Which of the following is a method of multiplexing data where a communication channel is divided into an
arbitrary number of variable bit-rate digital channels or data streams. This method allocates bandwidth
dynamically to physical channels having information to transmit?

A.
Time-division multiplexing

B.
Asynchronous time-division multiplexing

C.
Statistical multiplexing

D.
Frequency division multiplexing

Explanation:
Statistical time-division multiplexing (STDM) transmits several types of data simultaneously across a single
transmission cable or line. The communication channel is divided into an arbitrary number of variable bit-rate
digital channels or data streams.
Incorrect Answers:
A: Time-division multiplexing (TDM) is less complex compared to Statistical multiplexing. In its primary form,
TDM is used communication with a fixed number of channels and constant bandwidth per channel.
B: Asynchronous time-division multiplexing (TDM) is similar to TDM. It uses a fixed number channels, not an
arbitrary number of channels like STDM.
D: Frequency-division multiplexing (FDM) uses an available wireless spectrum, not a communication channel,
to move data.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 672