02.The _______________________approach suggests that the spectrum can be treated like land, and private ownership of the spectrum is viable.

03.The ________________________allows the bands to be open to technologies as long as they follow the rules of access in the specific band.

04.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.

05.In the IEEE802.22 MAC Layer Frame How many frames constitute a Super Frame?

06.In the IEEE802.22 MAC Layer

Frame, What is the duration of one super frame ?

07.What is the purpose of Frame

Preamble?

08.Purpose of Coexistence window

in a MAC frame is_________________________

09.In 802.22 services - Spectrum Management Model ,each BS inside a WRAN will have a central entity , that is assumed to be a ___________________

10.During Quiet Period the base station____________________

11.To achieve seamless transition to the backup channel; without service interruption, what are the two channel management modes that are specified in 802.22 standard for WRAN?

12.What is the necessity of Synchronisation between CPE and BS?

13.Self Coexistence mechanism gives protection to incumbent users by synchronising the ______________

14.Suppose if a slave (CPE ) has the central entity for spectrum management, then that CPE is known as

15.Through _______________ packets that carries information about the cell,the BS initiate a Network Discovery

16.This function detects spectrum holes and senses the presence of the LU when the CU operates on a

licensed band. Name the spectrum function?

17.This function is used to select the best available channel based on the QoS requirements of a CU. This

also covers Spectrum Mobility. Name the Function?

18.This Function is used to coordinate channel access with other users, which involves multi-user multi-address and resource allocation. This statement corresponds to __________________ function.

19.This function changes communication parameters to adaptively react to environmental change.Name the Function?

20.A cognitive radio should be designed to be aware of and sensitive to the changes in its surroundings time

to time.True/False?

21.In ______________________________ spectrum sensing ,a single CR node independently identifies spectrum characteristics based on local radio frequency environment.

22.The _______________________ is the optimal linear filter for maximizing the signal-to-noise ratio (SNR) in the presence of additive stochastic noise.

23. In Matched Filter detection method a single CR node senses the spectrum hole and incumbent user's presence based on the parameter known as_______________

24. In Energy sensing method a single CR node senses the spectrum hole and incumbent user's presence based on the parameter known as_______________

25. In Cyclostationary feature estimation method a single CR node senses the spectrum hole and incumbent user's presence based on the parameter known as_______________

26.The limitation in Match filtering are each CR should have the information of all primary users and large power consumption. TRUE/FALSE ?

27.The two degrading factorsassociated with energy sensing methods are ____________________________

28.The performance of energy detector is susceptible to uncertainty in noise power.In order to solve this problem, a __________________ signal from the primary transmitter is used to help improve the accuracy of the energy detector.

29.Signals have _________________________ in the frequency domain that are not easily seen in the time domain.

30.Theoritically,a Cyclo-stationary feature detector can perform better than the energy detector in discriminating against noise due to its robustness to the uncertainty in noise power.TRUE/FALSE?

31.With the transmitter detection methods, the CR user cannot avoid the interference due to the lack of the primary receiver’s information.This inability is known as________________

32.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 __________________

33.Cooperative sensing algorithms require participation of cooperative partners and hence are much more complicated to implement than non-cooperative ones.TRUE/FALSE?

34.Cooperative sensing uses _____________________ to share the spectrum sensing result.

35.In centralized sensing,a___________________ 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.

36.Distributed sensing is more advantageous than centralized sensing in the sense that there is no need for a backbone infrastructure and it has reduced cost. TRUE/FALSE?

37. In ___________________________ cooperative spectrum sensing method,An external agent performs the sensing and broadcasts the channel occupancy information to the cognitive radios.

38.Cognitive radio will measure the interference environment through___________________________parameter and adjust their transmission such that the interference to Primary User is not above the regulatory limits in case of interference based sensing method.

39. _______________________ is the sum of total interference plus the sum of total noise present in a receiver system due to all CR users.

40.OFDM-based CR networks are known to be excellent fit for the physical architecture of CR networks.TRUE/FALSE?

41.________________represents the region of guaranteed decodability of CR Signals to primary receivers.

42.The main issues covered in spectrum sharing include coexistence of Cognitive Users and Licensed Users and management of available non-continual bandwidths.

43.The _________________________________ means all nodes (i.e. users) in the network send their spectrum sensing information to the central control unit, and the control unit draws spectrum allocation mapping.

44.In the _____________________________ means all nodes decide their spectrum access by and among themselves.

45.In ___________________________________________________, each node shares its sensing results of ambient environment with other nodes and spectrum allocation algorithm makes decisions based on all this information.

46. In _____________________________________, each node only considers its own behaviors, that is to say, each node is selfish.

47.___________________________________________________means a Cognitive Users accesses the network via unused spectrum hole. It actually realizes time division multiplexing of a spectrum between Licensed Users and Cognitive Users, so the interference with Licensed Users is the least.

48._________________________________________________means a Cognitive Users can use such spectrum spreading technologies as CodeDivision Multiple Access (CDMA) and Ultra Mobile Broadband (UWB) to share the same band with a Licensed Users .

49. The Virtual Cube concept defines a common spectrum unit structure based on the resource allocation techniques used in existing networks. TRUE/FALSE?

50.It would be much efficient to select control channels in the lower portions of the spectrum where the transmission range will be higher and to select data channels in the higher portions of the spectrum where a localized operation can be utilized with minimized interference. Validate this statement.