Self-organized time-division multiple access (STDMA) is a channel access method designed by Håkan Lans, based on

time-division multiplexing Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fracti ...

. The term "self-organized" describes the manner in which time slots are assigned to users.

Time-division multiple access Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, o ...

(TDMA) divides a channel into

frames A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent. Frame and FRAME may also refer to: Physical objects In building construction *Framing (co ...

, which furthermore are subdivided into a vast number of time slots. Users transmit in rapid succession, one after the other, each using their own time slot. One of the drawbacks of TDMA is that it requires a central station for slot assignment and time synchronisation. STDMA proposes for assigning slots without the involvement of a central station. Time synchronisation is usually taken care of using Coordinated Universal Time (UTC). 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. While the method was patented, a

US patent Under United States law, a patent is a right granted to the inventor of a (1) process, machine, article of manufacture, or composition of matter, (2) that is new, useful, and non-obvious. A patent is the right to exclude others, for a limited ...

ex-parte reexamination certificate was issued in 2010 canceling all claims. USPTO ex-parte reexamination certificate (7428th), issued on March 30, 2010.

References

External links

Håkan Lans, designer of STDMA
(DMOZ entry)
GP&C Systems International AB
Holding company of STDMA patent rights in Europe {{Channel access methods Maritime communication