Abstract: A display control device includes a display controller executing display control to display, on a display screen of a display device displaying an image, a whole of a display target image that is to be displayed and that has an aspect ratio differing from an aspect ratio of the display screen, and to display a partial enlarged image, which is obtained by enlarging a partial image corresponding to a part of the display target image and which has a smaller size than the display screen, at a displayed position of the partial image in superimposed relation to the display target image.

Abstract: The present invention eliminates a transmission-waiting operation which is unnecessary while accommodating a prioritized traffic. Although a communication station enters a transmission-disallowed state in response to detection of a signal addressed to another station in accordance with medium access control based on CSMA, if the communication station receives a frame transmitted with priority to a local station during the transmission waiting, it cancels the transmission-disallowed state, sends back a frame responding the frame transmitted with priority and effectively operates a transmission prioritized period. The communication station starts a search procedure to perform a processing of evading duplication of the transmission prioritized periods if it judges a possibility of a problem occurring in a time zone in which reception with priority is possible.

Abstract: The present invention eliminates a transmission-waiting operation which is unnecessary while accommodating a prioritized traffic. Although a communication station enters a transmission-disallowed state in response to detection of a signal addressed to another station in accordance with medium access control based on CSMA, if the communication station receives a frame transmitted with priority to a local station during the transmission waiting, it cancels the transmission-disallowed state, sends back a frame responding the frame transmitted with priority and effectively operates a transmission prioritized period. The communication station starts a search procedure to perform a processing of evading duplication of the transmission prioritized periods if it judges a possibility of a problem occurring in a time zone in which reception with priority is possible.

Abstract: In a self-organized distributed communication system utilizing a plurality of communication channels, improvement of a channel capacity is intended increase while using an access control method by carrier sensing. A station receives a beacon signal through each communication channel and grasps relative time information regarding to transmission/reception time of the beacon signal and communication channel information regarding a communication channel through which the beacon signal is transmitted/received. A new entry station obtains logical add (OR) of the grasped information to hold the time information and the communication channel information of the beacon signal. On transmitting/receiving data, the station switches the communication channel to use in accordance with the time information and the communication channel information to transmit a beacon signal to try communication.

Abstract: A wireless communication system in which each of communication stations performs networking operation in an autonomous, distributed manner, wherein each of the communication stations gathers information indicative of a band use situation in peripheral stations, grasps bands usable and unusable by the own station from the gathered information to set a band to be actually used by the own station, and mutually recognize bands to be used and unusable by the own station by informing to the peripheral stations.

Abstract: The present invention eliminates a transmission-waiting operation which is unnecessary while accommodating a prioritized traffic. Although a communication station enters a transmission-disallowed state in response to detection of a signal addressed to another station in accordance with medium access control based on CSMA, if the communication station receives a frame transmitted with priority to a local station during the transmission waiting, it cancels the transmission-disallowed state, sends back a frame responding the frame transmitted with priority and effectively operates a transmission prioritized period. The communication station starts a search procedure to perform a processing of evading duplication of the transmission prioritized periods if it judges a possibility of a problem occurring in a time zone in which reception with priority is possible.

Abstract: The present invention eliminates a transmission-waiting operation which is unnecessary while accommodating a prioritized traffic. Although a communication station enters a transmission-disallowed state in response to detection of a signal addressed to another station in accordance with medium access control based on CSMA, if the communication station receives a frame transmitted with priority to a local station during the transmission waiting, it cancels the transmission-disallowed state, sends back a frame responding the frame transmitted with priority and effectively operates a transmission prioritized period. The communication station starts a search procedure to perform a processing of evading duplication of the transmission prioritized periods if it judges a possibility of a problem occurring in a time zone in which reception with priority is possible.

Abstract: Access control based on CSMA is favorably carried out with the RTS/CTS method used together. If the RTS/CTS procedure is used together, CTS information is transmitted in response to the reception of RTS information, and data is transmitted in response to the reception of CTS. The CTS transmitting station measures the quality of RTS receive signal, and thereby determines a transmission rate at which it can receive and notifies a station as the destination of CTS. The station as the destination of CTS transmits data in response to CTS information. As the transmission rate for this data, the transmission rate indicated in the RATE field in CTS is applied.

Abstract: A deadlocked state in which each communication station cannot recognize mutual existence is evaded to form a self-organized distribution type multi-channel wireless network. In some interference situations, a beacon transmission channel selected on a self criterion is not always a receivable channel for all of neighbor communication stations. A communication station receiving interference from another system periodically transmits an interference annunciation signal (IAS) through all channels under no interference, and informs the neighbor stations of the existence and the channel under interference. Thereby, transmission of a beacon is restrained through the channel under interference up to a beacon-unhearable degree.

Abstract: Access control based on CSMA is favorably carried out with the RTS/CTS method used together. If the RTS/CTS procedure is used together, CTS information is transmitted in response to the reception of RTS information, and data is transmitted in response to the reception of CTS. The CTS transmitting station measures the quality of RTS receive signal, and thereby determines a transmission rate at which it can receive and notifies a station as the destination of CTS. The station as the destination of CTS transmits data in response to CTS information. As the transmission rate for this data, the transmission rate indicated in the RATE field in CTS is applied.

Abstract: Access control based on CSMA is favorably carried out with the RTS/CTS method used together. If the RTS/CTS procedure is used together, CTS information is transmitted in response to the reception of RTS information, and data is transmitted in response to the reception of CTS. The CTS transmitting station measures the quality of RTS receive signal, and thereby determines a transmission rate at which it can receive and notifies a station as the destination of CTS. The station as the destination of CTS transmits data in response to CTS information. As the transmission rate for this data, the transmission rate indicated in the RATE field in CTS is applied.

Abstract: A wireless communication system in which each of communication stations performs networking operation in an autonomous, distributed manner, wherein each of the communication stations gathers information indicative of a band use situation in peripheral stations, grasps bands usable and unusable by the own station from the gathered information to set a band to be actually used by the own station, and mutually recognize bands to be used and unusable by the own station by informing to the peripheral stations.

Abstract: The present invention eliminates a transmission-waiting operation which is unnecessary while accommodating a prioritized traffic. Although a communication station enters a transmission-disallowed state in response to detection of a signal addressed to another station in accordance with medium access control based on CSMA, if the communication station receives a frame transmitted with priority to a local station during the transmission waiting, it cancels the transmission-disallowed state, sends back a frame responding the frame transmitted with priority and effectively operates a transmission prioritized period. The communication station starts a search procedure to perform a processing of evading duplication of the transmission prioritized periods if it judges a possibility of a problem occurring in a time zone in which reception with priority is possible.

Abstract: A communication station needs to autonomously and synchronously operate by maintaining an equal frame interval. A clock error is measured from a received packet in a wireless communication system where a beacon is transmitted periodically. This clock error is used to synchronize a counter to count the beacon's transmission/reception time and adjust a clock cycle deviation for synchronization. The synchronization is possible even in the case of restoration from a sleep state when the reference clock accuracy is poor. A period to maintain the sleep state can be extended irrespectively of the clock accuracy. It is possible to prevent desynchronization due to incorrect synchronization with an abnormal value.

Abstract: Access control based on CSMA is favorably carried out with the RTS/CTS method used together. If the RTS/CTS procedure is used together, CTS information is transmitted in response to the reception of RTS information, and data is transmitted in response to the reception of CTS. The CTS transmitting station measures the quality of RTS receive signal, and thereby determines a transmission rate at which it can receive and notifies a station as the destination of CTS. The station as the destination of CTS transmits data in response to CTS information. As the transmission rate for this data, the transmission rate indicated in the RATE field in CTS is applied.

Abstract: A communication station forms a multi-channel self-organized distribution type wireless network effectively without providing an unnecessary transmission pause period. The communication station refers to neighbor apparatus information described in a beacon received from a neighbor station to judge whether or not a beacon transmission channel of a corresponding next neighbor station matches a transmission scheduled channel of its own. In a case where these channels match, a transmission pause period for the next neighbor station is provided and the transmission is postponed. Accordingly, blocking against the beacon reception from the next neighbor station by the neighbor station can be avoided and provision of an unnecessary transmission pause period is not required so that the throughput is improved.

Abstract: Access control based on CSMA is favorably carried out with the RTS/CTS method used together. If the RTS/CTS procedure is used together, CTS information is transmitted in response to the reception of RTS information, and data is transmitted in response to the reception of CTS. The CTS transmitting station measures the quality of RTS receive signal, and thereby determines a transmission rate at which it can receive and notifies a station as the destination of CTS. The station as the destination of CTS transmits data in response to CTS information. As the transmission rate for this data, the transmission rate indicated in the RATE field in CTS is applied.

Abstract: In a wireless communication environment provided with a plurality of channels, a suitable ad hoc network is formed without mutual interference between communication stations. Each communication station acquires an average level of interference that a neighbor station receives for every channel, and a channel with the lowest average interference level is determined as a transmission channel. By weighting the interference of the neighbor station with a high priority for the local station, such as a destination station to which a large amount of packets is transmitted from the local station, to obtain a weighted average for each channel, a channel with less interference for a prioritized neighbor station for the local station is selected as the transmission channel. As a result, throughput of the entire system is improved.

Abstract: A deadlocked state in which each communication station cannot recognize mutual existence is evaded to form a self-organized distribution type multi-channel wireless network. In some interference situations, a beacon transmission channel selected on a self criterion is not always a receivable channel for all of neighbor communication stations. A communication station receiving interference from another system periodically transmits an interference annunciation signal (IAS) through all channels under no interference, and informs the neighbor stations of the existence and the channel under interference. Thereby, transmission of a beacon is restrained through the channel under interference up to a beacon-unhearable degree.

Abstract: In a self-organized distributed communication system utilizing a plurality of communication channels, improvement of a channel capacity is intended increase while using an access control method by carrier sensing. A station receives a beacon signal through each communication channel and grasps relative time information regarding to transmission/reception time of the beacon signal and communication channel information regarding a communication channel through which the beacon signal is transmitted/received. A new entry station obtains logical add (OR) of the grasped information to hold the time information and the communication channel information of the beacon signal. On transmitting/receiving data, the station switches the communication channel to use in accordance with the time information and the communication channel information to transmit a beacon signal to try communication.