Question 1
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
View Answer
Answer: Option B
Explanation:
IS-95 was proposed by Qualcomm in early 1990s. Later it was adopted as a standard by Telecommunications Industry Association in TIA/EIA/IS-95 release published in 1995.
Question 2
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
View Answer
Answer: Option C
Explanation:
GSM was earlier known as Group Special Mobile. As it became more global, the meaning of acronym was changed to Global System for Mobile.
Question 3
How many users are supported in IS-95 for each 1.25 MHz?
A. Eight
B. Sixty four
C. Sixteen
D. Twenty five
View Answer
Answer: Option B
Explanation:
IS-95 supports upto 64 users which are orthogonally coded and simultaneously transmitted on each 1.25 MHz. The services of IS-95 standard are short messaging service, slotted paging, over-the-air activation, enhanced mobile station identities etc.
Question 4
How many users or voice channels are supported for each 200 KHz channel in GSM?
A. Eight
B. Three
C. Sixty four
D. Twelve
View Answer
Answer: Option A
Explanation:
GSM is a circuit switched system that divides each 200 KHz channel into eight 25 KHz time slots, i.e. each radio channel is divided into eight voice channels.
Question 5
How many voice channels are supported for each 30 KHz radio channel in IS-136?
A. Eight
B. Thirty
C. Three
D. Sixteen
View Answer
Answer: Option C
Explanation:
Interim Standard 136 (IS-136) was popularly known as North American Digital Cellular (NADC) system. It divides each 30 KHz radio channel into three time slots, each of 10 KHz.
Question 6
IS-136 uses which modulation technique?
A. π/4 DQPSK
B. BPSK
C. GMSK
D. AFSK
View Answer
Answer: Option A
Explanation:
IS-136 uses π/4 DQPSK modulation technique. This technique allows a bit rate of 48.6 Kbit/s with 30 KHz channel spacing which gives a bandwidth efficiency of 1.62 bit/s/Hz.
Question 7
IS-95 uses which modulation technique?
A. GMSK
B. BPSK
C. QAM
D. AFSK
View Answer
Answer: Option B
Explanation:
IS- 95 uses BPSK (Binary Phase Shift Keying) with quadrature spreading. It is regarded as one of the most robust digital modulation technique and is used for long distance wireless communication.
Question 8
Popular 2G CDMA standard IS-95 is also known as ______________
A. CdmaOne
B. CdmaTwo
C. IS-136
D. IS-95B
View Answer
Answer: Option A
Explanation:
The popular 2G CDMA standard, Interim Standard (IS-95) is also known as CdmaOne. The 2.5G CDMA standard, IS-95B is called CdmaTwo. And IS-136 is a TDMA standard for 2G.
Question 9
The 2G GSM technology uses a carrier separation of _____________
A. 1.25 MHz
B. 200 KHz
C. 30 KHz
D. 300 KHz
View Answer
Answer: Option B
Explanation:
The Global System for Mobile (GSM) uses a carrier separation of 200 KHz, each channel supporting upto eight users.
Question 10
Which is one of the disadvantages of 2G standards?
A. Short Messaging Service (SMS)
B. Digital modulation
C. Limited capacity
D. Limited Internet Browsing
View Answer
Answer: Option D
Explanation:
2G technologies use circuit switched data modems that limits data users to a single circuit switched voice channel. The advantages of 2G network are that they are digital in nature and supports SMS service.
Question 11
Which modulation technique is used by GSM?
A. GMSK
B. BPSK
C. QPSK
D. GFSK
View Answer
Answer: Option A
Explanation:
GSM uses a form of modulation known as GMSK (Gaussian Minimum Shift Keying). It is a form of modulation with no phase discontinuities and provides data transmission with efficient spectrum usage.
Question 12
Which of the following is a CDMA standard of second generation network?
A. IS-95
B. IS-136
C. ETACS
D. EDGE
View Answer
Answer: Option A
Explanation:
Interim Standard 95 (IS-95) is the most popular CDMA standard of second generation networks. IS-136 is a TDMA standard of 2G. EDGE is a standard of 2.5G and ETACS is a 1G standard.
Question 13
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
View Answer
Answer: Option B
Explanation:
First generation cellular system used FDMA/FDD techniques. Second generation standards uses TDMA/FDD and CDMA/FDD multiple access techniques. 2G networks are digital.
Question 14
Which one is not a TDMA standard of second generation networks?
A. GSM
B. IS-136
C. AMPS
D. PDC
View Answer
Answer: Option C
Explanation:
GSM (Global System Mobile), IS-136 (Interim Standard 136) and PDC (Pacific Digital Cellular) are the three most popular TDMA standards of second generation. AMPS is a first generation standard.
Question 15
Which one of the following 2G standard is used in Japan?
A. IS-136
B. GSM
C. PDC
D. AMPS
View Answer
Answer: Option C
Explanation:
PDC (Personal Digital Cellular) was standardized by Japanese Ministry of Posts and Telecommunication in 1991. It is similar to IS- 136, but with 25 KHz voice channels to be compatible with the Japanese analog channels.