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Demand Assigned Multiple Access (DAMA) is a protocol used in satellite communications, particularly Very Small Aperture Terminal (VSAT) systems. DAMA enables efficient and instantaneous assignment of transponder channels on a first come, first served basis according to data priority.
In computing, DAMA refers to switching circuits in a manner designed to meet infrequent or periodic system and/or user demand requirements.
DAMA, which was developed by the United States government, is not a new technology. In 1968, it was used along with KRUG, a similar satellite communication system developed by the Russians.
DAMA does not require continuous connection from user terminals to a network control system. Typically, an assigned channel consists of a pair of frequencies--one for transmission and another for reception.
After DAMA assigns a pair of frequencies to a user terminal, other network terminal users may not be assigned to those frequencies until the session is completed. Then, the frequencies are returned to a list, or central pool, of frequencies available to other terminal users.
The number of transient clients that use DAMA network terminals increases according to efficient user sequencing at specific frequencies and different timeslots. Thus, DAMA is used for infrequently-used networks, versus Permanently Assigned Multiple Access (PAMA) technology. Both technologies are related only by channel or frequency resource allocation and should not be confused with multiple access/multiplexing, which divides a single communication channel into multiple channels.
Typical VSAT systems use DAMA for point of sale (POS) transactions, such as credit card, polling or radio frequency identification; remote location Internet access and mobile maritime communications. DAMA is also used by the military for satellite communications (SATCOM).