MITS5003: Wireless Networks & Communication Assignment Report 2019SS

This report provides a comprehensive analysis of wireless networks and communication, covering various aspects such as data representation, signal delay calculations, and MFSK frequency calculations. It delves into amplitude and frequency modulation techniques, including their equations and waveforms, and explains constellation diagrams of 8 QAM. The report also explores mobile communication handoff strategies, CRC calculation for error detection, traffic calculations, and the cell concept in mobile communication. Each section includes detailed explanations, mathematical calculations, and relevant figures to illustrate the concepts. The report concludes with a summary of the key findings and references to support the analysis.

Wireless Networks & Communication
MITS5003
SUFI

Contents
1. Data: 101010000111 analog waveform...................................................................................................3
2. Signal delay calculation [1]...................................................................................................................10
3. MFSK frequency calculation..................................................................................................................11
4. Amplitude and frequency Modulation [1]............................................................................................12
5. Constellation diagram of 8 QAM...........................................................................................................15
6. Mobile communication Handoff strategies[6]......................................................................................16
7. CRC calculation for error detection.......................................................................................................17
8. Traffic calculation in wireless comm......................................................................................................19
9. Cell concept in mobile communication..................................................................................................20
Conclusion.................................................................................................................................................21
References.................................................................................................................................................22

1. Data: 101010000111 analog waveform
Solution [1]
The balance of analog flag is vital strategy for remote communication because it utilizes the channel
in productive way and the message flag in computerized bits are changed into analog remote able
signals. The balance method can be classified agreeing to the parameters being shifted in analog
tweaked flag to be specific amplitude, frequency, or stage. Usually said to be sufficiency move
keying, Recurrence move keying, and stage move keying. Other half breed procedures like QAM are
moreover utilized for tweak. The tweak procedure is explained below and each one is charted for
the information given within the problem. Data: 101010000111
a) Two level ASK
The amplitude of the carrier signal is the parameter in this case where binary 0 bit has lower amplitude
and higher amplitude at binary 1

b) Frequency shift Keying
The frequency of the carrier is lower in binary 0 bit and at binary 1 bit frequency is higher. This
classification makes it easy to distinguish at receiver and find the actual message bits.

c) Two level phase shift
In this modulation the phase is altered according to the binary signal. We have taken 180 degree phase
shift as the number of bits to be taken is one at a time. [1]

d) Differential phase shift keying
This a type of phase shift keying which will depend on the binary bits to in consequence , if binary 1
comes then there is 180 degree phase shift and binary 0 has no phase shift of previous signal.

e) Four level ASK
this modulation is also amplitude shift keying only difference is that the amplitude varies as we take two
bits a time , so we will have four possibilities 00,01,10, and 11 , accordingly we must have four
amplitude level for each bit combination. This reduces the time delay of sending the signal but increases
the quantization noise.

f) Four level PSK
this modulation is also phase shift keying only difference is that the amplitude varies as we take two bits
a time , so we will have four possibilities 00,01,10, and 11 , accordingly we must have four phase for
each bit combination. This reduces the time delay of sending the signal but increases the noise.

g) 8 level ASK
this modulation is also phase shift keying only difference is that the amplitude varies as we take three
bits a time , so we will have eight possibilities 000,001,010,011,100,101,110,111 , accordingly we must
have eight amplitude for each bit combination. This reduces the time delay of sending the signal but
increases the noise.

2. Signal delay calculation [1]
Solution: 1 us is given in the problem for sending each signal , so for calculating time delay for each
case , we use the number of bits to be sent at a time , as shown below
1. 12x1us = 12 us for Two level ASK
2. 12x1us = 12 us for Two level FSK
3. 12x1us = 12 us for Two level PSK
4. 12x1us = 12 us for DPSK
5. 6x1us = 6 us for Four level ASK
6. 6x1us = 6 us for Four level PSK
7. 4x1us = 4 us for Eight level ASK

3. MFSK frequency calculation
The possible frequency in MFSK is calculated by
Fi= fc+ (2i-1-M) Fd
Where FC = 1000 KHz, fd= 50 KHz, and M=16
The frequency in KHz is calculated as given in the table below

4. Amplitude and frequency Modulation [1]
The message signal’s equation for the given message waveform.
-0.5 cos (2πft), where f=1/60

The amplitude modulation concept is the one in which the amplitude of carrier signal is modulated with
the message signal and the equation for this is shown below with the waveform

The frequency modulation is concept where the carrier signal’s frequency is modulated as per the
message signal to be transmitted , the equation for this case is shown below.

5. Constellation diagram of 8 QAM
The quadrature amplitude modulation is amplitude and phase shift keying considering both at a time as
in case of hybrid modulation. This can be of various types like 8 QAM, considering two different
amplitudes and four phases, or 16 QAM of two amplitudes and 8 different phases. The constellation
diagram simplifies the visualization of signal when we consider different amplitude and phase of the
signal. IN the figure below two circles represent two different amplitude levels and four axes represent
four different phases of the signal, each signal is depicted in the form of dots in the constellation
diagram.

6. Mobile communication Handoff strategies[6]
The handoff is done when the gotten flag from current base station drops underneath edge
and the target base station is more grounded.

I. L4 location is the place where handoff will occur when considering only relative signal
strength
II. L4 location is the place where handoff will occur when considering relative signal
strength and TH1 threshold.
III. L3 location is the place where handoff will occur when considering relative signal
strength and TH2 threshold.
IV. L1 location is the place where handoff will occur when considering relative signal
strength and TH3 threshold.
V. L2 location is the place where handoff will occur when considering relative signal
strength and hysteresis
VI. L4
VII. L2
VIII.L1
7. CRC calculation for error detection
The CRC error detection concept is used in data communication for reducing error during the
transmission of data. In this concept the transmitter and receiver is synchronized with regular generator
function which is same in both ends. The message data is added with crc value and sent to the receiver
where it is checked by division method same as transmitter and error is detected. The process is
explained below [2]
At the transmitter
Step1: The message data is appended with p-1 zeros where p is the number of bits in message signal.
Step 2: The remainder is calculated by dividing the appended message bits with the generator function
bits
Step 3: The remainder is then added with the message bits and sent to the receiver where it will be
checked for any error during transmission process.
At the receiver
Step1: The data received is combination of message bits of n bits and crc bits, this is divided by the same
generator function bits and remainder is calculated.

Step2: The remainder is then analyzed; if the remainder is non zero then some error occurred in the
message signal or remainder if zero then no error occurred.

8. Traffic calculation in wireless comm.
Solution:
Given parameters
Users number of calls number of durations(Min )
User 1 10 5
User 2 15 15
User 3 2 40
User 4 20 70
User 5 5 20
I. Total occupied time[3]

The total time occupied in minutes is calculated by adding all the talk time of the users
So, it will be T1+T2+T3+T4+T5
= 5+15+40+70+20 = 150 mins
II. Total number of calls
The total number of call by the users in cellular communication is addition of all the calls
initiated by the users
So, it will be C1+C2+C3+C4+C5
= 10+15+2+20+5 = 52 calls
III. Mean occupied time per call
It will be equal to total time occupied divided by total number of calls
= 150 /52 = 2.88 mins
IV. Mean rate of calls per minute
It will be equal to total number of calls divided by total time occupied
= 52/150 0.386 calls
V. Traffic intensity
It will be equal to mean occupied time per call divided by Mean rate of calls per minute
= 2.88 /0.386 = 7.46
9. Cell concept in mobile communication
Solution:
The cell concept is a theoretical concept used in mobile communication for cellular communication
planning. The area is divided into small cells to use the frequency and power in more efficient way, as

these are two very crucial resources that a cellular network must keep in mind. The cell power must not
be more than regulations given by government and frequency spectrum is limited, so using frequency
reusability concept all area without interference is covered under the wireless communication. The cell
is designed keeping in mind the antenna radiation and geographic area distribution and area overlap.
The circle best fits the criteria of area coverage but it overlaps some part that will cause interference
between neighbor cells. The triangle over other hand has 17.7% area coverage relative to circle, and the
square has 63.7 % area coverage relative to circle. The most important hexagonal cell shape has 83 %
area coverage relative to circle. [4]
So, the hexagonal cell shape is preferred due to following
 It has largest area than square and triangle relative to circle.
 The requirement of number of cell in a given area is minimized.
 It fits with the concept of antenna radiation pattern and geographic terrain area coverage.
Figure : Cell shape concept .
Conclusion
The data communication and network is a important technology that this world relies now a days. in this
assignment some of the major aspects of data communication like signals and its waveforms , error
detection and cellular concept is analyzed and mathematical calculations are done. The mathematical
calculation is supported by brief introduction to the theory and related equations which are shown in
the report. The figures and graphs are duly mentioned as per requirement and the report is compiled
and formatted in MS word.

References
[1] Computer Networks , Andrew S. Tanenbaum,2018 5th Edition
[2] Cyclic redundancy check", En.wikipedia.org, 2020. [Online]. Available:
https://en.wikipedia.org/wiki/Cyclic_redundancy_check. [Accessed: 21- Jan- 2020].
[3] Wireless Communications & Networks, Stallings.2009, 2nd edition
[4] "Cellular network", En.wikipedia.org, 2020. [Online]. Available:
https://en.wikipedia.org/wiki/Cellular_network. [Accessed: 21- Jan- 2020].
[5] "Digital Modulation Techniques - Tutorialspoint", Tutorialspoint.com, 2020. [Online]. Available:
https://www.tutorialspoint.com/principles_of_communication/principles_of_communication_di
gital_modulation_techniques.htm. [Accessed: 21- Jan- 2020].
[6] "Handoff in Cellular Telecommunications - GeeksforGeeks", GeeksforGeeks, 2020. [Online].
Available: https://www.geeksforgeeks.org/handoff-in-cellular-telecommunications/. [Accessed: 21-
Jan- 2020].
[7] “Handover", En.wikipedia.org, 2020. [Online]. Available: https://en.wikipedia.org/wiki/Handover.
[Accessed: 21- Jan- 2020].