Page 11
Semester 3: M.Sc. Electronics and Communication Semester -III
Mobile Communication systems, cellular concepts, Frequency reuse, GSM, GPRS, CDMA
Mobile Communication Systems
Introduction to Mobile Communication Systems
Mobile communication systems enable wireless communication between mobile devices and network infrastructure.
Cellular Concepts
Cellular communication divides geographic areas into smaller cells for efficient frequency use and communication management.
Frequency Reuse
Frequency reuse allows multiple users to share the same frequency band across different cells, enhancing spectral efficiency.
GSM
Global System for Mobile Communications is a standard for 2G mobile networks, focusing on digital transmission and integrated services.
GPRS
General Packet Radio Service is an extension of GSM that provides mobile data services and enables packet-switched data transmission.
CDMA
Code Division Multiple Access is a communication protocol that allows multiple users to occupy the same time and frequency bandwidth by assigning unique codes.
Telecommunication Network fundamentals, OSI model, Broadband systems
Telecommunication Network Fundamentals, OSI Model, Broadband Systems
Telecommunication Network Fundamentals
Telecommunication networks are systems that enable communication between people and devices over distances. Key components include transmission mediums (cabling, radio waves), switching equipment (routers, switches), and protocols that dictate how data is transmitted and received.
OSI Model
The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven layers. These layers include: 1. Physical Layer - deals with physical connection. 2. Data Link Layer - responsible for node-to-node data transfer. 3. Network Layer - determines how data is sent between devices. 4. Transport Layer - ensures complete data transfer. 5. Session Layer - manages sessions between applications. 6. Presentation Layer - translates data between the application and network format. 7. Application Layer - serves as the window for users to interact with the network.
Broadband Systems
Broadband systems refer to high-capacity transmission techniques that enable simultaneous transmission of multiple signals. This includes technologies like DSL, cable, fiber optics, and wireless solutions. Broadband is crucial for high-speed internet access, supporting various applications from streaming services to online gaming.
Optical Fiber systems: Evolution, Ray optics, Modes, Attenuation, Fiber losses
Optical Fiber Systems
Evolution of Optical Fiber Systems
Optical fiber technology began in the late 19th century with the invention of the first optical fiber by Daniel Colladon and Jacques Babinet, who demonstrated light transmission through water. The true evolution occurred in the 1960s with the development of low-loss silica fibers by researchers like Charles Kettle and Robert Maurer, paving the way for modern telecommunications.
Ray Optics in Optical Fibers
Ray optics explains the behavior of light in optical fibers using principles of reflection and refraction. The concept of total internal reflection is crucial, where light entering the fiber core at a certain angle is reflected within the core, allowing light to travel long distances with minimal loss.
Modes of Optical Fiber
Optical fibers can support multiple modes of light propagation. Single-mode fibers allow only one mode to propagate, offering higher bandwidth and lower attenuation. Multi-mode fibers support multiple light paths, which can lead to modal dispersion and reduced performance over long distances.
Attenuation in Optical Fibers
Attenuation refers to the reduction in signal strength as it travels through the fiber. It is measured in decibels per kilometer (dB/km) and is affected by factors like absorption, scattering, and bending losses. Understanding and minimizing attenuation is crucial for long-distance communication.
Fiber Losses
Fiber losses can be categorized into intrinsic and extrinsic losses. Intrinsic losses are inherent to the fiber material, such as Rayleigh scattering and absorption due to impurities. Extrinsic losses involve splice and connector losses. Reducing these losses is essential for efficient fiber optic communication.
Data communication networks: OSI layers, LAN, MAC, Bridging, switching
Data communication networks
OSI Layers
The OSI model is a conceptual framework used to understand network interactions in seven layers: 1. Physical - transmission of raw bitstreams over a physical medium. 2. Data Link - node-to-node data transfer, error detection or correction. 3. Network - routing of data packets, addressing, and traffic control. 4. Transport - end-to-end communication and data flow control. 5. Session - management of sessions or connections. 6. Presentation - translation of data formats and encryption. 7. Application - user interface and application protocols.
LAN
Local Area Networks (LANs) connect computers within a limited area such as a building. They enable resource sharing, high-speed connections, and reliable communication. Types of LANs include wired (Ethernet) and wireless (Wi-Fi), serving various applications in homes, businesses, and schools.
MAC
Media Access Control (MAC) is a sublayer of the Data Link layer. It controls how devices on a network uniquely identify themselves and share the communication medium. MAC addresses are unique identifiers assigned to network interfaces for communication. Protocols like CSMA/CD (Carrier Sense Multiple Access with Collision Detection) manage how devices access the medium.
Bridging
Bridging connects two or more network segments, allowing them to function as a single network. Bridges operate at the Data Link layer, filtering traffic and reducing collision domains. They utilize MAC addresses to forward data only to the segments that require it, thereby improving overall network efficiency.
Switching
Switching is a process used to connect devices within a LAN effectively. Switches operate at the Data Link layer, forwarding data packets based on MAC addresses. They create separate collision domains for each connected device, enhancing bandwidth utilization and improving network performance.
Packet switching networks, Routing protocols, TCP/IP, Network security, Wireless LANs
M.Sc. Electronics and Communication Semester -III
M.Sc. Electronics and Communication
3
Core - 8 MOBILE, OPTICAL AND DATA COMMUNICATION SYSTEMS
Networking Concepts
Packet Switching Networks
Packet switching networks transmit data by breaking it into packets that are sent independently across a network. This approach contrasts with circuit switching, where a dedicated path is established. Packet switching allows for more efficient use of network resources, as multiple packets can share the same transmission medium. Key concepts include packet size, routing algorithms, and network latency.
Routing Protocols
Routing protocols govern how data packets are directed through a network. They determine the best path for data to travel based on various metrics such as distance, hop count, or link speed. Common types include static routing, dynamic routing, and distance-vector protocols such as RIP and link-state protocols like OSPF.
TCP/IP
TCP/IP is the fundamental suite of protocols for the Internet. TCP (Transmission Control Protocol) ensures reliable communication through sequencing and error correction. IP (Internet Protocol) handles addressing and routing. Together, TCP/IP provides the necessary framework for data transmission and helps ensure that data can travel across diverse networks.
Network Security
Network security involves measures to protect data during transmission. It includes strategies like encryption, firewalls, and intrusion detection systems. The goal is to safeguard networks from unauthorized access, breaches, and damage. Common protocols for securing networks include SSL/TLS and IPsec.
Wireless LANs
Wireless LANs enable devices to connect to a network without cables, using radio waves for connectivity. They are typically based on standards like IEEE 802.11. Key considerations include signal range, data rates, and security protocols like WPA2/WPA3. Wireless networks offer flexibility and mobility, but can face issues like interference and limited bandwidth.
