Ministry Of Higher Education Sohar College Of Applied Scienc

Ministry Of Higher Educationsohar College Of Applied Sciencesinformati

Ministry Of Higher Educationsohar College Of Applied Sciencesinformati

Ministry Of Higher Educationsohar College Of Applied Sciencesinformati

Ministry of Higher Education Sohar College of Applied Sciences Information Technology Department A.Y Spring Semester 2020 Assignment # 1 ITNW4104 WIRELESS NETWORKING Issue Date: 22 April 2020 Student Name: Student ID G Group No.10 Max. Marks: 40 Instructions: 1. Assignment 1 is for 40 marks and worth 40 % of final marks for ITNW4104 Course. 2. Answer all the questions 3.

Answer should be handwritten using blue or black pen only. Diagram or figures can be drawn using pencil. 4. Follow the plagiarism policy as per the academic regulation. 5.

Upload the Assignment 1 in Blackboard and try to upload once it is completed at the earliest.

Paper For Above instruction

The following paper addresses the core questions regarding wireless networking as per the given assignment, including fundamental principles, technical specifics, and practical applications. It discusses the distinctions between guided and unguided media, frequency domain characteristics, fading phenomena, signal attenuation, error coding, cellular system design, antenna radiation patterns, and wireless network planning. Additionally, it explores advanced concepts such as Code Division Multiple Access (CDMA) encoding, antenna gain calculations, and network mobility considerations, providing comprehensive insights into wireless communication systems.

Introduction

Wireless networking has become an integral aspect of modern communication, enabling flexible, mobile, and efficient data transmission. Understanding the foundational principles—such as media types, frequency domains, fading effects, and network topology—is essential for designing and optimizing wireless systems. The assignment encapsulates these aspects, highlighting technical intricacies and practical implementations.

Guided vs. Unguided Media and Data Transmission

The use of guided (wired) or unguided (wireless) media significantly impacts data transmission. Guided media like fiber optics or Ethernet cables offer predictable pathways with minimal interference, maintaining data integrity and security. In contrast, unguided media such as radio waves or infrared signals are susceptible to environmental factors like obstacles, noise, and interference, which can cause variations in data quality. Hence, the data transmitted over guided media remains more consistent, whereas wireless media data may experience fluctuations due to external influences.

Frequency Domain Characteristics

Most of the signal energy in wireless systems is concentrated within certain frequency bands, often determined by the transmission medium and regulatory constraints. For example, in microwave communications, the primary energy resides within the GHz spectrum. This is because higher frequencies allow for more bandwidth and higher data rates, yet they are also more susceptible to attenuation. Understanding the frequency domain characteristics helps optimize system performance and spectrum allocation.

Urban Fading Phenomena

In urban environments, multipath fading is the most prevalent type of signal fading. This occurs because signals reflect off buildings, vehicles, and other structures, causing multiple copies of the signal to arrive at the receiver with different delays and phases. Such multipath effects result in fluctuations of the received signal strength, known as fast or slow fading, degrading the quality of wireless links in densely built-up areas.

Attenuation and Its Maximum Points

Attenuation—the reduction in signal strength—is highest when signals traverse long distances or pass through obstructive materials like walls and dense vegetation. It is also maximized at higher frequencies due to atmospheric absorption. The attenuation peaks when the signal encounters environmental obstacles or at specific frequencies where absorption by atmospheric particles is significant, such as in fog or rain.

Spread Spectrum and XOR Operations

In Direct Sequence Spread Spectrum (DSSS), the spreading code or chip sequence influences the output. For example, with a spreading code “0010” and input data “1001,” the resultant data after XOR operations is calculated by XORing each bit with the corresponding spreading code bit:

• 1 XOR 0 = 1
• 0 XOR 0 = 0
• 0 XOR 1 = 1
• 1 XOR 0 = 1

Thus, the output becomes “1011.”

Data Bits and Frequency-Hopping

In DSSS, each data bit is spread over multiple chips, and often, in systems with frequency hopping, one data bit might be transmitted over different frequencies sequentially to mitigate interference and improve security. The statement that one data bit is divided across frequency-hop channels is TRUE, as frequency hopping spreads the data across different channels to reduce interference.

Cell Sectoring and Capacity Expansion

Cell sectoring is an effective strategy to increase channel capacity by dividing a cell into sectors, each served by a different antenna. This enables frequency reuse and reduces interference, thereby significantly increasing the total capacity of the cellular system. Therefore, sectoring is considered a very good idea for capacity enhancement.

Cellular Geometry

Cellular systems are typically designed using hexagonal geometric shapes because hexagons efficiently tessellate without gaps or overlaps, providing uniform coverage and minimizing interference.

Wireless LAN for Ad-Hoc Networks

The IEEE 802.11 ad-hoc mode (also known as Independent Basic Service Set) is suitable for decentralized, peer-to-peer wireless LANs, where devices communicate directly without a central access point.

Ad-Hoc Networks Between Buildings

Using an ad-hoc network to connect two buildings is suitable because it allows direct, temporary, or flexible wireless links without requiring structured infrastructure—especially useful for bridging small campus areas or temporary connections.

Brief Technical and Mobility Concepts

Signal-to-Noise Ratio (SNR) is crucial for determining the quality of a wireless link, affecting data rates and reliability. A higher SNR indicates a cleaner, more reliable channel, enabling higher data throughput. Regarding mobility, the concept of association in wireless networks enables devices to connect and maintain connections as they move across different access points, which is fundamental for seamless mobility in wireless systems.

Advanced Concepts in CDMA and Cellular Networks

In CDMA, each user’s data is encoded with a unique spreading code; when users transmit simultaneously, the signals overlap but can be separated at the receiver using the code. The chip pattern, as per the codes provided, determines the transmitted signals. The bit rate before and after DSSS encoding relates directly; the spreading operation reduces the effective data rate but increases robustness and security.

Advantages of CDMA and 3G Evolution

CDMA offers advantages like increased capacity, resistance to interference, and improved call quality. The transition from 2G to 3G brings higher data rates, multimedia support, and integrated services, distinguishing newer systems through features like IP-based networking, higher bandwidth, and advanced modulation techniques.

Sequence of Call Events

The typical sequence involves user device registration, authentication, resource allocation, and establishing a communication link that includes handovers, call setup, and tear-down processes, which are more complex in mobile environments but enable seamless connectivity.

Conclusion

The comprehensive understanding of wireless networking principles—from media types and signal behavior to cellular design and advanced coding—supports the development of efficient, robust, and scalable wireless systems that meet modern communication demands.

References

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• Stallings, W. (2014). Foundations of Modern Networking: SDN, NFV, QoE, IoT, and Cloud. Pearson.
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• IEEE Std 802.11-2016. (2016). IEEE Standard for Information technology—Telecommunications and information exchange between systems—Local and metropolitan area networks—Specific requirements. IEEE.