2024 LATEST Digital Technician 100% SOLUTIONS REVISED

Which was the first version of the Data Over Cable Service Interface Specification (DOCSIS) that enabled multiple downstream and upstream channels to be used to transport data to and from a single modem? - ANSWER Docsis 3.0 Which generation of wireless access technology is operation in the millimeter frequency band around 30 GHz being considered? - ANSWER 5G Which is the only 802.11 series of standards that operate at 900 MHz for reliable, slower-throughput connectivity with Internet of Things (IoT) sensors in the customer's home? - ANSWER 802.11ah Voice activated personal assistants are always listening for commands, but are programmed to respond only when hearing what? A wake word, such as the assistant's name. - ANSWER A wake word, such as the assistant's name. What technology is plain old telephone service (POTS) built on? - ANSWER Circuit switching. Why is the transmission control protocol (TCP) unsuitable for voice over Internet protocol (VoIP) applications? - ANSWER TCP is a connectionless protocol that operates without packet management. What does a cell phone seek when it tunes to its control channel frequency? - ANSWER How is the perception of three-dimensional high definition TV (3D HDTV) created? - ANSWER By displaying an image from two slightly different angles, like a pair of human eyes. High-dynamic range (HDR) video calls for a minimum color depth of 10-bits, which provides up to how many shades of each color? - ANSWER 1,024 In what applications are broadband cable operators implementing Internet protocol TV (IPTV) technology? - ANSWER In TV everywhere applications. How many base-10 numbers can be expressed with two digits? - ANSWER 99 What is the decimal range of an 8-bit binary number? - ANSWER 0 - 255 What position in the American Standard Code for Information Interchange (ASCII) character string is a single parity bit added? - ANSWER The eighth-bit position to become the most significant bit (MSB). What form of compression is Huffman coding? - ANSWER Lossless. In what scenario does an AND gate have a logical 1 output? - ANSWER When all inputs are logical 1 What characterizes an OR gate? - ANSWER In a NAND gate, what reverses the voltage state from that of an AND gate? - ANSWER The NOT gate that follows the AND gate. Why are NAND and NOR gates the most used logic gates and categorized as universal gates? - ANSWER In combinations of two or three, they can be configured to construct any other logic gate. Which logic gate combines different logic gates to act as a logical either/or operator? - ANSWER The exclusive-OR (XOR) gate. Which logic gate acts as a logical either/or operator followed by a NOT gate? - ANSWER The exclusive-NOR (XNOR) gate. What geometric shape is a sine wave based upon? - ANSWER Right - degree triangle What is the ideal sampling rate for any analog signal? - ANSWER Twice the highest frequency perceived by human eyes and ears. What does quantizing do? - ANSWER It rounds the values of sampled voltage levels to the closest numeric value in a numeric set. In the audio compression coding schemes defined by ITU-T G.711 that compress 16-bit linear data down to 8-bit logarithmic data, what does the most significant bit (MSB), bit 1, identify? - ANSWER The segment polarity. For quadrature phase shift keying (QPSK), how many bits are in each symbol? - ANSWER 2 bits What is the purpose of the forward error correction (FEC) interleaving layer? - ANSWER To reduce the probability of an impairment event corrupting more than one bit in a string. Why is randomizing included in the forward error correction (FEC) process? - ANSWER To help the receiver maintain synchronization with the modulator. How does Trellis coding provide error correction? - ANSWER It adjust the symbol transitions to a robust set, enabling the receiver decoder to calculate the most probable transition, even if the received data is corrupt. In which forward error correction (FEC) stage does an algorithm calculate a 3- bit binary code that is transmitted as the 8-level symbols of eight-level vestigial sideband (8- VSB)? - ANSWER The trellis encoder stage. - How is Fourier analysis used in orthogonal frequency division multiplexing (OFDM)? - ANSWER To calculate the transformation of signals from the time domain to the frequency domain or from the frequency domain to the time domain. Which signal parameters can be viewed in the frequency domain? - ANSWER Channel amplitude, bandwidth, and nearby impairments. In a broadband cable network, why are power measurements taken by measuring a channel's voltage level across an assumed load impedance, rather than with a wattmeter? - ANSWER It is usually easier and less disruptive to measure a channel's voltage level. Why is amplitude measurement of a quadrature amplitude modulation (QAM) channel taken from the average power across the channel bandwidth, instead of the carrier? - ANSWER The carrier in a QAM channel is 1.25 Mhz above the edge of the channel bandwidth What do all signal level measuring test instruments have through which the instrument sees the energy to be measured? - ANSWER A resolution bandwidth (RBW) filter. In a digital modulation channel, what is the uniform distribution of energy as a function of frequency called? - ANSWER Spectral density