The term "self-organized" describes the manner in which time slots are assigned to users.
Time-division multiple access (TDMA) divides a channel into frames, which furthermore are subdivided into a vast number of time slots.
One of the drawbacks of TDMA is that it requires a central station for slot assignment and time synchronization.
STDMA proposes a method for assigning slots without the involvement of a central station.
STDMA is in use by the Automatic Identification System (AIS), a standard marine short-range coastal tracking system, and is the base of the International Civil Aviation Organization VHF Data Link Mode 4.