Abstract: Provided is a technique for efficiently using a channel bandwidth in a wireless communication system provided with a function for dividing a frequency channel into a plurality of segments and performing relay using the segments that differ from relay section to relay section. In a second scheme, an upstream direction of a first relay section is a DL section, and two segments are used. An upstream direction of a second relay section is a UL section, and two segments are used. That is, 2/3 of an area is used in a frequency-axis direction, and 1/2 of the area is used in a time-axis direction similarly to a first scheme. A data area ratio for the second scheme becomes 1/3. A data area ratio for the first scheme is 1/6. Thus, a throughput for the second scheme is twice a throughput for the first scheme.

Abstract: Provided is a technique for efficiently using a channel bandwidth in a wireless communication system provided with a function for dividing a frequency channel into a plurality of segments and performing relay using the segments that differ from relay section to relay section. In a second scheme, an upstream direction of a first relay section is a DL section, and two segments are used. An upstream direction of a second relay section is a UL section, and two segments are used. That is, ? of an area is used in a frequency-axis direction, and ½ of the area is used in a time-axis direction similarly to a first scheme. A data area ratio for the second scheme becomes ?. A data area ratio for the first scheme is ?. Thus, a throughput for the second scheme is twice a throughput for the first scheme.

Abstract: The present invention introduces a multichannel MAC into a white-space-using system. A base station and a terminal station are each configured from a plurality of wireless communication units and centralized control units thereof. Each of the wireless communication units wirelessly transmits/receives for one channel. The base station operates one or more channels according to white-space-channel status, and is assigned to a terminal station. When operating a plurality of channels, it is possible to select a redundancy mode for assigning data by duplicating the terminal-station data in a plurality of channels, and a high-speed mode for dividing the data and distributing the data among the plurality of channels.

Abstract: In the wireless communication system, each of a base station 11 and a terminal station 12 obtains its location information, and upon establishment of synchronization, the terminal station 12 transmits a terminal station free channel list and its location information by extremely low power wireless communication, and the base station 11 compares a base station free channel list created based on information from a database 40 with the terminal station free channel list from the terminal station 12, and determines, when there is a common free channel, the free channel as uplink/downlink channels and determines, when there is no common free channel, an uplink channel and a downlink channel as different channels, calculates a base station-terminal station distance from the location information of the base station 11 and the location information of the terminal station 12, and determines terminal station's uplink transmission power based on the distance.

Abstract: Provided is a wireless communication system that is capable of preventing interference between secondary use systems that do not use a database. The wireless communication system uses a white space for opposing communication between a base station and a terminal station. At startup, the base station transmits a preamble over a cycle that is n-times a frame length (where n is an integer 2 or greater), changes a set frequency channel if ranging is not detected from a terminal station within a fixed time interval, and begins normal operation using the set frequency channel if ranging is detected. At startup, the terminal station detects a preamble within a received signal, changes a set frequency channel if a peak is detected at each frame length, and transmits a ranging signal if peaks are detected for cycles that are n-times the frame length and peaks are not detected for other cycles.

Abstract: There is provided a wireless communication system that is capable of preventing interference with a primary use system caused by a CPE emitting radio waves at a frequency which is not a transmittable frequency before acquiring a list of transmittable frequencies based on its position information. In a wireless communication system that uses white space, a BS 10 and a CPE 22 store a specific frequency which is guaranteed to not interfere with a primary user. The BS 10 regularly switches between a first period when communication is performed at an operating frequency that uses white space and a second period when communication is performed at the specific frequency.

Abstract: Disclosed is a wireless communication system using white spaces and a base station that does not have its own backhaul, starts wireless communications without radiating radio waves of frequencies causing interference with primary users. A BS being in isolation starts a wireless communication with a CPE, connected to the internet, so as to access a database to acquire a list of frequencies available for transmission. The BS uses a predetermined frequency to perform the wireless communication with the CPE, and acquires, via this wireless communication, the list of frequencies available for transmission. Thereafter, the BS performs wireless communications with the CPE and with another CPE on the basis of the acquired list of frequencies available for transmission. The BS can hold, in advance, information of the predetermined frequency for which it has been estimated that the BS will cause no interference with the wireless communications of the primary users.

Abstract: Disclosed is a wireless communication system using white spaces and a base station that does not have its own backhaul, starts wireless communications without radiating radio waves of frequencies causing interference with primary users. A BS being in isolation starts a wireless communication with a CPE, connected to the internet, so as to access a database to acquire a list of frequencies available for transmission. The BS uses a predetermined frequency to perform the wireless communication with the CPE, and acquires, via this wireless communication, the list of frequencies available for transmission. Thereafter, the BS performs wireless communications with the CPE and with another CPE on the basis of the acquired list of frequencies available for transmission. The BS can hold, in advance, information of the predetermined frequency for which it has been estimated that the BS will cause no interference with the wireless communications of the primary users.

Abstract: Provided is a wireless communication system that is capable of preventing interference between secondary use systems that do not use a database. The wireless communication system uses a white space for opposing communication between a base station and a terminal station. At startup, the base station transmits a preamble over a cycle that is n-times a frame length (where n is an integer 2 or greater), changes a set frequency channel if ranging is not detected from a terminal station within a fixed time interval, and begins normal operation using the set frequency channel if ranging is detected. At startup, the terminal station detects a preamble within a received signal, changes a set frequency channel if a peak is detected at each frame length, and transmits a ranging signal if peaks are detected for cycles that are n-times the frame length and peaks are not detected for other cycles.

Abstract: There is provided a wireless communication system that is capable of preventing interference with a primary use system caused by a CPE emitting radio waves at a frequency which is not a transmittable frequency before acquiring a list of transmittable frequencies based on its position information. In a wireless communication system that uses white space, a BS 10 and a CPE 22 store a specific frequency which is guaranteed to not interfere with a primary user. The BS 10 regularly switches between a first period when communication is performed at an operating frequency that uses white space and a second period when communication is performed at the specific frequency.

Abstract: In the wireless communication system, each of a base station 11 and a terminal station 12 obtains its location information, and upon establishment of synchronization, the terminal station 12 transmits a terminal station free channel list and its location information by extremely low power wireless communication, and the base station 11 compares a base station free channel list created based on information from a database 40 with the terminal station free channel list from the terminal station 12, and determines, when there is a common free channel, the free channel as uplink/downlink channels and determines, when there is no common free channel, an uplink channel and a downlink channel as different channels, calculates a base station-terminal station distance from the location information of the base station 11 and the location information of the terminal station 12, and determines terminal station's uplink transmission power based on the distance.

Abstract: The present invention introduces a multichannel MAC into a white-space-using system. A base station and a terminal station are each configured from a plurality of wireless communication units and centralized control units thereof. Each of the wireless communication units wirelessly transmits/receives for one channel. The base station operates one or more channels according to white-space-channel status, and is assigned to a terminal station. When operating a plurality of channels, it is possible to select a redundancy mode for assigning data by duplicating the terminal-station data in a plurality of channels, and a high-speed mode for dividing the data and distributing the data among the plurality of channels.

Abstract: A network management unit included in a base station of WRAN, and a heterogeneous-systems coexistence function unit included in a relay station perform communications by taking advantage of the wireless line of WRAN. In this way, the network management unit and the heterogeneous-systems coexistence function unit make the determination and management of a frequency channel to be utilized by WLAN. Concretely, the QP (Quiet Period) of WRAN and that of WLAN are synchronized with each other with respect to the above-described frequency channel. During the synchronized QPs, WRAN and WLAN make the absence confirmation of a primary user.

Abstract: A network management unit included in a base station of WRAN, and a heterogeneous-systems coexistence function unit included in a relay station perform communications by taking advantage of the wireless line of WRAN. In this way, the network management unit and the heterogeneous-systems coexistence function unit make the determination and management of a frequency channel to be utilized by WLAN. Concretely, the QP (Quiet Period) of WRAN and that of WLAN are synchronized with each other with respect to the above-described frequency channel. During the synchronized QPs, WRAN and WLAN make the absence confirmation of a primary user.

Abstract: A housing (20) of a connector has a front end that can be introduced through a mount hole (H) in a panel (P). A detector (50) is mounted on the front end of the housing (20) is movable between a standby position and a detecting position. Movement of the detector (50) toward the detecting position is prevented by interference with the inner peripheral surface of the mount hole (H) while the housing (20) is being mounted on the panel (P). However, the inner peripheral surface of the mount hole (H) when the male housing (20) is mounted properly on the panel (P). Thus, the detector (50) can be moved to the detecting position.

Abstract: A connector includes male and female connector housings (10, 20). The male housing (10) has a receptacle (11) and a lock arm (15) projects into the receptacle (11) for locking the female housing (20). A slider (34) is assembled into the female housing (20) and is biased forwardly by coil springs (33). The lock arm (15) is resiliently deformable between an engaging position where it is engageable with the slider (34) and a disengaging position where it is disengaged from the slider (34). If a connecting or separating operation is interrupted halfway, spring forces accumulated in the compression coil springs (33) resiliently compressed by the slider (34) are released. Thus, the lock arm (15) is pushed forward by the slider (34) to separate the housings (10, 20) from each other.

Abstract: A connector has first and second housings (10, 30). The first housing (10) has male terminal fittings (13) and a shorting terminal (15) that is biased into shorting contact against the male terminal fittings (13). A pushing portion (36) displaces receiving pieces (20) of the shorting terminal (15) toward a bottom wall (12W) during connection of two housings (10, 20). The bottom wall (12W) has an escaping portion (22) for avoiding an interference with the receiving pieces (20). The receiving pieces (20) are displaced toward the bottom wall (12W) by the pushing portion (36) and enter the escaping portion (22). Thus the shorting terminal 15 is deformed to a large degree.

Abstract: A housing (20) of a connector has a front end that can be introduced through a mount hole (H) in a panel (P). A detector (50) is mounted on the front end of the housing (20) is movable between a standby position and a detecting position. Movement of the detector (50) toward the detecting position is prevented by interference with the inner peripheral surface of the mount hole (H) while the housing (20) is being mounted on the panel (P). However, the inner peripheral surface of the mount hole (H) when the male housing (20) is mounted properly on the panel (P). Thus, the detector (50) can be moved to the detecting position.

Abstract: A connector includes first and second housings (10, 30). During connection of the housings (10, 20), a slanted surface (38) of a pushing portion (37) comes into contact with receiving pieces (20) of a shorting terminal (15), which in turn is deformed resiliently by the inclination of the pushing portion (37) and moves away from male terminal fittings (13) to cancel a shorted state of the male terminal fittings (13). The pushing portions (37) are hard to deform and are provided with slanted surface (38) for resiliently deforming the shorting terminal (15). Therefore, the pushing portions (37) can deform the shorting terminal (15) without losing its guiding function even if the pushing portion (37) and the shorting terminal (15) get caught with each other at their contact portions.

Abstract: A connector has first and second housings (10, 30). The first housing (10) has male terminal fittings (13) and a shorting terminal (15) that is biased into shorting contact against the male terminal fittings (13). A pushing portion (36) displaces receiving pieces (20) of the shorting terminal (15) toward a bottom wall (12W) during connection of two housings (10, 20). The bottom wall (12W) has an escaping portion (22) for avoiding an interference with the receiving pieces (20). The receiving pieces (20) are displaced toward the bottom wall (12W) by the pushing portion (36) and enter the escaping portion (22). Thus the shorting terminal 15 is deformed to a large degree.