Statistical Time Division Multiplexing
Statistical multiplexing is a type of communication link sharing, very similar to dynamic bandwidth allocation (DBA). In statistical multiplexing, a communication channel is divided into an arbitrary number of variable bit-rate digital channels or data streams. The link sharing is adapted to the instantaneous traffic demands of the data streams that are transferred over each channel. This is an alternative to creating a fixed sharing of a link, such as in general time division multiplexing (TDM) and frequency division multiplexing (FDM). When performed correctly, statistical multiplexing can provide a link utilization improvement, called the statistical multiplexing gain.
Statistical multiplexing is facilitated through packet mode or packet-oriented communication, which among others is utilized in packet switched computer networks. Each stream is divided into packets that normally are delivered asynchronously in a first-come first-serve fashion. In alternative fashion, the packets may be delivered according to some scheduling discipline for fair queuing or differentiated and/or guaranteed quality of service.
Statistical multiplexing of an analog channel, for example a wireless channel, is also facilitated through the following schemes:
- Random frequency-hopping orthogonal frequency division multiple access (RFH-OFDMA)
- Code-division multiple access (CDMA), where different amount of spreading codes or spreading factors can be assigned to different users.
Statistical multiplexing normally implies "on-demand" service rather than one that preallocates resources for each data stream. Statistical multiplexing schemes do not control user data transmissions.
Read more about Statistical Time Division Multiplexing: Comparison With Static TDM, Channel Identification, Usage, Statistical Multiplexer, See Also
Famous quotes containing the words time and/or division:
“As the Americans slaughter millions of turkeys every year for the celebration of their deliverance, the Indians, who should be celebrated as saviors, have long been slaughtered. There was even a time when a white man was paid a very decent price for every Indian scalp he could produce.”
—Friedrich Dürrenmatt (1921–1990)
“That crazed girl improvising her music,
Her poetry, dancing upon the shore,
Her soul in division from itself
Climbing, falling she knew not where,
Hiding amid the cargo of a steamship
Her knee-cap broken.”
—William Butler Yeats (1865–1939)