The topic of wireless is permeating
technology news. We cover a lot of it here at Weblogs Inc. So, in an effort to keep our readers updated on all
the names, acronyms, numbers, and brands, here is an overview of wireless technology in layreader terms.
Data Technologies:
Wi-Fi - Wireless Fidelity, Protocol designed to allow data communications over radio waves.
Comprised of the IEEE standards 802.11b, 802.11g, and 802.11a. Used most often to allow laptops with wireless adapters
to connect to the Internet. Highly compatible with TCP/IP so it works well with applications like Voice over IP
(VOIP).
WiMax - Worldwide Interoperability for Microwave Access, One of several emerging standards for
long-distance wireless data communications. Could displace Wi-Fi as the preferred last-mile solution for WISPs
and other Internet carriers. Probably will co-exist with Wi-Fi in WLAN and Hotspot deployments. Speeds as
high as 70 Mbps, and out-of-the-box distance of 30 miles. Keep this one on your technology watch list.
Bluetooth - Wireless protocol for short-distance voice and data transmissions. Meant to be a
cable replacement for devices within 30 feet of eachother. Currently used mostly in cellular telephones to
connect headsets and allow wireless synchronizing.
UWB - Ultra Wide Band, A technology for modulating radio frequency signals across a wide peice of the
spectrum in short bursts. Formerly a military technology, it promises to allow for higher throughput (up to 1
gigabit per second) with less interference and further distance than other short-range technologies.
ZigBee - A short-range wireless technology that promises to be cheap (about six dollars per radio)
while supporting speeds of 20 kbps or higher. Shows good promise for deployment in wireless sensors, home
automation, telemtry, and other dynamic, but low-bandwidth applications.
RFID - Radio Frequency Identification, Small wireless "tags" that can contain a small amount of
information to be "read" by wireless RFID scanning equipment. Tags usually store static data like a serial number
that gets assigned in a database not unlike a barcode. Tags may also allow writing, reading, and re-writing of
data stored in the RFID chip. Range is usually limited to 30 feet with very low bandwidth. Small RFID tags
do not generally require internal power to operate. The low cost, small size, and easily read data stored in the
tag make them ideal as a replacement for barcodes and other serialized materials tracking methods.
Standards (IEEE):
802.11 - Several IEEE standards, most of which pertain to Wi-Fi. Followed by a letter to describe
exact standard. Often referred to with the three letters "b/a/g" meaning any one or all of the standards.
802.11a - Wi-Fi, 5.0 GHz, 54 Mbps, wireless protocol, only works with other 802.11a devices
802.11b - Wi-Fi, 2.4 GHz, 11 Mbps, wireless protocol, works with 802.11b compatible devices
802.11g - Wi-Fi, 2.4 GHz, 54 Mbps, wireless protocol, works with 802.11g and backwards compatible (slower)
with 802.11b devices
802.16(something) - WiMax, the (something) letters are still being ratified (stay tuned)
802.20 - Emerging standard, would allow for 1 Mbps or higher while travelling at a speed of 155 mph
or less. May end up being compatible with WiMax.
Security:
WEP - Wired Equivalent Privacy, Method of encryption using two shared sets of numbers. Easiest to set
up is also the weakest encryption for wireless. Akin to "locking the front door". Good for home users, businesses
should use something stronger.
WPA - Wi-Fi Protected Access, An encryption method that is stronger than WEP and is available on most
newer wireless devices.
802.1x - IEEE standard defining a server for authentication of users in a wireless LAN, works with
WPA.
Radius - Database protocol, used for storing usernames and passwords in a secure network.
Encryption - Method of scrambling data so it cannot be understood without decryption of the
traffic. Wireless networks use encryption/decryption to scramble and unscramble data in a known procedure with a
common encryption key. Others that intercept encrypted traffic would either need the decryption key or break the
encryption in some manner to read the underlying data.
Cellular:
CDMA2000 - (R) Qualcomm, Branded name for several 3G and 2.5G cellular technologies for increased
bandwidth over the cellular network. Includes CDMA2000 1x, 1xRTT, 1xEV (1xEV-DO & 1xEV-DV)
GPRS - General Packet Radio Service, Mobile data technology supporting a real-world bandwidth of up
to 70 kbps. Operates on GSM and TDMA networks.
GSM / TDMA / CDMA - Mobile radio technologies for cellular carrier networks. Usually considered 2.5G
technologies that support add-on data services like CDMA2000 and GPRS.
EDGE - Enhanced Data Rates for Global Evolution, Add-on technology riding on top of GPRS. Compatible
with TDMA and GSM networks. Provides speeds up to 400 kbps.
2.5G - Generic term for cellular technology that is in between Second and Third generation
networks. Most US-based carriers are currently operating 2.5G service. Sometimes used synonymously with
3G.
3G - Generic term for Third generation cellular technology. 3G devices aim to support speeds of
up to 500 kbps. 3G and 2.5G are often used interchangably as the underlying technology on a cellular carrier is
sometimes hard to define in a non-technical environment.
4G - Generic term for Fourth generation cellular technology. 4G would potentially support
speeds above 10 Mbps. 4G as terminology is mostly used as a conversation point and useful as a target on the
cellular roadmap.
Words, Brands, Acronyms:
IEEE - International standards body that defines technology protocols (like 802.11b, etc.)
Licensed - Frequencies on the spectrum that require FCC approval to use. Generally requires high cost
to acquire spectrum and pay license fees. Advantage is little interference for license-holder. Cellular phones
use Licensed spectrum. Requires approval before operating any equipment on a licensed frequency.
Unlicensed - Frequencies on the spectrum that do not require governmental approval to use.
Hardware must still be FCC certified but costs remain low. Wi-Fi and others use unlicensed spectrum so you don't
need approval before turning on a Wi-Fi network.
Spectrum - Usually means several radio frequencies in a cert
21. Wardriving is a popular hobby among WLAN enthusiasts, much like geocaching. Wardrivers generally use a laptop or PDA with a wireless card, and scan the airwaves for installed access points. Access points broadcast their existance as far as their little signal can be heard, and can easily be picked up from a car on the road. GPSs are used to record the location of these signals, which you can see (shameless plug) the results of (here it comes) at online map sites like http://www.WiFiMaps.com . Wardriving does not involve breaking into these wireless networks, or connecting to them at all. Instead, wardriving is a passive sport, the results of which prove just how popular WLAN technologies have become.
Posted at 6:09AM on Dec 19th 2005 by Drew from Zhrodague