Telecomm and Wireless Communications - D413 - Review Q&A Ch.4

A(n) _____ is an electromagnetic wave of a set frequency that is used to carry data in radio-wave-and microwave-based networks.

Carrier Wave.

Explanation: A carrier wave is an electromagnetic wave used to carry data by modulating its amplitude, frequency, or phase.

What is an SSID?

Service Set Identifier.

Explanation: SSID is a unique name assigned to a wireless network, allowing devices to identify and connect to it.

What is modulation?

Modulation is the process of varying a carrier wave’s properties (amplitude, frequency, or phase) to encode data.

Explanation: Modulation allows digital information to be transmitted over analog communication channels.

A simple radio broadcast consists of a(n) _____, which generates a carrier wave and a(n) _____, which receives a carrier wave.

Transmitter; Receiver.

Explanation: A transmitter sends out the carrier wave, while a receiver detects and demodulates the wave to extract the transmitted information.

What is a channel?

A channel is a specific frequency range used for communication in a network.

Explanation: Channels divide the available frequency spectrum into manageable segments to allow multiple communications to occur simultaneously.

What is the main disadvantage to infrared?

Infrared signals require line-of-sight and are blocked by obstacles.

Explanation: Infrared communication relies on a direct path between the transmitter and receiver, making it susceptible to interference from physical barriers.

What are the two major classifications of antennae?

Omnidirectional and Directional.

Explanation: Omnidirectional antennas transmit signals in all directions, while directional antennas focus their signal in a specific direction.

Which of the following antenna types is not used in point-to-point links?

A. Flat panel

B. Omni

C. Parabolic

D. Yagi

B. Omni.

Explanation: Omni-directional antennas are used for coverage in all directions rather than focused point-to-point communication.

Which antenna style was developed with aesthetics in mind?

Flat panel.

Explanation: Flat panel antennas were designed to be visually less intrusive and blend with the surroundings.

What is spread spectrum?

Spread spectrum is a technique where a signal is spread over a wide frequency range to minimize interference and enhance security.

Explanation: This technique makes signals less susceptible to interference and allows for better signal resilience.

The spread-spectrum technique that transmits data on multiple channels simultaneously is called _____.

Direct Sequence Spread Spectrum (DSSS).

Explanation: DSSS spreads data across multiple frequencies simultaneously, enhancing signal robustness and reducing interference.

Why is frequency hopping used?

Frequency hopping is used to avoid interference and eavesdropping by rapidly switching the carrier signal across different frequency channels.

Explanation: It enhances communication security and reliability by spreading the signal over a range of frequencies.

The spread-spectrum technique that transmits data on multiple channels sequentially is called _____.

Frequency Hopping Spread Spectrum (FHSS).

Explanation: FHSS transmits data by hopping between different frequency channels in a predefined sequence.

The _____ transmission technique uses the 5-GHz frequency and can achieve data rates as high as 54 Mbps.

IEEE 802.11a.

Explanation: IEEE 802.11a operates in the 5 GHz band and supports data rates up to 54 Mbps, offering higher performance compared to 802.11b.

List the frequency range for each of the three U-NII classifications.

U-NII-1: 5.15-5.25 GHz, U-NII-2: 5.25-5.35 GHz, U-NII-3: 5.725-5.825 GHz.

Explanation: The U-NII bands are specific frequency ranges allocated for wireless networking to reduce interference and improve performance.

What frequency does IEEE 802.11g specify?

2.4 GHz.

Explanation: IEEE 802.11g operates in the 2.4 GHz band, offering backward compatibility with 802.11b devices.

What frequency does IEEE 802.11n specify?

IEEE 802.11n operates in both the 2.4 GHz and 5 GHz bands.

Explanation: This dual-band capability allows IEEE 802.11n to offer higher data rates and better performance compared to previous standards.

What does the acronym MIMO represent?

Multiple Input, Multiple Output.

Explanation: MIMO technology uses multiple antennas at both the transmitter and receiver to improve wireless network performance.

What is MIMO wireless technology?

MIMO is a technology that employs multiple antennas to transmit and receive more data simultaneously, enhancing the capacity and reliability of wireless networks.

Explanation: MIMO increases data throughput and improves signal quality by leveraging multiple spatial channels.

Describe the IEEE 802.11ac standard.

IEEE 802.11ac is a wireless networking standard that operates exclusively in the 5 GHz band, supports wider channels (up to 160 MHz), and can achieve data rates exceeding 1 Gbps.

Explanation: IEEE 802.11ac improves on previous standards with higher data rates, increased bandwidth, and better performance in high-density environments.

Which media access method does the 802.11 wireless standard specify?

B. CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance).

Explanation: CSMA/CA is used to avoid collisions in wireless networks by checking the channel before transmitting data.

What is the difference between CSMA/CA and CSMA/CD?

CSMA/CA (used in wireless networks) prevents collisions by avoiding them, while CSMA/CD (used in wired Ethernet) detects collisions after they occur and retransmits.

Explanation: CSMA/CA minimizes collisions before transmission, whereas CSMA/CD handles collisions after they happen.

What is the maximum achievable distance of a Bluetooth device?

The maximum range of a Bluetooth device is up to 100 meters for Class 1 devices.

Explanation: Bluetooth devices are classified into classes based on their maximum range, with Class 1 having the longest range.

What is the data rate of the Bluetooth 3.0 standard?

Bluetooth 3.0 can achieve a maximum data rate of 24 Mbps.

Explanation: Bluetooth 3.0 includes an enhanced data rate (EDR) feature that increases the maximum data transfer speed.

_____ technology is based on radio waves connecting to designated areas referred to as cells.

Cellular.

Explanation: Cellular technology divides geographic areas into cells, each served by a base station, to facilitate mobile communication.

Long Term Evolution (LTE) is also known as _____.

4G LTE.

Explanation: LTE is a 4G wireless technology standard offering high-speed data transfer for mobile devices.

What is a geosynchronous orbit?

A geosynchronous orbit is one where a satellite orbits the Earth at the same rotational speed as the Earth, staying fixed relative to a specific point on the Earth's surface.

Explanation: This orbit allows the satellite to maintain a constant position relative to the Earth’s surface, ideal for communications.

What is a disadvantage of satellite communication?

Latency (delay) due to the long distance signals travel between Earth and the satellite.

Explanation: The time it takes for signals to travel to and from geostationary satellites can cause noticeable delays in communication.

What is an advantage of wireless networking?

Mobility and flexibility, allowing devices to connect without physical cables.

Explanation: Wireless networks provide users with the freedom to move around while staying connected to the network.

What is the one major disadvantage of wireless technology?

Susceptibility to interference and security vulnerabilities.

Explanation: Wireless signals can be disrupted by physical obstacles and are more prone to unauthorized access compared to wired networks.

What does the acronym WEP represent?

Wired Equivalent Privacy.

Explanation: WEP was an early encryption standard used in wireless networks to secure data transmissions, but it has been largely replaced due to security vulnerabilities.

What does the acronym TKIP stand for?

Temporal Key Integrity Protocol.

Explanation: TKIP was an enhancement over WEP to provide better security for wireless networks, though it has also been superseded by WPA2.

Which IEEE 802.11 standard specifies a data rate of 300 Mbps?

A. 802.11a

B. 802.11b

C. 802.11g

D. 802.11n

D. 802.11n.

Explanation: IEEE 802.11n supports data rates up to 300 Mbps using MIMO technology.

Michelle is setting up wireless networks for her company. Which media access method is used by wireless networks?

A. ARCnet

B. CSMA/CA

C. CSMA/CD

D. Token Ring

B. CSMA/CA.

Explanation: Wireless networks use CSMA/CA to manage access to the shared wireless medium and avoid collisions.

Which of the following items is used to connect a wireless network to an Ethernet network?

A. Wireless access point

B. Ad hoc converter

C. Ethernet converter

D. Ethernet sequencing device

A. Wireless access point.

Explanation: A wireless access point (WAP) connects wireless clients to a wired Ethernet network.

Gabriel has realized that the Wi-Fi he setup for his company is not getting the bandwidth it should. He thinks this is probably due to interference. What would most likely generate radio interference for an 802.11b network device?

A. Microwave oven

B. Another computer using an 802.11g network adapter card

C. Wireless keyboard

D. HP LaserJet printer

A. Microwave oven.

Explanation: Microwave ovens operate on the 2.4 GHz frequency, which can interfere with 802.11b devices operating on the same frequency.

Who is responsible for regulating the electromagnetic spectrum and dictating the frequency that is to be used for each group of devices?

A. IEEE

B. The telephone company in the local area

C. FCC

D. WECA

C. FCC.

Explanation: The Federal Communications Commission (FCC) regulates the use of the electromagnetic spectrum in the U.S. and assigns frequencies for various types of communication.

Farris wants to get the most out of his wireless network. The maximum bandwidth is critical for his networking needs. Therefore, he is interested in eliminating devices that are likely to cause interference. Which item would most likely interfere with the operation of an 802.11ac wireless network?

A. Hub

B. Cordless phone

C. Incandescent lights

D. Copier

B. Cordless phone.

Explanation: Cordless phones operating in the 5 GHz band could interfere with 802.11ac networks, which also use the 5 GHz band.

What is the function of an SSID?

A. Replaces the network MAC address

B. Encrypts all wireless communication

C. Identifies the wireless network by name

D. Increases the data throughput of a wireless network

C. Identifies the wireless network by name.

Explanation: The SSID helps users identify and connect to the correct wireless network.

Helena works as a network administrator for a bank. She has been instructed to ensure that all wireless access points are configured securely. Which protocol fully implements 802.11i requirements?

A. WPA

B. WPA2

C. WAP

D. WEP

B. WPA2.

Explanation: WPA2 implements the full 802.11i security standard, providing strong encryption and authentication for wireless networks.

Which IEEE standard is used to describe how to achieve secure authentication to a wireless network?

A. 802.3

B. 802.1x

C. 802.5b

D. 802.4a

B. 802.1x.

Explanation: IEEE 802.1x provides the framework for network access control, including secure authentication methods for wireless networks.

Jerome has been tasked with setting up a WLAN that operates in the TV white-space spectrum in the VHF and UHF bands between 54 and 790 MHz. Which standard should he use?

A. 802.11n-2009

B. 802.11ac

C. 802.11af

D. 802.11ag

C. 802.11af.

Explanation: IEEE 802.11af operates in the TV white-space spectrum, making it suitable for WLANs using these frequencies.