在双频网络中,有900M和1800M两个共站址的基站,它们处在同一LAC下,它们的小区参数设置如下: 900M:rxlev_access_min=5,ms_txpwr_max_cch=5, cell_reselect_param_ind=1,cell_bar_qulify=0,cell_reselect_offset=0,temporary_offset=0,penity_timer=0 1800M:rxlev_access_min=20,ms_txpwr_max_cch=0, cell_reselect_param_ind=1,cell_bar_qulify=0,cell_reselect_offset=10,temporary_offset=0,penity_timer=0 请问:手机刚开机以后会占在哪个小区下,几秒钟以后,手机会重选到哪个小区.请给出计算依据.