A base station determines a restriction rate for each of plural kinds of restrictions; by using a timing at which a user device in idle mode wakes up in a discontinuous reception cycle, groups the user device into one of a total number of groups and determine a timing for transmitting a paging signal for each of the groups; determines a restriction group number that is less than a sum of all restriction-rate-corresponding group numbers where one of the restriction-rate-corresponding group numbers corresponds to the restriction rate of one of the plural kinds of restrictions, determines the restriction group number of groups as restriction target groups, and changes a group corresponding to the restriction-target groups in each of predefined periods; and transmits the paging signal to the user device that belongs to one of the restriction-target groups, and transmits system information indicating that the plural kinds of restrictions are applied.