Abstract: The present invention provides a system for wireless data communications that allows, in P-MP wireless data communications, equally giving communications opportunities to mobile stations that directly communicate with a wireless base station and mobile stations that indirectly communicate therewith via a relay station and a communications method thereof. In comparison with the OFDM frame configuration prescribed in IEEE802.16, an OFDM frame configuration is characterized in that, in an uplink subframe, a ranging period and BW (bandwidth) request periods for a relay station are provided, and furthermore, a remaining message number notice period for which each relay station notifies the wireless base station of the number of remaining messages is provided. These periods are not of a contention base but bandwidths dedicated to the relay station.

Abstract: A packet control apparatus connected between an interconnected network and a wireless apparatus includes a quality detection unit for detecting whether a quality of transmission toward the wireless apparatus is in a predetermined deteriorated state, and a packet filtering unit for deleting a link state watching packet received from the interconnected network, when the transmission quality is in the predetermined deteriorated state.

Abstract: A wireless LAN system comprising a plurality of wireless stations, and a switching apparatus for switching a frequency channel used between stations communicated with each other. The switching apparatus includes means for selecting the frequency channel to be used, and means for sending a switching request packet for specifying the selected frequency channel to the stations. Each of the stations include means for switching a current frequency channel to the frequency channel specified by the switching request packet received.

Abstract: The present invention provides a system for wireless data communications that allows, in P-MP wireless data communications, equally giving communications opportunities to mobile stations that directly communicate with a wireless base station and mobile stations that indirectly communicate therewith via a relay station and a communications method thereof. In comparison with the OFDM frame configuration prescribed in IEEE802.16, an OFDM frame configuration is characterized in that, in an uplink subframe, a ranging period and BW (bandwidth) request periods for a relay station are provided, and furthermore, a remaining message number notice period for which each relay station notifies the wireless base station of the number of remaining messages is provided. These periods are not of a contention base but bandwidths dedicated to the relay station.

Abstract: A radio LAN master station system which provides long distance communication and suffers from small interference by another system located inside and/or outside of a service area comprises a transceiver, and a plurality of directional antennas each directed to a respective section with some angular spacing, through a power distributor which couples said transceiver with said antennas. Polarization plane of any antenna is orthogonal to polarization plane of an adjacent antenna.

Abstract: A polling period controlling apparatus capable of polling with a period traceable temporal variations of management information values of a managed unit is provided with a polling period calculator 5 which decomposes a sequence of management information values, stored in the sequence memory 4, into the sum of sinusoids with different frequencies to find the maximum frequency and determines the polling period from an inverse of two times the largest frequency. A central controller 2 then compares between the required bandwidth specified by the polling period and a network management bandwidth and, when the former is smaller than the latter, obtains the management information value from the managed unit 11 using the polling period. When the former is greater, the central controller 2 obtains the management information value using the polling period determined from the network management bandwidth.

Abstract: A packet control apparatus connected between an interconnected network and a wireless apparatus includes a quality detection unit for detecting whether a quality of transmission toward the wireless apparatus is in a predetermined deteriorated state, and a packet filtering unit for deleting a link state watching packet received from the interconnected network, when the transmission quality is in the predetermined deteriorated state.

Abstract: A wireless LAN system comprising a plurality of wireless stations, and a switching apparatus for switching a frequency channel used between stations communicated with each other. The switching apparatus includes means for selecting the frequency channel to be used, and means for sending a switching request packet for specifying the selected frequency channel to the stations. Each of the stations include means for switching a current frequency channel to the frequency channel specified by the switching request packet received.

Abstract: A radio LAN master station system which provides long distance communication and suffers from small interference by another system located inside and/or outside of a service area comprises a transceiver, and a plurality of directivity antennas each directed to respective section with some angular spacing, through a power distributor which couples said transceiver with said antennas. Polarization plane of any antenna is orthogonal to polarization plane of an adjacent antenna.

Abstract: If an error range is specified with regard to the cost beforehand, a route satisfying all of a plurality of QoS conditions at a low cost and having a cost in the error range is selected as an optimum route. Such a route selection method is provided. At step S1, a plurality of QoS conditions to be satisfied are set. At step S2, an approximation error &egr; is input. At step S3, a range of a cost for searching for an optimum route is tentatively set. At step S4, an optimum solution cost approximation procedure is executed. At step S5, it is determined whether the cost searching range has been sufficiently narrowed. If the narrowed cost searching range is still too wide, then the processing returns to the step S4 and the optimum solution cost approximation procedure is repeated. If the cost searching range has already been narrowed, an optimum solution deriving procedure is executed at step S6.

Abstract: The managed object instance is used as access control unit, then access denial and permission are quickly decided. After a pre-process to the naming tree which is an object of access control, MOI included within every scope which can be designated by the management operation is obtained. At every issue of the management operation, access denial and permission are decided by using the data obtained in the pre-process. When the configuration of the naming tree is changed, the data are easily and rapidly revised, then the access control is adaptive to the dynamic change of the naming tree.

Abstract: The gateway apparatus for SNMP/OSI management enables that an SNMP manager manages an OSI management agent, by using a basic conversion of a management operation and a management information between SNMP and CMIP and by using a cache, a replica and a link object.