Fujitsu Corporation

Mamoru Machida

Makoto Yoshida

Nobutsugu Fujino

Yuuta Nakaya

Kazumasa Ushiki

Ichiro Iida

Yusuke Suzuki

Hirokazu Murakami

Masayoshi Moriya

A second transmission power control different from a first transmission power control being performed on a first wireless terminal connected to a wireless base station without a relay station is performed on a second wireless terminal connected to the wireless base station through the relay station.

Wireless base station, wireless communication system, and transmission power control method

A base station includes a communicating unit that relays communication between a network and a mobile terminal that is capable of using plural communication schemes that respectively use differing transmission routes to a network; a measuring unit that measures a delay amount in the transmission route of each of the communication schemes; and a switching unit that among the communication schemes and based on predetermined information that includes the measured delay amount, switches the communication scheme used for relaying the communication.

Base station, control method, and communication system

A base station provided with an interference judging unit judging if an amount of interference which occurs between the base station and a peripheral cell in wireless resources, allocated to a mobile station, is in an allowable range, a registering unit receiving a reception operation for registering a mobile station in a storage device which the base station can access, and a resource control unit allocating wireless resources to only mobile stations which are registered at the registering unit and changing the wireless resources to be allocated to the registered mobile station, when the amount of the interference is not in the allowable range.

Base station, communication system, and wireless resource allocation method

A wireless communication system includes: a plurality of mobile terminals; a plurality of transceivers, each of the transceivers performing wireless communication with a mobile terminal; a plurality of baseband processors which modulates data to be transmitted to one of the transceivers and demodulates data received from one of the transceivers; a switch which switches the connection of the transceivers and the baseband processors; and a controller which calculates an operation rate of the transceivers and the baseband processors, respectively, continues or stops a power supply for driving the transceivers and the baseband processors in accordance with a calculation result of the operation rate, and controls the switch to reconnect the transceivers coupled to one of the baseband processor of which the power supply has been stopped to another baseband processor of which the power supply is continued.

Wireless communication system

An on-vehicle device sends an allocation request for a wireless resource to a roadside device. The roadside device, in response to receiving this allocation request, allocates a roadside-vehicle resource that is a wireless resource for roadside-vehicle communication with the on-vehicle device, and an inter-vehicle resource that is a wireless resource for inter-vehicle communication between on-vehicle devices; and sends the allocation information to the on-vehicle device. The on-vehicle device carries out roadside-vehicle communication with the roadside device using the roadside-vehicle resource identified with the allocation information received from the roadside device, and carries out inter-vehicle communication with other on-vehicle devices using the inter-vehicle resource identified with the allocation information. Thereby, roadside-vehicle communication and inter-vehicle communication can be achieved with higher utilization of wireless resources while avoiding the hidden terminal problem.

Wireless communication method in traffic system, wireless base station, and wireless terminal

A mobile communication apparatus includes a storage unit that stores therein correspondence information correlating area and transmission resource; an area deducing unit that deduces in which area the mobile communication apparatus is located; a selecting unit that selects the transmission resource correlated, in the correlation information stored by the storage unit, with the area deduced by the area deducing unit; and a transmitter that using the transmission resource selected by the selecting unit, transmits data to a second mobile communication apparatus.

Communication system including correlation information correlating area and transmission resource

In a communication method, a wireless base station apparatus periodically sends a reference signal to a mobile station apparatus; the mobile station apparatus selects resources to be used for sending communication data to the wireless base station apparatus based on a receive time when receiving the reference signal first; the mobile station apparatus sends information on selected resources to the wireless base station apparatus, and sends communication data to the wireless base station apparatus using the selected resources; the wireless base station apparatus receives and demodulates the communication data based on the information on the resources sent from the mobile station apparatus.

Communication method, mobile station apparatus and wireless base station apparatus

In order to realize road-road communications, a roadside device is provided with an MS function unit and a BS function unit that have a termination function of a signal. In a case of performing road-road communications, any of plural roadside devices can function as a BS, and others as an MS. In a wireless communication system that only enables wireless communications between MS and BS, road-road communication can be performed. In order to realize vehicle-vehicle communication, an in-vehicle device has the BS function unit and the MS function unit having a termination function of the signal and performs the same operations as the road-road communication. In road-vehicle communication, any of the roadside devices can function as the BS, and other roadside devices and in-vehicle devices are operated as the MS.

Intelligent transport (IT) system using wireless communication between a roadside device and an in-vehicle device

A communication system allocates a discrete line between a base station and each terminal device that allows discrete communication in a time span equivalent to several frames. The communication system includes a base station that has a processing function unit processing a physical layer using a given data format, and terminal devices each using an up-link line allocated by the base station. In the system, the base station and each terminal device communicates with each other by the orthogonal frequency division multiplexing method. The base station sends out a preamble signal cyclically, and has a means that sends out a vacant discrete connection identifier for identifying a vacant up-link line for a terminal device to send data to the base station when the base station receives an up-link line request from the terminal device.

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Kawasaki, Japan

Mamoru Machida