Gsm uses ________ number of frequency range.

Wireless & Mobile Communications MCQ & Answers- Paging System

1. Which of the following is not a standard used for paging system?
a] POCSAG
b] ERMES
c] IS-95
d] FLEX

Answer :-  c] IS-95

2. Paging system uses which mode of transmission?
a] Full duplex
b] Simplex
c] Half Duplex
d] Duplex
Answer :-  b] Simplex

3. The information sent by paging system is known as a ___________
a] Note
b] Line
c] Message
d] Page
Answer :-  d] Page

4. Which type of message cannot be sent with the help of paging system?
a] Alphanumeric message
b] Video message
c] Voice message
d] Numeric message
Answer :- b] Video message

5. What is a paging access number?
a] An e mail id
b] A username
c] A toll free telephone number
d] A registration number
Answer :- c] A toll free telephone number

6. Which type of transmission technique is employed by paging system?
a] Simulcasting
b] Multicasting
c] Unicasting
d] Hybrid
Answer :- a] Simulcasting

7. Which of the following is not the property of paging system?
a] Asymmetric communication
b] Light weight
c] High cost
d] Wide area coverage
Answer :- c] High cost

8. Which of the following properties describes the transmitters and receivers in paging system?
a] High complexity and high power transmitter, high complexity and high power receivers
b] Low complexity and low power transmitter, low complexity and low power receivers
c] Low complexity and low power transmitter, high complexity and high power receivers
d] High complexity and high power transmitter, low complexity and low power receivers
Answer :- d] High complexity and high power transmitter, low complexity and low power receivers

9. What is a pager in the paging system?
a] A transmitter
b] A receiver
c] A transceiver
d] An equalizer
Answer :- b] A receiver

10. Who introduced the paging system for the first time?
a] Al Gross
b] Teri Pall
c] Alexander Graham Bell
d] Martin Cooper
Answer :- a] Al Gross

Wireless & Mobile Communications WCQ & Answers- Cordless Telephone Systems

1. Which of the following is a protocol used for cordless telephone system?
a] PACS
b] ERMES
c] IS-95
d] FLEX
Answer :- a] PACS

2. In which frequency range do the cordless phones mostly work?
a] 43-50 MHz
b] 88-108 MHz
c] 540-1600 KHz
d] 200-540 KHz
Answer :- a] 43-50 MHz

3. Which of the following is the drawback for cordless telephones?
a] Wireless technology
b] Limited coverage area
c] Mobile
d] Security
Answer :- b] Limited coverage area

4. Which of the following is a fully digital cordless system?
a] CT0
b] CT1
c] CT1+
d] DECT
Answer :-d] DECT

5. Which of the following is an example of local wireless system?
a] GSM
b] Cordless telephone system
c] UMTS
d] EDGE
Answer :- b] Cordless telephone system

6. Which of the following is not a standard for cordless telephony?
a] CT-2
b] DECT
c] UMTS
d] PHS
Answer :- c] UMTS

7. What is the range of cell diameter of DECT?
a] 300 m
b] 2 km
c] 10 km
d] 70 km
Answer :- a] 300 m

8. Which of the following standard of cordless telephone system is also approved as a 3G standard?
a] PHS
b] PACS
c] DECT
d] CT2
Answer :-  c] DECT

9. Cordless telephone system will not work under which of the following criteria?
a] Within a home
b] Within a building
c] Within campus
d] Within a city
Answer :- d] Within a city

10. Which of the following is not an application of DECT?
a] Multimedia processing
b] Cordless private branch exchange
c] Wireless local loop
d] Home cordless phones
Answer :- a] Multimedia processing

Wireless & Mobile Communications WCQ & Answers- Cellular Telephone Systems

1. Which of the following is not a characteristic of cellular telephone system?
a] Accommodate a large number of users
b] Large geographic area
c] Limited frequency spectrum
d] Large frequency spectrum
Answer :- d] Large frequency spectrum

2. What is the responsibility of MSC in cellular telephone system?
a] Connection of mobile to base stations
b] Connection of mobile to PSTN
c] Connection of base station to PSTN
d] Connection of base station to MSC
Answer :- b] Connection of mobile to PSTN

3. Who has the responsibility of billing and system maintenance function in cellular system?
a] Base Station
b] PSTN
c] MSC
d] Mobile system
Answer :- c] MSC

4. What is the function of FVC [Forward Voice Channel]?

a] Voice transmission from base station to mobiles
b] Voice transmission from mobile to base station
c] Initiating mobile calls
d] Broadcast all traffic request for all mobile
Answer :- a] Voice transmission from base station to mobiles

5. Which two channels are responsible for initiating mobile calls?
a] FVC and FCC
b] FVC and RVC
c] FCC and RCC
d] FCC and RVC
Answer :- c] FCC and RCC

6. Of the total channels present in the cellular system, what is the percentage of voice and control channels?
a] 95% voice channels, 5% control channels
b] 5% voice channels, 95% control channels
c] 50% voice channels, 50% control channels
d] 25% voice channels, 75% control channels
Answer :- a] 95% voice channels, 5% control channels

7. What is MIN?
a] Subscriber’s telephone number
b] Paging message
c] Traffic request number
d] Mobile Internet
Answer :- a] Subscriber’s telephone number

8. What is transmitted along with the call initiation request during the origin of call by a mobile?
a] MIN
b] ESN
c] ESN and SCM
d] MIN, ESN and SCM
Answer :- d] MIN, ESN and SCM

9. What does SCM indicates?
a] Maximum receiver power level for a particular user
b] Maximum transmitter power level for a particular user
c] Minimum receiver power level for a particular user
d] Minimum transmitter power level for a particular user
Answer :- b] Maximum transmitter power level for a particular user

10. What is the shape of the cell present in the cellular system?
a] Circular
b] Square
c] Hexagonal
d] Triangular
Answer :- c] Hexagonal

11. Why the size of the cell is kept small in cellular network?
a] Increase capacity
b] Decrease capacity
c] Increased size of base station electronics
d] Slow process of handoffs
Answer :- a] Increase capacity

12. What is handoff?
a] Forward channel
b] Switching technique
c] Roamer
d] Guard channel
Answer :- b] Switching technique

13. Which one is not an advantage of using frequency reuse?
a] Increased capacity
b] Limited spectrum is required
c] Same spectrum may be allocated to other network
d] Number of base stations is reduced
Answer :- d] Number of base stations is reduced

14. The process of transferring a mobile station from one base station to another is ____________
a] MSC
b] Roamer
c] Handoff
d] Forward channel
Answer :- c] Handoff

15. The interference between the neighbouring base stations is avoided by ____________
a] Assigning different group of channels
b] Using transmitters with different power level
c] Using different antennas
d] Using different base stations
Answer :- a] Assigning different group of channels

Wireless & Mobile Communications WCQ & Answers- Second Generation [2G] Cellular Networks

1. Which of the following multiple access techniques are used by second generation cellular systems?
a] FDMA/FDD and TDMA/FDD
b] TDMA/FDD and CDMA/FDD
c] FDMA/FDD and CDMA/FDD
d] FDMA/FDD only
Answer :- b] TDMA/FDD and CDMA/FDD

2. Which one is not a TDMA standard of second generation networks?
a] GSM
b] IS-136
c] AMPS
d] PDC
Answer :- c] AMPS

3. Which of the following is a CDMA standard of second generation network?
a] IS-95
b] IS-136
c] ETACS
d] EDGE
Answer :- a] IS-95

4. Popular 2G CDMA standard IS-95 is also known as ______________
a] CdmaOne
b] CdmaTwo
c] IS-136
d] IS-95B
Answer:- a] CdmaOne

5. How many users or voice channels are supported for each 200 KHz channel in GSM?
a] Eight
b] Three
c] Sixty four
d] Twelve
Answer:- a] Eight

6. How many voice channels are supported for each 30 KHz radio channel in IS-136?
a] Eight
b] Thirty
c] Three
d] Sixteen
Answer:- c] Three

7. How many users are supported in IS-95 for each 1.25 MHz?
a] Eight
b] Sixty four
c] Sixteen
d] Twenty five
Answer:- b] Sixty four

8. Which modulation technique is used by GSM?
a] GMSK
b] BPSK
c] QPSK
d] GFSK
Answer :- a] GMSK

9. IS-95 uses which modulation technique?
a] GMSK
b] BPSK
c] QAM
d] AFSK
Answer :- b] BPSK

10. IS-136 uses which modulation technique?
a] π/4 DQPSK
b] BPSK
c] GMSK
d] AFSK
Answer :- a] π/4 DQPSK

11. Which is one of the disadvantages of 2G standards?
a] Short Messaging Service [SMS]
b] Digital modulation
c] Limited capacity
d] Limited Internet Browsing
Answer :- d] Limited Internet Browsing

12. GSM [Global System for Mobile] was earlier also known as _____________
a] Group System Mobile
b] Global Special Meaning
c] Group Special Mobile
d] Global Special Mobile
Answer :- c] Group Special Mobile

13. 2G CDMA standard, IS-95, was proposed by which company?
a] Nippon Telephone and Telegraph [NTT]
b] Qualcomm
c] Bellcore and Motorola
d] AT&T Bell Laboratories
Answer :- c] Bellcore and Motorola

14. Which one of the following 2G standard is used in Japan?
a] IS-136
b] GSM
c] PDC
d] AMPS
Answer :- c] PDC

15. The 2G GSM technology uses a carrier separation of _____________
a] 1.25 MHz
b] 200 KHz
c] 30 KHz
d] 300 KHz
Answer :- b] 200 KHz

Wireless & Mobile Communications WCQ & Answers –2.5G

1. What is the name of the web browsing format language supported by 2.5G technology?
a] Wireless Application Protocol
b] Hypertext Markup Language
c] Extensible Markup Language
d] Hypertext Transfer Protocol
Answer  a] Wireless Application Protocol

2. What is the name of the internet microbrowser technology used by NTT DoCoMo in Japan?
a] Wireless Application Protocol
b] I-mode
c].W-mode
d] Hypertext Markup Language
Answer:- b] I-mode

3. 2.5G upgrade path for a particular wireless carrier does not match the original 2G technology choice made earlier by the same carrier.
a] True
b] False
Answer:- b] False

4. Which of the following is not a TDMA standard of 2.5G network?

a] HSCSD
b] GPRS
c] EDGE
d] GSM
Answer:- d] GSM

5. Which of the following is a 2.5G CDMA standard?
a] IS-95
b] Cdma2000
c] IS-95B
d] CdmaOne
Answer:- c] IS-95B

6. HSCSD supports which 2G standard?
a] GSM
b] IS-136
c] GSM and IS-136
d] PDC
Answer:-  a] GSM

7. How does HSCSD differs from the GSM to obtain higher speed data rate?
a] By allowing single user to use one specific time slot
b] By allowing single user to use consecutive user time slots
c] By using 8-PSK modulation technique
d] By allowing multiple users to use individual time slot
Answer:- b] By allowing single user to use consecutive user time slots

8. GPRS and EDGE supports which 2G standard?
a] GSM only
b] IS-136 only
c] GSM and IS-136 both
d] PDC
Answer:- c] GSM and IS-136 both

9. How is HSCSD different from GPRS?
a] Infrastructure
b] Multiple Access Scheme
c] Modulation technique
d] Switching Technique
Answer:- d] Switching Technique

10. What changes GPRS need to acquire while upgrading itself from GSM?
a] A whole new base station
b] New transceiver at base station
c] New channel cards
d] New packet overlay including routers and gateways
Answer:- d] New packet overlay including routers and gateways

11. Which new modulation technique is used by EDGE?
a] BPSK
b] 8- PSK
c] DQPSK
d] AFSK
Answer:- b] 8- PSK

12. Various air interface formats used by EDGE are also known as ___________
a] Modulation and coding schemes
b] Coding schemes
c] Modulating air interface
d] Air interface coding schemes
Answer:- a] Modulation and coding schemes

13. EDGE is sometimes also referred as ____________
a] HSCSD
b] 3GPP
c] EGPRS
d] EGSCSD
Answer:- c] EGPRS

14. What is one disadvantage of EDGE in comparison to HSCSD and GPRS?
a] Low data rates
b] Small coverage range
c] Low speed
d] No advancement
Answer:- b] Small coverage range

Wireless & Mobile Communications WCQ & Answers – Third Generation [3G] Wireless Networks

1. Which of the following is not a characteristic of 3G network?
a] Communication over VoIP
b] Unparalleled network capacity
c] Multi-megabit Internet access
d] LTE based network
Answer:- d] LTE based network

2. What is the term used by ITU for a set of global standards of 3G systems?
a] IMT 2000
b] GSM
c] CDMA
d] EDGE
Answer:-  a] IMT 2000

3. Which of the following leads to evolution of 3G networks in CDMA systems?
a] IS-95
b] IS-95B
c] CdmaOne
d] Cdma2000
Answer:-  d] Cdma2000

4. Which of the following leads to the 3G evolution of GSM, IS-136 and PDC systems?
a] W-CDMA
b] GPRS
c] EDGE
d] HSCSD
Answer:- a] W-CDMA

5. What is 3GPP?
a] Project based on W-CDMA
b] Project based on cdma2000
c] Project based on 2G standards
d] Project based on 2.5G standards
Answer:- a] Project based on W-CDMA

6. What is 3GPP2?
a] Project based on W-CDMA
b] Project based on cdma2000
c] Project based on 2G standards
d] Project based on 2.5G standards
Answer:- b] Project based on cdma2000

7. Which of the following is not a standard of 3G?
a] UMTS
b] Cdma2000
c] TD-SCDMA
d] LTE
Answer:- d] LTE

8. Which of the following 3G standard is used in Japan?
a] Cdma2000
b] TD-SCDMA
c] UMTS
d] UTRA
Answer:- c] UMTS

9. What does the number 2000 in IMT-2000 signifies?
a] Year
b] Number of subscribers per cell
c] Number of cells
d] Area [Km]
Answer:- a] Year

10. Which of the following is not an application of third generation network?
a] Global Positioning System [GPS]
b] Video conferencing
c] Mobile TV
d] Downloading rate upto 1 Gbps
Answer:- d] Downloading rate upto 1 Gbps

Wireless & Mobile Communications WCQ & Answers – 3G W-CDMA [UMTS]

1. What is the full form of UMTS?
a] Universal Mobile Telephone System
b] Ubiquitous Mobile Telephone System
c] Ubiquitous Mobile Telemetry System
d] Universal Machine Telemedicine System
Answer:- a] Universal Mobile Telephone System

2. UMTS use which multiple access technique?
a] CDMA
b] TDMA
c] FDMA
d] SDMA
Answer:-  a] CDMA

3. UMTS does not has backward compatibility with ____________
a] GSM
b] IS-136
c] IS-95
d] GPRS
Answer:- c] IS-95

4. UMTS is also known as _____________

a] IS-95
b] GPRS
c] CdmaOne
d] W-CDMA
Answer:- d] W-CDMA

5. What is the chip rate of W-CDMA?
a] 1.2288 Mcps
b] 3.84 Mcps
c] 270.833 Ksps
d] 100 Mcps
Answer:- b] 3.84 Mcps

6. W-CDMA works in FDD mode only.
a] True
b] False
Answer:- b] False

7. How much packet data rate per user is supported by W-CDMA if the user is stationary?
a] 2.048 Kbps
b] 100 Mbps
c] 2.048 Mbps
d] 1 Gbps
Answer:- c] 2.048 Mbps

8. What is the minimum spectrum allocation required by W-CDMA?
a] 5 MHz
b] 20MHz
c] 1.25 MHz
d] 200 KHz
Answer:- a] 5 MHz

9. W-CDMA requires a complete change of RF equipment at each base station.
a] True
b] False
Answer:- a] True

10. How much increase in spectral efficiency is provided by W-CDMA in comparison to GSM?
a] Two times
b] Three times
c] No increase
d] Six times
Answer:- d] Six times

Wireless & Mobile Communications WCQ & Answers – 3G Cdma2000

1. Which of the following has no backward compatibility with 3G Cdma2000?
a] IS-95
b] GPRS
c] IS-95A
d] IS-95B
Answer:-  b] GPRS

2. 2G and 2.5G CDMA operators may selectively introduce 3G capabilities at each cell without changing entire base stations and reallocate spectrums.
a] True
b] False
Answer:-  b] GPRS  a] True

3. Which of the following the first 3G CDMA air interface?
a] IS-95
b] IS-95B
c] Cdma2000 1xRTT
d] CdmaOne
Answer:-  b] GPRS c] Cdma2000 1xRTT

4. Within ITU IMT-2000 body, Cdma2000 1xRTT is also known as ____________

a] Cdma2000 1xEV-DO
b] Cdma2000 1xEV-DV
c] IS-95B
d] G3G-MC-CDMA-1X
Answer:-  b] GPRS d] G3G-MC-CDMA-1X

5. How many users are supported by Cdma2000 1X in comparison to 2G CDMA standard?
a] Half
b] Twice
c] Six times
d] Ten times
Answer:-  b] GPRS b] Twice

6. Cdma2000 works in TDD mode only.
a] True
b] False
Answer:-  b] GPRS b] False

7. Which of the following is not a characteristic of Cdma2000?
a] Adaptable baseband signalling rates
b] Adaptable baseband chipping rates
c] Multicarrier technologies
d] OFDMA
Answer:-  b] GPRS d] OFDMA

8. Cdma2000 1xEV was developed by ________
a] Motorola
b] AT&T Laboratories
c] Qualcomm
d] NTT
Answer:-  b] GPRS c] Qualcomm

9. How is bandwidth increased in Cdma2000?
a] Clubbing adjacent radio channels
b] Changing the hardware of base stations
c] Change of spectrum
d] Change of RF equipment
Answer:-  b] GPRS a] Clubbing adjacent radio channels

10. What are the two options provided by Cdma2000 1xEV?
a] Cdma2000 1xRTT. Cdma2000 3xRTT
b] Cdma2000 1xEV-DO, Cdma2000 1xEV-DV
c] Cdma2000 1xEV-DT, Cdma2000 1xEV-DO
d] Cdma2000 1xRTT, Cdma2000 1xEV-DV
Answer:-  b] GPRS b] Cdma2000 1xEV-DO, Cdma2000 1xEV-DV

11. Which of the following is not backward compatible with Cdma2000?
a] Cdma2000 1xRTT
b] Cdma2000 3xRTT
c] Cdma2000 1xEV-DO
d] Cdma2000 1xEV-DT
Answer:-  b] GPRS c] Cdma2000 1xEV-DO

Wireless & Mobile Communications WCQ & Answers -Wireless Local Area Networks [WLANs]

1. What is the full form of WLAN?
a] Wide Local Area Network
b] Wireless Local Area Network
c] Wireless Land Access Network
d] Wireless Local Area Node
Answer:-  b] Wireless Local Area Network

2. WLANs use high power levels and generally require a license for spectrum use.
a] True
b] False
Answer:- b] False

3. What is the name of 300 MHz of unlicensed spectrum allocated by FCC in ISM band?
a] UNII
b] Unlicensed PCS
c] Millimetre wave
d] Bluetooth
Answer:- a] UNII

4. Which of the following specifies a set of media access control [MAC] and physical layer specifications for implementing WLANs?
a] IEEE 802.16
b] IEEE 802.3
c] IEEE 802.11
d] IEEE 802.15
Answer:- c] IEEE 802.11

5. Which of the following is not a standard of WLAN?
a] HIPER-LAN
b] HIPERLAN/2
c] IEEE 802.11b
d] AMPS
Answer:- d] AMPS

6. Which of the following is the 802.11 High Rate Standard?
a] IEEE 802.15
b] IEEE 802.15.4
c] IEEE 802.11g
d] IEEE 802.11b
Answer:- d] IEEE 802.11b

7. Which of the following spread spectrum techniques were used in the original IEEE 802.11 standard?
a] FHSS and DSSS
b] THSS and FHSS
c] THSS and DSSS
d] Hybrid technique
Answer:- a] FHSS and DSSS

8. Which of the following WLAN standard has been named Wi-Fi?
a] IEEE 802.6
b] IEEE 802.15.4
c] DSSS IEEE 802.11b
d] IEEE 802.11g
Answer:- c] DSSS IEEE 802.11b

9. Which of the following is developing CCK-OFDM?
a] IEEE 802.11a
b] IEEE 802.11b
c] IEEE 802.15.4
d] IEEE 802.11g
Answer:- d] IEEE 802.11g

10. What is the data rate of HomeRF 2.0?
a] 10 Mbps
b] 54 Mbps
c] 200 Mbps
d] 1 Mbps
Answer:- a] 10 Mbps

11. HIPER-LAN stands for ____________
a] High Precision Radio Local Area Network
b] High Performance Radio Local Area Network
c] High Precision Radio Land Area Network
d] Huge Performance Radio Link Access Node
Answer:- b] High Performance Radio Local Area Network

12. What is the range of asynchronous user data rates provided by HIPER-LAN?
a] 1-100 Mbps
b] 50-100 Mbps
c] 1-20 Mbps
d] 500 Mbps to 1 Gbps
Answer:- c] 1-20 Mbps

13. What is the name of the European WLAN standard that provides user data rate upto 54 Mbps?
a] UNII
b] WISP
c] MMAC
d] HIPERLAN/2
Answer:- d] HIPERLAN/2

14. What is WISP?
a] Wideband Internet Service Protocol
b] Wireless Internet Service Provider
c] Wireless Instantaneous Source Provider
d] Wideband Internet Source Protocol
Answer:- b] Wireless Internet Service Provider

15. The price of WLAN hardware is more than 3G telephones and fixed wireless equipment.
a] True
b] False
Answer:- b] False

Wireless & Mobile Communications WCQ & Answers -Bluetooth and Personal Area Networks [PANs]

1. Which of the following is not an open standard?
a] Bluetooth
b] WWW
c] HTML
d] VPN
Answer:- d] VPN

2. What is the nominal range of Bluetooth?
a] 1 Km
b] 10 m
c] 1 m
d] 10 Km
Answer:- b] 10 m

3. Bluetooth standard is named after ___________
a] King Ronaldo Bluetooth
b] Pope Vincent Bluetooth
c] King Herald Bluetooth
d] Pope Francis Bluetooth
Answer:- c] King Herald Bluetooth

4. Bluetooth operates in which band?

a] Ka Band
b] L Band
c] Ku Band
d] 2.4 GHz ISM Band
Answer:- d] 2.4 GHz ISM Band

5. Which of the following scheme is used by Bluetooth?
a] Frequency hopping TDD scheme
b] Frequency hopping FDD scheme
c] DSSS TDD scheme
d] DSSS FDD scheme
Answer:- a] Frequency hopping TDD scheme

6. What is the range of time slot in Bluetooth?
a] 120 milliseconds
b] 625 microseconds
c] 577 microseconds
d] 5.7 seconds
Answer:- b] 625 microseconds

7. Which modulation scheme is used by Bluetooth?
a] DQPSK
b] MSK
c] GFSK
d] BPSK
Answer:- c] GFSK

8. What is the channel symbol rate in Bluetooth for each user?
a] 270.833 Kbps
b] 1 Gbps
c] 100 Mbps
d] 1 Mbps
Answer:- d] 1 Mbps

9. What is the raw channel bit error rate of Bluetooth?
a] 10-3
b] 10-10
c] 103
d] 10-1
Answer:- a] 10-3

10. Which of the following standard committee specifies Bluetooth and other Personal Area Networks [PAN]?
a] IEEE 802.11b
b] IEEE 802.15
c] IEEE 802.11g
d] IEEE 802.16
Answer:- b] IEEE 802.15

Wireless & Mobile Communications WCQ & Answers – Frequency Reuse

1. Cellular concept replaces many low power transmitters to a single high power transmitter.
a] True
b] False
Answer:- b] False

2. Why neighbouring stations are assigned different group of channels in cellular system?
a] To minimize interference
b] To minimize area
c] To maximize throughput
d] To maximize capacity of each cell
Answer:- a] To minimize interference

3. What is a cell in cellular system?
a] A group of cells
b] A group of subscribers
c] A small geographical area
d] A large group of mobile systems
Answer:- c] A small geographical area

4. What is frequency reuse?
a] Process of selecting and allocating channels
b] Process of selection of mobile users
c] Process of selecting frequency of mobile equipment
d] Process of selection of number of cells
View Answer a] Process of selecting and allocating channels

5. Which of the following is a universally adopted shape of cell?
a] Square
b] Circle
c] Triangle
d] Hexagon
Answer:- d] Hexagon

6. Actual radio coverage of a cell is called __________
a] Fingerprint
b] Footprint
c] Imprint
d] Matrix
Answer:- b] Footprint

7. Why the shape of cell is not circle?
a] Omni directionality
b] Small area
c] Overlapping regions or gaps are left
d] Complex design
Answer:- c] Overlapping regions or gaps are left

8. What is the main reason to adopt hexagon shape in comparison to square and triangle?
a] Largest area
b] Simple design
c] Small area
d] Single directional
Answer:- a] Largest area

9. Which type of antenna is used for center excited cells?
a] Dipole antenna
b] Grid antenna
c] Sectored antenna
d] Omnidirectional antenna
Answer:- d] Omnidirectional antenna

10. Which type of antenna is used for edge excited cells?
a] Omnidirectional antenna
b] Grid antenna
c] Sectored directional antenna
d] Dipole antenna
Answer:- c] Sectored directional antenna

11. For a cellular system, if there are N cells and each cell is allocated k channel. What is the total number of available radio channels, S?
a] S=k*N
b] S=k/N
c] S=N/k
d] S=kN
Answer:- a] S=k*N

12. What is a cluster in a cellular system?
a] Group of frequencies
b] Group of cells
c] Group of subscribers
d] Group of mobile systems
Answer:- b] Group of cells

13. What is a frequency reuse factor for N number of cells in a system?
a] N
b] N2
c] 2*N
d] 1/N
Answer:- d] 1/N

14. Capacity of a cellular system is directly proportional to __________
a] Number of cells
b] Number of times a cluster is replicated
c] Number of Base stations
d] Number of users
Answer:- b] Number of times a cluster is replicated

15. A spectrum of 30 MHz is allocated to a cellular system which uses two 25 KHz simplex channels to provide full duplex voice channels. What is the number of channels available per cell for 4 cell reuse factor?
a] 150 channels
b] 600 channels
c] 50 channels
d] 85 channels
Answer:- a] 150 channels

Wireless & Mobile Communications Questions & Answers – Channel Assignment Strategies

1. Which of the following is not an objective for channel assignment strategies?
a] Efficient utilization of spectrum
b] Increase of capacity
c] Minimize the interference
d] Maximize the interference
Answer:- d] Maximize the interference

2. The choice of channel assignment strategy does not impact the performance of the system.
a] True
b] False
Answer:- b] False

3. In fixed channel assignment strategy, each cell is allocated a predetermined set of _______
a] Voice channels
b] Control channels
c] Frequency
d] base stations
Answer:- a] Voice channels

4. What happen to a call in fixed channel strategy, if all the channels in a cell are occupied?
a] Queued
b] Cross talk
c] Blocked
d] Delayed
Answer:- c] Blocked

5. What is a borrowing strategy in fixed channel assignments?
a] Borrowing channels from neighbouring cell
b] Borrowing channels from neighbouring cluster
c] Borrowing channels from same cell
d] Borrowing channels from other base station in same cell
Answer:- a] Borrowing channels from neighbouring cell

6. In dynamic channel assignment strategy, voice channels are allocated to different cells permanently.
a] True
b] False
Answer:- b] False

7. In dynamic channel assignment strategy, base station requests channel from ____________
a] MSC
b] Neighbouring cell
c] Neighbouring cluster
d] Neighbouring base station
Answer:- a] MSC

8. Dynamic channel assignment reduces the likelihood of blocking in comparison to fixed channel assignment.
a] True
b] False
Answer:-a] True

9. RSSI stands for ________
a] Received Signal Strength Indicator
b] Restricted Signal Strength Indicator
c] Radio Signal Strength Indication
d] Restricted System Software Indicator
Answer:- a] Received Signal Strength Indicator

10. What is the drawback of dynamic channel assignment?
a] Decrease channel utilization
b] Increase probability of blocked call
c] Cross talk
d] Increase storage and computational load on system
Answer:- d] Increase storage and computational load on system

Wireless & Mobile Communications Questions & Answers – Handoff Strategies

1. What is the condition for handoff?
a] A mobile moves into a different cell while in conversation
b] A mobile remains in the same cell while in conversation
c] A mobile moves to different cell when idle
d] A mobile remains in the same cell and is idle
Answer:- a] A mobile moves into a different cell while in conversation

2. Handoff does not require voice and control channel to be allocated to channels associated with the new base station.
a] True
b] False
Answer:- b] False

3. The time over which a call can be maintained within a cell without handoff is called _________
a] Run time
b] Peak time
c] Dwell time
d] Cell time
Answer:- c] Dwell time

4. Dwell time does not depend on which of the following factor?
a] Propagation
b] Interference
c] Distance between subscriber and base station
d] Mobile station
Answer:- d] Mobile station

5. Which of the following is associated with the handoff in first generation analog cellular systems?
a] Locator receiver
b] MAHO
c] Cell dragging
d] Breathing cell
Answer:- a] Locator receiver

6. MAHO stands for ______
a] MSC assisted handoff
b] Mobile assisted handoff
c] Machine assisted handoff
d] Man assisted handoff
Answer:- b] Mobile assisted handoff

7. A handoff is initiated when the power received from the base station of a neighbouring cell falls behind the power received from the current base station by certain level.
a] True
b] False
Answer:- b] False

8. What is the condition for intersystem interference?
a] Mobile moves from one cell to another cell
b] Mobile remains in the same cell
c] Mobile moves from one cellular system to another cellular system
d] Mobile remains in the same cluster
Answer:- c] Mobile moves from one cellular system to another cellular system

9. What is the disadvantage of guard channel?
a] Efficient utilization of spectrum
b] Cross talk
c] Near far effect
d] Reduce total carried traffic
Answer:- d] Reduce total carried traffic

10. Which of the following priority handoff method decrease the probability of forced termination of a call due to lack of available channels?
a] Queuing
b] Guard channel
c] Cell dragging
d] Near far effect
Answer:- a] Queuing

11. Umbrella cell approach is possible by using _________
a] Antenna of same heights
b] Antenna of different heights
c] Different voice channels
d] Different control channels
Answer:- b] Antenna of different heights

12. Cell dragging is a problem occur due to __________
a] Pedestrian users
b] Stationary users
c] High speed mobile systems
d] Base stations having same frequency
Answer:- a] Pedestrian users

13. What was the typical handoff time in first generation analog cellular systems?
a] 1 second
b] 10 seconds
c] 1 minute
d] 10 milliseconds
Answer:- b] 10 seconds

14. How much time it takes for handoff in digital cellular systems like GSM?
a] 1 second
b] 10 seconds
c] 1 minute
d] 10 milliseconds
Answer:- a] 1 second

15. Soft handoff is also known as _________
a] MAHO
b] Hand over
c] Break before make
d] Make before break
Answer:- d] Make before break

Wireless & Mobile Communications Questions & Answers – Interference and System Capacity

1. Which of the following is not a source of interference?
a] Base station in a different cluster
b] Another mobile in same cell
c] A call in progress in neighbouring cell
d] Any BS operating on same frequency
Answer:- a] Base station in a different cluster

2. Interference on voice channels causes _______
a] Blocked calls
b] Cross talk
c] Queuing
d] Missed calls
Answer:- b] Cross talk

3. Interference in control channel leads to ________
a] Cross talk
b] Queuing
c] Blocked calls
d] Voice traffic
Answer:-c] Blocked calls

4. Interference is more severe in rural areas.
a] True
b] False
Answer:- a] True

5. What are co-channel cells?
a] Cells having different base stations
b] Cells using different frequency
c] Cells using adjacent frequency
d] Cells using same frequency
Answer:- d] Cells using same frequency

6. Co-channel interference is a function of _________
a] Radius of cell
b] Transmitted power
c] Received power
d] Frequency of mobile user
Answer:- a] Radius of cell

7. Co-channel reuse ratio is define by _________
a] Q=D*R
b] Q=D/R
c] Q=D^R
d] Q=1/R
Answer:- b] Q=D/R

8. Co-channel ratio in terms of cluster size is defined as _________
a] √[3N]
b] N
c] 3N
d] √N
Answer:- a] √[3N]

9. What is the cluster size for CDMA?
a] N=10
b] N=100
c] N=1
d] N=50
Answer:- c] N=1

10. What is breathing cell effect?
a] Fixed coverage region
b] Dynamic and time varying coverage region
c] Large coverage region
d] Very small coverage region
Answer:- b] Dynamic and time varying coverage region

11. Adjacent channel interference occurs due to _______
a] Power transmitted by Base station
b] MSCs
c] Same frequency of mobile users
d] Imperfect receiver filters
Answer:- d] Imperfect receiver filters

12. Which of the following problem occur due to adjacent channel interference?
a] Blocked calls
b] Cross talk
c] Near-far effect
d] Missed calls
Answer:- c] Near-far effect

13. In near-far effect, a nearby transmitter captures the __________
a] Receiver of the subscriber
b] Transmitter of the subscriber
c] Nearby MSC
d] Neighbouring base station
Answer:- a] Receiver of the subscriber

14. Adjacent channel interference can be minimized through _______
a] Changing frequency of base stations
b] Careful filtering and channel assignments
c] Increasing number of base stations
d] Increasing number of control channels
Answer:- b] Careful filtering and channel assignments

15. In dynamic channel assignment, any channel which is being used in one cell can be reassigned simultaneously to another cell in the system at a reasonable distance.
a] True
b] False
View Answer a] True

Wireless & Mobile Communications Questions & Answers – Trunking and Grade of Service

1. What is the concept for accommodating a large number of users in a limited radio spectrum?
a] Grade of service
b] Trunking
c] Multiplexing
d] Multitasking
Answer:- b] Trunking

2. On termination of call, the occupied channel is not returned to the pool of available channels in trunking.
a] True
b] False
View Answer b] False

3. In trunking system, when the channel is already in use, the call is blocked or queued.
a] True
b] False
Answer:- a] True

4. Who developed the fundamental of trunking theory?
a] Newton
b] Ohm
c] Erlang
d] Einstein
Answer:- c] Erlang

5. What is the unit for the measure of traffic intensity?
a] Meters
b] Henry
c] Ohm
d] Erlang
Answer:- d] Erlang

6. One Erlang represents _________
a] One call- hour per hour
b] One call-minute per hour
c] One call- hour per minute
d] Many calls- hour per hour
Answer:- a] One call- hour per hour

7. What is the measure of the ability of user to access a trunked system during the busiest hour?
a] Trunking
b] Grade of Service [GOS]
c] Multiplexing
d] Sectoring
Answer:- b] Grade of Service [GOS]

8. GOS is typically given as a likelihood that a ________
a] Call is in progress
b] Channels are busy
c] Call is blocked
d] Channel are free
Answer:- c] Call is blocked

9. The time requires to allocate a trunked radio channel to a requesting user is called _______
a] Dwell time
b] Holding time
c] Run time
d] Set up Time
Answer:- d] Set up Time

10. Average duration of a typical call is called ________
a] Holding time
b] Dwell time
c] Set up time
d] Run time
Answer:- a] Holding time

11. The average number of call requests per unit time is also known as ________
a] Request rate
b] Load
c] Grade o Service
d] Traffic intensity
Answer:- a] Request rate

12. Traffic intensity offered by each user is the product of __________
a] Set up time and holding time
b] Call request rate and holding time
c] Load and holding time
d] Call request rate and set up time
Answer:- b] Call request rate and holding time

13. AMPS cellular system is designed for a GOS of _____ blocking.
a] 10%
b] 50 %
c] 2%
d] 1%
Answer:- c] 2%

14. Blocked calls cleared formula is also known as _______ formula.
a] Erlang C
b] Erlang A
c] Erlang D
d] Erlang B
Answer:- d] Erlang B

15. Blocked calls delayed formula is also known as _______
a] Erlang A
b] Erlang B
c] Erlang C
d] Erlang D
Answer:- c] Erlang C

Wireless & Mobile Communications Questions & Answers – Improving Coverage and Capacity in Cellular Systems

1. Which of the following techniques do not help in expanding the capacity of cellular system?
a] Sectoring
b] Scattering
c] Splitting
d] Microcell zone concept
Answer:- b] Scattering

2. ________ uses directional antennas to control interference.
a] Sectoring
b] Cell splitting
c] Repeaters
d] Micro cell zone concept
Answer:- a] Sectoring

3. _______ allows an orderly growth of cellular system.
a] Sectoring
b] Scattering
c] Cell splitting
d] Micro cell zone technique
Answer:- c] Cell splitting

4. Which of the following technology distributes the coverage of the cell and extends the cell boundary to hard-to-reach places?
a] Cell splitting
b] Scattering
c] Sectoring
d] Micro cell zone concept
Answer:- d] Micro cell zone concept

5. Which of the following increases the number of base stations in order to increase capacity?
a] Cell splitting
b] Sectoring
c] Repeaters
d] Micro cell zone concept
Answer:- a] Cell splitting

6. Which of the following trunking inefficiencies?
a] Cell splitting
b] Micro cell zone technique
c] Sectoring
d] Repeaters
Answer:- c] Sectoring

7. The process of subdividing a congested cell into smaller cells is called _______
a] Cell splitting
b] Sectoring
c] Micro cell technique
d] Repeaters
Answer:- a] Cell splitting

8. Cell splitting increases the capacity of a cellular system since it increases the number of times ________ are reused.
a] Cells
b] Channels
c] Transmitters
d] Mobile stations
Answer:- b] Channels

9. Cell splitting do not maintain the minimum c-channel reuse ratio.
a] True
b] False
Answer:- b] False

10. Which of the following technique is used to limit radio coverage of newly formed microcells?
a] Sectoring
b] Splitting
c] Antenna downtilting
d] Scattering
Answer:- c] Antenna downtilting

11. Sectoring increases SIR [Signal to Interference Ratio].
a] True
b] False
Answer:- a] True

12. Which of the following has range extension capability?
a] Sectoring
b] Repeaters
c] Scattering
d] Micro cell zone concept
Answer:- b] Repeaters

13. Repeaters has one drawback of reradiating ____________
a] Frequency
b] Channels
c] Power
d] Repeater noise and interference
Answer:- d] Repeater noise and interference

14. Which of the following is not an advantage of micro cell zone technique?
a] Reduced co channel interference
b] Improved signal quality
c] Increase in capacity
d] Increasing number of base stations
Answer:- d] Increasing number of base stations

15. In a micro cell zone concept, when a mobile travels from one zone to another within the cell, it retains the same _________
a] Power level
b] Base station
c] Channel
d] Receiver
Answer:- c] Channel

Wireless & Mobile Communications Questions & Answers – Free Space Propagation Model

1. The mechanism behind electromagnetic wave propagation cannot be attributed to ___________
a] Reflection
b] Diffraction
c] Scattering
d] Sectoring
Answer:- d] Sectoring

2. The propagation model that estimates radio coverage of a transmitter is called ___________
a] Large scale propagation model
b] Small scale propagation model
c] Fading model
d] Okumura model
Answer:- a] Large scale propagation model

3. Propagation model that characterize rapid fluctuation is called _________
a] Hata model
b] Fading model
c] Large scale propagation model
d] Okumura model
Answer:- b] Fading model

4. Small scale propagation model is also known as _________
a] Fading model
b] Micro scale propagation model
c] Okumura model
d] Hata model
Answer:- a] Fading model

5. Free space propagation model is to predict ______
a] Received signal strength
b] Transmitted power
c] Gain of transmitter
d] Gain of receiver
Answer:- a] Received signal strength

6. Which of the following do not undergo free space propagation?
a] Satellite communication system
b] Microwave line of sight radio links
c] Wireless line of sight radio links
d] Wired telephone systems
Answer:- d] Wired telephone systems

7. The free space model predicts that received signal decays as a function of _________
a] Gain of transmitter antenna
b] T-R separation
c] Power of transmitter antenna
d] Effective aperture of the antenna
Answer:- b] T-R separation

8. Relation between gain and effective aperture is given by ______
a] G=[4πAe]/λ2
b] G=[4π λ2]/Ae
c] G=4πAe
d] G=Ae/λ2
Answer:- a] G=[4πAe]/λ2

9. Relation between wavelength and carrier frequency is _________
a] λ=c/f
b] λ=c*f
c] λ=f/c
d] λ=1/f
Answer:- a] λ=c/f

10. Which of the following antenna radiates power with unit gain uniformly in all directions?
a] Directional antenna
b] Dipole antenna
c] Isotropic antenna
d] Loop antenna
Answer:- c] Isotropic antenna

11. EIRP is abbreviated as __________
a] Effective isotropic radiated power
b] Effective isotropic radio power
c] Effective and immediate radiated power
d] Effective and immediate ratio of power
Answer:-a] Effective isotropic radiated power

12. Path loss in free space model is defined as difference of ________
a] Effective transmitted power and gain
b] Effective received power and distance between T-R
c] Gain and received power
d] Effective transmitter power and receiver power
Answer:- d] Effective transmitter power and receiver power

3. Far field region is also known as _________
a] Near field region
b] Fraunhofer region
c] Erlang region
d] Fresnel region
Answer:- b] Fraunhofer region

14. Fraunhofer distance is given by _____
a] 2D2/λ
b] 2D/λ
c] D/λ
d] 2D/λ2
Answer:- a] 2D2/λ

15. Which of the following is called an ideal antenna?
a] Dipole antenna
b] Directional antenna
c] Isotropic antenna
d] Loop antenna
Answer:- c] Isotropic antenna

Wireless & Mobile Communications Questions & Answers – Reflection

1. Which of the following mechanism do not impact propagation in mobile communication system?
a] Reflection
b] Diffraction
c] Scattering
d] Refraction
Answer:- d] Refraction

2. What is the dimension of object as compared to wavelength of propagating wave when reflection occurs?
a] Large
b] Small
c] Same
d] Very small
Answer:- a] Large

3. When does the wave propagating from one medium to another gets partially reflection and partially transmitted?
a] Both mediums have same electrical properties
b] Both mediums have different electrical properties
c] Both mediums have same magnetic properties
d] Both mediums have different magnetic properties
Answer:-  b] Both mediums have different electrical properties

4. What is the case of reflection, in course of second medium being a perfect dielectric?
a] Loss of energy during absorption
b] Total energy reflected back to first medium
c] No loss of energy in absorption
d] Total energy transmitted into second medium
Answer:-  c] No loss of energy in absorption

5. What is the case of reflection, in course of second medium being a perfect conductor?
a] Loss of energy during absorption
b] Total energy reflected back to first medium
c] Partly transmission and reflection
d] Total energy transmitted into second medium
Answer:-  b] Total energy reflected back to first medium

6. Which of the following relates the incident and reflected & transmitted wave?
a] Fresnel transmission coefficient
b] Scattering coefficient
c] Diffraction coefficients
d] Fresnel reflection coefficient
Answer:-  d] Fresnel reflection coefficient

7. Reflection coefficient is not a function of __________
a] Material property
b] Diffraction loss
c] Wave polarization
d] Angle of incidence
Answer:-  b] Diffraction loss

8. Polarized wave can be mathematically represented as sum of ________
a] Four orthogonal components
b] Two spatially adjacent components
c] Two spatially orthogonal components
d] Six orthogonal components
Answer:-  c] Two spatially orthogonal components

9. The plane of incidence contains only incident rays.
a] True
b] False
Answer:-  b] False

10. Permittivity and conductivity are insensitive to ______ for a good conductor.
a] Operating frequency
b] Polarization density
c] Electric field
d] Property of material
Answer:-  a] Operating frequency

11. Velocity of electromagnetic wave can be given by _______
a] 1/√[μ∈]
b] μ/∈
c] 1/[μ∈]
d] μ∈
Answer:-  a] 1/√[μ∈]

12. The boundary condition at the surface of incidence obeys ________
a] Kepler’s law
b] Gauss law
c] Faraday law
d] Snell’s law
Answer:-  d] Snell’s law

13. The angle at which no reflection occurs in the medium of origin is called _________
a] Azimuth angle
b] Elevation angle
c] Brewster angle
d] Inclination angle
Answer:-  c] Brewster angle

Wireless & Mobile Communications Questions & Answers – Diffraction

1. Diffraction occurs when radio path between Tx. And Rx. Is obstructed by ____________
a] Surface having sharp irregularities
b] Smooth irregularities
c] Rough surface
d] All types of surfaces
Answer:-  a] Surface having sharp irregularities

2. At high frequencies, diffraction does not depends on ___________
a] Geometry of the object
b] Distance between Tx and Rx
c] Amplitude of incident wave
d] Polarization of incident wave
Answer:-  b] Distance between Tx and Rx

3. Diffraction allows radio signals to propagate around ________
a] Continuous surface
b] Smooth surface
c] Curved surface of Earth
d] Does not allow propagation
Answer:-  c] Curved surface of Earth

4. Which principle explains the phenomenon of diffraction?
a] Principle of Simultaneity
b] Pascal’s Principle
c] Archimedes’ Principle
d] Huygen’s principle
Answer:-  d] Huygen’s principle

5. Diffraction is caused by propagation of secondary wavelets into _______
a] Bright region
b] Shadowed region
c] Smooth region
d] Large region
Answer:-  b] Shadowed region

6. Difference between the direct path and the diffracted path is called _______
a] Average length
b] Radio path length
c] Excess path length
d] Wavelength
Answer:-  c] Excess path length

7. The phase difference between a direct line of sight path and diffracted path is function of _______
a] Height and position of obstruction
b] Only height
c] Operating frequency
d] Polarization
Answer:-  a] Height and position of obstruction

8. Which of the following explains the concept of diffraction loss?
a] Principle of Simultaneity
b] Pascal’s Principle
c] Fresnel zone
d] Archimedes’ Principle
Answer:-  c] Fresnel zone

9. In mobile communication system, diffraction loss occurs due to ______
a] Dielectric medium
b] Obstruction
c] Electric field
d] Operating frequency
Answer:-  b] Obstruction

10. For predicting the field strength in a given service area, it is essential to estimate ______
a] Polarization
b] Magnetic field
c] Height of transmitter
d] Signal attenuation
Answer:-  d] Signal attenuation

Wireless & Mobile Communications Questions & Answers – Scattering

1. Scattering occurs when medium consists of objects with dimensions _______ compared to the wavelength.
a] Same
b] Small
c] Large
d] Very large
Answer:-  b] Small

2. Scattered waves are produced at ________
a] Rough surface
b] Shadowed region
c] Smooth surface
d] Horizon
Answer:-  a] Rough surface

3. The actual received signal is ______ than what is predicted by reflection and diffraction model.
a] Weaker
b] Equal
c] Stronger
d] Very weak
Answer:-  c] Stronger

4. Scattered energy in all directions provides _________ at a receiver.
a] Channels
b] Loss of signal
c] No energy
d] Additional radio energy
Answer:-  d] Additional radio energy

5. Surface roughness are often tested using __________
a] Rayleigh criterion
b] Lawson criterion
c] Barkhausen stability criterion
d] Nyquist criterion
Answer:-  a] Rayleigh criterion

6. A surface is considered rough if protuberance is ________ than critical height.
a] Equal
b] Less
c] Greater
d] No relation
Answer:-  c] Greater

7. RCS of scattering object is defined as the ratio of _______
a] Power density of signal scattered to power density of radio wave incident
b] Power density of radio wave incident to power density of signal scattered
c] Power density of incident waves to power density of reflected wave
d] Power density of reflected wave to power density of incident waves
Answer:-  a] Power density of signal scattered to power density of radio wave incident

8. Which equation is used to calculate the received power due to scattering for urban mobile radio system?
a] Laplace equation
b] Bistatic radar equation
c] Poisson’s equation
d] Maxwell equation
Answer:-  b] Bistatic radar equation

9. In ionosphere propagation, waves arriving at the receiving antenna using the phenomenon of _______
a] Scattering
b] Refraction
c] Diffraction
d] Radiation
Answer:-  a] Scattering

10. Power density is basically termed as ________ power per unit area.
a] Reflected
b] Refracted
c] Radiated
d] Diffracted
Answer:-  c] Radiated

Wireless & Mobile Communications Questions & Answers – Practical Link Budget Design Using Path Loss Models

1. Empirical approach is based on fitting curve or analytical expressions.
a] True
b] False
Answer:-  a] True

2. Which of the following is not a practical path loss estimation technique?
a] Log distance path loss model
b] Log normal shadowing
c] Determination of percentage of coverage area
d] Hata model
Answer:-  d] Hata model

3. Average received signal power decreases __________ with distance.
a] Exponentially
b] Logarithmically
c] Two times
d] Four times
Answer:-  b] Logarithmically

4. What does path loss exponent indicates?
a] Rate at which path loss decreases with distance
b] Rate at which path loss increases with distance
c] Rate at which path loss decreases with power density
d] Rate at which path loss increases with power density
Answer:-  b] Rate at which path loss increases with distance

5. The reference distance should not be in the far field of the antenna.
a] True
b] False
Answer:-  b] False

6. Which distribution describes the shadowing effect?
a] Log normal distribution
b] Nakagami distribution
c] Cauchy distribution
d] Rayleigh distribution
Answer:-  a] Log normal distribution

7. Log normal shadowing is a phenomenon that occurs with same T-R separation having same level clutter on the propagation path.
a] True
b] False
Answer:-  b] False

8. Log normal shadowing implies that measured signal levels at specific T-R separation have ______ distribution when signal levels have values in dB units.
a] Rayleigh
b] Gamma
c] Gaussian
d] Nakagami
Answer:-  c] Gaussian

9. A link budget is accounting of all __________
a] Gain and losses from the transmitter
b] Power transmitted by transmitter
c] Power received by receiver
d] Power transmitted and received
Answer:-  a] Gain and losses from the transmitter

10. Antenna’s efficiency is given by the ratio of __________
a] Losses
b] Physical aperture to effective aperture
c] Signal power to noise power
d] Effective aperture to physical aperture
Answer:-  d] Effective aperture to physical aperture

Wireless & Mobile Communications Questions & Answers – Outdoor Propagation Models

1. Which of the following is not an outdoor propagation model?
a] Longley-Rice model
b] Ericson Multiple Breakpoint Model
c] Hata model
d] Okumura model
Answer:- b] Ericson Multiple Breakpoint Model

2. Longley –Rice model is applicable to _________
a] Point to point communication
b] All to all communication
c] Point to multipoint communication
d] Multipoint microwave distribution sstem
Answer:- a] Point to point communication

3. Longley-Rice prediction model is also referred as _________
a] Okumura model
b] Hata model
c] ITS irregular terrain model
d] Bertoni model
Answer:- c] ITS irregular terrain model

4. The extra term for additional attenuation due to urban clutter near the receiving antenna is called __________
a] Power factor
b] Urban gain
c] Clutter factor
d] Urban factor
Answer:- d] Urban factor

5. Longley Rice model’s merit is to provide corrections due to environmental factors.
a] True
b] False
Answer:- b] False

6. Which method is used by Edwards and Durkin algorithm to calculate the loss associated with diffraction edges?
a] Epstein and Peterson method
b] Interpolation method
c] Knife edge diffraction method
d] Fresnel- Kirchoff method
Answer:- a] Epstein and Peterson method

7. Durkin’s model can read digital elevation map.
a] True
b] False
Answer:- a] True

8. Which of the most widely used model for signal prediction in urban areas?
a] Ericsson Multiple Breakpoint Model
b] Log distance path loss model
c] Okumura model
d] Attenuation factor model
Answer:- c] Okumura model

9. Okumura model is applicable for distances of _________
a] 1 m to 10 m
b] 1 km to 100 km
c] 100 km to 1000 km
d] 10 km to 10000 km
Answer:- b] 1 km to 100 km

10. Okumura model is considered to be complex in predicting path loss.
a] True
b] False
Answer:- b] False

11. Which of the following is the major disadvantage of the Okumura model?
a] Complex
b] Inaccurate
c] Not practical
d] Slow response to rapid change in terrain
Answer:- d] Slow response to rapid change in terrain

12. The Hata model is empirical formulation of which model?
a] Okumura model
b] Longley- Rice model
c] Durkin’s model
d] Walfisch and Bertoni model
Answer:- a] Okumura model

13. Hata model is well suited for _________
a] Personal communication system
b] Large cell mobile radio system
c] Small cell mobile radio system
d] Every mobile radio system
Answer:- b] Large cell mobile radio system

14. Which of the following considers the impact of rooftops and building?
a] Okumura model
b] Hata model
c] Walfisch and Bertoni model
d] Longley- Rice model
Answer:- c] Walfisch and Bertoni model

Wireless & Mobile Communications Questions & Answers – Indoor Propagation Models

1. The variability of the environment is slower for a smaller range of T-R separation distances in indoor models.
a] True
b] False
Answer:- b] False

2. Propagation within building is not influenced by _________
a] Layout of the building
b] Construction materials
c] Building type
d] Trees outside the building
Answer:- d] Trees outside the building

3. Smaller propagation distances make it more difficult to insure far-field radiation for all receiver location and types of antenna.
a] True
b] False
Answer:- a] True

4. What is hard partition?
a] Partition as part of the building
b] Partition that can be moved
c] Partition not touching ceiling
d] Partition between different floors
Answer:- a] Partition as part of the building

5. Partitions that can be moved are called _______
a] Soft partitions
b] Hard partitions
c] Disk partition
d] Dynamic partition
Answer:- a] Soft partitions

6. Losses between the floors of the building can be determined using ________
a] Internal dimensions
b] Material used to create antenna
c] External dimension
d] Line of sight path
Answer:- c] External dimension

7. Technique of drawing a single ray between the transmitter and receiver is called ______
a] Secondary ray tracing
b] Primary ray tracing
c] Line of sight
d] Straight line tracing
Answer:- b] Primary ray tracing

8. ________ is a process of converting plain text into cipher text.
a] Authentication
b] Decryption
c] Encryption
d] Compression
Answer:- c] Encryption

9. _______ reduces the cell size to increase capacity.
a] Intelligent cell approach
b] Microcell approach
c] Top down approach
d] Bottom up approach
Answer:- b] Microcell approach

10. _________ configuration describes a desktop in an office.
a] Mobile and wired
b] Fixed and wired
c] Fixed and wireless
d] Mobile and wireless
Answer:- b] Fixed and wired

Wireless & Mobile Communications Questions & Answers – Small-Scale Multipath Propagation

1. Small scale fading describes the _________ fluctuations of the amplitude, phases of a signal.
a] Rapid
b] Slow
c] Instantaneous
d] Different
Answer:- a] Rapid

2. Fading is caused by interference.
a] True
b] False
Answer:- a] True

3. Which of the following is not an effect caused by multipath in radio channel?
a] Rapid changes in signal strength
b] Random frequency modulation
c] Power of base station
d] Time dispersion
Answer:- c] Power of base station

4. In urban areas, fading occurs due to height of mobile antenna ________ than height of surrounding structure.
a] Same
b] Smaller
c] Greater
d] Very larger
Answer:- b] Smaller

5. Fading does not occur when mobile receiver is stationary.
a] True
b] False
Answer:- b] False

6. Apparent shift in frequency in multipath wave is caused due to relative motion between________
a] Base station and MSC
b] Mobile and surrounding objects
c] Mobile and MSC
d] Mobile and base station
Answer:- d] Mobile and base station

7. Doppler shift is directly proportional to __________
a] Velocity
b] Height of antenna
c] Power of receiving antenna
d] Power of transmitter
Answer:- a] Velocity

8. Which of the following factor does not influence small scale fading?
a] Multipath propagation
b] Power density of base station
c] Speed of mobile
d] Speed of surrounding objects
Answer:- b] Power density of base station

9. Signal will distort if transmitted signal bandwidth is greater than bandwidth of __________
a] Receiver
b] Radio channel
c] Multipath channel
d] Transceiver
Answer:- c] Multipath channel

10. What is a measure of the maximum frequency difference for which signals are strongly correlated in amplitude?
a] Coherence bandwidth
b] Narrow bandwidth
c] Incoherent bandwidth
d] Wide bandwidth
Answer:- a] Coherence bandwidth

11. The Doppler shift for mobile moving with constant velocity, v is given by _______
a] [v*cos θ]/λ
b] v/λ
c] v*cos θ
d] v*λ
Answer:- a] [v*cos θ]/λ

12. Doppler shift is positive if mobile is moving away from direction of arrival of the wave.
a] True
b] False
Answer:- b] False

Wireless & Mobile Communications Questions & Answers – Impulse Response Model of a Multipath Channel

1. Small scale variations of a mobile radio signal are directly related to _______
a] Impulse response of mobile radio channel
b] Impulse response of base station
c] Frequency response of antenna
d] Frequency response of base station
Answer:- a] Impulse response of mobile radio channel

2. Impulse response is a narrowband characterization.
a] True
b] False
Answer:- b] False

3. Mobile radio channel can be modelled as a ______ filter.
a] Non-linear
b] Low-pass
c] Linear
d] Bandpass
Answer:- c] Linear

4. Impulse response does not play any role in characterization of the channel.
a] True
b] False
Answer:- b] False

5. Received signal can be expressed as ______ of transmitted signal with channel impulse response.
a] Addition
b] Subtraction
c] Division
d] Convolution
Answer:- d] Convolution

6. Discretization of multipath delay axis of impulse response into equal time delay segments is called __________
a] Excess delay bins
b] Delay bins
c] Discrete bins
d] Digital bins
Answer:- a] Excess delay bins

7. Small scale received power is ________ of average powers received in each multipath component.
a] Log
b] Exponential
c] Multiplication
d] Sum
Answer:- d] Sum

8. The received power of a wideband signal fluctuates significantly when a receiver is moved about a local area.
a] True
b] False
Answer:- b] False

9. Average power for a CW signal is _______ to average received power for a wideband signal in small scale region.
a] Equivalent
b] Two times
c] Four times
d] Ten times
Answer:- a] Equivalent

10. The received local ensemble average power of wideband and narrowband signals are ________
a] Different
b] Equivalent
c] Not dependent
d] Double
Answer:-  b] Equivalent

Wireless & Mobile Communications Questions & Answers – Small- Scale Multipath Measurements

1. Which of the following is not a small scale multipath measurement technique?
a] Indirect pulse measurement
b] Direct pulse measurement
c] Spread spectrum sliding correlator measurement
d] Swept frequency measurement
Answer:-  a] Indirect pulse measurement

2. Direct RF pulse systems are complex.
a] True
b] False
Answer:- b] False

3. What is the main disadvantage of RF pulse system?
a] Complexity
b] Not real time
c] Interference and noise
d] Simplicity
Answer:- c] Interference and noise

4. Why is the phase of individual multipath components are not received in RF Pulse system?
a] Due to use of duplexer
b] Due to use of ADC
c] Due to use of flip flops
d] Due to use of envelope detector
Answer:- d] Due to use of envelope detector

5. Spread spectrum sliding correlator has better ________ in comparison to RF pulse system.
a] Dynamic range
b] Frequency
c] Power density
d] Structure
Answer:- a] Dynamic range

6. If a PN sequence has chip duration of Tc, then chip rate is given by ___________
a] Tc
b] 1/Tc
c] 2 Tc
d] Tc2
Answer:- b] 1/Tc 

7. The maximal length of PN sequence, the sequence length for n number of shift register is ______
a] 2n
b] 1/2n
c] 2n – 1
d] 2n + 1
Answer:- c] 2n – 1

8. The ratio between transmitter chip clock rate and the difference between the transmitter chip clock and difference between transmitter and receiver chip clock rates is called ___________
a] Slide factor
b] Chip factor
c] Reuse factor
d] Shape factor
Answer:- a] Slide factor

9. Which of the following is not an advantage of spread spectrum channel sounding system?
a] Rejection of passband noise
b] Real time
c] Coverage range improvement
d] Less transmitter power required
Answer:-  b] Real time

10. Which of the following is a disadvantage of spread spectrum channel sounding system?
a] Passband noise
b] Less coverage area
c] Large transmitter power required
d] Not in real time
Answer:- d] Not in real time

11. There is no relationship between time domain and frequency domain techniques.
a] True
b] False
Answer:- b] False

12. Transmissivity is a _________ domain response.
a] Time
b] Frequency
c] Time-frequency
d] Spatial
Answer:- b] Frequency

13. Frequency domain channel sounding technique do not require hard wired synchronization between transmitter and receiver.
a] True
b] False
Answer:- b] False

14. Frequency domain channel sounding system is _______ in nature.
a] Real time
b] Digital
c] Non real time
d] Analog
Answer:- c] Non real time

15. Faster sweep time can be accomplished by ________
a] Increasing frequency steps
b] Increasing time slots
c] Reducing time slots
d] Reducing frequency steps
Answer:- d] Reducing frequency steps

Wireless & Mobile Communications Questions & Answers – Parameters of Mobile Multipath Channels

1. Power delay profile is represented as plots of __________ with respect to fixed time delay reference.
a] Relative received power
b] Frequency
c] Transmitted power
d] Relative power
View Answer a] Relative received power

2. Which of the following is not a multipath channel parameter that can be determined from power delay profile?
a] Mean excess delay
b] RMS delay spread
c] Excess delay spread
d] Doppler spread
View Answer d] Doppler spread

3. The time dispersive properties of wideband multipath channel are quantified by ______ and _______
a] Mean excess delay, rms delay spread
b] Doppler spread, rms delay spread
c] Doppler spread, coherence time
d] Mean excess delay, Doppler spread
View Answer a] Mean excess delay, rms delay spread

4. _______ is the square root of the second central moment of the power delay profile.
a] Mean excess delay
b] Rms delay spread
c] Excess delay spread
d] Coherence time
View Answer b] Rms delay spread

5. Which of the following is the first moment of the power delay profile?
a] Rms delay spread
b] Excess delay spread
c] Mean excess delay
d] Doppler spread
View Answer c] Mean excess delay

6. What is the order of typical values of rms delay spread in outdoor mobile radio channels?
a] Microseconds
b] Nanoseconds
c] Seconds
d] Minutes
View Answer a] Microseconds

7. Power delay profile and magnitude frequency response of a mobile radio channel are related through _______
a] Laplace Transform
b] Fourier Transform
c] S Transform
d] Wavelet Transform
View Answer b] Fourier Transform

8. ______ and coherence bandwidth are inversely proportional to one another.
a] Rms delay spread
b] Mean excess delay
c] Excess delay spread
d] Doppler spread
View Answer a] Rms delay spread

9. Coherence bandwidth is a statistical measure of range of frequencies over which channel is considered _______
a] Time dispersive
b] Frequency selective
c] Time variant
d] Flat
View Answer d] Flat

10. Which of the following describes time varying nature of the channel in a small scale region?
a] Delay spread and coherence time
b] Coherence bandwidth and delay spread
c] Doppler spread and coherence time
d] Delay spread and doppler spread
View Answer c] Doppler spread and coherence time

11. Doppler spread is a range of frequencies over which received Doppler spread is _______
a] Zero
b] Non zero
c] Infinite
d] One
View Answer b] Non zero

12. _______ is a statistical measure of time duration over which channel impulse response is invariant.
a] Coherence time
b] Doppler spread
c] Mean excess delay
d] Rms delay spread
View Answer a] Coherence time

Wireless & Mobile Communications Questions & Answers – Types of Small- Scale Fading

1. Which of the following is not a channel parameter?
a] Bandwidth
b] Coherence time
c] Rms delay spread
d] Doppler spread
View Answer a] Bandwidth

2. ______ leads to time dispersion and frequency selective fading.
a] Doppler spread
b] Multipath delay spread
c] Time dispersive parameters
d] Frequency delay spread
View Answer b] Multipath delay spread

3. Which of the following s not a characteristic of flat fading?
a] Mobile radio channel has constant gain
b] Linear phase response
c] Non linear phase response
d] Bandwidth is greater than the bandwidth of transmitted signal
View Answer c] Non linear phase response

4. Spectral characteristics of the channel changes with time in flat fading.
a] True
b] False
View Answer b] False

5. Flat fading channel is also known as _______________
a] Amplitude varying channel
b] Wideband channel
c] Phase varying channel
d] Frequency varying channel
View Answer a] Amplitude varying channel

6. In a frequency selective fading, mobile radio channel possess a constant gain and a linear phase over bandwidth smaller than bandwidth of transmitted signal.
a] True
b] False
View Answer a] True

7. Frequency selective fading channels are also known as ________
a] Narrowband channel
b] Wideband channel
c] Amplitude varying channel
d] Phase varying channel
View Answer b] Wideband channel

8. Frequency selective fading does not induce intersymbol interference.
a] True
b] False
View Answer b] False

9. For fast fading channel, the coherence time of the channel is smaller than _______ of transmitted signal.
a] Doppler spread
b] Bandwidth
c] Symbol period
d] Coherence bandwidth
View Answer c] Symbol period

10. In slow fading channel, Doppler spread of the channel is much less than the ________ of baseband signal.
a] Symbol period
b] Phase
c] Coherence time
d] Bandwidth
View Answer d] Bandwidth

Wireless & Mobile Communications Questions & Answers – Rayleigh and Ricean Distribution

1. Which of the following distribution is used for describing statistical time varying nature of received envelope of multipath component?
a] Log normal distribution
b] Levy distribution
c] Rayleigh distribution
d] Gaussian distribution
View Answer c] Rayleigh distribution

2. Envelope of the sum of two quadrature Gaussian noise signal obeys _________ distribution.
a] Rayleigh
b] Inverse Gaussian
c] Nakagami
d] Gamma
View Answer a] Rayleigh

3. For a Rayleigh fading signal, mean and median differ by _______
a] 2 dB
b] 10 dB
c] 0.55 dB
d] 100 dB
View Answer c] 0.55 dB

4. It is easy to compare different fading distributions using mean values instead of median values.
a] True
b] False
View Answer

5. For a nonfading b] False
signal component present, the small scale fading envelope distribution is ____________
a] Rayleigh
b] Gaussian
c] Log normal
d] Ricean
View Answer d] Ricean

6. Ricean distribution degenerates to ________ distribution when the dominant component fades away.
a] Log normal
b] Gamma
c] Rayleigh
d] Gaussian
View Answer c] Rayleigh

7. The envelope of a bandpass noise is __________
a] Uniformly distributed
b] Rayleigh
c] Ricean
d] Gaussian
View Answer b] Rayleigh

8. The envelope of a sinusoid plus bandpass noise has __________
a] Uniformly distributed
b] Rayleigh
c] Ricean
d] Gaussian
View Answer c] Ricean

9. What do you call an attenuation that occurs over many different wavelengths of the carrier?
a] Rayleigh fading
b] Ricean fading
c] Wavelength fading
d] Slow fading
View Answer d] Slow fading

10. Which of the reception problems below that is not due to multipath?
a] Delayed spreading
b] Rayleigh fading
c] Random Doppler shift
d] Slow fading
View Answer d] Slow fading

Wireless & Mobile Communications Questions & Answers – Statistical Models for Multipath Fading Channels

1. Which of the following is not a statistical models for multipath fading channels?
a] Clarke’s model for flat fading
b] Saleh and Valenzuela indoor statistical model
c] Two ray Rayleigh fading model
d] Faraday model
View Answer d] Faraday model

2. Who presented the first statistical model for multipath fading channel?
a] Ossana
b] Rayleigh
c] Newton
d] Faraday
View Answer a] Ossana

3. Clarke’s model assumes a horizontal polarized antenna.
a] True
b] False
View Answer b] False

4. A wave that is incident on mobile does not undergo Doppler shift.
a] True
b] False
View Answer

5. Which of the following is an important statistics of a Rayleigh fading useful for designing error control codes and diversity schemes?
a] Mobile speed
b] Doppler frequency
c] Level crossing rate [LCR]
d] Power density
View Answer

6. The level crossing rate [LCR] is defined as expected rate at which _______ fading envelope crosses a specified level.
a] Rayleigh
b] Saleh
c] Vanezuela
d] Faraday
View Answer  

7. Level crossing rate is a function of _______
a] Power transmitted by base station
b] Power density of receiver
c] Mobile speed
d] Bit error rate
View Answer c] Mobile speed

8. Clarke’s model considers the multipath time delay.
a] True
b] False
View Answer b] False

9. Saleh and Venezuela reported the results of ______ propagation measurements.
a] Indoor
b] Outdoor
c] Air
d] High frequency
View Answer a] Indoor

10. Saleh and Venezuela show that indoor channel is _______ time varying.
a] Not
b] Very slow
c] Fast
d] Very fast
View Answer b] Very slow

11. What is the full form of SIRCIM?
a] Simulation of Indoor Radio Channel Impulse response Model
b] Statistical Indoor Radio Channel for Impulse Model
c] Statistical Impulse Radio Channel for Indoor Model
d] Simulation of Impulse Radio Channel for Indoor Model
View Answer a] Simulation of Indoor Radio Channel Impulse response Model

Wireless & Mobile Communications Questions & Answers – Multipath Shape Factors for Small – Scale Fading

1. The term small scale fading describes the slow fluctuations of received power level due to changes in receiver position.
a] True
b] False
View Answer b] False

2. The rapid fluctuations due to small scale fading affect the _________ design.
a] Receiver
b] Transmitter
c] MSC
d] Base station
View Answer a] Receiver

3. An approximately omnidirectional channel model accurately describes fading statistics if directional antennas are employed at the receiver.
a] True
b] False
View Answer a] True

4. Which of the following is not a principle shape factor?
a] Angular spread
b] Angular constriction
c] Azimuthal direction of maximum fading
d] Angle of arrival
View Answer d] Angle of arrival

5. Angular spread is a measure of how multipath concentrates about __________
a] Angle of arrival
b] Transmitted power
c] Single azimuthal direction of arrival
d] Received power
View Answer c] Single azimuthal direction of arrival

6. Angular constriction is a measure of how multipath concentrates about ______ azimuthal direction.
a] Single
b] Two
c] Three
d] Four
View Answer b] Two

7. Shape factor, azimuthal direction of maximum fading is a directional parameter.
a] True
b] False
View Answer a] True

8. _______ of a stationary process is actually the variance of the rate of change.
a] Mean
b] Mean square
c] Mean squared derivative
d] Mean squared integral
View Answer c] Mean squared derivative

9. Complex received voltage is a summation of __________ that have impinged upon receiver antenna.
a] Multipath waves
b] Waves
c] Power density
d] Single path waves
View Answer a] Multipath waves

10. Which of the following is equal to received power?
a] Square of complex voltage
b] Complex voltage
c] Magnitude of complex voltage
d] Magnitude squared of complex voltage
View Answer d] Magnitude squared of complex voltage

11. Which of the following is equal to received envelope?
a] Square of complex voltage
b] Complex voltage
c] Magnitude of complex voltage
d] Magnitude squared of complex voltage
View Answer c] Magnitude of complex voltage

12. Which of the following describes the average fading rate within a local area?
a] Angular spread
b] Angular constriction
c] Azimuthal direction of maximum fading
d] Angle of arrival
View Answer a] Angular spread

13. Angular constriction affects the average fading rate within local area.
a] True
b] False

Wireless & Mobile Communications Questions & Answers – Frequency Modulation Vs. Amplitude Modulation

1. Which is the process of encoding information from a message source in suitable manner for transmission?
a] Modulation
b] Demodulation
c] Encryption
d] Decryption
View Answer a] Modulation

2. The bandpass signal is called the modulating signal.
a] True
b] False
View Answer b] False

3. AM signal have all information in ______ of the carrier.
a] Amplitude
b] Magnitude
c] Frequency
d] Power
View Answer a] Amplitude

4. In frequency modulation, the amplitude of modulated carrier signal is ______and its frequency is ______ by the modulating message signal.
a] Constant, constant
b] Varied, constant
c] Constant, varied
d] Varied, varied
View Answer c] Constant, varied

5. FM signals have all their information in ______ of the carrier.
a] Amplitude
b] Magnitude
c] Frequency
d] Power
View Answer c] Frequency

6. Amplitude modulation has ______ relationship between the quality of the received signal and the power of the received signal.
a] No
b] Non linear
c] Constant
d] Linear
View Answer d] Linear

7. FM has _______ noise immunity when compared to amplitude modulation.
a] Same
b] Less
c] No
d] Better
View Answer d] Better

8. FM signals are _____ susceptible to atmospheric and impulse noise as compared to AM.
a] Largely
b] Less
c] Not
d] Better
View Answer b] Less

9. Burst noise affects FM systems.
a] True
b] False
View Answer b] False

10. AM has a modulation index.
a] True
b] False
View Answer b] False

11. Which of the following is an advantage of AM systems in comparison to FM sysytems?
a] Occupy less bandwidth
b] Superior performance in fading
c] Better noise immunity
d] Not susceptible to impulse noise
View Answer a] Occupy less bandwidth

12. An FM signal is a ______ envelope signal.
a] Varied
b] Small
c] Large
d] Constant
View Answer d] Constant

13. FM uses class______ amplifiers and AM uses class ______ amplifiers.
a] C, C
b] A, C
c] C, A
d] AB, C
View Answer c] C, A

14. AM exhibits capture effect characteristics.
a] True
b] False
View Answer b] False

15. Which of the following is a drawback of FM systems?
a] Burst noise
b] Susceptible to atmospheric noise
c] Wider frequency band
d] Poor performance in fading
View Answer c] Wider frequency band

Wireless & Mobile Communications Questions & Answers – Amplitude Modulation

1. Carrier signal in modulation technique is _______ signal.
a] High frequency
b] Low frequency
c] High amplitude
d] Low amplitude
View Answer a] High frequency

2. Modulation index of an AM signal is ratio of __________ to the _______
a] Peak carrier amplitude, Peak message signal amplitude
b] Peak message signal amplitude, Peak carrier amplitude
c] Carrier signal frequency, Message signal frequency
d] Message signal frequency, Carrier signal frequency
View Answer b] Peak message signal amplitude, Peak carrier amplitude

3. If the peak message signal amplitude is half the peak amplitude of the carrier signal, the signal is _____ modulated.
a] 100%
b] 2%
c] 50%
d] 70%
View Answer c] 50%

4. A percentage of modulation greater than ___________ will distort the message signal.
a] 10%
b] 25%
c] 50%
d] 100%
View Answer d] 100%

5. The RF bandwidth of AM is ____________ the maximum frequency contained in the modulating message signal.
a] Equal
b] Two times
c] Four times
d] Ten times
View Answer b] Two times

6. Single sideband AM systems occupy same bandwidth as of conventional AM systems.
a] True
b] False
View Answer b] False

7. How is the performance of SSB AM systems in fading channels?
a] Poor
b] Best
c] Good
d] Average
View Answer a] Poor

8. Which of the following is a disadvantage of tone-in-band SSB system?
a] High bandwidth
b] Bad adjacent channel protection
c] Effects of multipath
d] Generation and reception of signal is complicated
View Answer d] Generation and reception of signal is complicated

9. FFSR in AM systems stands for ________
a] Feedforward signal regeneration
b] Feedbackward signal regeneration
c] Feedbackward system restoration
d] Feedforward system restoration
View Answer a] Feedforward signal regeneration

10. AM demodulation technique can be divided into _____ and _____ demodulation.
a] Direct, indirect
b] Slope detector, zero crossing
c] Coherent, noncoherent
d] Quadrature detection, coherent detection
View Answer c] Coherent, noncoherent

11. Non coherent detection requires the knowledge of transmitted carrier frequency and phase at the receiver.
a] True
b] False
View Answer b] False

12. A product detector in AM systems is also called ___________
a] Envelope detector
b] Differentiator
c] Integrator
d] Phase detector
View Answer d] Phase detector

13. AM system use only product detector for demodulation. They never use envelope detectors.
a] True
b] False
View Answer b] False

Wireless & Mobile Communications Questions & Answers – Angle modulation

1. FM is a part of general class of modulation known as ______
a] Angle modulation
b] Phase modulation
c] Amplitude modulation
d] Frequency modulation
View Answer a] Angle modulation

2. FM is called constant envelope because ______ of carrier wave is kept constant.
a] Frequency
b] Amplitude
c] Phase
d] Angle
View Answer b] Amplitude

3. Which of the following are two most important classes of angle modulation?
a] Amplitude modulation, frequency modulation
b] Amplitude modulation, phase modulation
c] Frequency modulation, phase modulation
d] Single sideband amplitude modulation, phase modulation
View Answer c] Frequency modulation, phase modulation

4. Frequency modulated signal is regarded as the phase modulated signal in which the modulating wave is differentiated before modulation.
a] True
b] False
View Answer b] False

5. Frequency modulation index defines the relationship between the ______ and bandwidth of transmitted signal.
a] Frequency of message signal
b] Amplitude of message signal
c] Amplitude of carrier signal
d] Frequency of carrier signal
View Answer b] Amplitude of message signal

6. FM bandwidth is approximated using _______ rule.
a] Carson’s
b] Faraday’s
c] Maxwell’s
d] Armstrong’s
View Answer a] Carson’s

7. Which of the following are two methods for generating FM signal?
a] Coherent method, noncoherent method
b] Product detector, envelope detector
c] Direct method, indirect method
d] Slope detector, Zero crossing detector
View Answer c] Direct method, indirect method

8. In indirect method, the carrier frequency is directly varied in accordance with the input modulating signal.
a] True
b] False
View Answer b] False

9. Which of the following is used to vary the frequency of the carrier frequency in accordance with the baseband signal amplitude variations in direct method of FM generation?
a] Integrator
b] Envelope detector
c] Multivibrator
d] Voltage controlled oscillators
View Answer d] Voltage controlled oscillators

10. Frequency demodulator is a frequency to amplitude converter circuit.
a] True
b] False
View Answer a] True

11. Which of the following is not a technique for FM demodulation?
a] Slope detection
b] Zero crossing detection
c] Product detector
d] Phase locked discriminator
View Answer b] Zero crossing detection

12. Which of the following FM demodulator is sometimes known as pulse averaging discriminator?
a] Slope detection
b] Zero crossing detection
c] Quadrature detection
d] Phase locked discriminator
View Answer b] Zero crossing detection

13. PLL in FM detection stands for ______
a] Phase locked loop
b] Programmable logic loop
c] Phase locked logic
d] Programmable locked loop
View Answer a] Phase locked loop

14. In angle modulation, signal to noise ratio before detection is a function of ______
a] Modulation index
b] Input signal to noise ratio
c] Maximum frequency of the message
d] IF filter bandwidth
View Answer d] IF filter bandwidth

15. FM can improve the receiver performance through adjustment of transmitted power.
a] True
b] False
View Answer b] False

Wireless & Mobile Communications Questions & Answers – Digital Modulation

1. Modern mobile communication systems use analog modulation techniques.
a] True
b] False
View Answer b] False

2. Which of the following is not an advantage of digital modulation?
a] Greater noise immunity
b] Greater security
c] Easier multiplexing
d] Less bandwidth requirement
View Answer d] Less bandwidth requirement

3. A desirable modulation scheme provides _________ bit error rates at __________ received signal to noise ratios.
a] Low, low
b] Low, high
c] High, high
d] High, low
View Answer a] Low, low

4. The performance of modulation scheme is not measured in terms of __________
a] Power efficiency
b] Bandwidth efficiency
c] Cost and complexity
d] Transmitted power
View Answer  d] Transmitted power

5. In digital communication system, in order to increase noise immunity, it is necessary to increase _________
a] Signal power
b] Signal amplitude
c] Signal frequency
d] Signal magnitude
View Answer a] Signal power

6. Which of the following is the ratio of signal energy per bit to noise power spectral density?
a] Bandwidth efficiency
b] Spectral density
c] Power efficiency
d] Power density
View Answer c] Power efficiency

7. Increasing the data rate implies the increase in pulse width of digital symbol.
a] True
b] False
View Answer b] False

8. Which of the following is the ratio of the throughput data rate per Hertz?
a] Bandwidth efficiency
b] Spectral density
c] Power efficiency
d] Power density
View Answer a] Bandwidth efficiency

9. Which of the following is defined as the range of frequencies over which the signal has a non zero power spectral density?
a] Null to null bandwidth
b] Half power bandwidth
c] 3 dB bandwidth
d] Absolute bandwidth
View Answer d] Absolute bandwidth

10. _______ is equal to width of main spectral lobe.
a] Null to null bandwidth
b] Half power bandwidth
c] 3 dB bandwidth
d] Absolute bandwidth
View Answer a] Null to null bandwidth

Answer: a
Explanation: Null to null bandwidth is a simpler and more widely accepted measure of bandwidth. It is equal to the width of main spectral lobe.

11. Half power bandwidth is also called ______
a] Absolute bandwidth
b] Null to null bandwidth
c] 3 dB bandwidth
d] Zero dB bandwidth
View Answer c] 3 dB bandwidt

What is GSM used for?

What are the 3 different types of GSM?

Which technique is used in GSM?

How many categories of GSM are Mcq?