Hitachi, Ltd.

Godo Kaisha IP Bridge 1

Hitachi Communication Technologies, Ltd.

Go Ono

Kenzaburo Fujishima

Koki Uwano

May Takada

Mikio Kuwahara

Shinya Sasaki

Satoshi Tamaki

Katsuhiko Tsunehara

Kazuma Yumoto

Takehiro Morishige

Hiroshi Kodaka

Kenichiro Tomizawa

It is provided a wireless communication system comprising base stations that transmit data to a terminal with cooperation by the base stations. The terminal communicates with the base stations. The terminal periodically transmits, to one of the base stations, information necessary for data transmission from a single base station out of the base stations. Each of the base stations determines whether the terminal needs data transmission through a cooperation among the base stations, and transmits a cooperation information transmission instruction to the terminal, which includes information necessary to execute the data transmission in order to cooperate among the base stations in the case where it is determined that the terminal needs the data transmission through the cooperation among the base stations. The terminal transmits the cooperation information to the base stations in a case of receiving the cooperation information transmission instruction.

Base station and wireless communication system

The present invention is directed to achievement of a data transmission control to cause base stations to cooperate with one another, taking into account efficient use of radio resources. A wireless communication system, which is an aspect of the present invention, includes: a first base station; a second base station connected via a wired network; and a wireless communication terminal that conducts at least one of single data transmission in which a single base station transmits data and cooperative data transmission in which a plurality of base stations cooperate to transmit data. The base stations notify the wireless communication terminal of a condition indicating a case where the cooperative data transmission can be performed. If the communication quality of the propagation path meets the condition, the wireless communication terminal transmits, to the base stations, information that is required for the cooperative data transmission.

Wireless communication system with multiple base stations cooperating to transmit data

A radio communications system includes at least one terminal communication unit having one antenna that conducts a radio communication with a plurality of terminals; and at least one baseband modem that generates and decrypts a data signal, a cell being configured by at least one of the antenna, wherein the baseband modem divides a radio frequency band used for the radio communication into two or more subbands, generates and decrypts the data signal specific to each of the divided subbands, and allocates the data signal specific to the subband to the terminal communication unit, and wherein the terminal communication unit receives the data signal specific to the subband generated by the baseband modem, and forms the cell of each the subband by the data signal specific to the received subband.

Radio communications system

A wireless IP telephone system including a dynamic address lease server for leasing an IP address to each of terminals and a controller. The controller has information about the IP address, a SIP URI of the terminal, a type thereof, and a function thereof. The information of the controller is dynamically set by a system administrator who manually sets the information or by the dynamic address lease server and the controller which are cooperated. The controller decides an effective period of the address to be leased to each terminal, informs the dynamic address lease server of the fact, and requires the address lease server to release the address which became unnecessary.

Wireless IP telephone system

Mobile terminals have the problem of large packet loss during movement because the mobile terminal has no opportunity to detect movement and generate a new care-of address until a new router advertisement is received, and also cannot register the position in the home agent. The present invention is characterized in including a means to automatically collect network information on access router devices in the vicinity of a particular access router device, and a means to send information in the router advertisement including information on at least one or more adjacent access router devices. The mobile terminal selects an access router device to become the next movement destination, and the most essential characteristic is a means to register the position information beforehand in the home agent.

Communication system, server, router, and mobile communications terminal

Growing community of inventors

Musashino, Japan

Go Ono