Lecture 12: Wireless broad band technologies

10.05.2022
Lecture 12: Wireless broad band technologies.
Plan:

1. 
   Wi-Fi standart (IEEE 802.11)
   
2. 
   Wi-Max standart
   
3. 
   Others Wireless broadband technologies
   

1. 
   Wi-Fi standart (IEEE 802.11)
   

Wi-Fi is acronym for For Wireless Fidetiy, which means wireless figility.This name was given to the technology of wireless data trnsmission by analogy with the term Hi-Fi (Hi Fidelity) that has long come into use. Unlike conventional cable networks, WLANs (an abbreviation for Wireless Local Area Network) use high-frequency radio waves to transmit data. The IEEE 802.11 family of standarts, referred to as Wi-Fi, includes several options – 802.11a, 802.11b and 802.11g, eachof which.

Wi-Fi

• 
  Overview
  
• 
  IEEE Standart
  
• 
  2.4 GHz Channel Disterubition (non-owerlab)
  
• 
  Security standart
  
• 
  Network architecture
  
• 
  How does it work
  
• 
  Elements
  
• 
  Security enhancements
  
• 
  Wimax – wi-fi internetworking
  
• 
  Wimax – wi-fi hotstop
  

Wi-Fi: IEEE Standart

Wi-Fi Networks use radio technologies to transmit & receive data at high speed
IEEE 802.11b
IEEE 802.11a
IEEE 802.11g
IEEE 802.11n

IEEE 802.11b

• 
  Appear in late 1999
  
• 
  Operates at 2.4 ghz radio spectrum
  
• 
  11 mbps (theoretical speed) – 30 m range
  
• 
  4-6 mbps (actual speed)
  
• 
  100-150 feat range
  
• 
  Most popular, least expensive
  
• 
  Has 11 chanells , with 3 non-overlapping
  

IEEE 802.11a

• 
  Intraduced in 2001
  
• 
  Operates at 5 ghz (less popular)
  
• 
  54mbps (theoretical speed)
  
• 
  15-20 mbps (actual speed)
  
• 
  50-75 feat range
  
• 
  More expensive
  
• 
  Not compatible with 802.11b
  

IEEE 802.11g

• 
  Intraduced in 2003
  
• 
  Combine the faturye of both standarts(a,b)
  
• 
  100-150 feat range
  
• 
  2.4ghz radio frequencies
  
• 
  Compatible with ‘b’
  

IEEE 802.11n

• 
  Intraduced in 2009
  
• 
  175 feat range
  
• 
  300 mbps speed
  
• 
  Multiple input multiple output (mimo)added
  
• 
  40 mgz channels to the phy, and frame aggregation to the MAC layer
  
• 
  2.4/5 ghz radio frequencies