Wireless Networks and Communication Assignment Solutions - University

This document presents a comprehensive solution to a wireless networks and communication assignment. The assignment covers a range of topics including converting binary data into analog waveforms using various modulation techniques like Amplitude Shift Keying, Frequency Shift Keying, and Phase Shift Keying. It also includes computations related to frequency assignments for different bit combinations and the drawing of analog and frequency modulation waveforms. Furthermore, the solution details the construction of a 16 QAM constellation diagram, explains the error detection process for Cyclic Redundancy Check (CRC), and computes the frame check sequence. It also covers the computation of a transmitted signal using Direct Sequence Spread Spectrum (DSSS), compares infrastructure and ad hoc modes in WLAN, and differentiates between TCP and OSI protocols. Finally, it explains the advantages of hexagonal cells in cellular communication. The document provides detailed explanations and diagrams to illustrate each concept, making it a valuable resource for students studying wireless networks and communication.

Running head: WIRELESS NETWORKS AND COMMUNICATION 1
Wireless Networks and Communication
Name of Student
Institution Affiliation

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Question one (1): Convert the binary data “011010” into analog waveforms using following
modulation techniques:

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Question 2: With fc = 500 kHz, fd = 25 kHz, and M = 16 (L = 4 bits), compute the
frequency
Assignments for each of the sixteen possible 4-bit data combinations.

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Question 3 Draw the approximate Analog Modulation and Frequency Modulation
waveforms in complete steps for the following signal:
Modulation
Modulation refers to the process of altering the wave characteristics designed to be
transmitted through the superimposition of a message signal into a high-frequency signal. The
carrier wave is usually modified by signals such as noise, video, or data signals. This carrier
wave can either be pulse chain, ac or dc, with respect to the application that has been used. The
carrier wave is often taken as the sine wave with the high frequency [2].
Analog Modulation
Analog modulation, the used carrier wave, is a continuously varying sine wave which modulates
the data signal or the message signal. Primarily, the sine wave contains three parameters which

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can be changed to obtain the modulation. These parameters include phase, frequency, and
amplitude. The various types of analog modulation include
 Amplitude modulation (AM), the amplitude gets modulated depending on the message
signal being transmitted. Other factors, such as the frequency and phase, remain constant. In
this type of modulation, more power and bandwidth is required. However, one factor which
proves difficult is filtering [1].
 Frequency modulation (FM) – the frequency gets modulated depending on the message
signal being transmitted. Other factors, such as the amplitude and phase, remain constant.
One benefit with this modulation is a more significant noise suppression with respect to the
FM bandwidth. It is applied in telemetry, radar and, radio, excreta. The maximum
modulating frequency and the modulation index determines the bandwidths and efficiency.
 Phase modulation (PM)- the phase gets modulated depending on the message signal being
transmitted. Other factors, such as the frequency and amplitude, remain constant. However,
varying the phase also affects the frequency [2].

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Question 4: Draw the 16 QAM Constellation Diagram having two different amplitude
levels and eight
different phase levels.

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Question 5. Explain and draw the Error Detection Process for Cyclic Redundancy Check
(CRC).
Generally, (CRC) is an error-detecting code that is used in storage devices and digital networks
to detect random variations to raw data. Based on the remainder of a polynomial division of
contents, the input block into these systems undergoes a short check value attached. This method
helps in detecting accidental errors present in a communication channel. Besides, on the sides of
the receiver and sender, there is a Generator Polynomial which the CRC uses. For instance: x3 +
x + 1 [1].
Diagram of Cyclic Redundancy Check (CRC).
Below is the numerical explanation

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Question 6: Compute the frame check sequence for the following information:
Message = 10111100, Pattern = 11011
Solution: Steps

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Question 7: Compute the transmitted signal using Direct Sequence Spread Spectrum for
the
Following information:
Input: 1011, Locally Generated PN bit stream: 101011011010, T = 3Tc

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The transmitted signal is : 010011100101
Question 8. What is the difference between Infrastructure and ad hoc modes in WLAN? In
Infrastructure mode, a central access point which connects all devices is required. On the other
hand. Ad-hoc networks do not necessitate for a centralized access point. The devices present on
the wireless network are directly connected. The will always get attached to the devices in a
peer-to-peer manner, making the infrastructure mode a lasting one i.e., more everlasting
applications of a network [1].
Draw their relative diagrams as well

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Ad hoc modes
Infrastructure
Question 9: Compare the differences between TCP and OSI protocols for wired and
wireless LANs using diagrams.
The OSI and TCP protocols have been widely applied in enabling communication
between devices. They exhibit some similarities as well as differences of entirely dissimilar
significance, is the usefulness, where the OSI conceptual model proves not to be useful as such
in communication whereas TCP protocols are essential in enabling the connection between two
devices.

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TCP/IP model:
 This protocol can be expanded to the internet or control protocol
 With the help of the internet, the TCP protocol can be used in aiding the transfer of data
either between the server and the client.
 The total number of layers comprising the TCP model is four.
 The DoD departments of defense can develop this protocol.
 When making a comparison with other protocols, TCP is the most usable one
OSI protocol
 This protocol is one of the open systems interconnected connection types
 The OSI protocol; comprises of a total of seven layers
 When compared to the TCP protocol, it mostly applied in the computing system of a
computer.
 The International Standard Organization's ISO designed its layer.
The diagram below shows the difference between the two.

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Question 10. Explain why the square and circle shapes cells for cellular communications
are not appropriate as compared to hexagonal shaped cells.
The basic unit of a cellular system is known as a cell. It is in the forms of hexagonal shape, with
the mobile service area being divided into small hexagonal regions. Collectively, the isolated
cells cover a wide range of geographical regions. When the comparison is made between the
hexagonal shape and other shapes such as triangular, rectangular, and square and circle shapes,
the hexagonal shape is still outstanding since it has the capability of covering a wide zone
without overlapping [2].

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References
[1].H. Sigit. Telecommunication Service and Experience Quality. Dago Press, 2015.
[2].I. Eugenio. Telecommunication networks. CRC Press, 2016.