Tech 2-3 Progression
(-25) + (42) + (-62) + (20) =
-25
(17) x (-19) =
-323
8.13 X 0.123 =
0.99999
7 3/8 divided by 7 1/4 =
1 1/58
(-17) - (-34) =
17
(250 x 10 to the power of -6) - (7 x 10 to the power of -5) =
180 x 10 to the power of -6
3 6/9 + 6 1/3 + 9 5/9 =
19 5/9
(20) / (-4) + (-2) x (-10) - (-2) x (7) =
29
0.5349 divided by 0.1420 =
3.7669014
When using a digital signal analyzer to troubleshoot data throughput in the Data Over Cable Service Interface Specification (DOCSIS) network, what is the minimum modulation error ratio (MER) into the cable modem for a 256- quadrature amplitude modulation (QAM) carrier?
32 dB or greater.
(75 x 10 to the power of 3) + (25 x 10 to the power of 4) =
32.5 x 10 to the power of 4
(75 × 103) + (25 × 104) =
32.5 × 104
0.00004 = ______ x 10 to the power of ______.
4, -5
The square of 7 =
49
4/7 x 9 4/11 =
5 27/77
-49/-7 =
7
What would be the downstream throughput if two quadrature amplitude modulation (QAM) channels with a throughput of 38 megabits per second (Mbps) were bonded?
76 Mbps.
(480 x 10 to the power of -5) divided by (60 x 10 to the power of -3) =
8 x 10 to the power of -2
The square root of 81 =
9
In unshielded twisted-pair (UTP) cable, what is the term that describes when an information-carrying conductor makes contact with a grounded conductor?
A Transposition
What is the likely problem when there is dial tone on one phone connected to an outlet, but not on two other phones connected to two different outlets?
A short caused by a break in a conductor, poor contact in a modular connector, or an incorrect wire connection.
It is essential to pay attention to warning signs of stress overload. Poor attitude is one of the behaviors that may indicate that you are overstressed. What are the symptoms of poor attitude behavior?
A significant change in attitude with a noticeable movement toward negative, hostile, cynical, or paranoid thoughts.
What is the difference between the fiber-to-the-node (FTTN) and fiber-to-the-curb (FTTC) topologies?
An FTTC is allowed a smaller number of RF amplifiers between the optical fiber and the customer premises.
If the telephone wiring is in the bus topology and the twisted-pair cable tester is connected at the embedded multimedia terminal adapter (EMTA) with the remote unit connected to the last outlet in the loop, what is the quickest way to locate the incorrectly wired outlet if the tester indicates a wiring error?
Break the loop into smaller sections and retest the two sections to identify which one has the wiring error. Continue to divide the section with the error into smaller sections until the wiring error is identified.
What is one reason why broadband cable operators install fiber-optic cable in stages instead of changing the infrastructure all at once?
Changing the infrastructure all at once would cause too many service disruptions.
In a Data Over Cable Service Interface Specification (DOCSIS) network, why is the data throughput over the return or upstream path typically less than the throughput of data over the forward or downstream path?
Compared to the downstream path, the narrower bandwidths and lower orders of modulation used to transport data over the return path cause the downstream and upstream data throughput to be unequal or asymmetrical.
When replacing a splitter to resolve a digital TV (DTV) service problem, what does confirming the splitter output levels before attaching the output connectors do?
Confirmation reinforces the technician's confidence that the problem will be resolved by replacing the splitter.
During which step of the six-step troubleshooting process for a digital TV (DTV) service problem are quadrature amplitude modulation (QAM) channel measurements typically taken?
Diagnosing symptoms.
Which type of star topology used in a passive optical network (PON) places the PON splitters into fiber access terminal (FAT) located deep in the network and closer to the customer premises than the centralized split?
Distributed star.
Simplify and solve the equation: If E = IR then I = ?
E/R
Which of the following describes a fiber pigtail?
Fiber-optic cable with pre-connectorized ends.
How does Internet protocol (IP) multicast differ from IP broadcast?
IP multicast traffic is only sent to specific modem addresses on the network; IP broadcast traffic is sent to all modems on the network.
Which of the following is a method for controlling expectations?
Identify the source of emotional overload.
How are optical splitters used in the forward path?
In the forward path, optical splitters are used as passive branching devices that divide an optical signal across multiple output fibers.
After a digital TV (DTV) service problem has been analyzed and possible causes considered, what is accomplished by isolating the various network elements?
It narrows the scope of likely problem sources.
What layers of the Open Systems Interconnection (OSI) reference model are specific to cable networks and are present only between Data Over Cable Service Interface Specification (DOCSIS) modems and the cable modem termination system (CMTS)?
Layers 1 through 4 (Physical layer, Data Link Layer, Network Layer, and Transport Layer) are applied between the DOCSIS modem and CMTS.
A customer reports a problem of no dial tone (NDT). Upon inspection, the technician notices that new carpeting has been installed. What should the technician do next?
Look for a cable that runs under the carpet; it is likely that the cable has a short from the carpeting tack strip.
By taking control of the expectations you have, you are
More likely to improve your motivation and be a better problem solver.
Why should you take the time to take notes and accurately record data at each job location?
Notes and recorded data are tools that can help you accurately remember events at a site that can help you determine a plan of action or evaluate the decisions you made.
Because the spectral density of a quadrature amplitude modulation (QAM) channel is much higher than that of an analog TV channel, what is done to ensure equal power in all channels in a network with analog and digital modulation channels?
Operate the analog TV channels at higher amplitude level than the QAM channels.
Which element of a passive optical network (PON) uses patch panels?
Optical distribution network (ODN).
Which element of a passive optical network (PON) uses a Bragg grating filter?
Optical line terminal (OLT).
Which of these components is used in a passive optical network (PON)?
Optical splitters.
What are two features that were added in Data Over Cable Service Interface Specification (DOCSIS) 3.1 to extend the viability of hybrid fiber/coax (HFC) networks into the next decade?
Orthogonal frequency division multiplexing (OFDM) and low-density parity-check (LDPC).
Which of the following best describes stereotyped thinking?
Presuming that all members of a group have certain characteristics.
What is it about radio frequency over glass (RFoG) that made broadband cable operators envision using it to make a seamless transition from the legacy hybrid fiber/coax (HFC) architecture over to a gigabit-capable passive optical network (GPON) or Ethernet passive optical network (EPON)?
RFoG can operate in parallel with GPON or EPON, which eliminates the need for any downtime during the transition.
How is silver satin cable used to connect telephone equipment to wall outlets typically pinned?
Reversed at opposite ends, or cross-pinned.
When troubleshooting a digital TV (DTV) authorization issue, what can be verified using the set-top box (STB) diagnostic page?
STB reception of authorization message data.
Which type of set-top box (STB) operates more like Data Over Cable Service Interface Specification (DOCSIS) cable modems with return channels on the same frequencies used for cable modems?
STB with DOCSIS Set-top Gateway (DSG) client software and embedded DOCSIS modems.
What should be checked as a possible cause of hum on a customer's telephone line?
Shielding problems in the station wiring, poor terminations, or poor grounding and bonding connections.
Which of the following characterizes the successful troubleshooter?
Someone with an inquisitive and relentless desire to solve and fix problems.
Which step in the troubleshooting process requires a discussion with the customer to gather more detail about the problem?
Step 1: Identify the problem.
To break the habit of a negative self-talk cycle
Tell yourself "not now" and move onto a positive thought whenever negative thoughts occur.
Which Data over Cable Service Interface Specification (DOCSIS) layer is used by the cable modem termination system (CMTS) to differentiate between cable modems?
The DOCSIS Media Access Control (MAC) Layer.
What does a set-top box (STB) diagnostic page of a quadrature amplitude modulation (QAM) channel showing signal-to-noise ratio (SNR) near or below 30 dB indicate?
The QAM channel quality is on the edge for reliable reception, and the source of the problem is likely in the distribution network or customer premises.
What was introduced in Data Over Cable Service Interface Specification (DOCSIS) 3.0 to allow enough bandwidth for upstream carriers from previous DOCSIS versions?
The option to increase the top frequency of the upstream to 85 MHz.
What is the difference between the wiring configurations for a residential, 8-position, 8-contact (8P8C) modular plug and jack in the Universal Service Order Codes (USOC) and ANSI/TIA/EIA 570-B?
The placement of pair numbers 3 and 4.
When analyzing a problem, what can the technician learn by asking the customer to show or demonstrate the problem?
The symptoms of the problem can be viewed and any unusual screens or customer entries can be identified.
In the customer premises, what could cause some dual tone multifrequency (DTMF) touch-tone telephones to have continuous dial tone caused by polarity reversal, but not other DTMF telephones
The telephone wiring polarity is incorrect, and the customer has a mix of older and newer DTMF touch-tone telephones.
What must a technician be aware of when analyzing a digital TV (DTV) problem?
There is frequently more than one contributor to a specific DTV service problem.
How should the digital multimeter (DMM) be used to troubleshoot problems in the telephone wiring?
Use the voltmeter function; both the network interface device (NID) and the embedded multimedia terminal adapter (EMTA) provide a steady on-hook voltage.
After resolving the problem with the premises wiring issue, which of the following is the next step in the six-step process that the technician should take?
Verify that the problem has been resolved and that phone service is running perfectly on all phones.
You are at a customer's home and you believe you have solved the problem. When you check to be sure the resolution did not introduce any new problems, which step are you using from the six-step troubleshooting process?
Verifying the solution.
Which of the following are statements of true axioms?
When A = C and B = C, then A = B because both are equal to C, which supports the axiom: Quantities equal to the same quantity are equal to each other.
The attribute of being "active" as a critical thinker means
You observe and take notes relevant to the issue.
What kind of reasoning is described as applying a general statement that you know to be true to a new situation?
deductive.
You are at a customer's home and you are asking the customer whether the problem is intermittent or constant. Which step are you using from the six-step troubleshooting process?
identifying the problem.
10 to the power of -3 has a metric prefix of ______.
milli
