100 as shown in the left side of fig8 in step s 1001 to step s 1009 the center frequency of the communication band of terminal 100 matches the sch frequency position in unit band a of the initial access unit band in this condition as explained using fig2 the capability of terminal 100 is not utilized by contrast with this by moving the center frequency of the communication band of terminal 100 in step s 1010 as shown in the right side of fig8 it is possible to contain the whole assignment unit band group in the communication band of terminal 100 also the width of each unit band is the same in fig8 and therefore the center frequency of the communication band of terminal 100 matches the boundary frequency between unit band a and unit band b referring back to the flow of fig7 in step s 1011 to step s 1013 a broadcast signal and control channel are transmitted and used to prepare rach preamble transmission in an additional assignment unit band upon completing the preparation of the rach preamble in the additional assignment unit band control section 140 cuts off uplink communication between terminal 100 and base station 200 in step s 1014 and transmits the rach preamble in the additional assignment unit band in step s 1015 in step s 1016 control section 265 of base station 200 having received the rach preamble allocates uplink frequency to terminal 100 having transmitted the.