Patent ID: 7468953
Filing Date: 2008-12-23
Classification: H04B,H04L,H04W,Y02D

Abstract:
1. In a network including a plurality of relay stations and a parent station which are connected with each other through a transmission line, a path setting method for generating fixed paths from the parent station to respective ones of the relay stations, the path setting method enabling a parent station to set the fixed path to respective ones of the plurality of relay stations, the path setting method comprising: allowing each of the parent station and the plurality of relay stations to transmit a basic-information notification signal to the network at a first time interval by a repetitive broadcast, the basic-information notification signal containing basic information which includes an identifier identifying its own station and the status of the path setting to its own station; allowing, in response to receiving the basic-information notification signal, each of the parent station and the plurality of relay stations to detect a receiving state and calculate a transmission quality on a transmission line interconnecting with the station which has transmitted the basic-information notification signal, in accordance with the receiving state; allowing each of the parent station and the plurality of relay stations to create or update a receiving-environment table correlating the basic information contained in the basic-information notification signal to the transmission quality on the transmission line interconnecting with the station which has transmitted the basic-information notification signal, and store the created or updated receiving-environment table therein; allowing each of the plurality of relay stations to repeatedly refer to the path-setting status in the receiving-environment table at a second time interval greater than the first time interval, and, when the reference result shows that temporary-path setup information representing the completion of setting a temporary path exists in the path-setting status, transmit a receiving-environment-table communication signal containing the receiving-environment table of its own station through the transmission line used for transmitting the basic-information notification signal containing the temporary-path setup information; allowing, in response to receiving the receiving-environment-table communication signal, each of the plurality of relay stations to forward the received receiving-environment-table communication signal to the parent station through the use of the temporary path; allowing, in response to receiving the receiving-environment-table communication signal, the parent station to create or update a transmission-quality table correlating the inter-station transmission line to the transmission quality thereof, in accordance with the identifier and the transmission quality contained in the receiving-environment-table communication signal, and store the created or updated transmission-quality table in the parent station; allowing, in response to receiving the receiving-environment-table communication signal, the parent station to set a temporary path to the relay station which has transmitted the receiving-environment-table communication signal, and return a temporary-path setup information containing the temporary path to the relay station; and allowing, in response to a lapse of a third time interval greater than the second time interval, the parent station to set the fixed paths to respective ones of the plurality of relay stations, in accordance with the transmission qualities in the transmission-quality table, and transmit the set fixed paths to respective ones of the plurality of relay stations.