having received the handover pre notification response messages ho pre notification response from the target stations 13 respectively transmits the information regarding the service levels that can be provided by the target base stations 13 to the mobile subscriber station 11 step s 110 referring to fig2 in another embodiment of the present invention there exists a plurality of target base stations from which a mobile subscriber station mss 21 can choose to perform a handover operation with preferably once the mobile subscriber station 21 is provided with an application service as described in steps s 101 s 105 of fig1 for example the mobile subscriber station 21 scans neighbor base stations 22 23 24 step s 201 if the mobile subscribe station 21 decides to perform handover the mobile subscriber station 21 transmits a handover request message mob_mssho_req to a serving base station 22 bs 1 step s 202 the serving base station 22 then transmits a handover request pre notification message ho pre notification to notify target base stations 23 and 24 bs 2 and bs 3 respectively that there exists the mobile subscriber station 21 requesting the handover steps s 203 and s 204 for example table 1 and table 2 show configurations for handover request pre notification messages ho pre notification in the present invention parameters associated with a qos corresponding.