MIS3302Mod06 (1)

Module 6: Data Communication

• Focus on delivering information anytime and anywhere.

Module Objectives

• 6.1 Describe the major applications of a data communication system.

• 6.2 Explain the three major components of a data communication system.

• 6.3 Describe the three major types of processing configurations.

• 6.4 Explain the three types of networks.

• 6.5 Describe the five main network topologies.

• 6.6 Explain important networking concepts, including protocols, TCP/IP, routing, routers, and the client/server model.

• 6.7 Examine wireless and mobile technologies and networks in a business setting.

• 6.8 Describe networking trends such as Wi-Fi, WiMAX, and Bluetooth.

• 6.9 Discuss the importance of wireless security and techniques used.

• 6.10 Summarize the concept of convergence and its applications for business and personal use.

Data Communication System Overview

• Definition: Electronic transfer of data from one location to another.

• Importance: Critical for organizations, supporting efficiency and effectiveness, especially in virtual organizations and e-collaboration.

Major Components of Data Communication System

• Components:

  • Sender and Receiver Devices: Devices that send and receive data.

  • Modems or Routers: Equipment needed for data transmission.

  • Communication Channel: The medium through which data travels.

• Key Terms:

  • Bandwidth: Measures data transfer capacity (amount of data per second).

  • Attenuation: Loss of signal strength over distance.

  • Communication Media: Connects devices through conducted (cables) or radiated (antennas) means.

Types of Data Transmission

• Broadband: Simultaneous transmission of multiple data pieces.

• Narrowband: Voice-grade transmission limited in information delivery.

• Protocols: Set of rules for data communication.

Processing Configurations

• Three Types:

  • Centralized: All processing is performed at one central computer.

  • Decentralized: Each user or division has its computer, offering responsiveness but at a higher cost.

  • Distributed: Processing is spread out across multiple systems, combining aspects of both previous models. Faces challenges like security and network management.

• OSI Model: A seven-layer architecture that standardizes data transmission across networks (Application, Presentation, Session, Transport, Network, Data Link, Physical layers).

Types of Networks

• Three Major Types:

  • Local Area Networks (LAN): Connects computers in a small geographical area, typically using Ethernet.

  • Wide Area Networks (WAN): Spans large geographical areas, can cover multiple locations, and includes the Internet.

  • Metropolitan Area Networks (MAN): Provides network coverage within a city.

Network Topologies

• Physical Layout of networks can affect performance:

  • Star: Central hub, easy to add devices, problem detection is simpler.

  • Ring: No central host, arranged in a circle, data travels in one direction.

  • Bus: Connects nodes along a single cable, terminators at both ends.

  • Hierarchical: Multi-level networks, allows for different processing strengths.

  • Mesh: Highly reliable as every node connects to every other node, but is costly.

Network Concepts

• Protocols govern data transmission rules and formats.

• TCP/IP: Dominant communication protocols suite, critical for internet communication.

  • Routing helps determine optimal paths for data packets.

• Client/Server Model: Relationship where client requests services from a server, enabling efficient data processing.

• Wireless and Mobile Networks: Use radio frequencies for communication rather than wired connections, offering advantages such as mobility but limiting throughput and range.

  • Technologies: Wi-Fi for local networking, WiMAX for wider area networking, Bluetooth for short-distance data transfer.

Wireless Security

• Concerns exist due to accessibility of networks.

• Techniques to improve security include:

  • SSID visibility, use of WEP, WPA, WPA2, and EAP.

Convergence of Voice, Video, and Data

• Integration that enables multimedia sharing for enhanced decision-making.

• Supported by advanced technologies (ATM, Gigabit Ethernet, 5G), important for applications in various fields.

OSI Model Layers Functionality

1. Application Layer: This is the topmost layer where end-user software applications reside. It provides network services directly to user applications, enabling functionalities such as email, file transfer, and web browsing.

2. Presentation Layer: Responsible for data translation and presentation. It formats or translates data between the application layer and the lower layers by providing encryption, compression, and data representation.

3. Session Layer: Manages sessions or connections between applications. It establishes, manages, and terminates connections, maintaining communication sessions and ensuring proper synchronization and recovery if interrupted.

4. Transport Layer: This layer ensures reliable data transfer between two host systems. It provides error detection and correction, flow control, and guarantees that data packets are delivered in sequence and without duplication.

5. Network Layer: Responsible for packet forwarding, including routing through different routers. It handles addressing and determines the best path for data transmission across the network.

6. Data Link Layer: Provides node-to-node data transfer and error detection/correction across a physical link. It manages how data is formatted for transmission and how access to the network is controlled.

7. Physical Layer: This is the lowest layer of the OSI model, dealing with the physical connection between devices. It includes the transmission mediums, such as cables and radio frequencies, and defines the electrical/physical specifications for the devices.