ISDS 485 5-8 Review Questions

Wireless LAN devices in an 802.11a peer-to-peer network will connect to which device(s)?

802.11a client devices

Stations (STA) operating in which two IEEE 802.11 amendments are interoperable?

802.11b and 802.11g are two IEEE 802.11 amendments that are interoperable

Which are absolute measures of RF power? (Choose two.)

Watt and mW are absolute measures of RF power

Which items describe a service set identifier (SSID)? (Choose two.)

-32 characters maximum -Is case sensitive

Which two channels could be used so that the access points do not interfere with each other in an 802.11b wireless network? (Choose three.)

-Channel 3 and channel 9, -Channel 6 and channel 11 -Channel 2 and channel 8

Which two channels are considered nonoverlapping in the 2.4 GHz band?

1 , 11, 6 are considered nonoverlapping in the 2.4 GHz band

How many channels are available for wireless LAN use in the unlicensed middle UNII-2e band?

11

What is the maximum data rate of HR/DSSS 802.11b devices?

11 Mbps

How many channels are available for wireless LAN use in the unlicensed 2.4 GHz ISM band?

14

Without any regulatory domain taken into consideration, the 2.4 GHz frequency range allows for how many channels using 802.11b?

2.4 GHz frequency range allows for 14 channels using 802.11b

HR/DSSS devices operate in which frequency range?

2.400 GHz ISM frequency range

An 802.11b channel is how wide in MHz?

22 MHz wide

An HR/DSSS channel is how wide?

22 MHz wide

In the 2.4 GHz range, what distance between the center frequencies (in megahertz) is required for two channels to be considered nonoverlapping for HR/DSSS?

25 MHz between the center frequencies (in megahertz) is required for two channels to be considered nonoverlapping for HR/DSSS.

How many non-overlapping channels are available in the unlicensed 2.4 GHz ISM band?

3

A service set identifier (SSID) has a maximum limit of how many characters or octets?

32

Omnidirectional antennas have a horizontal beamwidth of degrees.

360 horizontal beamwidth of degrees

How many channels are available for wireless LANs to use in the unlicensed UNII-1 band?

4 channels are available for wireless LANs to use in the unlicensed UNII-1 ban

Which frequency ranges are used in an IEEE 802.11a-compliant wireless LAN? (Choose two.)

5.25 GHz UNII and 5.35 GHz UNII frequency ranges are used in an IEEE 802.11a

Wireless network cables and devices have impedance (AC resistance) of ohms.

50 ohms

A point-to-point wireless link requires what percent of the Fresnel zone to be clear in order to be considered to have an acceptable RF line of sight?

60 percent

The curvature of the earth will have impact on the wireless LAN signal after how many miles?

7 miles

Devices compliant with which amendment to the IEEE standard use multiple radio and multiple antennas?

802.11n use multiple ratio and multiple antennas or (MIMO)

How many access points can be co-located without channel reuse in the same radio frequency area to maximize total system throughput while minimizing RF interference in an IEEE 802.11g network?

A total of three wireless access points can be used until interference becomes an issue.

Which can cause a loss of signal strength? (Choose two.)

Cable or connector

A basic service set identifier (BSSID) is the unique identifying MAC address of the

AP radio

You are a technical support engineer and provide help desk support for the network in a manufacturing company. You receive a call from the sales manager, who wants to know how power save operations should be set up on her notebook computer to optimize the system performance. The notebook computer is plugged into an AC power source and rarely used on battery. Which mode would you recommend her to set on the wireless adapter?

Active mode

Two characteristics of RF signals are:

Amplitude and phase

What is the gain of an antenna measured in?

Antenna gain is measured in dBi

n order for a wireless client to become completely part of the basic service set, it must first ___ and then ___

Authenticate, associate

The IEEE 802.11 association process happens after which phase?

Authentication

Bluetooth devices use, which can potentially cause interference with WLANs.

Bluetooth devices use frequency hopping spread spectrum (FHSS) which can potentially cause interference with WLANs

Which network access method attempts to avoid collisions?

CSMA/CA is a network access method that attempts to avoid collisions.

DSSS uses which spreading code at 1 Mbps?

DSSS uses a Barker code for spreading code at 1 Mbps

As a device moves away from an access point, which of the following is true regarding dynamic rate switching?

Data rate decreases

When RF passes or bends around an obstacle such as a building or column, the behavior is:

Diffraction

You are a sales engineer connected to an IEEE 802.11a access point with a mobile computer. As you move away from the access point, the connection speed slows to the next lowest supported data rate. The change in data rate is described by which term?

Dynamic rate switching

You are a help desk support technician at a retail department store and you receive a call from a manager in the administrative offices. He complains that the performance of his 802.11g notebook computer decreases several times throughout the day. Upon visiting the customer, you realize several people are performing inventory using 802.11b barcode scanners in the adjacent room. What is most likely the cause of the poor performance for the manager's notebook computer?

ERP protection

What IEEE 802.11 PHY technology specifies that frequencies change regularly while transmitting and receiving data?

FHSS technology specifies that frequencies change regularly while transmitting and receiving data

FHSS uses which communication method to exchange data?

FHSS uses 1 MHz-wide subcarriers communication method to exchange data

What is the term defining the number of times a cycle of an RF signal will oscillate in one second?

Frequency

Which wireless LAN technology can be used to obtain the highest data transfer rate possible?

HT-OFDM wireless LAN technology can be used to obtain the highest data transfer rate possible

hen an IEEE 802.11g wireless LAN consists only of wireless client stations, the network is operating as what type of basic service set?

Independent

Which wireless LAN technology in wireless networking uses the effects of multipath to provide data rates of 600 Mbps?

MIMO wireless LAN technology

A beacon frame advertises information about the wireless network. A beacon frame is what type of frame?

Management

You are a technical support engineer and receive a call from a customer regarding a problem with their wireless network connection. The building has an ESS network with five 802.11g access points. The customer claims that when they move from their office to a conference room using the 802.11g network they lose their connection and cannot connect to the access point in the conference room. Which is the most likely cause for this user to lose their connection when they roam on the wireless network?

Mismatched SSID

Which item has an effect on RF line of sight?

Obstacles

According to the IEEE 802.11 standard, an extended service set (ESS) consists of how many interconnected basic service sets?

One or more

When a wireless LAN device listens for beacon frames, it is participating in which phase?

Passive scanning

When an RF signal bounces off a smooth nonabsorptive surface, the behavior is:

Reflection

The process in which a wireless LAN client connection moves from one access point to another is called

Roaming

In order to set up an ad hoc network, a user must know which two parameters? (Choose two.)

SSID Channel

What technology is used to send WLAN data over a wireless medium using many subcarrier frequencies?

Spread-spectrum is used to send WLAN data over a wireless medium using many subcarrier frequencies

What two devices use RF to communicate? (Choose two.)

The transmitter and the receiver devices use RF to communicate.

Which weather element would commonly have an effect on a wireless LAN system?

Wind

Horizontal beamwidth is ____ to the earth's surface.

parallel to the earth's surface

Antennas provide an increase in RF coverage by using ____ gain.

passive

RF line of sight is required for what type of IEEE 802.11 WLAN installation? (Choose two.)

point-to-point and point-to-multipoint

Amplifiers provide an increase in signal strength by using __ gain.

active

802.11a access points support which antenna technology to help reduce the effects of multipath?

antenna diversity technology

Which are relative measures of RF power? (Choose two.)

dB and dBi are relative measures of RF power

IEEE 802.11a/b/g/n devices use what type of communication?

half-duplex

FM radio stations use what type of RF communication?

high power, narrow bandwidth

An azimuth chart shows which RF radiation pattern?

horizontal RF radiation pattern

What device is used to shunt transient current to ground in the event of an indirect lightning strike?

lightning arrestor

Highly directional antennas are typically used for ___ connectivity.

long-range

OFDM that is used with 802.11a and 802.11g stations (STA) supports a maximum data rate of Mbps.

maximum data rate of 54 Mbps.

The capacity of an access point is dependent on which factors? (Choose two.)

number of users and the software applications being used.

The following graphic shows what type of antenna? |---

omnidirectional

A basic service set (BSS) consists of how many access points?

one

An IEEE 802.11g access point requires a minimum of how many antennas to move data?

one

You are a network engineer. While moving a handheld wireless LAN device, you notice that the signal strength increases when the device is moved from a horizontal to a vertical position. This is because ____ is changing.

polarization

When an RF signal passes between media of different densities and may change speeds and bend, the behavior is known as:

refraction

A patch antenna is an example of what type of antenna?

semi-directional

The image below shows what type of antenna? (--

semidirectional

As seen in a two-dimensional (X/Y) view, the amplitude of an RF signal is:

the amplitude of an RF signal is height

An access point requires antennas for diversity functionality.

two

The open system authentication process uses how many frames?

two

The range of a 2.4 GHz signal is mostly dependent on which RF characteristic?

wavelength

An independent basic service set (IBSS) consists of how many access points?

zero