05.11.2020_EC8071_CR_MODEL EXAM-2_PART-B

1.Which of the following, gives the closest meaning to the term,'cognitive' in the context of Cognitive Radio? (CO1) (B4).

• The ability to think and decide
• The ability to donate
• The ability to fight
• The ability to speak

2.Due to the lack of exclusivity among the users,in the unlicensed spectrum ,which among the following becomes the biggest problem to radio users?. (CO1) (B4).

• interference
• signal jamming
• noise
• attenuation

3. Which among the following is another Software Radio Technology, in that few or all the physical layer functions of a radio transceiver are controlled by software? (CO1) (B4).

• Software Defined Radio
• Software Denoted Radio
• Software Controlled Radio
• Hard-wired Radio

4.Assuming a 6 MHz TV channel bandwidth and a 40:1 over subscription ratio resulting from the stochastic nature of the data network usage, this translates into a total of ________________________user terminals that can be served by the base station per TV channel. (CO2)(B5).

• 511
• 127
• 1023
• 255

5.The purpose of Coexistence window in a MAC frame is_________________________ (CO2) (B4).<br />

• to ensure the maximum utilization of spectrum
• to reduce the error in transmission
• to increase the frame rate
• to reduce noise

6.In 802.22 services - Spectrum Management Model ,each BS inside a WRAN will have a central entity which is assumed as a___________________ (CO2) (B4).

• Spectrum manager
• Spectrum server
• spectrum allocator
• spectrum agent

7.A CR transmitter can have a good line-of-sight to a receiver, but may not be able to detect the transmitter due to the __________________ (CO3) (B4).

• Receiver uncertainty
• Shadowing uncertainity
• Physical Uncertainity
• Transformal Uncertainity

8.In centralized sensing, which among the following collects sensing information form cognitive devices, identifies the available spectrum, and broadcasts this information to other cognitive radios or directly controls the cognitive radio traffic. (CO3) (B4).<br />

• central unit
• control unit
• command unit
• computer unit

9.Which of the following spectrum sharing method allows each and every node to decide their spectrum access by themselves? (CO3) (B4).<br />

• Centralized spectrum sharing
• Distributed spectrum sharing
• Cooperative spectrum sharing
• Non-cooperative spectrum sharing

10.In case of an ALOHA method of channel allocation,If no acknowledgment is received by the sender, it indicates which among the following situation? (CO4) (B4).<br />

• Packet Loss
• Collision
• Packet Damage
• Delayed packet reception