In a 5G or 6G wireless network, a user device that wishes to transmit an uplink message must first transmit a scheduling request to the base station, generally in an allocated time-frequency region sized according to the number of user devices. In general, most of the user devices are not requesting access most of the time, and therefore most of the allocated region is blank. To reduce the amount of wasted resources, the base station can divide the user devices into sections, and allow the user devices to indicate which sections include at least one ready user device. Then, the base station can allocate a much smaller region containing only those indicated sections, and the ready user devices can send their requests in that smaller region. The base station can then determine which user devices request access, provide them with grants, and receive their messages. By avoiding allocating scheduling-request resources to sections that have no waiting messages, the base station may save time and avoid wasting limited resources, according to some embodiments.