Patent ID: 8085706
Filing Date: 2011-12-27
Classification: H04W

Abstract:
1. A wireless communication method comprising: performing, at an access control start time, an access control based on CSMA method that acquires a right to transmit by a carrier-sensing; transmitting a data packet of a predetermined data length when the right to transmit is acquired by the access control; calculating a data packet transmission time ratio for a purpose of determining whether the time ratio exceeds a second threshold, the time ratio being defined as a ratio of (a) a time when a data packet can be received from one other communication apparatus to (b) a fixed period of time; selecting one of the other communication apparatuses that have transmitted a data packet during the fixed interval as a paired apparatus if the time ratio exceeds the second threshold; determining an estimated time from a start of data packet transmission by the paired apparatus as a next access control start time of a subject apparatus until the right to transmit is acquired by the access control by calculating the next access control start time of the paired apparatus as the estimated time based on a data packet reception time of the data packet that has been transmitted by the paired apparatus; instructing the paired apparatus to start a paired communication by adding pairing information indicating a start of the paired communication with the paired apparatus to the data packet when the data packet is transmitted after acquisition of the right to transmit by the access control started at the next access control start time that has been determined; waiting thereafter for reception of the data packet from the paired apparatus, determining whether or not the pairing information indicative of performing a paired communication with the subject apparatus is included in the data packet when the data packet from the paired apparatus is received; setting the access start time as the fixed interval from the start of previous data packet transmission by the subject apparatus if the pairing information is not included in the data packet from the paired apparatus; performing the paired communication with the paired apparatus at the fixed interval by substantially doubling an initial fixed interval for an alternative acquisition of the right to transmit with the paired apparatus if the pairing information is included in the data packet from the paired apparatus; if the data packet transmitted by the one of the other communication apparatuses includes the pairing information that indicates the paired communication between the subject apparatus and the other communication apparatus while the paired communication is not performed, identifying the one of the other communication apparatuses as the paired apparatus; estimating a time after the fixed interval from a start of the data packet transmission by the identified paired apparatus as an estimated time based on a reception time of the data packet that have been transmitted by the identified paired apparatus for setting the estimated time as the next access control start time; performing thereafter the paired communication by substantially doubling the fixed interval from the previous data packet transmission by the subject apparatus for setting the access control start time; and adding the pairing information to the data packet that is transmitted after identifying the paired apparatus while the paired communication is not performed.