CABLE THEORY 102 2024/2025 REVISION QUESTIONS WITH VERIFIED ANSWERS ALREADY GRADED A++

CABLE THEORY 102 2024/2025 REVISION QUESTIONS WITH VERIFIED ANSWERS ALREADY GRADED A++ 5 factors that affect Attenuation - RIGHT ANSWER -frequency, temperature, dielectric used, center conductor diameter, and cable length. A black and white TV needed a minimum of 1 milli-volt across 75 ohms to provide a good picture. The CATV industry therefore created the - RIGHT ANSWER -Decibel Millivolt (dBmV) A cable signal can be transmitted and received in either an ______________ or a _____________ format. - RIGHT ANSWER -analog; digital A cable television system's master control operation where signals are received (sometimes from a variety of sources: satellite, land-lines, microwave, even taped or live origination) and delivered on various cable system channels. - RIGHT ANSWER -The Headend A figure of merit derived mathematically from the number and severity of signal leaks in a cable system. - RIGHT ANSWER -Cumulative Leakage Index A list of channel numbers and their associated stations for a particular headend. - RIGHT ANSWER -Channel map A mandate by the Federal Communications Commission which requires cable operators only deploy digital set-top boxes that have a PC card slot for a multichannel CableCARD, to decrypt channels. - RIGHT ANSWER -Separable Security A network architecture developed by the cable industry, which typically uses fiber optic cables to bring signals to selected areas of the system called nodes, which are usually based on the number of subscribers to be served. An advantage of fiber is that it has bandwidth many times greater than coaxial cable and can travel great distances without amplification. From the node, conventional coaxial cable, and amplifiers where required, deliver the signals to the feeder cables. - RIGHT ANSWER -Hybrid Fiber-Coaxial (HFC) A range of frequencies - RIGHT ANSWER -Frequency Band A removable security card available from cable TV providers. - RIGHT ANSWER -CableCARDTM A signal modulated at the sender's end must be demodulated at the receiver's end to extract the - RIGHT ANSWER -information the wave carries a sound wave or musical note is characterized by its _______________ (strength) and ______________ (pitch). - RIGHT ANSWER -amplitude; frequency A specification developed for protecting digital entertainment content that travels over HDMI cables. HDCP encrypts the transmission of digital content between the video source or transmitter (such as a computer, DVD player or Xfinity digital receiver) and the digital display, or receiver (such as a monitor, television or projector). - RIGHT ANSWER -High-Bandwidth Digital Content Protection Absolute signal power that describes the signal at a specific location - RIGHT ANSWER -Decibel Millivolt (dBmV) All newer Xfinity set-top boxes have these cards installed in them. It is this card that translates encrypted signals on the Comcast network. - RIGHT ANSWER -CableCARDTM AM - RIGHT ANSWER -Amplitude Modulation Radio An electromagnetic signal above the audio and below the infrared frequencies. - RIGHT ANSWER -RF or Radio Frequency An electromagnetic wave used to transport information from one point to another. It is therefore a controlled variation of electrical energy over time. - RIGHT ANSWER -RF signal An unwanted alteration of the original shape of a signal, is usually caused by the medium it travels through. - RIGHT ANSWER -Signal distortion Analog waveforms have an infinite number of ______________ and ________________ variations. - RIGHT ANSWER -frequency; amplitude Any of the key elements of the signal, such as _______________or ______________, can be changed to get the modulated signal - RIGHT ANSWER -amplitude; frequency Any technology used to protect the interests of owners of content and services (such as copyright owners). Typically, authorized recipients or users must acquire a license in order to consume the protected material—files, music, movies—according to the rights or business rules set by the content owner. - RIGHT ANSWER -Digital Rights Management Architecture, which allows the transmission of several services, such as analog and digital TV, video-on-demand, voice, and high-speed data. - RIGHT ANSWER -Hybrid Fiber-Coaxial (HFC) As a result, though the quality of MPEG-4 compression is much higher than MPEG-2, the distortion lasts __________ if a frame is corrupted during transmission due to the amount of time between key frames - RIGHT ANSWER -longer BER - RIGHT ANSWER -Bit-Error Rate CAE - RIGHT ANSWER -Customer Account Executive Can upgrade or downgrade a customer's level of service with a change to their billing/account information. - RIGHT ANSWER -CAE carry information about which pixels change in relation to the i-frame for transmitted and to-be-transmitted frames - RIGHT ANSWER -B - pictures (bi-directional frames) CFR - RIGHT ANSWER -Code of Federal Regulations CLI - RIGHT ANSWER -Cumulative Leakage Index Code of Federal Regulations the FCC uses to monitor our leakage - RIGHT ANSWER -(CFR), Title 47, Part 76, Cable Television Service regulation Comcast uses the following frequency bands for Forward Path (Downstream) on Legacy Systems : - RIGHT ANSWER -54 up to 1002 MHz Comcast uses the following frequency bands for Forward Path (Downstream) on Mid-Split Systems : - RIGHT ANSWER -54 up to 1.2 GHz Comcast uses the following frequency bands for Return Path (Upstream) on Legacy Systems : - RIGHT ANSWER -5 to 42 MHz Comcast uses the following frequency bands for Return Path (Upstream) on Mid-Split Systems : - RIGHT ANSWER -5 to 85 MHz contain all the information to be transmitted and serve as reference points - RIGHT ANSWER -I - pictures (key frames) Controls the level of service received by the customer by allowing or blocking specific channels or services. - RIGHT ANSWER -Signal security dB - RIGHT ANSWER -Decibel dBmV - RIGHT ANSWER -Decibel Millivolt Degradation of a signal quality may occur due to interference - RIGHT ANSWER -Ingress Degradation of a signal quality may occur due to leakage - RIGHT ANSWER -Egress Digital signal values are expected to fall within certain elements for the circuit to work, such as ______________ or ______________. - RIGHT ANSWER -zero; one digtal signals have _____________ values. - RIGHT ANSWER -discrete DRM - RIGHT ANSWER -Digital Rights Management Each device at the customer's end contains a QAM __________ and __________. - RIGHT ANSWER -modulator; demodulator Earlier, the FCC would allocate a large block of frequencies between channels 6 and 7 for uses other than television, such as for - RIGHT ANSWER -aircraft and police communications. Early television tuners consisted of a drum made up of - RIGHT ANSWER -12 sections Egress can be caused by any of the following: - RIGHT ANSWER --Staples or nails carelessly pushed through the cable -Incorrect center conductor length -Jumpers with push-on connectors -Scraped, cut, or chewed cable -Wrong-size, loose/poorly installed, or corroded F-connectors -Improper seal or weatherproofing -Damaged equipment -Customer-installed devices Examples of devices that demodulate a QAM signal are - RIGHT ANSWER -a set-top box and a cable modem FCC - RIGHT ANSWER -Federal Communications Commission FM - RIGHT ANSWER -Frequency modulation Radio or FM Frequency band in which services are carried on RF signals - RIGHT ANSWER -5 MHz to 1002 MHz HDCP - RIGHT ANSWER -High-Bandwidth Digital Content Protection HFC - RIGHT ANSWER -Hybrid Fiber Coax If the receiver can recognize the zeros and ones of the binary bit stream the picture - RIGHT ANSWER -does not degrade If there is a signal distortion, the ability of the tuner to lock onto and decode the data gets harder. If the signal can't be decoded, we call that a - RIGHT ANSWER -modulation error In the case of digital waveforms, degraded signals can be reproduced as long as the receiver can recognize the - RIGHT ANSWER -binary bits Installation of a jumper may be required based on - RIGHT ANSWER -local system procedures Involve the physical installation of devices to either block content or make certain content available. - RIGHT ANSWER -Traps/Filters Is affected by several factors, such as frequency, temperature, dielectric used, center conductor diameter, and cable length. - RIGHT ANSWER -Attenuation Is also used to denote signal-to-noise ratio (SNR) and cable loss factors. - RIGHT ANSWER -Decibel (dB) Is an absolute signal level, which describes the signal level at a specific location. - RIGHT ANSWER - Is comprised of station airing rules that describe specific program airing times, channels and priority. - RIGHT ANSWER -Channel map information Is determined by comparing the ratio (dB) to one millivolt (mV). - RIGHT ANSWER -Decibel millivolt (dBmV) is one-tenth of this Bel, was first used to measure signal strength by the telephone industry. - RIGHT ANSWER -Decibel (dB) Is the difference between transmitted and received power resulting from the loss through equipment, lines, passive devices, or other transmission devices. - RIGHT ANSWER -Attenuation Is used to express a ratio between two signal power levels, i.e., the loss of signal through a splitter. - RIGHT ANSWER -Decibel (dB) is used to modulate video, voice, and data signals - RIGHT ANSWER -Quadrature Amplitude Modulation (QAM) It is important to eliminate egress and ingress not only to maintain network health, but also because it is regulated and monitored by - RIGHT ANSWER -FCC List 3 preventative measures to protect against egress - RIGHT ANSWER --Ensure that connectors are corrosion free, tight, and waterproofed. -Check that cables are not corroded or do not bear signs of water migration. -Check the fittings. -Ensure that wiring in the homes meets Comcast specifications. List five conditions that can cause Egress - RIGHT ANSWER --Staples or nails carelessly pushed through the cable -Incorrect center conductor length -Jumpers with push-on connectors -Scraped, cut, or chewed cable -Wrong-size, loose/poorly installed, or corroded F-connectors -Improper seal or weatherproofing -Damaged equipment -Customer-installed devices MER - RIGHT ANSWER -Modulation Error Ratio methods are being widely used on Web sites that offer streaming video. - RIGHT ANSWER -MPEG-2 and MPEG-4 MoCA frequency bands - RIGHT ANSWER -1125 to 1625 MHz modulates the amplitude of two incoming carrier waves (I signal and Q signal) to one RF carrier wave - RIGHT ANSWER -Quadrature Amplitude Modulation (QAM) Modulates the frequency of the carrier wave - RIGHT ANSWER -Frequency modulation Radio Modulates the power of the carrier wave thousands of times a second. - RIGHT ANSWER -Amplitude Modulation Radio or AM Modulating a wave means changing its - RIGHT ANSWER -characteristics Monitoring signal leakage limits: The standard specifies the following limits: - RIGHT ANSWER --Not exceed 15 microvolts per meter (µV/m) at a distance of 30 meters (about 100 feet), at 0 to 54 MHz and above 216 MHz -Not exceed 10µV/m at a distance of 3 meters (about 10 feet), at 54 to 216 MHz. Comcast has a stricter limit than the FCC on this limit. monitors our leakage to ensure we don't interfere with military, emergency, or aeronautical frequencies. - RIGHT ANSWER -FCC MPEG - RIGHT ANSWER -Moving Picture Experts Group NTIA - RIGHT ANSWER -National Telecommunications and Information Administration OES requires a jumper to be installed if the trap exceeds the length of a - RIGHT ANSWER -locking terminator On the Comcast Cable Network, there are receivers and demodulators such as _______ _______ and _______ _______ at the customer's end that decode the carriers and convert them back into ones and zeros. - RIGHT ANSWER -set-top boxes; cable modems only carry information about which pixels change in relation to the i-frame - RIGHT ANSWER -P - pictures (predictive frames) Passage of an outside signal into the cable; can result in noise and disruption of the desired signal. - RIGHT ANSWER -Ingress Passage of signal intended to remain within the cable into the outside world; can result in a weaker signal at the end of the cable and radio frequency interference to nearby devices. - RIGHT ANSWER -Egress Passive and active equipment in a Mid-Split system must be designed to operate in the - RIGHT ANSWER -5 MHz to 1,675 MHz range QAM - RIGHT ANSWER -Quadrature Amplitude Modulation Ratio Between two signal power levels - RIGHT ANSWER -Decibel (dB) Rearranges the content of a signal in such a fashion that it cannot be easily decoded by those not authorized to receive such transmissions. - RIGHT ANSWER -Encryption, or Scrambling Refers only to loss or gain, and not the actual signal measurements. - RIGHT ANSWER -Decibel (dB) Refers to an FCC mandated baseline of 1 millivolt across a 75 ohm load. This would indicate a measurement of 0 dBmV. So, 0 dBmV is equal to 1 millivolt across 75 Ohms. - RIGHT ANSWER -Decibel millivolt (dBmV) refers to reducing the number of bits required to carry information (such as digital video images) by removing the redundant bits in the data. - RIGHT ANSWER -Digital Compression Remove an interfering carrier from a channel that a customer wants to receive. - RIGHT ANSWER -Positive traps or filters Signal security can be applied at the: - RIGHT ANSWER --Headend -Tap -Set-top box The ability to compress or encode a signal is an advantage of digital signal formats over analog ones. - RIGHT ANSWER -Digital Compression The basic example of a signal that can be generated, transmitted, and received with RF equipment. - RIGHT ANSWER -Sine Wave The collection of frames to be transmitted in one unit of time is called a - RIGHT ANSWER -'picture group.' The degradation in analog transmission affects the amount of fine detail in the - RIGHT ANSWER -picture quality The difference between a signal's maximum or minimum value during one cycle and usually indicates signal strength or intensity. - RIGHT ANSWER -Amplitude The difference between an analog and digital signal can be checked by using a - RIGHT ANSWER -Signal Level Meter The difference between the two compression methods is that the distance between the key frames is much __________ in MPEG-4, as compared to MPEG-2. - RIGHT ANSWER -more The distance between two consecutive peaks or troughs of a waveform. It is also defined as the space occupied by one complete cycle of a wave. - RIGHT ANSWER -Wavelength The FCC (Federal Communications Commission) began requiring service providers to make CableCARDs™ available as of - RIGHT ANSWER -July 1, 2004 The FCC allocates a certain bandwidth for each digital channel, which can be used either for a ____________ _____________ ____________or for ___________ ____________. - RIGHT ANSWER -single high-definition channel; multiple sub-channels The FCC had originally allocated a ____ MHz wide channel to carry analog video, audio, and color components of a TV channel. - RIGHT ANSWER -6 The FCC monitors our ________ to ensure we don't interfere with military, emergency, or aeronautical frequencies - RIGHT ANSWER -leakage The Federal Communication Commission (FCC) regulations requires a CLI figure of merit of - RIGHT ANSWER -64 or less. The Federal Communications Commission (FCC) now requires any new box to have a card that can be removed, so that consumers can purchase the box and use it with any service provider. - RIGHT ANSWER -Separable Security The higher the frequency of a signal, the shorter its - RIGHT ANSWER -Wavelength The leakage of a signal from a cable network - RIGHT ANSWER -Egress The modulation technique that Comcast uses to encode digital cable channels is called - RIGHT ANSWER -Quadrature Amplitude Modulation (QAM) The most effective preventative measures regarding egress are to: - RIGHT ANSWER --Ensure that connectors are corrosion free, tight, and waterproofed. -Check that cables are not corroded or do not bear signs of water migration. -Check the fittings. -Ensure that wiring in the homes meets Comcast specifications. The MPEG compression methods allow the bandwidth allocated for each digital channel to be used for several high-definition and standard-definition channels - RIGHT ANSWER -Digital Compression The MPEG method splits the signal into three types of encoded pictures: - RIGHT ANSWER -I - pictures (key frames), P - pictures (predictive frames), B - pictures (bi-directional frames) The name of a family of standards used for coding audio-visual information (e.g., movies, video and music) in a digital compressed format. - RIGHT ANSWER -MPEG or Moving Picture Experts Group The NTSC channel allocation scheme allotted 6 MHz chunks of the RF spectrum to be designated as TV channels. Within each channel was the: - RIGHT ANSWER -AM video carrier frequency Burst carrier frequency (color) FM aural carrier frequency (sound) The number of times a signal goes through a complete cycle, i.e., repeats itself, in one second of time - RIGHT ANSWER -Frequency The point at which High-Speed Internet, video On Demand and local telephone signals are spliced into the cable signal. - RIGHT ANSWER -The Headend The primary means of signal security is achieved by: - RIGHT ANSWER -Encryption, or Scrambling The process of converting data into a coded form (ciphertext) to prevent it from being read and understood by an unauthorized party. - RIGHT ANSWER -Encryption the process of encoding a simple radio wave, also known as the carrier wave, with data. - RIGHT ANSWER -Modulation The ratio of the power in the good data points to the power in the bad data points. - RIGHT ANSWER -MER the term used to identify and tune programming. - RIGHT ANSWER -channel The U.S. government agency established in 1934 to regulate electronic communications. The FCC succeeded the Federal Radio Commission. - RIGHT ANSWER -Federal Communications Commission (FCC) There are two types of traps: - RIGHT ANSWER --Negative traps or filters -Positive traps or filters These filters are used to block the return-path noise and 'Multimedia over Coax Alliance' (MoCA) frequencies from exiting a customer's house. - RIGHT ANSWER -Negative traps or filters This effectively reduces the bandwidth required to transmit video over the network - RIGHT ANSWER -Digital Compression Though it is used widely in digital telecommunication systems, it is both a digital and analog modulation scheme. - RIGHT ANSWER -Quadrature Amplitude Modulation (QAM) Weatherproof traps/filters with a - RIGHT ANSWER -Thread What three parts make up an analog signal wageform? - RIGHT ANSWER -Video information carrier, Audio information carrier, and Color information carrier. When the modulated signal reaches the destination point, it is demodulated to obtain the information from the - RIGHT ANSWER -individual signals When the trap/filter is attached to a jumper, install thread protectors on - RIGHT ANSWER -both sides of the F-81 barrel connector to seal the trap/filter and the F-connector. When we shift the pitch of a musical note, we modulate its - RIGHT ANSWER -frequency When we shift the volume of the note, we modulate its - RIGHT ANSWER -amplitude You should use a meter that measures signal leakage on every job you visit to check for - RIGHT ANSWER -egress and ingress.