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Question 1. What is the primary advantage of wireless communication over wired systems? A) Higher data security B) Mobility and flexibility C) Greater bandwidth capacity D) Less susceptibility to interference Answer: B Explanation: Wireless communication offers mobility and flexibility, enabling users to connect without physical cables, unlike wired systems. Question 2. Which organization is responsible for international spectrum management and standardization of radio communications? A) IEEE B) ITU C) 3GPP D) FCC Answer: B
Explanation: The International Telecommunication Union (ITU) manages spectrum allocation and global standards for wireless communications. Question 3. Which is an example of a narrowband analog modulation technique? A) QAM B) ASK C) FM D) FHSS Answer: C Explanation: Frequency Modulation (FM) is an analog modulation technique that varies the frequency of the carrier signal. Question 4. What does the term "bandwidth" refer to in wireless communication? A) The maximum data rate achievable B) The range of frequencies occupied by a signal C) The power of the transmitted signal D) The distance a signal can travel
Answer: C Explanation: Small-scale fading results from multipath effects causing rapid variations over short distances or time. Question 7. What is the main purpose of diversity techniques in wireless communication? A) Increase transmission power B) Combat fading and improve signal quality C) Reduce interference from other users D) Enhance spectrum efficiency Answer: B Explanation: Diversity techniques are used to mitigate fading effects and enhance reliability by combining multiple signal paths or channels. Question 8. Which digital modulation technique encodes data by shifting the phase of the carrier signal? A) ASK B) FSK C) PSK
D) QAM
Answer: C Explanation: Phase Shift Keying (PSK) encodes data by changing the phase of the carrier wave. Question 9. Which spread spectrum technique involves hopping the carrier frequency according to a pseudo-random sequence? A) DSSS B) FHSS C) OFDM D) QAM Answer: B Explanation: Frequency Hopping Spread Spectrum (FHSS) rapidly switches the carrier among many frequency channels based on a pseudo-random sequence. Question 10. What is a key characteristic of Orthogonal Frequency Division Multiple Access (OFDMA)? A) Uses orthogonal subcarriers to enable multiple users B) Employs time division multiplexing exclusively
D) Power control Answer: B Explanation: Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) helps prevent collisions before they occur in wireless networks. Question 13. Which Bluetooth version introduced low energy operation suitable for IoT devices? A) Bluetooth 2. B) Bluetooth 3. C) Bluetooth Low Energy (BLE) in Bluetooth 4. D) Bluetooth 5. Answer: C Explanation: Bluetooth Low Energy (BLE), introduced with Bluetooth 4.0, is designed for low power consumption suitable for IoT applications. Question 14. In cellular systems, what is the purpose of cell sectoring? A) Increase frequency reuse B) Reduce interference and increase capacity
C) Enable handoff between different networks D) Improve modulation schemes Answer: B Explanation: Cell sectoring divides a cell into sectors to reduce interference and increase system capacity. Question 15. Which generation of mobile technology first introduced digital encryption for voice calls? A) 1G B) 2G C) 3G D) 4G LTE Answer: B Explanation: 2G systems, such as GSM, introduced digital encryption for securing voice communications. Question 16. Which architecture component is fundamental to the core network in cellular systems? A) Base station B) Mobile switching center (MSC)
C) Excessive bandwidth availability D) Fixed topology Answer: B Explanation: WSNs face challenges like limited energy resources and security vulnerabilities. Question 19. Which orbit type is characterized by satellites orbiting approximately 35,786 km above Earth? A) LEO B) MEO C) GEO D) HEO Answer: C Explanation: Geostationary Earth Orbit (GEO) satellites orbit at about 35,786 km, appearing stationary relative to Earth. Question 20. Which multiple access technique is primarily used in satellite communication systems? A) TDMA B) FDMA
C) CDMA
D) All of the above Answer: D Explanation: Satellite systems utilize TDMA, FDMA, and CDMA depending on the application and system design. Question 21. Which emerging wireless technology employs millimeter-wave (mmWave) frequencies? A) LTE B) 4G C) 5G D) Wi-Fi 4 Answer: C Explanation: 5G technology leverages mmWave frequencies to achieve high data rates and capacity. Question 22. Which concept in cognitive radio allows secondary users to utilize spectrum without interfering with primary users? A) Spectrum sensing B) Spectrum leasing
C) To schedule data packets efficiently D) To estimate user mobility patterns Answer: A Explanation: Link budget analysis calculates the total gain and losses to ensure sufficient signal strength for reliable links. Question 25. Which metric measures the ratio of the signal power to the noise power at the receiver? A) SNR B) BER C) SINR D) Throughput Answer: A Explanation: Signal-to-Noise Ratio (SNR) indicates the quality of the received signal relative to background noise. Question 26. Which modulation technique is most bandwidth-efficient for high data rate wireless systems? A) ASK B) BPSK
C) 64-QAM
D) FSK
Answer: C Explanation: 64-QAM provides high spectral efficiency, enabling high data rates in wireless systems. Question 27. Which is a key disadvantage of spread spectrum techniques? A) Susceptibility to interference B) Increased bandwidth requirement C) Limited security benefits D) Reduced resistance to jamming Answer: B Explanation: Spread spectrum techniques occupy more bandwidth, which can be a disadvantage in spectrum-limited environments. Question 28. In CDMA systems, what is the purpose of orthogonal codes such as Walsh codes? A) To maximize bandwidth efficiency
A) Massive MIMO B) Narrowband IoT C) Bluetooth 4. D) Wi-Fi 802.11b Answer: A Explanation: Massive MIMO employs large antenna arrays to enhance capacity and reduce latency in 5G. Question 31. Which type of multiple access is typically used in LTE systems? A) FDMA B) TDMA C) OFDMA D) CDMA Answer: C Explanation: LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) to efficiently serve multiple users. Question 32. Which component in a cellular system manages handoff between cells?
A) Base transceiver station (BTS) B) Mobile switching center (MSC) C) Radio network controller (RNC) D) User equipment (UE) Answer: C Explanation: The RNC manages handover procedures and resource allocation across cells. Question 33. Which wireless standard introduced MIMO technology for increased data rates? A) 3G B) 4G LTE C) 5G D) Wi-Fi 802.11n Answer: B Explanation: 4G LTE incorporated Multiple Input Multiple Output (MIMO) technology to enhance throughput. Question 34. In the context of Wi-Fi security, which protocol is considered most secure?
Question 36. Which satellite orbit provides continuous coverage over a specific geographic area? A) GEO B) LEO C) MEO D) HEO Answer: A Explanation: Geostationary Orbit (GEO) satellites maintain fixed positions relative to Earth, providing continuous coverage. Question 37. Which technology is used in IoT to enable devices to communicate over long distances with low power consumption? A) Wi-Fi B) LoRa C) Bluetooth D) Zigbee Answer: B Explanation: LoRa is designed for long-range, low-power IoT communications.
Question 38. Which concept in wireless communication involves dynamically adjusting transmit power to maintain link quality? A) Power control B) Frequency hopping C) Modulation adaptation D) Channel coding Answer: A Explanation: Power control adjusts transmission power to optimize link quality and reduce interference. Question 39. Which is a defining characteristic of Near-Field Communication (NFC)? A) Long-range communication over kilometers B) Short-range, close-proximity data exchange C) Uses microwave frequencies exclusively D) Requires line-of-sight only Answer: B Explanation: NFC enables short-range communication typically within a few centimeters.
