channel to subordinate ms 2 step s 4 at this time identification information indicating the selected spread code information for deriving the spread code or the spread code itself is simultaneously notified also information other than the spread code which is necessary for data reception by the ms 2 is notified after the starting of the multicast operation has been notified to the ms 2 with an appropriate time interval data is transmitted from the anchor bss 5 through the dht 12 to the branch bsss 4 and 6 subsequently in a branch bss that has received the data transmitted from the bss 5 a multicast operation is performed by using the pre selected and decided spread code step s 5 in the mss 1 and 2 the broadcast channel has been received for receiving the paging of an incoming call during waiting or system information upon having received the starting of the multicast operation through the broadcast channel in the mss 1 and 2 the identification information indicating the spread code the information for deriving the spread code or the spread code itself used for information transmission is received through the broadcast channel of the same bss if the identification information indicating the spread code or the information for deriving the spread code is received based on the information the.