Abstract: A portable wireless terminal has a GPS receiver which obtains the position information of the portable wireless terminal from a GPS satellite, a display which displays an image, a storage device which stores an image database in which common coordinates are defined in each of the portable wireless terminals without relying on the resolution of the display, a control unit which creates display screen information on the basis of the position information and the image database, and a wireless communication unit which transmits the display screen information to another portable wireless terminal. The wireless communication unit receives the display screen information transmitted from another portable wireless terminal. The control unit synthesizes the received display screen information with the image database stored in the storage device, to create a display image, and displays the synthesized display image on the display.

Abstract: According to the present invention, all terminals can establish synchronization in a radio communications system formed only of a plurality of mobile terminals. This radio terminal communicates by the time division connection method, and comprises a control portion for synchronizing its transmission/reception timing to that of a group including a plurality of radio terminals.

Abstract: An image transmission device and image reception device capable of quickly displaying zoomed images, even in a system using low-bitrate wireless transmission devices. The image transmission device includes a camera section that captures images, a transmission/reception section that transmits an image captured by the camera section to an image reception device, and an image processing section that performs image processing by changing the image compression ratio such that the time for transmission of images to the image reception device is substantially constant. By changing the image compression ratio such that the image transmission time is substantially constant, zoomed images can be displayed quickly on the image reception device, even in a system using low-bitrate wireless transmission devices.

Abstract: A cordless telephone system including a cordless telephone handset arranged to store or wirelessly transmit a captured image without having a large capacity of secondary battery built-in. The cordless telephone handset includes an imaging section, a secondary battery, a wireless section for transmission of images captured by the imaging section, a storage section for storing images captured by the imaging section, and a power supply circuit that supplies (i) secondary battery power to the imaging section, wireless section, and storage section, and (ii) power required for recording or wireless-transmission of the captured image, to the imaging section, wireless section, and storage section during the time when the secondary battery is charged by a battery charger.

Abstract: It is the objective of the present invention to realize a highly flexible communication system, in which a communication terminal can freely change from master station operating mode to slave station operating mode or vice versa at its own spontaneous request. In order to achieve this objective, a communication terminal of the present invention, by switching from one mode to the other, operates in either master station operating mode for communicating with a plurality of slave stations that constitute a communication system, and also for controlling the communication system, or slave station operating mode for operating as a slave station in response to a control message from a master station. When terminal 2 operating in slave station operating mode needs to operate as the master station, terminal 2 informs terminal 5, which is the master station, of a transition request REQ 1, for making the transition to the master station.

Abstract: Provided is a wireless terminal device and a communications system that is able to maximize the effect of expanding the communication availability range by interposing a virtual base station. The wireless terminal device of this invention is used in a communications system where one terminal in a group of terminals becomes a master station, and the remaining terminals become slave stations. The wireless terminal device with switchable operation modes comprises at least: a standby mode for performing communications within the group and obtaining information regarding a terminal that is able to communicate with its own terminal; a master station mode; and a slave station mode.

Abstract: Provided is a technique to execute stable one-to-N calls in a distributed system without a base station, by solving problems such as overhead due to the switching of the transmission terminal, variations in the combinations of terminals that can communicate with one another, and transmission collisions. The wireless terminal device of this invention operates either as a master station for transmitting data during a first time slot and receiving data during a second time slot, or as a slave station for transmitting data during the second time slot and receiving data during the first time slot. When the wireless terminal device of this invention operates as the master station, it comprises: a first unit for transmitting data input at its own terminal to another terminal; a second unit for, upon receiving data input at another terminal, transmitting the data to another terminal; and a switching unit to exclusively work the first and second units.

Abstract: According to the present invention, all terminals can establish synchronization in a radio communications system formed only of a plurality of mobile terminals. This radio terminal communicates by the time division connection method, and comprises a control portion for synchronizing its transmission/reception timing to that of a group including a plurality of radio terminals.