Study Guide 3
(-25) + (42) + (-62) + (20) =
-25
(17) x (-19) =
-323
8.13 X 0.123 =
0.99999
The Federal Communications Commission (FCC) rules regarding power output for frequency-hopping spread spectrum (FHSS) state that a maximum output to the intentional radiator (IR) with 5 megahertz (MHz) of carrier frequency bandwidth must be which one of the following?
125 milliwatts (mW).
-17 - (-34)
17
What initialization vector (IV) do most weak implementations of the Wireless Equivalency Protocol (WEP) use?
24 bit.
(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.
0.00004 = ______ x 10 to the power of ______.
4, -5
What does the Institute of Electrical and Electronics Engineers (IEEE) specify as the maximum allowable power output into the intentional radiator for IEEE 802.11a-, 802.11n-, and 802.11ac-compliant devices operating on the lower Unlicensed National Information Infrastructure (U-NII) radio band?
40 milliwatts (mW).
What test instrument is used to locate and measure interfering narrowband radio frequency (RF) signals in an IEEE 802.11 wireless local area network (WLAN), among other things?
A spectrum analyzer.
What is a slot time in an IEEE 802.11 wireless local area network (WLAN)?
A standard period of time on a WLAN that each station multiplies by a random number to determine the length of time to wait before performing a clear channel assessment (CCA).
What is a half-duplex device that is only capable of Open Systems Interconnection (OSI) reference model Layer 2 connectivity?
A wireless bridge.
What is the standard encryption method used with WPA2?
AES.
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.
Although there are many different implementations of spread spectrum technology, what are the only types specified by the FCC in the Codes of Federal Regulation (CFR), volume 47, part 15?
Direct Sequencing Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).
In what manner do radio waves propagate (move) away from the source (antenna)?
In a straight line in all directions at once.
What are some of the access points (AP) facts that should be detailed in a wireless local area network (WLAN) site survey?
Location within facility, antenna type to be used, power output settings, how power will be provided to unit, and the expected data throughput per unit
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.
10 to the power of -3 has a metric prefix of ______.
Milli
What should you note in the wireless local area network (WLAN) site survey if a semidirectional antenna is required for adequate coverage?
The antenna orientation along with the antenna's side and back lobes for coverage and security reasons.
How might you confirm the presence of a hidden node on the network?
Turn on the request to send/clear to send (RTS/CTS) protocol and watch for increased network data throughput.
You wish to build a wireless network that provides significantly better throughput than a single IEEE 802.11b access point (AP). Which of the following is an acceptable solution?
Use IEEE 802.11-compliant equipment operating in the 5 GHz U-NII bands, allowing for more more non-overlapping channels.
What causes the hidden node problem in a wireless local area network (WLAN)?
When a client (or node) can receive signals from an access point (AP), but an obstacle prevents the client from receiving signals from the other clients that are connected to the network.
When should you consider enabling Request to Send/Clear to Send (RTS/CTS) protocol on a wireless local area network (WLAN)?
When large frames experience high collision rates.
Which statement best describes a network application for which a wireless workgroup bridge is the best suited?
When remote buildings house small groups of wired clients needing wireless access to the main network.
(75 × 10^3) + (25 × 10^4) =
32.5 × 10^4
How does radio frequency line-of-sight (RF LOS) differ from visual LOS?
RF LOS is accompanied by a Fresnel Zone, a series of concentric ellipsoid-shaped areas around the visual LOS path.
What is Equivalent Isotropically Radiated Power (EIRP)?
The power actually radiated by the antenna element.
What is it called when several computers are sharing files without a WAP?
ad-hoc mode.
7 3/8 divided by 7 1/4 =
1 17/42
Which of the voltage standing wave ratios (VSWR) shown below is best for transferring radio frequency (RF) energy between connections?
1.2:1
What is the maximum range of Class 2, 2.5 milliwatt (mW), Bluetooth devices?
10 meters or 33 feet.
How wide is each of the three wireless local area network (WLAN) Unlicensed National Information Infrastructure (U-NII) bands?
100 megahertz (MHz).
How many channels are available with IEEE 802.11g?
11
(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
Which is the largest IEEE 802.11 data frame that can traverse a wireless local area network (WLAN) without fragmentation?
2,346 bytes.
All 802.11 standards use one of two frequency bands. What are these frequency bands?
2.4 GHz and 5 GHz bands.
What is the width of direct sequence spread spectrum (DSSS) channels and how far apart are their center frequencies spaced?
22 megahertz (MHz) and 5 MHz.
(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
What is the Federal Communications Commission (FCC) regulation for the maximum equivalent isotropically radiated power (EIRP) from a point-to-multipoint (P22P) wireless local area network (WLAN) antenna?
4 watts (W).
The square of 7 =
49
4/7 x 9 4/11 =
5 27/77
Given an access point (AP) with 100 milliwatts (mW) of output power connected through a cable with 3 decibels (dB) of loss to the antenna with a 10 decibels isotropic (dBi) gain, what is the approximate Equivalent Isotropically Radiated Power (EIRP) level from the antenna in milliwatts (mW)?
500 mW
-49/-7
7
A transmitter outputs 100 milliwatts (mW). An antenna cable connects the transmitter to an amplifier, and the power into the amplifier's input measures 50 mW. The amplifier increases the signal to the original transmitter's power level and sends the signal to the antenna. The antenna receives the signal from the amplifier at 75 mW, and then transmits at 150 mW. What is the intentional radiator's (IR) power level in this radio frequency (RF) circuit?
75 mW
What power over Ethernet (PoE) device picks off the direct current (DC) voltage that has been injected into the CAT-5e cable by the injector and makes it available to the equipment through the regular DC power jack?
A DC picker or tap.
What is the term for the error caused when one end of an unshielded twisted-pair (UTP) cable is terminated in the T568A configuration and the other end in the T568B configuration?
A Transposition
In addition to being accurate and detailed, a successful troubleshooter knows that
A critical step in troubleshooting is verifying the signal levels and signal quality at the tap to establish the baseline performance for the installation
What type of wireless local area network (WLAN) attack could cost an employee their job because network usage logs point directly to the employee whenever a hacker gains access to the employee's domain login information and causes havoc on the network?
A passive attack.
What antenna type is ideal for making a point-to-point (P2P) network connection between two office buildings that are across the street from one another?
A semidirectional antenna.
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 a man-in-the-middle attack on a wireless local area network (WLAN)?
A situation in which a hacker uses an access point (AP) to effectively hijack mobile nodes (clients) by sending a stronger signal than the legitimate AP is sending.
An independent basic service set (IBSS) is also commonly referred to as which one of the following?
Ad hoc network.
Which statement best describes protocol filtering that has been implemented in a wireless bridge?
Allowing or denying wireless traffic using Open Systems Interconnection (OSI) reference model Layer 4 ports to filter Layer 7 applications.
What is the last step of the basic wireless access point (WAP) setup?
Apply security.
In which of the following applications might a wireless local area network (WLAN) be deployed in a distribution layer role?
As a building-to-building bridge used to link corporate network segments.
Why would a wireless local area network (WLAN) administrator rarely see the "authenticated" step on the access point (AP)?
Because clients pass the authentication stage and immediately proceed into the association stage.
Heat shrink tubing is installed over the fusion-splice to strengthen and protect it. When should the heat shrink be installed on the fiber?
Before stripping the plastic coating from the fiber.
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.
How would you use a laptop computer, tablet, or cell phone when performing a site survey for a wireless local area network (WLAN)?
By checking for signal strength and coverage areas while roaming around the facility.
How can filtering augment some of the security limitations of Wired Equivalent Privacy (WEP) in a wireless local area network (WLAN)?
By defining parameters to which client stations must adhere in order to gain access to the network.
How does spread spectrum technology reduce the probability of signal jamming?
By transmitting over a wide frequency spectrum.
Which term describes a wireless system in which the access point (AP) removes the wireless local area network's (WLAN) service set identifier (SSID) from the beacon frames?
Closed system.
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.
What unit of measurement is used to express the gain of an antenna?
Decibels isotropic (dBi).
What kind of reasoning is described as applying a general statement that you know to be true to a new situation?
Deductive.
For maximum security, you should base your wireless local area network (WLAN) user authentication on which one of the following?
Device-independent schemes, such as user names and passwords.
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.
What challenges do Wireless Internet Service Providers (WISP) have to overcome in order to provide "last mile data delivery" to customers?
Distance to access points (AP), rooftop access, lightning, trees, mountains, tower access, and other physical obstacles to connectivity.
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.
How might a wireless local area network (LAN) administrator ensure compliance with security audits?
Document audit procedures in the security policy.
Simplify and solve the equation: If E = IR then I = ?
E/R
As a general rule, how does an increase in effective isotropic radiated power (EIRP) relate to the link budget range?
Each 6 decibels (dB) increase in EIRP equates to a doubling of range.
In what direction does an omnidirectional antenna radiate RF energy?
Equally in all directions around its axis.
Bluetooth uses which spread spectrum technology?
Frequency-hopping spread spectrum (FHSS).
Where do Data Over Cable Service Interface Specification (DOCSIS) modems receive their configuration files, billing system messages, and access control messages from?
From the cable modem termination system (CMTS), which interfaces with the operations support system (OSS) and acts as a proxy or messenger that transfers messages and files between the modems and the respective servers.
In unshielded twisted-pair (UTP) cable, what is the term that describes when an information-carrying conductor makes contact with a grounded conductor?
Ground fault.
Which version of the IEEE 802.11 wireless local area network (WLAN) standard was the first to use orthogonal frequency division multiplexing (OFDM)?
IEEE 802.11a.
Operation as an IEEE 802.11ac device occurs only in the 5 gigahertz (GHz) Unlicensed National Information Infrastructure (U-NII) radio band, so how are 802.11ac devices able to maintain compatibility with earlier standards that operate in the 2.4 GHz Industrial, Scientific, and Medical (ISM) radio bands?
IEEE 802.11ac devices also operate in the 2.4 GHz ISM range.
How are 8-position, 9-contact (8P8C) modular connectors pinned to unshielded twisted-pair (UTP) cable, which is used for connecting computers and broadband modems to a local area network (LAN)?
Identical at opposite ends, or straight-through.
Which of the following is a method for controlling expectations?
Identify the source of emotional overload.
When troubleshooting a continuous dial tone problem, what is it necessary to do?
Identify where the polarity of the telephone wiring is reversed.
What information should you gather during the wireless local area network (WLAN) site survey in a convention center for an upcoming trade show?
Identify who will be installing access points (AP) in ceilings that could be 40 feet high.
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.
What is a consideration when mounting a high-gain omnidirectional antenna indoors on the ceiling?
If the ceiling is too high, the coverage area might not reach the floor where the users are located.
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.
What can be done to increase the coverage area of a wireless local area network (WLAN)?
Increase the transmission power, replace the omnidirectional antenna with a parabolic antenna, and use the 2.4 GHz radio band instead of the 5 GHz radio band.
Which term describes the operation mode of a basic service set (BSS)?
Infrastructure mode.
Which mode uses a wireless access point (WAP) connected to a wired network?
Infrastructure.
What is a wireless local area network (WLAN) service set?
It describes the basic components of a fully operational WLAN.
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.
Which statement describes a passive injector?
It places direct current (DC) voltage onto a CAT-5e cable.
What happens when an active Ethernet switch fails to sense a power over Ethernet (PoE) device on a port?
It switches off the direct current (DC) voltage on that port.
Why is direct sequence spread spectrum (DSSS) the most widely known and the most used of the spread spectrum types?
Its ease of implementation and high data rates.
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.
By taking control of the expectations you have, you are
More likely to improve your motivation and be a better problem solver.
What technologies does the IEEE 802.11n wireless standard use to achieve data rates as high as 600 megabits per second (Mbps)?
Multiple input, multiple output (MIMO) technology and spatial multiplexing.
Which one of the following conditions occurs when an access point (AP) receives a distant client's signal at a lower power level than that of a nearer client?
Near/Far.
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).
What type of connectivity is needed to connect networks between two buildings located across the street from each other?
Point-to-point (P2P).
Wireless local area networks (WLAN) that use an IEEE 802.1x protocol control network access on what basis?
Port based.
Which one of the following power management modes populates a traffic indication map (TIM) in a basic service set (BSS) or extended service set (ESS)?
Power save polling (PSP) mode.
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.
Which one of the following radio frequency (RF) behaviors is defined as "the bending of a wave as it passes through a medium of different density"?
Refraction.
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.
Digital set-top box diagnostics can aid a technician with which of the following parameters while troubleshooting?
Service authorization, received signal quality, and return path operations.
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 type of interframe space provides the highest level of priority network function control over the medium for a short time period?
Short interframe space (SIFS).
Which of the following characterizes the successful troubleshooter?
Someone with an inquisitive and relentless desire to solve and fix problems.
To break the habit of a negative self-talk cycle
Tell yourself "not now" and move onto a positive thought whenever negative thoughts occur.
What are some common methods used to configure and manage access points (AP)?
Telnet/ssh (secure shell), universal serial bus (USB), and a built-in web server for browser access.
Access points (AP) must support what encryption techniques in order to comply with IEEE 802.11i security standards?
Temporal Key Integrity Protocol (TKIP), Advanced Encryption Standard (AES), and AES-CCMP (Counter-Mode/CBC-MAC Protocol).
How do you troubleshoot a hidden node?
Test for degraded data throughput at all client locations.
When connecting to a wireless local area network (WLAN), what is the most important point about the service set identifier (SSID)?
That the clients and all access points (AP) must be configured with matching SSIDs.
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.
In which Open Systems Interconnection (OSI) reference model layer do wireless local area networks (LAN) operate?
The Data Link Layer.
Why is the Fresnel Zone important to the integrity of the radio frequency (RF) link or path?
The Fresnel Zone defines an area around the RF line-of-sight (RF LOS) that can introduce RF signal interference if blocked.
Which Open Systems Interconnection (OSI) reference model layers does the Media Access Control (MAC) Layer in the Data Over Cable Service Interface Specification (DOCSIS) overlap so that the media access control (MAC) can be used by the cable modem termination system (CMTS) to differentiate between cable modems?
The Physical and Data Link Layers.
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.
As a subscriber enters a hotspot area, what signals their mobile wireless device of an available Wi-Fi network?
The access point (AP) advertises to the wireless device to enable connection.
Why is shared key authentication considered a security risk in a wireless local area network (WLAN)?
The access point (AP) transmits the challenge text in the clear and receives the same challenge text encrypted with the wired equivalent privacy (WEP) key.
What are some basic questions you should ask a customer before visiting the customer's facility to perform a site survey?
The anticipated number of users, security requirements, data throughput requirements, and budget.
Why has it become cost-effective for enterprise companies to integrate wireless local area network (WLAN) segments into their networks?
The cost of wireless technology has decreased and the quality has increased.
Why is it suggested that all data collected as part of a site survey for a wireless local area network (WLAN) be included in the survey report as an attachment, appendix, or separate set of documentation?
The data could be needed in the future.
Which of the following digital TV (DTV) trouble calls could have been avoided with customer education about the product?
The digital set-top box (STB) overheats.
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.
In a frequency-hopping spread spectrum (FHSS) system that uses 10 frequencies across a 12 megahertz (MHz) frequency band, what happens if narrowband interference occurs at only one of the 10 frequencies?
The spread spectrum signal remains intact. Instead of being lost, the data on the interfered frequency is retransmitted on one of the other nine frequencies.
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 are interframe spaces used in an IEEE 802.11 wireless local area network (WLAN)?
They are used to defer a station's access to the medium and provide various levels of priority.
What are some measures that can be taken to prevent high voltage standing wave ratios (VSWR) in transmitters and receivers?
Tighten connections between cables and connectors and use impedance-matched hardware throughout.
What communications access technology does the first version of the Data Over Cable Service Interface Specification (DOCSIS 1.0) use to send data upstream over the network's radio frequency (RF) return path?
Time division multiple access (TDMA).
What is the purpose of the IEEE 802.11 wireless local area network (WLAN) superframe?
To allow fair coexistence between point coordination function (PCF)-mode and distributed coordination function (DCF)-mode clients on the network.
When configuring a wireless router, why is changing the service set identifier (SSID) from the device default recommended?
To avoid telling hackers exactly what the device is.
What does the "on with threshold" setting of the Request to Send/Clear to Send (RTS/CTS) protocol allow the wireless local area network (WLAN) administrator to control?
To control which frames over a certain size are announced and cleared to send by the stations.
In a segmented wireless local area network (WLAN) that has a different Internet protocol (IP) address for each segment, which solution allows mobile clients to maintain their connectivity when roaming into different segments?
To deploy all access points (AP) on a single virtual local area network (VLAN) using a flat IP subnet for all APs so that no change of IP address for roaming clients occurs and all traffic goes through a central controller.
In regard to Wi-Fi networks, what is WPS used for?
To enable connection to a Wi-Fi network without a Windows interface.
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.
Why are wireless local area networks (WLAN) usually deployed in an access capacity instead of as the network's core layer?
WLANs are generally incapable of meeting the requirements of the network core layer, which needs to be very fast and stable, able to handle a tremendous amount of traffic with little difficulty, and must experience no down time.
Which encryption method is the most secure for a wireless network?
WPA2.
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.
Residential gateways have been around for quite some time, but what capability was added to connect to Institute of Electrical and Electronics Engineers (IEEE) 802.11b, 802.11g, 802.11n, and 802.11ac compliant devices?
Wireless capability.
The attribute of being "active" as a critical thinker means
You observe and take notes relevant to the issue.
Polarization is defined as which one of the following?
orientation of an electromagnetic wave's electric field in relationship to the Earth's surface or plane.
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.
Which of the following IEEE 802.11 wireless local area network (WLAN) standards specifies both spread spectrum RF and infrared (IR) transmission technologies?
802.11
Which one of the following wireless standards utilizes the 5 gigahertz (GHz) frequency band for its signal transmissions?
802.11n
The square root of 81 =
9
Why have 900 megahertz (MHz) Industrial, Scientific, and Medical (ISM) band wireless local area networks (WLAN) lost favor in comparison to 2.4 gigahertz (GHz) and 5 GHz frequency systems?
900 MHz devices are more expensive and provide slower data throughput.
What device would a wireless local area network (WLAN) administrator install between the access point (AP) or bridge and the network to give indoor local area network (LAN) users as much bandwidth as possible?
A bandwidth control unit (BCU).
What test should you perform during the site survey to enable the design engineer to understand and control what the user's experience will be on the wireless local area network (WLAN)?
A data throughput test.
What is the typical coverage pattern of a semidirectional antenna?
A hemispherical or cylindrical pattern.
(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
What uses the 2.4-GHz band and runs at 54 Mbps?
802.11g
Which of the following best describes stereotyped thinking?
Presuming that all members of a group have certain characteristics.
The ratio of the chipping code to data bits for a direct sequence spread spectrum (DSSS) signal is called which of the following?
Processing gain.
Which one of the following tasks is the best choice for troubleshooting the near/far problem?
Review the location of the stations (clients) on the network.
Bluetooth is a short range wireless personal area network (WPAN) technology that is covered under which Institute of Electrical and Electronics Engineers (IEEE) standard?
IEEE 802.15
Which of the following describes a fiber pigtail?
Fiber-optic cable with pre-connectorized ends.
Ideally, what should your next step be after you complete the wireless local area network (WLAN) site survey and provide the survey results in a report to the customer?
A wireless consulting firm should be given the site survey report so that it will then be able to provide effective information on equipment purchasing and security solutions.
What wireless local area network (WLAN) device can be described as a half-duplex device with intelligence equivalent to that of a sophisticated Ethernet switch?
An access point (AP).
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?
An open circuit caused by a break in a conductor, poor contact in a modular connector, or an incorrect wire connection.
What causes co-channel interference in a wireless local area network (WLAN)?
An overlap in the signal ranges of access points (AP) or different WLANs operating on the same channels.
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.
If a digital video serice customer reports that the set-top box does not respond to the remote control, what is the quickest and easiest thing to do first?
Check the line of sight between the remote control and the set-top box
What security service in an enterprise wireless gateway enables the wireless network administrator to assign levels of service to a particular user?
Class of service (CoS).
What criteria does the Data Over Cable Service Interface Specification (DOCSIS) certification process ensure?
Compliance with the DOCSIS standard and interoperability between suppliers.
What specific problem does a wireless local area network (WLAN) resolve for corporations and home users?
Excessive data cabling.
Why is spread spectrum technology used in applications such as Bluetooth wireless personal area networks (WPAN)?
Spread spectrum technology allows wireless networking to create a short range, personal communications network.
Which step in the troubleshooting process requires a discussion with the customer to gather more detail about the problem?
Step 1: Identify the problem.
Which organization regulates the use of wireless local area network (WLAN) devices in the United States?
The Federal Communications Commission (FCC).
The first version of the Data Over Cable Service Interface Specification (DOCSIS) was approved as an international standard by what organization?
The International Telecommunication Union (ITU).
To resolve where the source of a digital video problem lies, a technician uses
The divide-and-conquer method for troubleshooting, which can begin with measurements on customer premise equipment that offer easier access for testing.
Why should a wireless network administrator consider installing an enterprise wireless gateway in their network?
The enterprise wireless gateway enables the wireless network administrator to manage a large wireless network using only a few central devices instead of a very large number of access points.
Which of the following statements is true concerning Bluetooth technology?
To IEEE 802.11 networks operating in the 2.4 Industrial, Scientific, and Medical (ISM) radio bands, Bluetooth transmissions appear as all-band noise.
What are the three main conditions that influence the range of a wireless local area network (WLAN)?
Transmission power, antenna type and location, and environment.
Which wireless client devices require drivers to be installed on the client node?
Wireless client devices on printed circuit (PC) cards that are to be installed in peripheral component interconnect (PCI) or industry standard architecture (ISA) adapters.
Which of the following networks or products use spread spectrum technologies?
Wireless local area networks (WLAN), Bluetooth, and global positioning systems (GPS).
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.
What Internet protocol (IP) address modes can a Data Over Cable Service Interface Specification (DOCSIS) 3.0 and 3.1 modem be provisioned in?
IP version 4 (IPv4), IP version 6 (IPv6), alternate provisioning mode (APM), and dual-stack provisioning mode (DPM).
What is the purpose of the distributed coordination function (DCF) in an IEEE 802.11 wireless local area network (WLAN)?
It allows all clients on a WLAN to contend for access on the shared radio frequency (RF) transmission medium using the carrier sense multiple access with collision avoidance (CSMA/CA) protocol.
What requirements were needed for PacketCable to deliver a quality and reliable telephone service over a Data Over Cable Service Interface Specification (DOCSIS) access network?
Quality of service (QoS) controls, enhanced security, and adaptive equalization in the upstream path.
What are some requirements of a wireless local area network (WLAN) in a hospital that make it an effective training ground for individuals who want to immerse themselves in WLAN technology?
Roaming across large distances, a limited number of users on an access point (AP) due to mandated security, and medical applications that are often connection-oriented between the client and server.
You are designing a wireless network to which several functional workgroups are connected. You want to configure your enterprise wireless gateway to allow you to quickly assign identical network access rights to persons within the same workgroup. Which enterprise wireless gateway feature provides this capability?
Role-Based Access Control (RBAC).
To prevent hacker access to passwords and Internet protocol (IP) addresses, why would you want to place wireless access points (AP) on switches instead of hubs?
Switches prevent the broadcast of packets to all network segments.
How does a client locate a wireless local area network (WLAN) when performing passive scanning?
The client listens for beacons until it hears a beacon listing the service set identifier (SSID) of the network it expects to join.
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.
Which of the following ae among the reasons why a customer may not be able to order video-on-demand (VOD)
VOD order requests are unable to be received at the headend due to poor or nonexistent return path connectivity
What are some desired features of an access point (AP) used to perform wireless local area network (WLAN) site surveys?
Variable output power and external antenna connectors.
Which component of frequency hopping spread spectrum (FHSS) system creates more overhead than any similar component in a direct sequence spread spectrum (DSSS) system?
The interframe spacing.
What is the tradeoff between the fragmenting of packets into shorter fragments versus keeping longer packet fragments?
Shorter packet fragments have lower probability of errors from interference than longer packet fragments, but shorter packet fragments require more error correction.
