Communications-and-Networks_Intro

Introduction to Communications and Networks

Course Title: Introduction to Communications and NetworksInstructor: Engr. Melojean C. Marave

Communications

Definition: Communication is a multifaceted process that involves sending and receiving messages via various methods, which can be categorized as verbal (spoken or written language) and non-verbal (gestures, body language, visual cues). Effective communication is crucial in understanding and conveying messages clearly between individuals or groups.

Data Communication

Data Communication: This area examines the pathways and methods through which data is transmitted as energy across different mediums. It encompasses aspects of encoding, transmission, decoding, and protocols that allow for reliable data transfer from the source to a destination.

Simplified Communications Model

General Block Diagram Overview: The communication process can be visualized through a general block diagram:

• Source System: Initiates the communication process by generating the data or message.

• Destination System: The endpoint where the message is intended to arrive.

• Transmission Components: This includes both Transmitter (which encodes data for transmission) and Receiver (which decodes the received signals).Examples: This model can be applied to various devices including workstations, modems, servers, and public telephone networks.

Communications Model

Components involved:

• Source: The origin point that generates data to be communicated.

• Transmitter: Converts the generated data into signals that can be transmitted.

• Transmission System: The channel or medium that carries the data from the transmitter to the receiver.

• Receiver: Accesses the incoming signals and converts them back into the original data format.

• Destination: The final point where the data is delivered for processing or interpretation.

Importance of Studying Communication

The study of communication is essential as it enhances understanding of both personal and professional interactions, facilitating better collaboration, conflict resolution, and the effective dissemination of information across various contexts.

Brief History of Communications

• 1837: Samuel Morse invents the telegraph, revolutionizing long-distance communication.

• 1876: Alexander Graham Bell invents the telephone, introducing voice communication over wires.

• 1945: ENIAC, regarded as the first electronic general-purpose computer, is invented, setting the stage for digital communication.

• 1980s: The rise of personal computers transforms communication methods, enabling users to access information and communicate digitally.

• 1990s: The emergence of the Internet and the World Wide Web fosters global connectivity and dramatically changes how information is shared.

Communication Devices

Definition: Communication devices are hardware components designed to transmit analog or digital signals, essential for establishing connections in various communication networks.

Examples of Communication Devices

• Bluetooth Devices: Allow for short-range wireless communication between devices.

• Infrared Devices: Use infrared radiation to wirelessly transmit data; common in remote controls.

• Modem: Modulates and demodulates signals for data transmission over telephone lines or broadband.

• Network Interface Card (NIC): Facilitates a computer's connection to a network.

• Smartphones: Multifunctional devices that combine a mobile phone with computing capabilities.

• Wi-Fi Devices: Enables wireless networking, allowing multiple devices to connect to the internet without physical cables.

More Communication Devices

• PCI (Peripheral Component Interconnect): A standard for connecting peripheral devices to a computer's motherboard.

• USB (Universal Serial Bus): A widely used interface for connecting computers with various peripherals, enabling data transfer and power supply.

• Wi-Fi (Wireless Fidelity): A technology that allows devices to connect to the internet without physical connections, typically using radio waves.

Need for Communication Devices

Communication devices are essential for computers and networking systems, as they enable effective communication with other computers, devices, and networks, thereby ensuring the integration of systems and the seamless exchange of data across platforms.

Types of Signals Transmitted via Communication Media

• Voice: Signals encoded for audio communication, such as in telephone calls.

• Video: Encoded visual information for video conferencing or streaming.

• Data: Character streams transmitted for computing processes, often as files or transactions.

Communication Applications

• Voice Applications: Includes telephone services, FAX transmissions, and video conferencing platforms.

• Video & Audio Applications: Encompasses platforms like television broadcasting, VCRs, and DVDs for media consumption.

• Data Applications: Involves Local Area Networks (LANs), Wide Area Networks (WANs), and Internet services for data sharing and access.

Networking

Definition: Networking refers to a collection of interconnected computers and devices that allow for communication and data sharing over physical distances, utilizing various technologies and protocols to facilitate these exchanges.

Networking Terms

• Node (host): Any device on a network that is capable of sending and receiving data.

• Bandwidth: This term refers to the maximum rate at which data can be transmitted over a network in a given amount of time (e.g., 4G, 5G technologies).

• Data Transfer Rate: The speed at which data is transmitted across a network, measured in bits per second (bps).

Computer Network

Definition: A computer network is a collection of interconnected systems designed to facilitate data exchange and communication. Connections may be established through physical cabling or wireless technologies, promoting flexibility in network architecture.

Client/Server Model

In the client/server model, a client makes requests for services or resources from a server, which processes these requests and responds accordingly. This model forms the backbone of many networked applications and services.

Simplified Network Model

Overview of Components: A simplified network model consists of a source system that initiates the communication, a receiver that relays the information, and a destination where the data is ultimately directed or stored.

Types of Transmission Media

Guided Media:

• Fiber Optics: Utilizes light to transmit data, providing high bandwidth and low signal loss.

• Twisted Pairs: Assembles pairs of insulated copper wires twisted together to reduce electromagnetic interference.

• Coaxial Cabling: Comprises a central core conductor, insulating layer, and outer shielding, effective for cable television and internet.

Unguided Media:

• Radio Waves: Used for wireless communication over varying distances.

• Micro Waves: Serve in point-to-point communication systems.

• Infrared: Typically used for short-range communication between devices.

Types of Networks

• LAN (Local Area Network): Connects computers within a limited area such as a home, office, or campus.

• WAN (Wide Area Network): Spans large geographical areas, connecting multiple LANs, often facilitated by telecommunications links.

• MAN (Metropolitan Area Network): Covers a larger geographic area than a LAN but smaller than a WAN, often within a single city.

• Gateway: A hardware or software point that manages and translates communications between different networks, ensuring compatibility and connectivity.

Network Topology

Types include:

• Bus Topology: All nodes are connected to a single communication line, sharing the channel.

• Star Topology: Here, all nodes connect to a central hub, allowing for independent node communication.

• Ring Topology: Each device connects to exactly two others, forming a closed loop for data transmission.

• Fully Connected Topology: Provides a direct link between every pair of nodes, ensuring maximum redundancy.

• Hybrid Topology: Combines two or more different topologies to support various networking needs.

Network Topology Details

• Ring Topology: In this structure, messages circulate in one direction, with each node acting as a repeater, enhancing signal reliability.

• Star Topology: Centralizes data flow through one node, which can streamline communication and troubleshooting processes.

• Bus Topology: Cost-effective and easy to implement, this topology can become congested with high traffic but is simple to set up.

Advanced Network Topologies

• Fully Connected Topology: Ideal for applications requiring maximum reliability and performance, albeit expensive due to high cable usage.

• Hybrid Topology: Offers flexibility to scale and adapt to network demands, combining the strengths of different topologies.

Communication Software

Definition: This refers to software applications developed to enable the exchange of information across various systems, including platforms for email, chat, messaging apps, File Transfer Protocol (FTP), and Voice over Internet Protocol (VoIP) solutions, facilitating seamless communication between users.

OSI Model Layers

1. Physical Layer: Responsible for the transmission of raw bitstreams over a physical medium.

2. Data Link Layer: Provides node-to-node data transfer and handles error correction from the physical layer.

3. Network Layer: Manages the routing of data across networks, determining the best path for data transmission.

4. Transport Layer: Ensures reliable or unreliable delivery of messages through segmentation, flow control, and error correction.

5. Session Layer: Establishes, maintains, and terminates communication sessions between applications.

6. Presentation Layer: Translates data formats between the application layer and the network, ensuring interoperability.

7. Application Layer: Closest to the end user, this layer interacts with software applications to provide network services.

Protocol Overview

Definition: A protocol is a set of rules and standards guiding the transmission of data over a network. These protocols define how devices communicate, manage network traffic, and ensure data integrity and security.Types of network protocols: This includes network management protocols, communication protocols, and security protocols to facilitate reliable, efficient communication.

FTP (File Transfer Protocol)

FTP facilitates the exchange of files between computers and cloud storage services, allowing users to upload and download files, maintain file structure during transfer, and manage access permissions effectively.

Conclusion

Acknowledgements: We thank you for your participation and attention throughout this course. May God bless you in your learning endeavors!