What Does Digital Sense Multiple Access (DSMA) Mean?

Digital Sense Multiple Access (DSMA) refers to a protocol that is used in Cellular Digital Packet Data (CDPD) networks. DSMA’s main objective is to support narrow-band data services.

DSMA transmits channels as well as decode status flags on the forward channel to imply if the reverse channel is occupied and also if the data block received just now on the reverse channel was decoded correctly with no errors.

By having information on the reverse channel, DSMA functions in a way much like slotted Carrier Sense Multiple Access/Collision Detection (CSMA/CD). Slotted non-persistent DSMA is used in the CDPD network.

Techopedia Explains Digital Sense Multiple Access (DSMA)

  • Chance for high collision since other terminals have no idea of ongoing transmission on the reverse channel, thereby reducing the throughput.
  • Long delay in ending ongoing transmission in the event of a collision, thereby misusing bandwidth unnecessarily.