An RFID tag population is selected by an interrogator. Each tag of the selected tag population then responds to the interrogator in accordance with a slotted arbitration scheme. According to the slotted arbitration scheme, each tag of the selected tag population picks its own random value from a range of integers indicated by the interrogator. The random value corresponds to a slot. The interrogator may indicate that the range of integers is to be adjusted. Each tag of the selected tag population responds to the interrogator with a random number.