|
|
|
WIRELESS LAN
STANDARDS
.:Back To Connectivity:.
Different wireless technologies define a swiftly up-and-coming area
of growth in networking. The need for mobile computing, wireless peripherals,
voice and messaging, hand-held and other internet-enabled devices,
simple home networking, media streaming, and lucrative networking solutions
in general have driven the recent development of a number of wireless
networking standards.
All those wireless technologies target different
niches in the WLAN market, work over different frequencies, and only
a few are compatible
with each other.
This quick WLAN reference table will help differentiate
between the different wireless networking standards in use today.
|
| |
|
IEEE Standard
|
Speed (max)
|
Frequency
|
Transmission Method
|
Security
|
Details
|
|
802.11 legacy
|
2 Mbps
|
2.4 GHz
|
DSSS, FHSS
|
WEP, WPA
|
IEEE specification extended
into 802.11b
|
|
802.11a
|
54 Mbps
|
5.0 GHz
|
OFDM
|
WEP, WPA
|
Wi-Fi Alliance standard,
12 non-overlapping channels (each 20 MHz wide). Less potential for
RF interference at 5 GHz than 2.4 GHz. Shorter range than, and not
interoperable with 802.11b/g. Average actual throughput 10-25 Mbps.
|
|
802.11b
(Wi-Fi)
|
11 Mbps
|
2.4 GHz
|
DSSS, HR-DSSS
|
WEP, WPA
|
Wi-Fi Alliance standard.
11 channels (each 22 MHz wide, only 3 non-overlapping, 14 usable
channels outside the U.S.). Average
actual throughput 5 Mbps.
|
|
802.11g
|
54 Mbps
|
2.4 GHz
|
DSSS, HR-DSSS, OFDM
|
WEP, WPA
|
Wi-Fi Alliance standard,
11 channels (each 22 MHz wide, only 3 non-overlapping, 14 usable
channels outside the U.S.). Compatible with
802.11b, with improved speed and security. Will eventually replace
802.11b. Uses additional OFDM modulation technique above 20 Mbps.
Average actual throughput 10-25 Mbps.
|
|
802.11n
|
200+ Mbps
|
2.4/5 GHz
|
MIMO
|
WPA2 ???
|
Emerging Wi-Fi Alliance standard
(scheduled to be complete by the end of 2006), backward compatible
with 802.11a/b/g. It is to achieve that by adding MIMO (multiple-input,
multiple-output), using multiple antennas. Average throughput
of 100+ Mbps.
|
|
Bluetooth
|
2 Mbps
|
2.45 GHz
|
FHSS
|
PPTP, VPN or SSL
|
No native TCP/IP support.
Best suited to connect PDAs, cell phones and peripheral devices at
short distances.
|
|
HomeRF
|
10 MBps
|
2.4 GHz
|
FHSS
|
56-bit encryption, separate
IPs for each network.
|
No longer supported. 150
feet range, intended for home use. Reserves part of available bandwidth
for voice services. Responds well to interference because of FHSS.
|
|
HiperLAN/1
|
20 MBps
|
5 GHz
|
CSMA/CA
|
individual authentication
and per-session encryption keys
|
Only used in Europe.
Ad-hoc WLAN requires no configuration or central controller.
|
|
HiperLAN/2
|
54 MBps
|
5 GHz
|
OFDM
|
individual authentication
and per-session encryption keys
|
Only used in Europe.
It can carry ATM cells, IP packets, Firewire packets, as well as
digital voice (cellular phones).
|
|
| |
| .:Back To Connectivity:. |
| |
|
|
|
|
|
|
 |
|
|
|
| |
|
|
