Abstract: In a radio communication system, a first radio communication station transmits a radio signal including information for designating a condition for a radio communication counterpart. A second radio communication station which receives the radio signal transmitted by the one radio communication station, and transmits a response radio signal when a situation of the second radio communication station meets the condition designated by the information included in the radio signal. The condition for a radio communication counterpart is whether the radio communication counterpart moves, and the second radio communication station transmits the response radio signal when the second radio communication station meets the condition that the radio communication counterpart moves.

Abstract: In a radio communication system, a first radio communication station transmits a radio signal including information for designating a condition for a radio communication counterpart. A second radio communication station which receives the radio signal transmitted by the one radio communication station, and transmits a response radio signal when a situation of the second radio communication station meets the condition designated by the information included in the radio signal. The condition for a radio communication counterpart is whether the radio communication counterpart moves, and the second radio communication station transmits the response radio signal when the second radio communication station meets the condition that the radio communication counterpart moves.

Abstract: A subscriber radio access system in which it becomes possible to facilitate communications for realizing high throughput and by which a radio LAN communication can be realized even if a radio link section is longer according to the CSMA protocol on Ethernet is provided. The subscriber radio access system includes plural transceiver terminals; and a base station linked to each of the plural transceiver terminals via a radio communication channel, wherein one of the plural transceiver terminals communicates to the other transceiver terminal with an Ethernet packet employing a carrier sense multiple access (CSMA) protocol, of which a packet length is corrected to correspond to a transmission delay time between the one and other transceiver.

Abstract: A transmission path interface apparatus compatible with a CSMA mode capable of responding to a fault occurring in a transmission path flexibly and at a high speed, including a transmission unit for holding serial transmission information and transmitting a frame modulated by both of the transmission information and a preamble to a CSMA mode transmission path; a reception unit for taking out a loopback frame transmitted by an opposing node in accordance with that frame, restoring the transmission information contained in this, and holding the same; a collision decision unit for determining a correlation between transmission information held by the transmission unit and the reception unit and notifying a result of this to an information source of transmission information; and a collision decision acceleration unit for comparing an elapsed time from a timing when the information source gave the transmission information to the transmission unit to a timing when the transmission information contained in the loopba