THE WIRELESS PARADIGM. ISQS 6342 Spring 2003 R.K. Miller. INTRODUCTION.
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The concept of Wireless LAN or wireless home networking (wireless LAN on a small scale) is to use omni directional radio frequency analog carrier signals to transmit digital and analog data between desktop and laptop computers and between an internet gateway and these same devices. A home network or corporate LAN strung together by T1 operates in the same way as the wireless version, except you lose the “wire.” The market for home, SmallOffice/HomeOffice (SOHO) and large-scale corporate users has just begun to take off. Though the technology and availability of unlicensed bandwidth has been around since 1985, it has only been since 1999 when the equipment price range has come down sufficiently to make this option attractive to the corporate and individual consumer. Add to this the very recent advances in securing data packets transmitted over the ether and controlled access to “access points” and the security shortcomings of wireless are becoming the same as those associated with wired configurations.
900 -- 928 MHz Industrial band
2.4 -- 2.4835 GHz Scientific band
5.15 -- 5.825 GHz Medical band
failed to enable WEP and other security measures.
primary owner: the microwave oven manufacturers. Thus
if there is any overlap with the primary owner, he gets the
right-of-way. A WLAN NIC operates at 100 mW versus
microwaves at 600-1000 Watts.
direct sequencing (with a possibility of up to 33 Mbps by using
all three22-MHz-wide channels). With major corporate
networks wanting 100 Mbps pipes (and higher, especially
with video applications), this is a serious limitation.
(are we going backwards??)
802.11a -- uses a 300 MHz bandwidth divided into three 100 MHz sections: 5.15 – 5.25 GHz, 5.25 – 5.35 GHz and 5.725 – 5.825 GHz, each with differing maximum transmission wattages. Orthogonal Frequency-Division Multiplexing, which requires no guard band, is used. 802.11a’s faster speeds (54 Mbps), greater security and better data reliability through the addition of forward error correction (not in 802.11b), are presently somewhat outweighed by high equipment costs, putting it out of the range of most consumers, e.g. Circuit City has an Access Point (without router) from Linksys priced at $299. Both 802.11a and 802.11b use the same MAC protocol: carrier sense multiple access with collision avoidance (“CSMA-CA”).
What about the Europeans?
Are the standards the same?
HiperLAN/1 and HiperLAN/2 -- Developed by the European Telecommunications Standards Institute (“ETSI”), these standards are similar to 802.11b and 802.11a respectively. One major difference is the MAC protocol, where the Europeans use time division multiple access (“TDMA”), also seen in European cellular phone technology, instead of CSMA-CA. It is not likely to be in use in the U.S., but the 2.4 GHz and 5.4 GHz bands in Europe have been reserved for HiperLAN/1 and HiperLAN/2. Therefore 802.11b and 802.11a are not yet certifiable in those markets. IEEE and ETSI are trying to work out the incongruities.
Other Standards and Technologies
our own Door right here in Lubbock.
Cisco - SAFE Wireless LAN Security in Depth.htm and
Cisco Aironet Wireless LAN Security Overview.htm
Wireless Network Security
802.11, Bluetooth™ and Handheld Devices
Tom Karygiannis, Les Owens
Recommendations of the National Institute of Standards and Technology
NIST Special Publication 800-48
WEP Security Statement
Wireless Ethernet Compatibility Alliance (WECA)
September 7, 2001
O'Reilly Network Wireless LAN Security A Short History.htm
News Networks suffer from wireless insecurity.htm
OVERVIEW AND GUIDE TO THE IEEE 802 LMSC
December 2002, IEEE