Networking Fundamentals: LAN, WAN, Protocols, and Media Types

LAN

A Local Area Network that connects computers in a small area, like a home, school, or office.

MAN

A Metropolitan Area Network that spans a city or large campus, larger than a LAN but smaller than a WAN.

WAN

A Wide Area Network covering large areas, such as countries or continents, like the Internet.

PDN

A Public Data Network built for public use, often maintained by telecom companies.

Data Network

A system that transmits digital information between devices.

Voice Network

A system that carries voice communication, such as traditional telephony.

Network Cloud

An abstract representation of the Internet or large-scale network infrastructure.

Network Devices

Hardware like routers, switches, hubs, and firewalls that manage or direct network traffic.

Five Layers of TCP/IP

Application, Transport, Internet, Network Access, Physical.

Seven Layers of OSI

Physical, Data Link, Network, Transport, Session, Presentation, Application.

Logical Connection

A connection established between devices at a software or protocol level.

Physical Connection

A connection through actual media, such as cables or wireless links.

Data

Raw facts or information transmitted or processed by a computer system.

Signal

An electrical or electromagnetic representation of data.

Analog

A continuous signal that varies smoothly over time.

Digital

A discrete signal, often represented as 0s and 1s.

Amplitude

The strength or height of a wave.

Frequency

The number of wave cycles per second (Hz).

Phase

The position of a point in a wave cycle.

Attenuation/Decibel

The reduction in signal strength over distance, measured in decibels (dB).

Modulate

To alter a carrier signal in order to encode information.

NRZ-L

Non-Return-to-Zero-Level encoding, where the signal level represents bits directly.

NRZ-I

Non-Return-to-Zero-Inverted encoding, where the signal changes level to indicate 1s.

ASK

Amplitude Shift Keying, where data modulates the amplitude of a carrier signal.

FSK

Frequency Shift Keying, where data modulates the frequency of a carrier signal.

PSK

Phase Shift Keying, where data modulates the phase of a carrier signal.

PCM

Pulse Code Modulation, converting analog signals to digital.

EBCDIC

Extended Binary Coded Decimal Interchange Code, a character encoding system.

ASCII

American Standard Code for Information Interchange, a character encoding system.

UNICODE

A universal character encoding standard supporting multiple languages.

Conducted Media

Transmission media that uses physical wires or cables.

Twisted Pair (UTP)

Cable categories 1-7, with categories 5, 6, 7 commonly in use.

Coaxial Cable

Can transmit in Baseband (single signal) or Broadband (multiple signals).

Fiber Optics

Single-mode or Multi-mode glass fiber transmission for high-speed data.

Wireless Media

Transmission of data without physical cables, e.g., radio or microwave.

Cell Phones

Portable wireless communication devices.

AMPS

1st generation analog cellular system.

D-AMPS

1st generation digital cellular system using TDMA.

TDMA

Time Division Multiple Access, 2nd generation cellular technology.

CDMA

Code Division Multiple Access, 2nd generation cellular technology.

GSM

Global System for Mobile Communications, 2nd generation standard.

GPRS

2.5 generation mobile data technology.

UMTS

3rd generation mobile communication technology.

LTE

4th generation mobile broadband technology.

Broadband/Wi-Max

High-speed wireless internet access over wide areas.

Bluetooth

Short-range wireless communication for devices.

Terrestrial Microwave

Line-of-sight microwave communication between towers.

Satellite MW

Microwave communication via satellites, including LEO, MEO, GEO, and HEO.

Free Space Optics (FSO)

Optical communication using light through air.

Ultra Wideband

Wireless communication using a very wide frequency spectrum.

Infrared Transmission

Short-range wireless communication using infrared light.

Zigbee

Low-power wireless standard for IoT devices.

Media Selection Criteria

Considerations like cost, distance, environment, and security when choosing media.