1. 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
Explanation: Hata model is well suited for large cell mobile radio systems. But it is not well suited for personal communication system (PCS) which have cells on the order of 1 km radius. Hata model does not have any path specific corrections which are available in Okumura model
2. 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
Explanation: The impact of rooftops and building height is considered by Walfisch and Bertoni model. It uses diffraction to predict average signal strength at street level. It considers path loss to be a product of three factors.
3. The variability of the environment is slower for a smaller range of T-R separation distances in indoor models.
a) True
b) False
Explanation: The indoor radio channel differs from the traditional mobile radio channel. The distances covered are much smaller and variability of the environment is much greater for a much smaller range of T-R separation distances.
4. Propagation within building is not influenced by _________
a) Layout of the building
b) Construction materials
c) Building type
d) Trees outside the building
Explanation: It has been observed that propagation within buildings is strongly influenced by specific features. These features are layout of the building, the construction materials, and the building type.
5. Smaller propagation distances make it more difficult to insure far-field radiation for all receiver location and types of antenna.
a) True
b) False
Explanation: Smaller propagation distances make it more difficult to insure far field radiation for all receiver location and types of antenna. The condition is very variable for smaller propagation distances.
6. 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
Explanation: Partitions that are formed as part of the building structure are called hard partitions. Partitions vary widely in their electrical and physical characteristics. Thus, it makes difficult in applying general models to specific indoor installation.
7. Partitions that can be moved are called _______
a) Soft partitions
b) Hard partitions
c) Disk partition
d) Dynamic partition
Explanation:Partitions that may be moved are called soft partitions. They do not span to the ceiling. Office buildings often have large open areas which are constructed by using moveable office partitions. Thus, space can be reconfigured easily
8. 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
Explanation: The losses between floors of a building are determined by external dimensions as well as materials of the building. It is also determined using type of construction used to create the floors and external surroundings
9. 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
Explanation: PAF (path attenuation factor) represents a specific obstruction encountered by a ray drawn between the transmitter and receiver in 3-D. This technique of drawing a single ray between transmitter and receiver is called primary ray tracing.
10. ________ is a process of converting plain text into cipher text.
a) Authentication
b) Decryption
c) Encryption
d) Compression
Explanation: Encryption is the most effective way to achieve data security. It is the process of encoding a message in such a way that only authorized parties can access it. Encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor.