QUESTION 1

In Pulse Code Modulation (PCM), what is quantization ?

		a. Quantization describes the sampling of an analog signal using Nyquist's sampling theorem
		b. Quantization describes the mapping of a single sample to a bit sequence
		c. If the Nyquist Sampling Theorem s not adhered to, then quantization errors will exist
		d. None of the above describes quantization

10 points

QUESTION 2

You want to digitize an analog signal that has a 22kHz bandwidth. According to Nyquist, what should be your sampling rate?

		a. 11,000 samples per second
		b. 22,000 samples per second
		c. 44,000 samples per second
		d. 22 samples per second

10 points

QUESTION 3

If you do not apply the Nyquist Sampling Theorem when digitizing an analog signal, what will happen?

		a. Signal aliasing
		b. Quantization error
		c. Increased bit rate error
		d. All of the above

10 points

QUESTION 4

You want to digitize a 4000 Hz analog voice grade signal. You select a bit depth of 8 bits per sample. What will be the expected transmitted data rate?

		a. 4kbps
		b. 16kbps
		c. 32kbps
		d. 64kbps

10 points

QUESTION 5

The only way to reduce the transmission data rate required when converting an analog signal into a digital one, is to reduce the sampling rate.

True

False

10 points

QUESTION 6

ADPCM is an improvement over DPCM in that it can vary the size of quantization steps dynamically as needed.

True

False

10 points

QUESTION 7

Differential PCM works on the premise that voice signals change gradually over time, vice abruptly. As such, only changes from one sample to the next are required; thus the bit depth can be reduced.

True

False

10 points

QUESTION 8

Digital Speech Interpolation (DSI) is an analog-only voice compression technique that cannot be used for either digital voice or digital signals.

True

False

10 points

QUESTION 9

Which techniques convert logical data (1's and 0's) into an electrical signal?

		a. NRZ, MANCHESTER, AMI
		b. ASCII, Extended ASCII, Unicode
		c. ASK, FSK, PSK
		d. DPCM, ADPCM, DSI

10 points

QUESTION 10

Select the correct statement(s) regarding line coding.

		a. Line coding is a modulation technique that encodes analog data onto an analog carrier
		b. Line coding maps logical data to changes in an electrical signal (symbol)
		c. Line coding maps symbols (e.g., "ABC", "123") to bit patterns
		d. None of the statements are correct

10 points

QUESTION 11

B8ZS is a technique that specifically replaces a bytes (8 bits) containing all logical 0's with an unique voltage pattern before signal transmission. Select the correct B8ZS sequence that replaces the byte "00000000", if the last voltage before the byte was a +v.

		a. 000+-0-+
		b. 000-+0+-
		c. 0++--00+
		d. 00+-00-+

10 points

QUESTION 12

Which method is used to ensure receive clock synchronization by mapping four bit words into five bit representations?

		a. B8ZS
		b. AMI
		c. 4B/5B
		d. DSI

10 points

QUESTION 13

Select the description that best describes "synchronous transmission"

		a. The use of start/stop bits for each byte of information
		b. Master clock sources are used over the entire network
		c. Timing is recovered from the transitions in the received data stream
		d. Devices run at nominally the same rate with defined parameters of tolerance for variations

10 points

QUESTION 14

Select the correct statement(s) regarding "Error Control".

		a. With "Error Detection", additional bits are added to the data word to help identify bit errors experienced during transmission
		b. With "Error Correction", redundant bits are added to the data word to help identify and correct bit errors experienced during transmission
		c. Error control provides probabilities of experiencing errors, vice an absolute certainty of experiencing errors
		d. All of the above are correct

10 points

QUESTION 15

Select the correct statement(s) regarding error detection.

		a. A codeword represents information bits
		b. A dataword is comprised of both the codes work plus check bits
		c. The dataword goes through a specific error detection algorithm in order to compute error detection bits that are then appended to the dataword for transmission
		d. The codeword goes through a specific error detection algorithm in order to compute error detection bits that are then appended to the codeword for transmission

10 points

QUESTION 16

Which multiplexing technique can be used with analog basebands?

		a. FDMA
		b. TDMA
		c. CDMA
		d. Both FDMA and TDMA

10 points

QUESTION 17

-30dBW = _________dBm

		a. -30dBm
		b. 0dBm
		c. +30dBm
		d. -60dBm

10 points

QUESTION 18

-85 dBm = _________mW

		a. 3.16E-9 mW
		b. 3.16E-12 mW
		c. -115 mW
		d. -55 mW

10 points

QUESTION 19

600mW = _________dBW

		a. 60 dBW
		b. 0.6 dBW
		c. -2.2 dBW
		d. 27.8 dBW

10 points

QUESTION 20

45 dBW = _________mW

		a. 3.16E7 mW
		b. 3.16E4 mW
		c. 75 mW
		d. 45 mW

10 points

QUESTION 21

Given the following information, what is the power received (Rx) at the receiver? Tx=50dBm, FSL=-50dB, given the equation: Rx(dBm) = Tx(dBm) + FSL(dBs)

		a. Rx = 100 dBW
		b. Rx = 0 dBm
		c. Rx = -100dBm
		d. Rx = 30 dBW

10 points

QUESTION 22

The Signal-to-Noise Ratio (SNR or S/N) can be represented in decibel or non-decibel form. Select the correct decibel format where the use of brackets (i.e., [ ]) signifies dB values.

		a. [N]/[S]
		b. [S]/[N]
		c. [S] - [N]
		d. [S] + [N]

10 points

QUESTION 23

What is the noise temperature for a receiver operating at a temperature of T=305^oK and frequency bandwidth of the receiver is B=4kHz? (N=kTB)

		a. 1.68E-17 watts or -167.7dBW
		b. 1.68E-14 watts or -167.7dBW
		c. 1.22E+14 watts or +139dBW
		d. 4.07E+21 watts or +204dBW

10 points

QUESTION 24

Determine the SNR (dBs) for a received signal power, Pr=-10dBm, and a receiver noise, N=-203dBm?

		a. Pr(dBm)*N(dBm)= 2.03E3 dBm
		b. Pr(dBm)/N(dBm)= 49.26 dBm
		c. Pr(dBm)+N(dBm)= -213 dBm
		d. Pr(dBm)-N(dBm)= 193 dBm

10 points

QUESTION 25

The Shannon-Hartley equation give us the theoretical maximum data rate capacity achievable. In practice, this theoretical rate is rarely, if ever, achieved.

True

False

10 points

QUESTION 26

What does the Shannon-Hartley equation tell us?

		a. As the frequency bandwidth increases, so does data rate capacity
		b. Increasing signal power will increase data rate capacity
		c. Decreasing noise power will increase data rate capacity
		d. All of the above

10 points

QUESTION 27

Propagation delay only considers the time it takes for a signal to travel through a medium to its destination.

True

False

10 points

QUESTION 28

For UTP, the greater the copper wire diameter (i.e., smaller AWG), the less the signal attenuation experienced, and the further the signal can travel in distance.

True

False

10 points

QUESTION 29

In contrast to conductive guided medium, smaller diameter fiber optic cores means greater attenuation and decreased transmission distances when compared to larger fiber optic cores.

True

False

10 points

QUESTION 30

Guided UTP is configured as a balanced circuit.

True

False

10 points

QUESTION 31

Delay skew and crosstalk are only problems encountered when using coaxial cables for communications.

True

False

10 points

QUESTION 32

A BER of 10E-6 tells you that there is a probability of having one bit error for every 1,000,000 bits sent.

True

False

10 points

QUESTION 33

Signals on coaxial cables are unbalanced. When compared to UTP, coaxial medium has higher bandwidth and data rate carrying capability compared to UTP.

True

False

10 points

QUESTION 34

Select the correct statement(s) regarding fiber optic medium.

		a. TIR is the principle that makes light communications travel efficiently through a fiber optic cable
		b. MMF fiber can be step-indexed or graded-index
		c. SMF has a greater bandwidth and throughput capability over MMF
		d. ITU describes transmission windows associated with signal wavelength
		e. All of the above are correct

10 points

QUESTION 35

Both SMF optical cores are either step-index or graded-index. As such, SMF is susceptible to modal dispersion.

True

False