Types of Networks Overview

Types of Networks

• Local Area Network (LAN): Covers a small area (e.g., home, office); high-speed connection; uses Ethernet or Wi-Fi.
• Metropolitan Area Network (MAN): Covers a city or campus; larger than LAN, smaller than WAN; often used by organizations with multiple buildings.
• Wide Area Network (WAN): Covers large geographical areas (e.g., countries); connects multiple LANs/MANs; uses leased lines or satellites.
• Mobile Network: Wireless network for mobile devices; uses radio waves for communication; examples: 4G, 5G.

Mobile Network as Radio-Based Common Carrier

• Mobile networks use radio waves to transmit data between devices and towers.
• Operated by telecom companies (common carriers) providing public services.

Overview of Mobile Networks (2G to Current)

• 2G: Introduced digital voice and SMS; basic data services (e.g., GPRS).
• 3G: Faster data speeds for internet and video calls; enabled mobile browsing.
• 4G: High-speed internet for streaming and gaming; LTE (Long-Term Evolution) technology.
• 5G: Ultra-fast speeds, low latency; supports IoT, smart cities, and advanced applications.

Wireless Network Technologies

• Bluetooth: Short-range wireless communication; used for connecting devices (e.g., headphones, keyboards).
• Wi-Fi: Wireless local area networking; provides internet access within a limited range.
• Hotspot: A physical location offering Wi-Fi access; created by a router or mobile device.

Levels of Privacy

• Intranet: Private network within an organization; access restricted to authorized users.
• Extranet: Part of an intranet shared with external users (e.g., partners, clients); controlled access.
• Internet: Global public network; no access restrictions (open to all).

Basic Components and Functions

• Transmission Media:
  • Wired: Twisted Pair (common in LANs - e.g., Ethernet cables), Coaxial (used for cable TV and internet), Fiber (high-speed, long-distance data transmission).
  • Wireless: Infrared (short-range, line-of-sight communication), Microwave (long-distance, high-frequency waves), Satellite (global coverage, used in remote areas).
• Switch: Connects devices within a LAN; directs data to the correct device.
• Router: Connects different networks (e.g., LAN to WAN); directs data between networks.
• Modem: Converts digital data to analog signals for transmission over phone lines; connects to the ISP for internet access.
• Network Interface Card (NIC)/Network Adapter: Hardware that connects a device to a network; enables communication over the network.

Suitability of Mobile Networks to Various Applications

• Commerce: Enables mobile payments, e-commerce, and banking; supports real-time transactions.
• Journalism: Facilitates live reporting and instant updates; allows journalists to share content from remote locations.

Internet Concepts

• World Wide Web (WWW): A system of interlinked hypertext documents accessed via the internet.
• Hypertext Markup Language (HTML): The standard language for creating web pages.
• Hypertext Transfer Protocol (HTTP): The protocol used for transferring web pages on the internet.
• Hyperlinks: Clickable links that connect web pages or resources.
• Web Server: A server that hosts and delivers web pages to users.
• Web Page: A single document or page on the web, written in HTML.
• File Transfer Protocol (FTP): A protocol for transferring files over the internet.
• Web Browser: Software used to access and view web pages (e.g., Chrome, Firefox).
• Uniform Resource Locator (URL): The address of a web page or resource on the internet.
• Upload and Download: Upload: Sending data to a remote server; Download: Receiving data from a remote server.