Upgrade to remove ads
Only $35.99/year

CWNA - Chapter 2

Terms in this set (20)

An ERP (802.11g) network mandates support for which two spread-spectrum technologies?

A. ERP-OFDM
B. FHSS
C. ERP-PBCC
D. ERP-DSSS/CCK
E. CSMA/CA
A. ERP-OFDM
D. ERP-DSSS/CCK

Support for both Extended Rate Physical DSSS (ERP-DSSS/CCK) and Extended Rate Physical Orthogonal Frequency-Division Multiplexing (ERP-OFDM) are required in an ERP WLAN, also known as an 802.11g WLAN.
Which amendment defines performance enhancements using the much higher unlicensed frequency band of 60 GHz, and a transmission method known as directional multi-gigabit
(DMG)?

A. 802.11ac
B. 802.11ad
C. 802.11ay
D. 802.11q
E. 802.11z
B. 802.11ad

802.11ad supports data rates of up to 7 Gbps. The downside is that 60 GHz will have significantly less effective range than a 5 GHz signal and be limited to line-of-sight communications, as the high-frequency signal will have difficulty penetrating walls. The
802.11ay draft amendment is expected to improve 802.11ad, providing faster speeds and longer range.
Which types of devices were defined in the original 802.11 standard? (Choose all that apply.)

A. OFDM
B. DSSS
C. HR-DSSS
D. IR
E. FHSS
F. ERP
B. DSSS
D. IR
E. FHSS

The original 802.11 standard defines three Physical layer specifications. An 802.11 legacy network could use frequency-hopping spread-spectrum (FHSS), Direct-sequence spread-spectrum (DSSS), or IR (infrared) technology. 802.11b defined the use of High-Rate
DSSS (HR-DSSS); 802.11a defined the use of orthogonal frequency-division multiplexing (OFDM); and 802.11g defined Extended Rate Physical (ERP).
Which 802.11 amendment defines wireless mesh networking mechanisms?

A. 802.11n
B. 802.11u
C. 802.11s
D. 802.11v
E. 802.11k
C. 802.11s

The 802.11 Task Group s (TGs) has set forth the pursuit of standardizing mesh networking using the IEEE 802.11 MAC/PHY layers. The 802.11s amendment defines the use of mesh points (MPs), which are 802.11 QoS stations that support mesh services. An MP is capable of using a mandatory mesh routing protocol called Hybrid Wireless Mesh Protocol (HWMP) that uses a default path selection metric. Vendors may also use proprietary mesh routing protocols and metrics.
A robust security network (RSN) requires the use of which security mechanisms? (Choose all that apply.)

A. 802.11x
B. WEP
C. IPsec
D. CCMP/AES
E. CKIP
F. 802.1X
D. CCMP/AES
F. 802.1X

The required encryption method defined by an RSN wireless network (802.11i) is Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP), which uses the Advanced Encryption Standard (AES) algorithm. An optional choice of encryption is the
Temporal Key Integrity Protocol (TKIP). The 802.11i amendment also requires the use of an 802.1X/EAP authentication solution or the use of preshared keys.
An 802.11ac radio card can transmit on the _______________ frequency and uses _______________ spread-spectrum technology.

A. 5 MHz, OFDM
B. 2.4 GHz, HR-DSSS
C. 2.4 GHz, ERP-OFDM
D. 5 GHz, VHT
E. 5 GHz, DSSS
D. 5 GHz, VHT

802.11ac radio cards operate in the 5 GHz frequency bands using very high throughput (VHT).
What are the required data rates of an OFDM station?

A. 3, 6, and 12 Mbps
B. 6, 9, 12, 18, 24, 36, 48, and 54 Mbps
C. 6, 12, 24, and 54 Mbps
D. 6, 12, and 24 Mbps
E. 1, 2, 5.5, and 11 Mbps
D. 6, 12, and 24 Mbps

The IEEE 802.11-2016 standard requires data rates of 6, 12, and 24 Mbps for both orthogonal frequency-division multiplexing (OFDM) and Extended Rate Physical OFDM (ERP-OFDM) radios. Data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbps are typically supported. 54 Mbps is the maximum defined rate.
When implementing an 802.1X/EAP RSN network with a VoWiFi solution, what is needed to avoid latency issues during roaming?

A. Inter-Access Point Protocol
B. Fast BSS transition
C. Distributed Coordination Function
D. Roaming Coordination Function
E. Lightweight APs
B. Fast BSS transition

Fast basic service set transition (FT), also known as fast-secure roaming, defines fast handoffs when roaming occurs between cells in a WLAN using the strong security defined in a robust security network (RSN). Applications such as VoIP that necessitate timely delivery of packets require the roaming handoff to occur in 150ms or less.
Which new technologies debuted in the 802.11ac-2013 amendment? (Choose all that apply.)

A. MIMO
B. MU-MIMO
C. 256-QAM
D. 40 MHz channels
E. 80 MHz channels
B. MU-MIMO
C. 256-QAM
E. 80 MHz channels

The 802.11ac amendment debuted and defined the use of 256-QAM modulation, eight spatial streams, multi-user MIMO (MU-MIMO), 80 MHz channels, and 160 MHz channels. 802.11 MIMO technology and 40 MHz channels debuted with the ratification of the 802.11n amendment.
What is the primary reason that OFDM (802.11a) radios cannot communicate with ERP
(802.11g) radios?

A. 802.11a uses OFDM, and 802.11g uses ERP.
B. 802.11a uses DSSS, and 802.11g uses OFDM.
C. 802.11a uses OFDM, and 802.11g uses CCK.
D. 802.11a operates at 5 GHz, and 802.11g operates at 2.4 GHz.
E. 802.11a requires dynamic frequency selection, and 802.11g does not.
D. 802.11a operates at 5 GHz, and 802.11g operates at 2.4 GHz.

Both 802.11a and 802.11g use orthogonal frequency-division multiplexing (OFDM) technology, but because they operate at different frequencies, they cannot communicate with each other. 802.11a equipment operates in the 5 GHz Unlicensed National Information Infrastructure (U-NII) bands, whereas 802.11g equipment operates in the 2.4 GHz industrial, scientific, and medical (ISM) band.
Which two technologies are used to prevent 802.11 radios from interfering with radar and
satellite transmissions at 5 GHz?

A. Dynamic frequency selection
B. Enhanced Distributed Channel Access
C. Direct-sequence spread-spectrum
D. Temporal Key Integrity Protocol
E. Transmit power control
A. Dynamic frequency selection
E. Transmit power control

The 802.11-2016 standard defines mechanisms for dynamic frequency selection (DFS) and transmit power control (TPC) that may be used to satisfy regulatory requirements for operation in the 5 GHz band. DFS and TPC technology were originally defined in the 802.11h amendment, which is now part of the 802.11-2016 standard.
Which 802.11 amendments provide for throughput of 1 Gbps or higher? (Choose all that apply.)

A. 802.11aa
B. 802.11ab
C. 802.11ac
D. 802.11ad
E. 802.11ae
F. 802.11af
C. 802.11ac
D. 802.11ad

The 802.11ac and 802.11ad amendments are often referred to as the "gigabit Wi-Fi" amendments because they define data rates of greater than 1 Gbps. The 802.11ac and 802.11ad very high throughput (VHT) task groups define transmission rates of up to 7 Gbps in an 802.11 environment.
As defined by the 802.11-2016 standard, which equipment is compatible? (Choose all that
apply.)

A. ERP and HR-DSSS
B. HR-DSSS and FHSS
C. VHT and OFDM
D. 802.11h and 802.11a
E. HR-DSSS and DSSS
A. ERP and HR-DSSS
C. VHT and OFDM
D. 802.11h and 802.11a
E. HR-DSSS and DSSS

ERP (802.11g) requires the use of Extended Rate Physical OFDM (ERP-OFDM) and Extended Rate Physical DSSS (ERP-DSSS/CCK) in the 2.4 GHz industrial, scientific, and medical (ISM) band and is backward compatible with 802.11b High-Rate DSSS (HR-DSSS) and direct-sequence spread-spectrum (DSSS) equipment. 802.11b uses HR-DSSS in the 2.4 GHz ISM band and is backward compatible with only legacy DSSS equipment and not legacy frequency-hopping spread-spectrum (FHSS) equipment. 802.11ac uses Very High Throughput (VHT) and is backward compatible with 802.11a orthogonal frequency-division multiplexing (OFDM). The 802.11h amendment defines use of transmit power control (TPC) and dynamic frequency selection (DFS) in the 5 GHz Unlicensed National Information Infrastructure (U- NII) bands and is an enhancement of the 802.11a amendment. OFDM technology is used with all 802.11a- and 802.11h- compliant radios.
What is the maximum data rate defined by the 802.11ac amendment?

A. 54 Mbps
B. 1300 Mbps
C. 3466.7 Mbps
D. 6933.3 Mbps
E. 60 Gbps
D. 6933.3 Mbps

The 802.11ac amendment defines a maximum rate of 6933.3 Mbps. However, 802.11ac chipsets have gone through multiple generations with different capabilities. The maximum data rate for most first-generation 802.11ac devices was 1300 Mbps, and the maximum data rate for most second-generation 802.11ac devices is 3466.7 Mbps.
What are the security options available as defined in the original IEEE Std 802.11-1999
(R2003)? (Choose all that apply.)

A. CCMP/AES
B. Open System authentication
C. Preshared keys
D. Shared Key authentication
E. WEP
F. TKIP
B. Open System authentication
D. Shared Key authentication
E. WEP

The original 802.11 standard defined the use of Wired Equivalent Privacy (WEP) for encryption. The original 802.11 standard also defined two methods of authentication: Open System authentication and Shared Key authentication.
The 802.11u-2011 amendment is also known as what?

A. WIEN (Wireless Interworking with External Networks)
B. WLAN (wireless local area networking)
C. WPP (Wireless Performance Prediction)
D. WAVE (Wireless Access in Vehicular Environments)
E. WAP (Wireless Access Protocol)
A. WIEN (Wireless Interworking with External Networks)

The original 802.11 standard defined the use of Wired Equivalent Privacy (WEP) for encryption. The original 802.11 standard also defined two methods of authentication: Open System authentication and Shared Key authentication.
The 802.11-2016 standard defines which two technologies for quality of service (QoS) in a
WLAN?

A. EDCA
B. PCF
C. Hybrid Coordination Function Controlled Channel Access
D. VoIP
E. Distributed Coordination Function
F. VoWiFi
A. EDCA
C. Hybrid Coordination Function Controlled Channel Access

The 802.11e amendment (now part of the 802.11-2012 standard) defined two enhanced medium access methods to support quality of service (QoS) requirements. Enhanced Distributed Channel Access (EDCA) is an extension to Distributed Coordination Function (DCF). Hybrid Coordination Function Controlled Channel Access (HCCA) is an extension to PCF. In the real world, only EDCA is implemented.
The 802.11h amendment (now part of the 802.11-2016 standard) introduced which two major changes for 5 GHz radios?

A. TPC
B. IAPP
C. DFS
D. DMG
E. FHSS
A. TPC
C. DFS

The 802.11h amendment introduced two major enhancements: transmit power control (TPC) and dynamic frequency selection (DFS) for radar avoidance and detection. All aspects of the 802.11h ratified amendment can now be found in Clause 11.8 and Clause 11.9 of the 802.11- 2016 standard.
The 802.11n amendment defined which PHY?

A. HR-DSSS
B. FHSS
C. OFDM
D. PBCC
E. HT
F. VHT
E. HT

The 802.11n high throughput (HT) amendment defined MAC and PHY enhancements, whereas radios can transmit at data rates up to 600 Mbps.
Which layers of the OSI model are referenced in the 802.11 standard? (Choose all that apply.)

A. Application
B. Data-Link
C. Presentation
D. Physical
E. Transport
F. Network
B. Data-Link
D. Physical

The IEEE specifically defines 802.11 technologies at the Physical layer and the MAC sublayer of the Data-Link layer. By design, anything that occurs at the upper layers of the OSI model is insignificant to 802.11 communications.
Sets found in the same folder