Page 11
Semester 5: B.Sc Internet of Things
Transmission methods: Digital, Analog, Baud rate, multiplexing
Transmission methods: Digital, Analog, Baud rate, multiplexing
Digital Transmission
Digital transmission involves sending data in discrete signals, often represented as binary. This method is more robust against noise and interference than analog transmission. Digital signals can easily be compressed and encrypted, enhancing security and efficiency in communication, particularly suitable for computer networks.
Analog Transmission
Analog transmission refers to sending data in continuous signals. This method is commonly used in traditional telephony and broadcasting. While analog signals are more susceptible to degradation over distances, they can carry more information over a wider bandwidth compared to digital signals.
Baud Rate
Baud rate refers to the number ofsignal changes or symbols sent per second in a communication channel. It is a crucial measure in both digital and analog transmission systems, influencing the data transfer rate. A higher baud rate generally allows more data to be transmitted in a given time frame, assuming the channel can support it.
Multiplexing
Multiplexing is a technique that combines multiple signals into a single transmission channel to optimize the use of bandwidth. Different methods include Time Division Multiplexing (TDM) and Frequency Division Multiplexing (FDM). This approach is essential for efficient data transmission in networks, enabling multiple users to share the same communication medium.
Network topologies: Mesh, Star, Tree, Ring, Bus, Hybrid
Network topologies
Mesh Topology
In a mesh topology, every node is connected to every other node, allowing for multiple pathways for data to transfer. This topology is highly reliable and fault-tolerant, as if one connection fails, data can still find an alternate route. However, it can be costly and complex to install due to the number of cables required.
Star Topology
In a star topology, all nodes are connected to a central hub or switch. This configuration makes it easy to manage and requires less cable than a mesh topology. However, if the central hub fails, all connected devices will lose communication.
Tree Topology
Tree topology is a hierarchical structure that combines characteristics of star and bus topologies. It consists of groups of star-configured networks connected to a linear bus backbone. This allows for easy expansion and organization of the network, but if the backbone fails, it can segment the network.
Ring Topology
In a ring topology, each node is connected to two other nodes, forming a circular pathway for data to travel. Data travels in one direction, which minimizes collisions. However, if one node or connection fails, the entire network can be affected, making it less reliable.
Bus Topology
In a bus topology, all devices share a single communication line or cable. It is easy to set up and requires less cabling than other topologies. However, if the main cable fails, it brings down the entire network, and performance can degrade as more devices are added.
Hybrid Topology
A hybrid topology combines two or more different topologies. This flexibility allows organizations to tailor their networks to meet specific needs and optimize performance. However, hybrid topologies can be complex and may require sophisticated management.
Network protocols and OSI Model layers
Network protocols and OSI Model layers
Introduction to Network Protocols
Network protocols are rules and conventions for communication between network devices. They define how data is transmitted, compressed, encrypted, and validated across networks.
Importance of Network Protocols
Protocols ensure reliable communication, data integrity, and proper data formatting between devices. They allow interoperability between different hardware and software systems.
Overview of the OSI Model
The OSI (Open Systems Interconnection) Model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven abstraction layers, each serving specific functions.
Layer 1: Physical Layer
This layer deals with the physical connection between devices. It includes the transmission of raw bit streams over a physical medium, such as cables or wireless connections.
Layer 2: Data Link Layer
This layer provides node-to-node data transfer and error correction. It ensures data is packaged correctly for the physical layer and manages how devices on the same network communicate.
Layer 3: Network Layer
The network layer handles routing and forwarding of data packets across different networks. It is responsible for logical addressing and ensuring data is sent to the correct destination.
Layer 4: Transport Layer
This layer ensures reliable data transfer between host systems. It deals with error recovery and flow control, providing either reliable (TCP) or unreliable (UDP) communication.
Layer 5: Session Layer
The session layer manages sessions between applications. It establishes, maintains, and terminates connections, ensuring that data exchange occurs correctly.
Layer 6: Presentation Layer
This layer translates data between the format the network requires and the format the application uses. It handles data encryption, compression, and translation.
Layer 7: Application Layer
The application layer is the closest to the end user. It provides network services directly to user applications, handling protocols for file transfer, email, and web browsing.
LAN topologies, security, firewall, VPN, cryptography
LAN Topologies, Security, Firewall, VPN, Cryptography
LAN Topologies
LAN topologies refer to the physical or logical arrangement of network devices in a Local Area Network. Common topologies include star, bus, ring, and mesh. Each topology has its advantages and disadvantages in terms of scalability, fault tolerance, and installation complexity.
Security
Network security involves policies and practices designed to prevent unauthorized access, misuse, or damage to the network. Key aspects include access control, authentication, encryption, and intrusion detection systems.
Firewall
A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Firewalls can be hardware-based, software-based, or a combination of both, providing a barrier between a trusted internal network and untrusted external networks.
VPN
A Virtual Private Network (VPN) is a technology that creates a secure and encrypted connection over a less secure network, such as the internet. VPNs are used for remote access, secure data transmission, and protecting user privacy online.
Cryptography
Cryptography is the practice of securing communication by transforming information into an unreadable format, only accessible to those who possess a decryption key. It is essential for securing sensitive data, ensuring privacy, and maintaining data integrity.
