Multiplexing Techniques Practice MCQs

Questions: 15 | Attempted: 0

1. In the North American T1 carrier system, how many voice channels are multiplexed into a single frame compared to the European E1 standard?

A) 24 in T1 and 30 in E1B) 24 in T1 and 32 in E1C) 30 in T1 and 32 in E1D) 32 in T1 and 64 in E1

2. Which multiplexing technique assigns a unique mathematical code to each user to allow multiple users to share the exact same frequency and time?

A) FDMAB) TDMAC) CDMAD) WDM

3. In the E1 carrier system used by BSNL, which specific time slots (TS) are strictly reserved for frame synchronization and common channel signaling respectively?

A) TS0 and TS15B) TS0 and TS16C) TS1 and TS31D) TS16 and TS32

4. What is the exact frame duration of a standard E1 Time Division Multiplexed (TDM) signal?

A) 1 millisecondB) 125 microsecondsC) 250 microsecondsD) 1 second

5. Which multiplexing technique relies on allocating non-overlapping frequency bands to different users, separated by empty spectrum to prevent interference?

A) TDMB) FDMC) CDMD) SDM

6. What is the primary operational difference between Synchronous TDM and Statistical (Asynchronous) TDM?

A) Statistical TDM only works on optical fiber, while Synchronous TDM works on copper.B) Statistical TDM assigns time slots dynamically based on actual demand to save bandwidth, while Synchronous TDM statically assigns slots even if a user has no data to send.C) Statistical TDM uses analog signals, while Synchronous uses digital.D) Synchronous TDM encrypts data, while Statistical TDM does not.

7. In optical fiber networks, what is the defining characteristic that separates Dense Wavelength Division Multiplexing (DWDM) from Coarse Wavelength Division Multiplexing (CWDM)?

A) DWDM uses electrical signals while CWDM uses optical signals.B) DWDM is only used in multimode fiber, while CWDM is used in single-mode.C) DWDM packs wavelengths very closely together (typically ≤ 0.8 nm spacing) while CWDM uses wide channel spacing (typically 20 nm).D) DWDM uses only the 850 nm window, while CWDM uses the 1550 nm window.

8. What is the exact data rate of a single dedicated voice channel (timeslot) within an E1 or T1 multiplexed frame?

A) 8 KbpsB) 16 KbpsC) 64 KbpsD) 128 Kbps

9. In a Plesiochronous Digital Hierarchy (PDH) multiplexer, what technique is used to synchronize multiple lower-speed data streams (like E1s) that have slightly different clock speeds before combining them?

A) Carrier AggregationB) Pulse Amplitude ModulationC) Bit Stuffing (Justification)D) Forward Error Correction

10. Which of the following best describes 'Spatial Multiplexing' as used in modern 4G/5G MIMO antenna systems?

A) Transmitting different data streams simultaneously over the exact same frequency and time using multiple separated antennas to multiply data throughput.B) Transmitting the exact same data stream over multiple antennas to increase range.C) Using satellites to relay signals over a large geographic area.D) Splicing multiple physical fiber optic cables together.

11. What is the primary function of an Arrayed Waveguide Grating (AWG) in optical multiplexing?

A) To amplify the optical signal natively without electricity.B) To passively multiplex or demultiplex dozens of distinct, closely spaced optical wavelengths into or out of a single fiber using interference principles.C) To convert optical signals back to electrical signals.D) To encrypt the optical payload data.

12. In the context of duplexing (a two-way form of multiplexing), what is the primary advantage of Frequency Division Duplexing (FDD) over Time Division Duplexing (TDD)?

A) FDD uses half the total spectrum of TDD.B) FDD requires fewer antennas on the cell tower.C) FDD provides continuous, simultaneous transmission and reception because it uses two physically separate frequency bands.D) FDD is completely immune to physical obstacles like buildings.

13. Orthogonal Frequency Division Multiplexing (OFDM) prevents interference between its closely packed subcarriers without using traditional, wasteful guard bands by ensuring what mathematical condition?

A) All subcarriers are encrypted with different security keys.B) All subcarriers are transmitted at completely different times.C) The peak of each subcarrier's frequency aligns exactly with the mathematical 'zero' crossing point of all adjacent subcarriers.D) All subcarriers use identical amplitude.

14. If four standard E1 lines are multiplexed together in the traditional PDH hierarchy, what is the resulting designation and approximate data rate?

A) T1 at 1.544 MbpsB) E2 at 8.448 MbpsC) E3 at 34 MbpsD) STM-1 at 155 Mbps

15. In analog television and FM radio, an underlying multiplexing technique is often used to send a second audio program (SAP) or stereo audio on the same main carrier. Which technique creates this 'subcarrier'?

A) WDMB) TDMC) FDMD) Statistical Multiplexing