Since the early 1990s, the wireless communications field has witnessed explosive growth. The wide range of applications and existing new technologies nowadays stimulated this enormous growth and encouraged wireless applications.
- Python Django – Multiple Choice Questions (MCQ) with Answers
- Windows Server 2016 – Multiple Choice Questions (MCQ) With Answers
- Top 77 Linux Interview Questions to Ask Candidates
Wireless networks always play a crucial role in the lives of people at work, home, and public places. Even though a wireless network has a simple purpose, which is to provide connections between users and information sources without the use of wires, critical concepts of wireless networks must be mastered before understanding how they operate.
This article presents a set of 80 questions (with answers) related to wireless networks:
1) What is a distinguishing attribute of a wireless network as compared to a general wireless communication system?
Answer: In a wireless network, communications takes place between computer devices.
2) What types of information does a wireless network support?
Answer: E-mails, messages, web pages, database records, streaming video, and voice.
3) What are the four types of wireless networks?
Answer: Wireless PAN, LAN, MAN, and WAN.
4) What is the typical maximum range of a wireless PAN?
Answer: 50 feet.
5) True or false: A wireless PAN consumes little power from small handheld computer devices.
6) What is a common standard for wireless LANs?
Answer: IEEE 802.11 or Wi-Fi.
7) What relatively new standard applies to wireless MANs?
Answer: IEEE 802.16.
8) Why do wireless WANs not effectively satisfy requirements for indoor wireless networks?
Answer: Wireless WAN systems are generally installed outdoors, and the signals lose strength before reaching the inside of the facility.
9) What is a common application of wireless networks in homes and small offices?
Answer: Sharing Internet connections among multiple, mobile computers is a common application.
10) What are examples of applications for wireless WANs?
Answer: Access to Internet applications from outdoor locations, realestate transactions, field-service and sales calls, vending-machine status, and utility-meter reading are a few examples.
11) Which wireless NIC form factors are best for small wireless computer devices?
Answer: PC Card, Mini-PCI, and CompactFlash.
12) What are examples of elements that impair the propagation of wireless communications signals through the air medium?
Answer: Rain, snow, smog, and smoke.
13) What is the primary purpose of a base station?
Answer: Interfaces the wireless communications signals traveling through the air medium to a wired network.
14) What are common features of wireless middleware?
Answer: Optimization techniques, intelligent restarts, data bundling, screen shaping and reshaping, and end-system support.
15) On what layers of the OSI reference model do wireless networks operate?
Answer: Physical layer and data link layer.
16) How is throughput different from data rate?
Answer: Throughput doesn’t include overhead of protocols.
17) True or false: A computer device stores data in analog form.
18) A wireless NIC must convert the information into what type of signal before transmission through the air medium?
19) Which medium access protocol is common with wireless networks?
20) Explain how the ARQ form of error control works.
Answer: The receiving wireless NIC performs error checking and sends a request to the sending wireless NIC to retransmit the frame if errors are found.
21) RF signals offer relatively short range as compared to light signals. True or false?
22) What type of weather impacts RF signals the most?
Answer: Heavy rain.
23) Why does interference cause errors in wireless networks?
Answer: The interference causes the receiver to misunderstand the signal because two signals are present at the same time.
24) What are sources of RF interference?
Answer: General examples include cordless phones, microwave ovens, and Bluetooth devices.
25) Multipath affects higher data rates more than lower data rates for 2.4 GHz systems. True or false?
Answer: True. The receiver has difficulties with differentiating one bit from another when demodulating high data rate signals because the bits are close together.
26) What is meant by a diffused infrared light system?
Answer: A system that emits light in all directions that reflects off of the ceiling and walls.
27) Approximately up to what range do direct infrared systems operate?
Answer: 1 mile.
28) How does modulation make it possible to transmit information through the air?
Answer: Modulation superimposes an information signal onto a carrier signal that has a frequency suitable for propagating through the air.
29) What attributes of a signal does QAM change in order to represent information?
Answer: Amplitude and phase.
30) Spread spectrum generally requires user licenses. True or false?
31) What form factors are common for wireless PAN radio cards?
Answer: PC Card and CF.
32) What application can strongly benefit through the use of a wireless USB adapter (also referred to as a wireless dongle)?
Answer: Any application that can benefit from interfacing with a PC or laptop through the USB port, such as PDA, wireless mouse, and wireless digital camera for synchronization purposes.
33) When would the use of a wireless PAN router make sense?
Answer: For applications limited to the size of a room, such as in homes and small offices.
34) What is the general maximum coverage area of a wireless PAN?
Answer: Within 30 feet, such as within a room.
35) Which IEEE standards group uses Bluetooth as the basis for the standard?
36) In what frequency band does Bluetooth operate?
Answer: 2.4 GHz.
37) What is the primary issue of using Bluetooth around 802.11 wireless LANs?
Answer: They both operate in the same 2.4 GHz frequency band, which can result in interference and degradation in performance.
38) A Bluetooth-enabled device is always transmitting. True or false?
39) What is the highest possible data rate of an IrDA device?
Answer: 4 Mbps.
40) What is a benefit of IrDA as compared to Bluetooth?
Answer: IrDA is immune from RF interference with wireless LANs.
41) Which wireless LAN component is most commonly used in home and small offices?
Answer: Wireless LAN router.
42) What is the primary difference between an access point and a wireless LAN router?
Answer: A wireless LAN router actually routes packets to their destination. Access points don’t implement DHCP and NAT. Routers do implement DHCP and NAT.
43) When would the use of a wireless LAN repeater make sense?
Answer: When extending the range of an access point or router to an area where wires can’t be run feasibly.
44) How does a wireless LAN radio NIC identify with which access point to associate?
Answer: The radio NIC listens for beacons being sent periodically by each access point and associates with the access point having the strongest beacon signal.
45) WEP is a mandatory encryption mechanism. True or false?
46) In what frequency band does 802.11a operate in?
Answer: 5 GHz.
47) How many non-overlapping channels are available with 802.11b wireless LANs?
48) True of false: 802.11g operates at up to 54 Mbps and interoperates with 802.11b.
49) Which 802.11 frequencies are available almost worldwide?
Answer: 2.4 GHz (802.11b and 802.11g).
50) What does Wi-Fi provide?
Answer: A product having Wi-Fi certification will interoperate with other products that have Wi-Fi certification, regardless of the manufacturer.
51) Why does a wireless MAN offer good return on investment?
Answer: Wireless MANs eliminate the need to install expensive cabling or lease communications circuits.
52) A learning bridge forwards all packets. True or false?
53) What is the primary difference between a bridge and an access point?
Answer: A bridge connects networks together. An access point connects end users.
54) What are examples of semidirectional antennae?
Answer: Patch and Yagi.
55) In regards to beamwidth, what is the primary difference between a semidirectional and highly directional antenna?
Answer: A highly directional antenna has a much narrower beamwidth, which increases range if the power remains constant.
56) What is an example of a highly directional antenna?
Answer: Dish antenna.
57) What polarization would be most effective at a receiver if the transmitter were using vertical polarization?
Answer: Vertical polarization.
58) What are the advantages of using point-to-multipoint systems versus point-to-point for interconnecting multiple sites?
Answer: Point-to-multipoint can be less expensive and easier to add more sites.
59) What are the advantages of using packet radio for wireless MANs?
Answer: Packet radio routers don’t require any cabling between them, and the system is relatively survivable because packets can take a different route if a router becomes inoperative.
60) Which standards do wireless MANs employ?
Answer: 802.11, Wi-Fi, and 802.16.
61) What types of user devices are most common with wireless WANs?
Answer: Laptops, PDAs, and mobile phones.
62) Why do wireless WAN operators always charge for services?
Answer: Wireless WANs are expensive to install.
63) Why must you be careful when selecting a wireless WAN radio NIC for your user device?
Answer: There are many different types of wireless WANs that are not compatible with each other.
64) What is an advantage of a satellite system?
Answer: It can cover vast areas. A single satellite can cover roughly one-third of the Earth’s surface.
65) Which generation of cellular systems offers data rates up to 2 Mbps?
Answer: Third generation (3G).
66) Which type of wireless WAN system is most common?
Answer: Cellular systems.
67) Which of the two following cellular systems offers the highest data rates: GPRS or UMTS?
68) What is the primary issue with meteor burst communications?
Answer: Low data rates.
69) True or false: FDMA requires users to take turns transmitting signals.
70) How does CDMA keep users from interfering with each other?
Answer: Each user transmits using a different code.
71) What are the three major security threats of a wireless network?
Answer: Traffic monitoring, unauthorized access, and DoS.
72) What is the primary means for guarding against traffic monitoring?
Answer: Utilize encryption.
73) How do you keep hackers from gaining access to company resources through the wireless network?
Answer: Incorporate the use of effective authentication.
74) What method will help alleviate the implications of a successful DoS attack?
Answer: Have an alternative plan to carry on business in a manner that doesn’t require the use of the wireless network.
75) Why is WEP not acceptable for protecting sensitive information?
Answer: Hackers are able to crack the WEP encryption algorithm through the use of publicly available tools.
76) How is TKIP different than WEP?
Answer: TKIP make use of a dynamic key distribution mechanism that updates keys periodically, whereas WEP makes use of static keys that don’t change.
77) WPA uses TKIP and is a subset of the 802.11i standard. True or false?
78) Why is the use of MAC address filters not effective?
Answer: It’s difficult to manage and easy to spoof.
79) What is a rogue access point, and why does it pose a problem?
Answer: A rogue access point does not have any security features set and is put in by a hacker or employee. The rogue access point offers an open port to the network for hackers to exploit.
80) What should you install on a laptop that a user will utilize on a public wireless LAN to avoid unauthorized people from accessing files on the laptop?
Answer: Personal firewall.