RANDOM ACCESS METHOD COUPLED WITH SLOTTED ALOHA FORM AND INHIBIT SENSE MULTIPLE ACCESS FORM

摘要

PURPOSE: A random access method is provided to use an ISMA(Inhibit Sense Multiple Access) form with a slotted aloha form, so that all mobile stations under control of a base station can understand whether transmission of other mobile stations is performed. CONSTITUTION: A random access method coupled with a slotted aloha form and an inhibit sense multiple access form comprises the steps of: dividing an access slot section allocated by an arbitrary time unit into a plurality of sub slot sections; deciding whether transmission of a corresponding data packet is performed, according whether reverse transmission data exists by the access sub slot sections; and transmitting a data packet of plurality of mobile stations to a corresponding base station. The base station broadcasts a busy signal, when receiving an access preamble for synchronizing start time of the data packet of one mobile station among the mobile stations, and broadcasts an idle signal when not receiving the access preamble. The maximum size of data packet, capable of transmitting through an arbitrary i access sub slot section among the plurality of access sub slot sections, is decided as a value which decreased a value multiplying the number i to the size of the access sub slot section. One mobile station of the mobile stations transmits a corresponding packet to the base station, regardless of existence or nonexistence of the reverse transmission data, when transmitting self data packet in a starting point of the access slot section.