CWS-100 Practice Test-1
Which is a valid logical IPv4 address?
192.168.200.1
ERP, DSSS and HR/DSSS devices operate in which RF band?
2.4 GHz Note: ERP, DSSS and HR/DSSS are all 2.4 GHz-only PHYs (Physical Layers). OFDM and VHT are 5 GHz-only PHYs. HT operates in both 2.4 GHz and 5 GHz.
Why is a 2.4 GHz RF signal able to propagate through a section of drywall and be received at a higher signal strength than a 5 GHz RF signal when they are both transmitted using the same transmit power?
2.4 GHz signals have a longer wavelength. Note: Not only do lower frequencies propagate farther due to their longer wavelength, but they also penetrate obstructions better, resulting in higher signal strengths on the opposite side of the obstruction from the AP than would happen if a higher frequency were used. This is one of the reasons you see 2.4 GHz sill in use in so many places like logistics and warehousing.
IEEE 802.11g WLANs operate in what frequency range?
2.4-2.5 GHz
How many 20 MHz channels are available in the 5 GHz band?
25 Note: 25 channels are available as of 2017. More frequency space may be opened in the future.
An 802.11b channel is how wide in MHz?
25 MHz
Two characteristics of RF signals are
25 MHz
How many nonoverlapping channels are available in the unlicensed 2.4GHz ISM band?
3
According to the 802.11a amendment, which of the following data rates are mandatory?
6, 12, and 24Mbps
802.11g is backward- compatible with which of the following IEEE WLAN standards?
802.11 DSSS and 802.11b HR/DSSS
WPA was developed as an interim solution for which amendment to the 802.11 standard?
802.11i
A controller-managed access point connected to a port on the WLAN controller and not to an intermediate device is considered to have which of the following?
A
A device driver can be used in wireless networking. Which is an example of a device driver?
A
How many data bits does serial communication transmit at a time.
A
Which componect is required for a successful installation and operation of an 802.11ac wireless USB adapter?
A
Which of the following devices is an in-line device that will inject DC voltage into the Ethernet cable?
A
Increasingly, organizations want to manage guest access beyond the use of a single shared key for guest use. What has become the most often used means of accomplishing this goal?
A Guest Management System Note: A Guest Management System can allow unique credentials per user or per device while using a single SSID for guests.
When an RF signal strikes an object and is neither reflected nor diffracted by the object but fails to pass through the object, what term best describes this phenomenon?
Absorption Note: When an RF signal fails to penetrate an object, is not reflected by nor diffracted by the object, that phenomenon is called absorption.
When an access point is configured to provide connectivity for wireless client stations to the wired infrastructure, in which mode of operation is the access point functioning?
Access Mode Note: When an access point is supporting wireless client traffic to and from the wired network it is in Portal Mode or access mode.
When client devices are communicating with each other without the use of an access point, in which mode of operation are the functioning?
Ad Hoc Mode Note: Ad Hoc Mode allows stations to communicate with each other without the use of an access point. It is also a security concern.
Given: Users are reporting slow throughput. There is no interference in the service set area. The same report is found across all hardware platforms, laptops, tablets, phones and IoT devices alike. The same report exists for internal resource access as well as Internet access. What can you do to improve the throughput for your users?
Add additional access points using the same SSID on non-overlapping channels Note: If there is no interference and the problem is across all platforms, you most likely have a capacity issue. Breaking up the collision domain by more access points using the same SSID but on non-overlapping channels should solve the problem.
The term encapsulation means to ______
Add layer header and trailer information to a frame
Which of the following is correct regarding 802.11e
Addresses wireless QoS
A wireless workgroup bridge will allow to do which of the following?
B
Most manufacturers recommend installing a wireless IEEE 802.11ac USB adapter at what point?
B
Which WLAN adapter can be installed in a computer without the need to disassemble the computer in any way?
B
You want to connect a desktop computer to an IEEE 802.11ac wireless network. Which WLAN adapter would be the best solution if you do not want to disassemble the computer?
B
Which of the following are benefits of a wireless repeater?
BE Larger cell
What can be done to prevent guest traffic from taking away from employee use of the Internet?
Block streaming traffic on the guest WLAN Note: Streaming traffic takes up a lot of Internet bandwidth. Blocking it on the guest network will help to ensure more bandwidth for employee Internet use.
Enterpire-grade IEEE 802.11n/ac client utilities typally contain which advanced feature?
D
You have a notebook computer and wish to connect to an IEEE 802.11ac wireless network. The computer does not have a built-in WLAN card or a PC card interface. You do not want any peripherals connected to the notebook that use wires and do not want to disassembel the computer. Which wireless adapter would be the best solution?
D
Access point work at which layers of the OSI model?
AB
Enterprise access points may contain which of the following features?
ABD
WLAN controllers may may contain which of the following features?
ABD
IEEE 802.11a users which PHY tech
OFDM
Which item has an effect on RF line of sight?
Obstacles
What is the name used to describe the coverage pattern produced by many access points using internal antennas?
Omnidirectional Note: Most APs with internal antennas have either an omnidirectional pattern or a cardioid pattern.
What is the name given to the 802.11 authentication type that requires no username, password, or preshared key?
Open Note: Open authentication requires no credential use or shared key to connect. Also called Open System authentication.
What kind of antennas are usually only used when creating wireless bridge links?
Parabolic dish Note: Parabolic dish and grid antennas are highly directional, high gain antennas that are typically used only for wireless bridge links. Patch and panel antennas are semi-directional and may be used for short-distance bridge links but are also commonly used in high-density and special coverage implementations. Omni-directional antennas are the least common antenna type for use in bridge links, but are the most common antenna type overall as they are used in most AP and client devices.
Which layer of the OSI model is responsible for organizing bit-level data for communication devices on a network and detecting and correcting Physical layer errors?
Data Link
Which layer of the OSI model uses physical addresses to deliver data to the destination?
Data Link
_____ allows for Application layer data communication between two stations using lower layers as a support system.
Data encapsulation
What organization is responsible for unlicensed frequency band regulation in the United States
FCC
What is the number one cause of failed association?
Failed authentication Note: Before a device can associate it must authenticate. Failed authentication prevents association and, therefore, is the number one cause of failed association. Encryption is used by associated devices for data transmissions and, therefore, only occurs after association. Authorization would be performed after association as well.
As seen in a two-dimensional (X/Y) view, the amplitude of an RF signal is:
Height
Point-to-point links typically use which antenna types?
Highly directional and Semi directional
At which two layers of the OSI model does wireless LAN tech operate?
Physical and Data Link
The lower three layers of the OSI model are the?
Physical, Data Link, Network
Which protocol is responsilble for addressing and routing?
IP
When implementing mesh networks, what is required to connect the mesh to another network that is not 802.11-based?
Portal Note: A mesh BSS (MBSS) can use a mesh gate to connect to other 802.11 networks; however, a portal is required to connect to a non-802.11 network.
What is an important consideration specific to power provisioning when using a Power over Ethernet (PoE) switch to power an AP?
Power required by the AP Note: The power required by the AP is an essential factor. An AP requiring more than 12.95 W of power will require 802.3at support. An AP requiring 12.95 W or less will only require 802.3af support.
In the 802.11a amendment. the UNII-3 band is intended to be used for which of the following WLAN applications?
Indoor and outdoor
What component of Fast Secure Roaming allows stations to move from one access point to another without the user being prompted for credentials?
Pre-Authentication Note: When using Fast Basic Service Set Transitioning (FT), as allowed by the 802.11r amendment, when a station associates with an access point the access point or its controller can pass the pairwise master key to other access points in the service set, removing the need for user intervention when the station roams from one access point to another.
Which of the following is addressed by the Wi-Fi Multimedia (WMM) certification?
QoS
When acting as a RADIUS server, enterprise quality APs can use what kind of authentication database when no centralized identity database exists?
Local Note: Active Directory and eDirectory are centralized solutions. A local database is used when no centralized solution is available.
The IP address of a network adapter is also known as which address?
MAC address
The physical address of a network adapter is the ____
MAC address
IEEE 802.11ac devices use an enhanced radio tech know as multiple-input multiple-output (MIMO). Which statement correctly describes the benefit of MIMO?
MIMO uses reflections to allow for increased throughput.
What is the main advantage of using a grid antenna vs. using a dish antenna in a point-to -point WLAN bridged connection?
Reduced wind effect Note: Wind can move an antenna reducing the quality of the connection or even causing the connection to fail completely. Grid antennas are less susceptible to the effects of wind, since they aloe the wind to blow through them rather than being moved by the wind.
When an RF signal bounces off a smooth, nonabsorptive surface, the behavior is
Reflection
What is the term most commonly used to describe the phenomenon caused when an RF signal strikes an object it is unable to penetrate but is not diffracted by the object either?
Reflection Note: When an RF signal strikes an object and is unable to penetrate the object and is not diffracted by the object, that phenomenon is called reflection.
Which topology may use a token-passing access method?
Ring
Wireless bridge must be configured with ___ and ___
The same SSID and The same RF channel
A high-speed linear topology is defined as a?
Star
What kind of device would provide Power over Ethernet (PoE) if referenced as an endspan device?
Switch Note: A switch is an endspan injector and an in-line injector is a midspan injector.
Which protocol is used to guarantee delivery of data?
TCP
When an RF signal passes between media of different densities and may change speeds and bend, the behavior is known as:
Transmitter
Users have discovered that they are unable to walk between buildings on their campus using the company issued Wi-Fi phones. Both buildings use the same wireless profile configurations in the APs. What most likely went wrong with this deployment?
There was no survey conducted for outdoor use Note: An improperly conducted or missing survey will lead to many WLAN problems. It is common practice to provide coverage between buildings for roaming users, especially when they are using Wi-Fi phones. In this case, apparently, outdoor coverage was not designed into the deployment. Because the buildings use the same WLAN profiles, the same SSIDs should be in use in both buildings. In many cases, output power settings on mobile VoIP handsets are not exposed for configuration, so this is not the likely problem. If the phones were incompatible with the WLAN, they could not connect in the buildings either.
In computer network terminology, the definition of half-duplex is closest to which of the following?
Two-way communication one way at a time
Point-to-multi point link consist of ________ or more connections.
Three
What is the purpose of a WLAN Management system?
To allow centralized AP administration. Note: WLAN Management systems allow centralized administration of WLAN APs and controllers. The management system may be on premises or hosted in the Cloud so cloud based administration is not always provided.
What is the main reason networks allow guest wireless access?
To allow guests Internet access without exposing the private network Note: Guests expect wireless network access. Allowing them to connect to their offices and the Internet is good business. However, their access should be configures so as not to touch the private network. Creating a separate network using another SSID is a common security measure. Their traffic is often on another VLAN or physical wired network.
When there are no AC power outlets near the locations where access points are to be deployed and the switches used to connect the access points to the wired LAN do not provide PoE connectivity, how can you power the access points without adding AC power outlets or using extension cords?
Use midspan PoE injectors to power the access points Note: Midspan injectors draw power from AC outlets and inject the power into the Ethernet cables used to connect the access points. Placing generators at each location is not a cost-feasible solution and over-the-air power is not an available solution today.
802.1X authentication is implemented when using which type of WLAN security?
WPA/WPA2-Enterprise Note: WPA and WPA2 Enterprise both use 802.1X authentication. WPA and WPA2 Personal both use Pre-shared key authentication.
You support a wireless network for an office of five employees. The installation consists of one AP, three notebook computers, and two desktop computers. The AP and computers in the office have wireless adapters that are Wi-Fi WPA 2.0 certified. You want to use the highest level of security possible without additional cost or administration. Which of the following solutions would be best for this deployment?
WPA2 and WPS
Which of the following organizations is responsible for validating WLAN standards interoperability testing.
Wi-Fi Alliance
How many channels are available for WLANs to use in the unlicensed NNII-1 band?
dB
What two devices use RF to communicate?
dB and Watt
What is the gain of an antenna measured in?
dBi
What power metric is used to measure both transmit and receive signal strengths and allows for easier conceptualization of very low receive power levels?
dBm Note: dBm is the power metric used on both transmit and receive ends. For example, 100 mW of transmit power is equal to 20 dBm and it is common to say that the received signal strength is at some dBm level as well. dBi is used to measure antenna gain.
The 802.11g amendment to the standard uses which two PHY
ERP-OFDM and DSSS
Which access point mode involves connecting the access point to a distribution system for user access to the LAN?
C
Which two channels are considered nonoverlapping in the 2.4 GHz band?
1 and 6
Which data rates are supported by 802.11g?
1, 2, 5.5, 11, 6, 9, 18, 22, 24, 33, 36, 48 and 54 Mbps Note: 802.11g supports all of the data rates supported by 802.11b and 802.11a as well as adding support for ERP-PBCC of 22 and 33 Mbps
802.11b is capable of which of the following data rates?
1, 5.5, and 11Mbps
Within the 2.4 GHz spectrum, which combination of three channels is considered to be non-overlapping when used in the same space?
1, 7 and 13 Note: To be considered non-overlapping when used in the same physical space, 2.4 GHz channels must be separated by 25 MHz or more. Channels 1, 7 and 13 do not overlap. While channels 1, 6, and 11 are most often used, channels 1, 7, and 13 could be used in some regulatory domains. It is recommended to use channels 1, 6 and 11 to accommodate devices that may enter the network and are configured for regulatory domains that only allow 1, 6 and 11 as non-overlapping channels.
How many channels are available for WLAN use in the unlicensed middle UNII-2e band?
12
How many channels are available for WLAN use in the unlicensed 2.4 GHz ISM band?
14
The component used to connect an antenna to a radio that uses a different connector type is most commonly referred to by what name?
A Pigtail Note: The component that is used to connect antennas and radios using different connector types is most commonly referred to as a pigtail.
Which Wi-Fi device can only connect in the 5 GHz band using the specified options?
A laptop using an 802.11ac radio Note: 802.11ac only operates in the 5 GHz band. Any device using only an 802.11ac radio will only be able to connect in the 5 GHz band.
When expanding an existing wireless LAN, what is the most important thing to perform?
A new site survey Note: When expanding a WLAN and new site survey should be performed. Things learned in the original survey, such as neighboring network locations and noise sources, could have changed. Additionally, mounting needs for the new devices and possibly mounting need for existing devices requiring movement must be determined. Remember, a site survey is a living thing. Network environments can change.
What should you consider when deploying additional access points in a wireless LAN to increase capacity?
All of these important factors: a. Channels already in use by existing access points b. The number of concurrent connections required in the service set area c. Distance of new AP's from the mounting points of existing access points Note: When expanding a wireless LAN there are many factors to take into account with regard to existing access points. APs may need to be moved, power levels adjusted, channels adjusted, or APs may need to be replaced with newer devices. Expanding an existing WLAN can be as large a challenge as deploying a new one.
To improve roaming abilities, a consultant has recommended placing all of your access points on the same channel. Why is this not a recommended practice when SCA is not in use?
All of these: This will decrease the throughput of the WLAN This increases the number of devices in the same collision domain This increases contention for the medium Note: Placing all of the APs on the same channel, with the exception of the less commonly deployed Single Channel Architecture (SCA), will cause severe performance problems for the WLAN, including increased numbers of devices in the collision domain, increased contention for the WLAN medium, and decreased throughput for the WLAN.
Increasing the transmit power used by an access point will result in an increase in what characteristic of an RF signal?
Amplitude Note: The term amplitude is used to describe the power of an RF signal. Any change in transmit power of an RF signal will change the amplitude of that signal.
Which are relative measures of RF power?
Amplitude and Phase
Which layer of the OSI model provides an interface to the user?
Application
A self-contained intelligent access point is ____
Autoomous
In the 2.4GHz range, what distance between the center frequencies (in megahertz) is required for two channels to be considered nonoverlapping for HR/DSSS?
BB??
What is the common characteristic of both 2.4 GHz band Wi-Fi and 5 GHz band Wi-Fi with 802.11ac?
Both bands are unlicensed for 802.11 operations Note: Both the 2.4 GHz and 5 GHz bands are unlicensed. This means that you can use devices in each or both bands without acquiring a licenses as long as you comply with regulatory constraints for your region. 5 GHz 802.11 devices support wider channels and more channels than 2.4 GHz 802.11 devices. The lowest possible data rate in the 5 GHz band is 6 Mbps, while the lowest possible data rate in the 2.4 GHz band is 1 Mbps.
A neighboring office has just implemented a new hotspot for their guests using channel 9. What is the most likely reason your access points on channels 6 and 11 near this new access point are having difficulty providing good service to your clients in the same area?
Channel 9 overlaps with channels 6 and 11 causing interference Note: Channel 9 overlaps with channels 6 and 11. When your access points and their stations in range of the neighboring guest network try to transmit they do not detect the signals from the neighboring guest network as 802.11 frames but rather as noise. When your access points and stations on channels 6 and 11 in the area transmit, their frames are having a high collision rate due to the adjacent channel interference caused by your neighbor's guest network.
The capacity of an access point is dependent on what factors? (Choose two.)
Channel reuse
When deploying a single access point for a Small Office Home Office (SOHO) environment for use by fewer than five client devices, what is the most common thing a site survey would be used to determine?
Channels in use nearby Note: It is expected to have neighboring devices in most every deployment. In a SOHO deployment as described above, there is only one access point to be deployed and in a small space. Its placement is not as large a matter as in a multi access point enterprise solution. Channel use is an important consideration. The largest source of trouble for a WLAN is neighboring devices. Selecting the least populated channel for use is the most common thing a SOHO site survey is used to determine.
Even though you know there are several legacy clients on your network, you have disabled the two lowest data rates on all of your access points. What is a benefit of this configuration?
Clients must be closer to the access points to connect Note: By disabling the two lowest data rates, clients must be closer to the access points to connect. This will increase throughput for each service set due to the lack of data transmissions at the lower speeds causing undesirable contention and forcing clients at distance to roam to a closer access point.
Users within a company have a need to print wirelessly. The office manager has purchased a wireless printer for their use. What is the best way for printer be configured for use in the office?
Connect the printer to the network via Ethernet cable, disable the wireless card in the printer and treat the printer as any other network asset Note: Although the printer has a wireless card, ad-hoc networking should never be used in an office and enabling an AP in a printer is problematic as it is not typically considered in the access WLAN design. Additionally, users' computers can only be connected to one AP at a time. Connecting the printer wirelessly could work. However, you may have to enable station to station traffic on the WLAN which introduces too many security concerns, such as peer-to-peer attacks. The best thing to do is to connect the printer to the network using an Ethernet cable and treat it as any other network resource.
What device is often used to manage several APs in a centralized manner?
Controller Note: A controller is often installed to manage several APs from a centralized location. In fact, controllers can often manage thousands of APs.
What is required in many regulatory domains for the middle range of 5 GHz channels?
DFS Note: Dynamic Frequency Selection (DFS) is required in several 5 GHz channels in many regulatory domains. DFS allows for the detection of radar signals and the moving from the detected signal channel to another.
What frame type should always be encrypted for secure wireless transmissions?
Data Note: Management and control frames are usually not encrypted. Beacon frames are management frames. Data frames should always be encrypted for secure wireless communications.
At which layer of the OSI model are bits compiled into frames?
Data Link
End of CH4: When RF passes or bends around an obstacle such as a building or column, the behavior is:
Diffration
What is the best type of antenna to use when wirelessly connecting two buildings on the same campus?
Dish Note: Dish antennas are highly directional. This allows you to create point-to-point networks more securely while exposing them to fewer sources of interference.
As a station moves closer to an access point it begins to use a higher data rate than it was using before at a greater distance. What is the name used to describe this behavior?
Dynamic Rate Switching (DRS) Note: Client devices and access points negotiate the fastest data rate they both support to improve performance. As a stations moves about, the signal from the access point may be detected as growing weaker or growing stronger. The signal strength with which a station detects an access point is used by the station to determine the data rate it should be using to remain connected to the access point. The stronger the signal strength detected the higher the data rate used. The lower the signal strength the lower the data rate used. This process is called Dynamic Rate Switching (DRS).
Beginning of CH4: What is the defining the number of times a cycle of an RF signal will oscillate in one second?
Frequency
Which of the following best describes the Wi-Fi Alliance?
Interoperability testing organization
The Data Link layer of the OSI model is divided into which two sublayers?
LLC, MAC
Within what mode is an access point operating when it is collecting information wirelessly for a Wireless Intrusion Prevention System (WIPS) and not supporting clients?
Monitor Mode Note: Monitor Mode or Scanner Mode is used to turn an access point into a sensor for a WIPS. When used in this mode, client support is not available on the radios used by the access point to scan.
When designing a WLAN deployment for a warehouse, why would you typically recommend fewer access points than for an open conference center of exactly the same size?
More users and devices will be used in the conference center Note: With an increased number of devices per person and more people in a conference center than in a warehouse, more access points are required to handle the device density. Fewer APs would typically be required for the same square footage in a warehouse than in a conference center.
What phenomenon of wireless transmissions is deemed to have a negative impact on SISO deployments but is desirable in MIMO deployments?
Multipath Note: All of the reflected signals caused by multipath are something you try to mitigate using antenna diversity in a SISO network. However, in a MIMO network the reflections caused by multipath give the receiver additional instances of the same signal, allowing for better decoding of the special streams.
Which layer of the OSI model allows physical addresses to be converted to logical addresses?
Network
Which layer of the OSI model is responsible for addressing and routing?
Network
Which two of the following options are available for Wi-Fi Protected Access 2 (WPA 2.0)
Personal mode and Enterprise mode
Wi-Fi Protected Setup was designed for which of the following wireless applications?
SOHO
The 802.11i amendment to the standard addresses which of the following tech
Security
What name best describes the patterning of signals transmitted using a Yagi antenna?
Semi-directional Note: The Yagi antenna patterning is best described as semi-directional. Yagi antennas have a main beam but also have side and rear lobes of coverage as well, although they are often considered unintended coverage.
Your WLAN devices are powered using PoE switches. When you install a new PoE enabled access point it will not power up when connected to the PoE switch that is powering other APs. What is the most likely cause of this problem?
The access point is connected to a non-PoE port on the switch Note: Many PoE switches have both power providing and non-power providing ports. When expecting to power an access point using PoE, make sure that the AP is connected to a power providing port. The port may be configurable to either provide PoE power or not. The switch is not likely powered off because it is powering other APs. Any properly wired CAT 5 or CAT 6 Ethernet cable should allow for PoE power. Most APs do not have a power switch on them. When power is injected, either through PoE or AC wall power, the AP powers up.
To avoid running Ethernet cables to all of the access points in a deployment the APs are implemented in mesh mode. Users can connect to all of the access points with no trouble. The access points can also connect to other access points with no trouble. However, the users cannot connect to any network resources. What is the most likely cause of this phenomenon?
The access points configured for mesh mode do not have a backhaul connection Note: When configuring mesh mode, it is important to configure at least one access point with an Ethernet connection to provide user access to the wired network. This AP will act as a portal to the other network. More than one access point should be connected this way to provide redundancy.
Why is it so challenging to deploy Wi-Fi in a hospital?
The building has all of these challenges and many more Note: Often hospitals have many tenants, medical billing, special treatment clinics, etc. in addition to the main networking needs. There are several non 802.11 sources of interference in hospitals, in addition to metal walls, wireless phones, wireless cameras, microwaves, high density device use and lifesaving equipment that needs connectivity. Deploying in a hospital is one of the most challenging places you will ever install Wi-Fi.
Given: You have deployed an access point using dual band radios and supporting both 802.11n and 802.11ac. You have set the power levels on both the 2.4 GHz radio and the 5 GHz radio to 20dBm. When you inspect the administration interface of the access point, you see that all of the stations, which are also using dual band radios, are connecting in 2.4 GHz. What is the most likely cause of this phenomenon?
The clients are configured to prefer 2.4 GHz over 5 GHz and the access point is not using any form of band steering Note: It is fairly common for client devices to be configured by the manufacturer to prefer 2.4 GHz over 5 GHz connections. Smaller devices do this to save batter power.
Which of the following is an accurate description of peer communication?
The horizontal link between devices on the network
Your office has recently allowed the use of personal devices on the corporate network by using a separate SSID (wireless network name). The network as utilized at about 40% before making this change. Users now complain about long waits when downloading files from the corporate network using company owned devices. What is the most likely cause of the problem?
The personal devices and the new SSID have increased network use and channel contention slowing down throughput Note: Additional devices using the same access points, even with an additional SSID, will increase contention and slow throughput. The extra beacon frames (frames used to announce the network) from the additional SSID consume extra airtime. The additional devices are consuming extra airtime as well. The result will be decreased throughput for the corporate devices if the WLAN was already heavily utilized.
Given: All devices are equal distance from the access point and there is no blockage or interference within the Basic Service Set Area (BSA). All devices used support the same 802.11 technologies. Students using tablets to connect to the network are unable to achieve the higher data rates offered by the 802.11ac based access point while students using laptops are able to achieve the higher data rates. What is the most likely cause of this phenomenon?
The tablets are using 1x1:1 MIMO while the laptops are using 2x2:2 MIMO Note: Laptops more often than not use more efficient versions of MIMO than tablets due to their larger size and higher battery capacity. Laptops often use 2x2:2 or 3x3:3 wireless adapters, while tablets and mobile phones often use 1x1:1 adapters.
Why do clients take some time to roam from one AP to another even when the APs are part of the same Extended Service Set (ESS)?
They must reassociate and authenticate properly to the new AP Note: Even when two APs are part of the same ESS, they are separate networks from a Basic Service Set (BSS) perspective. The clients are connected to one BSS and must move to another BSS to roam within an ESS. The client is fully associated with only on BSS at a time. Therefore, some time is required to move from one BSS to the next.
Why is the recommended minimum signal strength for Voice over Wi-Fi often -67dBm when the recommended signal strength for data communications is often -70dBm?
To ensure that voice traffic can use higher data rates due to latency requirements Note: Voice traffic requires more rapid delivery of communications than data traffic. To ensure the higher data rates are available to voice enabled Wi-Fi devices and reduce the impact of interference on voice transmissions, it is recommended to use minimum signal strengths of -67dBm for voice, twice the signal strength of data transmissions. A better practice is to use a signal strength that is 28dBm above the noise floor for voice.
Physical addresses on a network device are responsible for which of the following?
To identify which device should receive the information
When a target building for a new WLAN is in a remote area with no nearby WLANs, why should the building be scanned with a spectrum analyzer before choosing channels for the new WLAN?
To locate non-802.11 interference areas Note: Many non-802.11 devices operating in the 2.4 GHz and 5 GHz frequency bands. These devices must be identified to avoid using channels that operating in the same frequencies when possible.
When deploying an access point in an office environment, what is a reason to use an external antenna vs. using an access point with an internal antenna?
To provide the desired coverage Note: Antennas not only amplify signals they also help to shape the coverage. However, most office use access points with internal antennas for looks and to reduce the number of stations that are able to see and connect to any one access point.
Which one of the following is often an issue that must be addressed in hospital environments?
Walls that block RF Note: X-Ray rooms often have lead-lined walls that block RF. To address this, if WLAN coverage is required in the X-Ray room, an AP may be installed within the room. Internet uplinks for mobile transportation are more commonly seen in planes, trains and other public transportation systems. PCI DSS is a constraint in retail where credit and debit cards are accepted. Frequent large trucks making deliveries is more common in industrial and warehousing deployments.
Which are absolute measures of RF power? (Choose two.)
Watt and mW
The range of a 2.4 GHz signal is mostly dependent on which RF characteristic?
Wavelength
Given: You need to provide wireless access within a warehouse for barcode scanners. To do so you have deployed one access point in the center of the warehouse using omnidirectional antennas. After the installation you verify that the barcode scanners can connect throughout the building. The company has now added Wi-Fi phones to the network that are failing to work in remote areas in which the barcode scanners have no problem. What is the most likely cause of this differing connectivity?
Wi-Fi phones require stronger signal strength from the access point than that required by barcode scanners Note: Wi-Fi phones require stronger signal strength from the access point than barcode scanners do to operate successfully. They require a higher data rate to carry the voice signals.