FACULTY OF
COMPUTER SCIENCE & ENGINEERING
Chapter 01. Introduction to Wireless LANs
OBJECTIVES
The Wireless LAN Market History of Wireless LANs Today’s Wireless LAN Standards
Define the roles of the organizations
-FCC (The Federal Communications Commission)
- IEEE
- Wi-Fi Alliance
Identify some of the uses for spread spectrum technologies
- Wireless LANs, PANs, MANs, and WANs
OBJECTIVES
Applications of Wireless LANs
Access Role
Network Extension
Building-to-Building Connectivityxtension
Last Mile Data Delivery
Mobility
Small Office-Home Office
Advantages and Disadvantages of WLAN
THE WIRELESS LAN MARKET
The market for wireless LANs seems to be
evolving in a similar fashion to the
networking industry
The big difference between LAN and WLAN
Wireless LANs allow so many flexibilities in their
implementation
History of Wireless LANs
The military needed a simple, easily
implemented, and secure method of
exchanging data in a combat environment.
Today’s Wireless LAN Standards
Wireless LANs transmit using radio frequencies
The Federal Communications Commission (FCC)
regulates the use of wireless LAN devices.
Wireless LAN Standards are created and
maintained by the Institute of Electrical
andElectronic Engineers (IEEE).
Following wireless LAN standards: 802.11, 802.11a, 802.11b, 802.11b+ 802.11g, 802.11h
TODAY’S WIRELESS LAN STANDARDS
IEEE 802.11 was born 1997
Standard beginning of WLAN
Use in both Spread Spectrum Technology
FHSS and DSSS
Bandwith max is 2 Mbps
Frequency band 2,4 Ghz ISM
TODAY’S WIRELESS LAN STANDARDS
IEEE 802.11 a
Open of 802.11 standard
Provides data rates up to 54 Mbps
Frequency band 5 Ghz UNII
Use tecnology Orthogonal Frequency Division
Multiplexing ( OFDM ).
Non-overlapping 8 channel
TODAY’S WIRELESS LAN STANDARDS
IEEE 802.11 b
Open of 802.11 standard
Uses high-rate direct-sequence spread spectrum (HR/DSSS)
instead of the original DSSS.
Provides data rates up to 11 Mbps
Frequency band 2,4 Ghz ISM
Non-overlapping 3 channel
IEEE 802.11 b+
Provides data rates up to 22 Mbps
TODAY’S WIRELESS LAN STANDARDS
IEEE 802.11 g
Open of 802.11b standard
Use tecnology Orthogonal Frequency Division
Multiplexing ( OFDM ). & DSSS
Provides data rates up to 11 Mbps 54 Mbps
Frequency band 2,4 Ghz ISM
TODAY’S WIRELESS LAN STANDARDS
ROLES ORGANIZATIONS PLAYWITHIN THE WLAN INDUSTRY
There are three primary categories of organizations that guide
the wireless industry. These categories include regulation,
standardization, and compatibility
The Federal Communications Commission (FCC) is an
example of regulatory bodies.
The Institute of Electrical and Electronics Engineers (IEEE)
is an example of a standards development organization
The Wi-Fi Alliance is a compatibility testing and certification
group
FCC (THE FEDERAL COMMUNICATIONS COMMISSION
WLAN devices use radio wave communications, they
fall under the regulatory control of the FCC.
The factors regulated by the FCC include:
■ Radio frequencies available
■ Output power levels
■ Indoor and outdoor usage
FCC (THE FEDERAL COMMUNICATIONS COMMISSION
The FCC regulates which frequencies may be used
within the regulatory domain it manages
The FCC provides two types of license-free bands for
radio communications: the Industrial Scientific Medical
(ISM) bands and the Unlicensed National Information
Infrastructure (U-NII) bands.
2.4 GHz ISM, U-NII bands exist in the 5 GHz frequency
range . They are all used by IEEE 802.11
IEEE
The Institute of Electrical and Electronics Engineers
The IEEE developed standards that impact and benefit
wireless networking.
These standards include wireless specific standards as
well as standards that have been implemented in the
wired networking domain, which are now being utilized
in the wireless networking domain.
IEEE
WI-FI ALLIANCE
The Wi-Fi Alliance is a certification organization that provides testing and interoperability analysis for the wireless industry.
While the FCC makes the rules and the IEEE determines how to live within those rules, the Wi-Fi Alliance ensures that devices are compatible with the IEEE’s way of implementing WLAN technology.
Only products of Alliance members that have been tested successfully by the Wi-Fi Alliance are actually allowed to claim that they are Wi-Fi Certified.
SPREAD SPECTRUM TECHNOLOGY USES
Spread spectrum technology is used in multiple ways that can be organized within four primary categories: wireless LANs, wireless PANs (WPANs), wireless MANs (WMANs) and wireless WANs.
WIRELESS LANS
Activities in Circle 200 m
There are three primary roles that wireless
LANs play in today’s enterprise
organizations:
Access role
Distribution role
Core role
WIRELESS PANS
A wireless PAN (personal area network) provides hands-free connectivity and communications within a confined range and limited throughput capacity.
Bluetooth is a perfect example of a wireless PAN technology that is both beneficial and in widespread use.
Operating in the 2.4 GHz ISM band, Bluetooth technologies can cause interference with wireless LAN technologies like DSSS, HR/DSSS, and ERP.
WIRELESS MANS
WiMAX is the most commonly referenced
wireless MAN technology
WiMAX is based on the IEEE 802.16 standard
and provides expected throughput of
approximately 40 Mbps for fixed, line of sight
connections and approximately 15 Mbps for
mobile, non–line of sight connections
WIRELESS MANS
Was born in October, 2001
Operating in the 2- 66 GHz band
Operating in the 2-11 Ghz at Europe
Operating in the 3.5 Ghz for Mobie
Operating in the 10-66 for Fixed points
WIRELESS WANS
What is the WAN ?
WIRELESS WANS
WIRELESS WANS
WAN services ?
WIRELESS WANS
Integrated Services Digital Network
Packet-Switched
Frame Relay
Cell –Switched
Switch ATM
WLAN,WPAN,WMAN,WWAN
APPLICATIONS OF WIRELESS LANS
Access Role
Network Extension
Building-to-Building Connectivityxtension
Last Mile Data Delivery
Mobility
Small Office-Home Office
Applications of Wireless LANs Corporate Data Access and End-User Mobility
APPLICATIONS OF WIRELESS LANS
Network Extension
APPLICATIONS OF WIRELESS LANS
Building-to-Building Connectivity: Bridging
APPLICATIONS OF WIRELESS LANS
Last-Mile Data Delivery: Wireless ISP
APPLICATIONS OF WIRELESS LANS
Small Office/Home Office (SOHO) Use
APPLICATIONS OF WIRELESS LANS
Mobile Office Networking Educational/Classroom Use
ADVANTAGES OF WLAN
Mobility is primary advantage of wireless
technology
Easier and Less Expensive Installation:
Installing network cabling in older buildings
difficult and costly
Increased Reliability
DISADVANTAGES OF WLAN
Security: Wireless signals broadcast in open air
Security for wireless LANs is the prime concern
Unauthorized users might access network
Attackers might view transmitted data
Employees could install rogue access points
Attackers could easily crack existing wireless security
Radio Signal Interference: Signals from other devices
can disrupt wireless transmissions
Health Risks: Wireless devices emit RF energy
SUMMARY
Review OSI, Protocol, IP Private, IP Public
Dynamic IP, Static IP
Enthenet 802.3
Today’s Wireless LAN Standards
802.11, 802.11a, 802.11b+, 802.11g,
802.11h
Infracstructure WLAN, WPAN, WMAN, WWAN
SUMMARY
Roles Organizations Play Within the WLAN Industry
The Federal Communications Commission
(FCC) is an example of regulatory bodies
The Institute of Electrical and Electronics
Engineers (IEEE) is an example of a
standards development organization
The Wi-Fi Alliance is a compatibility testing
and certification group