal, the response signal generation unit generating, if the status detection unit determines that the frequency band measurement period is activated, the response signal including an indication signal for causing the mobile apparatus to activate the frequency band measurement period and a response signal transmitting unit configured to transmit the generated response signal to the mobile apparatus is disclosed.

Base station apparatus and method

A mobile communication method according to the present invention is to communicate between a mobile station (UE) and a radio base station (eNB) by using a certain key generated using a first key. The mobile communication method includes the steps of: updating, at the mobile station (UE), the first key upon receiving a handover command signal from the radio base station (eNB); transmitting, from the mobile station (UE) to the radio base station (eNB), a handover complete signal by using the certain key generated using the updated first key; and performing, at the mobile station (UE), a cell selection processing when failing to transmit the handover complete signal and detecting a radio link failure, and transmitting, from the mobile station to a selected re-establishment target cell, a re-establishment request signal by using the first key before being updated.

A mobile communication method according to the present invention communicates between a mobile station (UE) and a radio base station (eNB) by using a certain key. The method includes the step of: (A) acquiring, at a radio base station managing a re-establishment target cell for the mobile station (UE), a first key (K) for generating a certain key from a switching center (MME) in a procedure for re-establishment of the mobile station (UE), the certain key to be used for communication between the mobile station (UE) and a next re-establishment target cell for the mobile station (UE).

Growing community of inventors

Tokyo, Japan

Shogo Yabuki