CN QUIZ 2

Binary codes are sometimes transformed in modems into

• Hexadecimal

• Huffman codes

• Gray code

• Complementary codes

PCM sampling rate is 8000 samples per second because

• that represents the maximum rate that technology supports.

• this rate allows unique values.

• this rate allows the faithful recon-traction of an analog signal.

• this rate is easily produced by a sampling chip.

 The D4 framing pattern contains a sequence of 

•  24 bits

• 4 terminals and 8 framing bits.

• 8 terminals and 4 framing bits

• 12 bits

 The path or channels over which information moves from one location to another make-up is called.

• lines

• remote computers

•  modems

• file transfer

A half-duplex communication channel permits information to travel

• both ways at once

• both ways, but not at once

•  one direction only

• at timed intervals

An error detecting code is the remainder resulting from dividing the bits to be checked by a predetermined binary number, is called

• cyclic redundancy check

• checksum

•  error detecting code

• error rate

Demultiplexing by a time division multiplexer occurs based on the

• the position of data within a frame

• the position of a frame within a group of frames

• the activity of a connected device

•  the priority assigned to a connected device

They key to the operation of ADPCM (adaptive delta pulse code modulation) is

• fast sampling

• high amplitude

• adaptive predictor

• digitization

The maximum modem operating rate that can be transported by ADPCM (adaptive delta pulse code modulation) is

• 300 bps

• 1200 bps

• 4800 bps

• 9600 bps

Higher the rate an analog signal is sampled

• smaller the difference between sampled amplitudes

• larger the difference between sampled amplitudes

• greater the noise level

• more bits required to represent the sample