1.What is Mobile computing and its applications?

Ans:

Mobile computing is the process of computation on a mobile device. In such computing, a set of distributed computing systems or service provider servers participate, connect, and synchronise through mobile communication protocols.
APPLICATIONS:
1) Mobile computing offers mobility with computer power.
2) It provides decentralized computations on diversified devices, systems, and networks, which are mobile, synchronized, and interconnected via mobile communication standards and protocols.
3) Mobile computing facilitates a large number of applications on a single device.

2.Give the differences between the network 1G,2G,2.5G,3G,4G,5G communications?

Ans:

1G - Voice-only communication.
2G – Communicate voice as well as data signals.
2.5G – Enhancements of the second generation and sport data rates up to 100 kbps.
3G - Mobile devices communicate at even higher data rates and support voice, data, and multimedia streams. High data rates in 3G devices enable transfer of video clips and faster multimedia communication.
4G - boosts of high speed, high quality, and enhanced security. The two most important technologies behind 4G are MIMO and OFDM and the two most widely used 4G standards are WiMAX and LTE.
5G Evolution of 4G, Higher data rates, longer reach Various things that improve economics for operators (virtualisation, slicing) but are invisible to user

3.DExplain Cellular systems.

Ans:

Cellular systems are mobile systems for two-way wireless communication between the fixed part of the system and mobile part of system which move in the area covered by each base station. In cellular systems, the entire coverage area is divided into cells i.e. they implement SDM (Space Division Multiplexing)

4.Difference between Mobile computing and mobile communication?

Ans:

Both mobile communication and mobile computing involve wireless data transfer. The difference is in the kind of data being transferred, and the kind of service being provided. The prevailing definition of mobile communication is any kind of communication that is done over a mobile phone interface. People often use the terms "mobile communication" and "wireless communication" somewhat interchangeably.
Whereas the term mobile computing specifically involves the kinds of data transfer that we think of as data, not voice. Telecom providers have done a good job of distinguishing between these two types of services, traditionally separating data from voice charges and vice versa.

5.Explain Multiplexing and its types

Ans:

Multiplexing is the process of combining multiple signals into one signal, over a shared medium. If analog signals are multiplexed, it is Analog
Multiplexing and if digital signals are multiplexed, that process is Digital Multiplexing.
Types of Multiplexing
Frequency Division Multiplexing (FDM)
Space Division Multiplexing (SDM)
Time Division Multiplexing (TDM)
Code Division Multiplexing (CDM)

6. What is Frequency reuse?

Ans:

Frequency Reuse is the scheme in which allocation and reuse of channels throughout a coverage region is done. Each cellular base station is allocated a group of radio channels or Frequency sub-bands to be used within a small geographic area known as a cell.

7. Explain Signal propagation and its ranges?

Ans:

Since wireless network use unguided media such as radio waves, the signal has no wires to determine the direction of propagation, where signals in wired network only travel along with wire. For wireless transmission, this predictable behavior is only valid in vacuum
Transmission range: communication possible in both directions relatively low error rate
Detection range: detection of the signal possible no communication possible (error rate too high)
Interference range: signal may not be detected signal adds to the background noise and may interfere other transmissions

8.Explain Antenna and its types?

Ans:

An antenna is used to transmit or capture radio electromagnetic signals is known as an antenna. These are available in different sizes as well as shapes. The small size antennas can be found on the roofs to watch television whereas big ones are used to capturing signals using satellites.
➢ Isotropic antenna
➢ Omnidirectional antenna
➢ Directional antenna
➢ Sectorized antenna

9.Explain Slow and Fast hopping.

Ans:

In slow hopping, multiple symbols are transmitted in one frequency hop. One or more symbols are transmitted over the same carrier frequency. Slow hopping is cheaper and has relaxed tolerance also it is less narrowband interference
In fast frequency hopping , multiple hops are required to transmit one symbol. One symbol is transmitted over multiple carriers in different hops. Fast hopping systems are complex to implement because transmitter and receiver should stay synchronised. ➢ Isotropic antenna ➢ Omnidirectional antenna
➢ Directional antenna
➢ Sectorized antenna