Unit 2: Wireless LANs and Mobile IP

Study Notes

Wireless LANs

A Wireless LAN (WLAN) connects two or more devices via wireless communication within limited areas (homes, schools, offices).
Most modern WLANs conform to IEEE 802.11 standards, marketed as Wi-Fi.
Advantages include:
- Clutter-free environments with no physical cables.
- Scalability allows easy addition/removal of devices.
- Portability enables users to move freely while connected.
- Simpler and less costly installation compared to wired LANs.
Disadvantages include:
- Wireless signals are susceptible to interference from other devices.
- Increased need for encryption due to security vulnerabilities.
- Higher error rates and bandwidth requirements compared to wired systems.
- Generally slower than wired LANs.

WLAN Communication using Infrared

Infrared WLAN communication transmits data wirelessly using infrared technology.
Primarily effective in short-range environments with minimal obstruction (e.g., wood, concrete).
Types of infrared wireless communication:
- Line of Sight Infrared: Requires direct alignment between transmitter and receiver, typically effective up to 10 meters.
- Scatter Mode Infrared: Broadcasts signals throughout a room, allowing devices within line of sight or reflected signals to receive the transmission.

Radio Frequency

Radio Frequency (RF) refers to oscillation rates of electromagnetic radiation from 300 GHz to 9 kHz.
RF is critical for many wireless technologies, facilitating radio wave propagation through antennas.
Key frequency bands in the electromagnetic spectrum include:
- Ultra-low frequency (ULF): 0-3 Hz
- Extremely low frequency (ELF): 3 Hz - 3 kHz
- Very low frequency (VLF): 3 kHz - 30 kHz
- Low frequency (LF): 30 kHz - 300 kHz
- Medium frequency (MF): 300 kHz - 3 MHz
- High frequency (HF): 3 MHz - 30 MHz
- Very high frequency (VHF): 30 MHz - 300 MHz
- Ultra-high frequency (UHF): 300 MHz - 3 GHz
- Super high frequency (SHF): 3 GHz - 30 GHz
- Extremely high frequency (EHF): 30 GHz - 300 GHz

Mobile IP

Mobile IP (MIP) is an IETF standard facilitating seamless movement across networks while retaining a permanent IP address.
An Internet Protocol address identifies devices on a network for communication and location addressing.
Functions of an IP address:
- Identifies the host or network interface.
- Provides a location for routing and communication purposes.

Description

Explore the fascinating world of Wireless LANs, Mobile IP, and WAP and WEB Services in this quiz. Understand how wireless communication works with infrared and radio frequency, and how devices connect to form a local area network. Test your knowledge on these crucial networking concepts.