Opportunity Driven Multiple Access

Opportunity-Driven Multiple Access (ODMA) is a UMTS communications relaying protocol standard first introduced by the European Telecommunication Standards Institute (ETSI) in 1996. ODMA has been adopted by the 3rd-Generation Partnership Project, 3GPP to improve the efficiency of UMTS networks using the TDD mode. One of the objectives of ODMA is to enhance the capacity and the coverage of radio transmissions towards the boundaries of the cell. While mobile stations under the cell coverage area can communicate directly with the base station, mobile stations outside the cell boundary can still access the network and communicating with the base station via multihop transmission. Mobile stations with high data rate inside the cell are used as multihop relays.

The initial concept of Opportunity Driven Multiple Access (ODMA) was conceived and patented in South Africa by David Larsen and James Larsen of SRD Pty Ltd in 1978

The ODMA standard was tabled by the 3GPP committee in 1999 due to complexity issues. The technology continues to be developed and enhanced by IWICS who holds the key patents describing the methods employed in ODMA to effect opportunity driven communications.