Section A: Multiple-Choice Questions

1) What is the primary advantage of wireless communication?

a) Increased hardware cost

b) High mobility and flexibility
c) Decreased signal interference
d) Limited network coverage

2) Who invented the wireless telegraph?

a) Alexander Graham Bell

b) Nikola Tesla
c) Guglielmo Marconi
d) Thomas Edison

3) What does GSM stand for?

a) General Satellite Module

b) Global System for Mobile Communications
c) General Signal Management
d) Global Smart Mobile

4) Which of the following is an example of a bidirectional wireless communication

system?

a) Paging system
b) Broadcast radio
c) Cellular telephony
d) Satellite TV

5) Which generation of cellular networks introduced packet switching?

a) 1G
b) 2G
c) 2.5G
d) 3G

6) What is the main purpose of ad hoc networks?

a) To replace wired connections

b) To provide infrastructure-based networks
c) To allow mobile devices to communicate without a central controller
d) To reduce battery consumption in mobile phones

7) Which wireless service allows multiple users to communicate within a closed

group?

a) Cellular telephony
b) Trunking radio
c) Paging
d) Fixed wireless access

8) Which of the following best defines mobile computing?

a) The ability to compute only in a fixed location

b) Performing computation in mobile units while moving
c) Using only wired network infrastructure
d) None of the above

9) Which of the following is not a characteristic of pervasive computing?

a) Context awareness
b) Ad-hoc networking
c) High resource consumption
d) Invisible computing

10What is the primary role of GPS in mobile computing?

a) Enhancing battery life

b) Providing location-based services
c) Increasing processing power
d) Reducing data transfer rates

11What is the primary challenge in mobile computing?

a) Increased hardware costs

b) High-speed data transmission
c) Security risks and frequent disconnections
d) Unlimited bandwidth availability

12)What is the main function of a PDA (Personal Digital Assistant)?

a) Voice communication only

b) Web browsing and gaming
c) Maintaining schedules and contacts
d) Printing documents

13)Which mobile computing paradigm is characterized by shared memory and

parallel processing?

a) Cloud computing
b) Distributed computing
c) Parallel computing
d) Ubiquitous computing

14)Which wireless network standard is commonly known as WiFi?

a) IEEE 802.15 b) IEEE 802.11 c) IEEE 802.16 d) IEEE 802.20

15)Which of the following mobile operating systems is not open-source?

a) Android b) Symbian c) iOS d) Windows Mobile

16)What is the major drawback of satellite communication?

a) High latency b) Low data rates

c) Poor mobility support d) Limited geographic coverage

17)What is a key feature of BlackBerry OS that differentiates it from other mobile

OS? a) Open-source licensing b) High-end gaming support

c) Push email service d) Extensive support for third-party apps

18)Which computing paradigm enables users to access services without knowledge of

hardware configuration?

a) Pervasive computing b) Cloud computing

c) Distributed computing d) Personal computing

19)Which of the following sensors is used to detect motion in mobile devices?

a) Ambient light sensor b) Proximity sensor

c) Accelerometer d) NFC sensor

20)What is the biggest limitation of mobile computing devices?

a) Unlimited storage b) High processing power

c) Limited battery life d) Wired connectivit

Section B: Short-Answer Questions (2 marks each)

1) Explain the difference between wireless communication and mobile

communication with examples.

 Wireless communication involves transmitting data without physical cables (e.g.,

WiFi, Bluetooth).
 Mobile communication refers to the ability of a device to move while
communicating (e.g., cellular networks).

2) Describe the role of electromagnetic spectrum in wireless communication.

 It provides the frequency bands for wireless signals (e.g., radio waves, infrared,
microwaves).

3) What are the key characteristics of 3G networks, and how do they differ from 2G?
 3G provides higher data speeds, supports video calls, and uses packet-switched
technology.
 2G primarily supports voice calls and text messaging with lower data rates.

4) List and explain three major issues associated with mobile computing.

 Security risks (data interception, hacking)

 Limited battery life
 Frequent disconnections due to signal loss

5) What are Location-Based Applications (LBAs)? Provide two real-world

examples.

 Applications that provide services based on user location.

 Examples: Google Maps (navigation), Uber (ride-sharing).

6) How do cellular networks handle increasing numbers of users efficiently?

 Using the cellular principle (dividing geographic areas into cells).

 Frequency reuse and improved spectrum management.

7) Describe ad hoc networks and provide an example of their use.

 Temporary networks formed by mobile devices without infrastructure.

 Example: Disaster recovery networks after an earthquake.

8) What is the difference between GSM and CDMA?

 GSM uses SIM cards and time-division multiple access (TDMA).

 CDMA assigns unique codes to each call for better spectrum efficiency.

9) Explain how cloud computing benefits mobile users.

 Provides remote storage, access to powerful computing resources, and cross-

device synchronization.

10) What are the advantages and disadvantages of Bluetooth technology in

mobile computing?

 Advantages: Low power consumption, simple connectivity, no need for internet.

 Disadvantages: Limited range, slow data transfer compared to WiFi
Multiple-Choice Questions (20 Questions)

1)Who invented the wireless telegraph in 1896?

1. a) Alexander Graham Bell

2. b) Nikola Tesla
3. c) Guglielmo Marconi ✅
4. d) Thomas Edison

Which cellular principle forms the basis for modern wireless communications?

1. a) Frequency hopping
2. b) Cellular division using hexagonal cells ✅
3. c) Time-division multiplexing
4. d) Spread spectrum

Which wireless service is unidirectional and intended for a single user?

1. a) Cellular telephony
2. b) Paging ✅
3. c) Trunking radio
4. d) WLAN

What is the primary difference between GSM and 1G systems like AMPS?

1. a) GSM uses analog signals; AMPS uses digital

2. b) GSM uses CDMA; AMPS uses TDMA
3. c) GSM is digital; AMPS is analog ✅
4. d) GSM operates at higher frequencies

Which frequency band is used by IEEE 802.11b/g Wi-Fi?

1. a) 900 MHz
2. b) 2.4 GHz ✅
3. c) 5 GHz
4. d) 40 GHz

What is a key disadvantage of frequency-division multiplexing (FDM)?

1. a) Requires precise synchronization

2. b) Inflexible bandwidth allocation ✅
3. c) High susceptibility to interference
4. d) Limited data rates

In CDMA, how are signals from multiple users distinguished?

1. a) Time slots
2. b) Unique frequency bands
3. c) Orthogonal codes ✅
4. d) Spatial separation
Which propagation mode is used by AM radio signals to travel long distances?

1. a) Line-of-sight
2. b) Sky wave
3. c) Ground wave ✅
4. d) Scattering

What does the Hamming distance between codewords 011011 and 110001 equal?

1. a) 2
2. b) 3 ✅
3. c) 4
4. d) 5

Which multiplexing technique combines time and frequency dimensions?

 a) TDMA
 b) CDMA
 c) OFDMA
 d) GSM ✅

Which OS had the highest smartphone market share in 2010?

 a) Android
 b) Symbian ✅
 c) iOS
 d) BlackBerry OS

What is a major challenge in mobile software development?

 a) High battery capacity

 b) Uniform screen sizes
 c) Heterogeneous hardware architectures ✅
 d) Unlimited bandwidth

Which sensor detects device orientation in smartphones?

 a) Proximity sensor
 b) Accelerometer ✅
 c) Ambient light sensor
 d) Gyroscope

What is the primary purpose of FHSS?

 a) Increase data rates

 b) Reduce interference through frequency hopping ✅
 c) Enable bidirectional communication
 d) Improve signal amplitude
Which mobile computing paradigm emphasizes "invisible, everywhere"
computing?

 a) Distributed computing
 b) Pervasive computing ✅
 c) Cloud computing
 d) Parallel computing

What is the main advantage of managed code in mobile development?

 a) Direct hardware access

 b) Portability and safety ✅
 c) Higher execution speed
 d) Lower memory usage

Which wireless network type uses directional antennas for point-to-point

communication?

 a) Broadcast radio
 b) Satellite microwave ✅
 c) Infrared
 d) Cellular

What causes the "hidden terminal problem" in wireless networks?

 a) Multipath propagation
 b) Nodes out of range of each other ✅
 c) Frequency hopping
 d) High mobility

Which error correction method uses the shortest Hamming distance?

 a) Turbo codes
 b) Block codes ✅
 c) CRC
 d) Parity checks

Which application is an example of an ad hoc network?

 a) GPS navigation
 b) Disaster relief communication ✅
 c) Cellular telephony
 d) Satellite TV

Short-Answer Questions (10 Questions)

Explain why lower frequencies (e.g., 900 MHz) are more congested than higher
frequencies.
Answer: Lower frequencies penetrate buildings better and travel farther, leading to
higher demand and congestion.
Compare FHSS and DSSS in terms of security and bandwidth efficiency.
Answer: FHSS spreads signals by hopping frequencies, making interception difficult,
while DSSS spreads data over a wider spectrum, providing better bandwidth
efficiency but less security.

Calculate the Hamming distance between the codewords 101010 and 111001.
Answer: 3 (positions differing: 2nd, 4th, 6th).

Describe two technical challenges unique to mobile computing.

Answer:

1. Battery limitations: Mobile devices must optimize power usage.

2. Network variability: Connectivity changes with movement, affecting
reliability.

How does CDMA allow multiple users to share the same frequency band
simultaneously?
Answer: CDMA uses orthogonal codes to distinguish user signals, allowing multiple
users to transmit simultaneously on the same frequency.

Why is synchronization critical in TDMA but not in CDMA?

Answer: TDMA divides time into slots, requiring precise synchronization to avoid
overlap, whereas CDMA relies on unique codes, allowing asynchronous transmission.

Explain the role of the "guard space" in multiplexing techniques.

Answer: Guard space prevents interference between adjacent signals by separating
them in time or frequency.

What distinguishes contention-based MAC protocols (e.g., CSMA) from

contention-free protocols (e.g., TDMA)?
Answer: Contention-based protocols dynamically allocate bandwidth based on
demand, while contention-free protocols use predefined slots, reducing collisions.

How does signal attenuation affect wireless communication, and what mitigates
it?
Answer: Signal attenuation weakens signals over distance; mitigation methods
include repeaters, amplifiers, and directional antennas.

Why is Android considered a dominant mobile OS? Provide three reasons.

Answer:

1. Open-source nature: Allows extensive customization and adoption.

2. Wide device compatibility: Available on various manufacturers'
devices.
3. Large app ecosystem: Google Play Store offers millions of
applications.