Ntt Docomo, Inc.

Nec Corporation

Yoshitsugu Shimazu

Masayuki Motegi

Takehiro Nakamura

Yasuhiro Kato

Wuri Andarmawanti Hapsari

Mikio Iwamura

Seizo Onoe

Daisuke Koizumi

Naoki Nakaminami

Hideaki Takahashi

Toshifumi Sato

Hiroki Tanaka

Motoya Iwasaki

Kohei Kiyoshima

Tatsuro Yajima

Masahiro Yamato

Atsushi Tsuyuki

Provided are a radio communication system, a radio base station and a communication method which enable an inter base-station handover while reducing a processing load on a core network. An eNBsends a handover request which requests an inter base-station handover of a UEfrom the eNBto an eNBvia an inter base-station transmission path. The eNBreceives the handover request from the eNB, and completes the handover of the UEfrom the eNBto the eNBby using a communication path to the UEvia a highway between an MMEand the eNBand the inter base-station transmission path.

Radio communication system, radio base station and communication method

In a mobile communication system according to the present invention, an AP/ULP layer of a transmission-side node (A) is configured to acquire, from a SCTP layer of the transmission-side node (A), a 'rwnd' for each connection of the SCTP layer, a 'cwnd' for each physical path, and a third data amount indicating an amount of data transmitted within a unit time by the transmission-side node (A) for each stream; and when an urgency flag is included in data subject to transmission, the AP/ULP layer of the transmission-side node (A) is configured to determine a stream and a physical path through which the data subject to transmission should be transmitted, based on the &#x201c;rwnd&#x201d;, the &#x201c;cwnd&#x201d;, and the third data amount, and to notify, to the SCTP layer, the determination.

Mobile communication system and transmission-side node

A multiplexing/demultiplexing device has a phase difference detection part for detecting a phase difference from a reference frequency of a multiplexed signal and a reference frequency of each of input/output lines, an interpolation part for performing an interpolation on a digital transmitting/receiving signal of each of the input/output lines with a signal delayed by time corresponding to the phase difference for each of the input/output lines based on the phase difference detected by the phase difference detection part to obtain a digital transmitting/receiving signal sampled with the reference frequency of the multiplexed signal for each of the input/output lines, and a signal multiplexing/demultiplexing part for performing a multiplex/demultiplex of the digital transmitting/receiving signals of the input/output lines with use of the reference frequency of the multiplexed signal.

Signal multiplexing method, signal demultiplexing method, digital signal reference frequency correction method, multiplexing device, demultiplexing device, radio communication system, and digital signal reference frequency correction device

A handover method according to the present invention includes the steps of: forwarding, at a handover-source radio base station (eNB), user data (A) for a mobile station (UE) to a handover-target radio base station (eNB) when it is determined that a handover processing is to be performed, the user data (A) being stored in the handover-source radio base station (eNB); activating, at the handover-target radio base station, a predetermined timer when transmitting a path switch request to a path control apparatus, and storing second user data for the mobile station received from the path control apparatus until the predetermined timer expires; and forwarding, at the handover-target radio base station, the stored second user data to the mobile station after the predetermined timer expires.

Handover method and radio base station

A plug-and-play radio base station autonomously establishes X2 logical interfaces and S1 logical interfaces with existing base stations and upper nodes. A new radio base station which is installed in a network advertises an IP address of the new radio base station over a transport network. An existing radio base station or an upper node which receives the IP address detects the number of hops from the new radio base station to the existing radio base station or the upper node. An initial logical interface with the new radio base station is established when the detected number of hops is below a predetermined threshold.

Logical interface establishing method, radio base station, and communication management apparatus

A radio base station (T-eNB) is configured to set up a data forwarding tunnel for forwarding user plane data to the radio base station (T-eNB) only for an access bearer for which the user plane data to be forwarded exists, when receiving a notification from a handover-source radio base station (S-eNB) as to whether or not the user plane data to be forwarded exists for each access bearer. The notification being made by using a handover request message for the mobile station (UE), and the access bearer being set up between the radio base station (T-eNB) and a upper level node (SGW).

Mobile communication method and radio base station

A shared transmission/reception apparatus (OF-TRX) includes: a transmission/reception processor section (TRX-B) for a mobile communication system B configured to perform frequency conversion processing on a transmission baseband signal for the mobile communication system B outputted from a signal converter section (E/O), and to output a transmission radio frequency signal for the mobile communication system B; a power level adjuster section (VA) configured to adjust a power level of a transmission radio frequency signal for a mobile communication system A inputted from a transmission/reception processor section (TRX-A) for the mobile communication system A; a combiner section (COM) configured to generate a transmission radio frequency signal by combining the transmission radio frequency signal for the mobile communication system A outputted from the power level adjuster section (VA) and the transmission radio frequency signal for the mobile communication system B outputted from the transmission/reception processor section (TRX-B) for the mobile communication system B; and a common amplifier section (PA) configured to amplify a power level of the transmission radio frequency signal outputted from the combiner section (COM) at a predetermined amplification rate, and to output the resultant signal.

Radio base station apparatus

A trace reporting method, in which a user terminal reports to a tracking area management apparatus a trace along which the user terminal has moved in a mobile communication system, includes the steps of storing, by the user terminal, identifiers of base stations where the user terminal has performed cell selection in an identifier storage unit; and reporting, by the user terminal, to the tracking area management apparatus the identifiers stored in the identifier storage unit upon communicating with a base station. The tracking area management apparatus may compare the reported identifiers with a prestored pattern and assign a tracking area to the user terminal based on the comparison.

Trace reporting method, tracking area assigning method, user terminal, base station, and tracking area management apparatus

A shared AMP includes: a transmission/reception processor section (TRX-B) for a second mobile communication system configured to perform frequency conversion processing on an inputted transmission baseband signal for a mobile communication system B, and to output a transmission radio frequency signal for the second mobile communication system; a power level adjuster section (VA) configured to adjust a power level of an inputted transmission radio frequency signal for a first mobile communication system; a combiner section (COM) configured to generate a transmission radio frequency signal, by combining the transmission radio frequency signal for the first mobile communication system outputted from the power level adjuster section (VA) and the transmission radio frequency signal for the second mobile communication system outputted from the transmission/reception processor section (TRX-B) for the second mobile communication system; and a common amplifier section (PA) configured to amplify a power level of the transmission radio frequency signal outputted from the combiner section (COM) at a predetermined amplification rate, and to output the resultant signal.

An upper node and a handover source radio base station store setup information on an access bearer having been set up between the upper node and the handover source radio base station. A mobile communication method according to the present invention includes the steps of: (A) informing, from the handover source radio base station to a handover target radio base station, the access bearer setup information; (B) storing, at the handover target radio base station, the access bearer setup information informed of by the handover target radio base station; and (C) setting up, at the upper node, an access bearer between the upper node and the handover target radio base station by using the stored access bearer setup information without performing reallocation processing of new access bearer setup information, the access bearer being set up in response to a path switching request from the handover target radio base station.

Growing community of inventors

Kawasaki, Japan

Yoshitsugu Shimazu