At this time
802.11b is considered the industry standard, it runs
at a speed of 11Mb on the 2.4 GHz spectrum, the same as most
cordless phones, this makes it prone to interference from
other devices however. With a realistic throughput of
2.5-4Mbps, it is fast enough for most network applications
and tolerable for file transfers. This speed is still faster
than all ISPs so you will notice no difference in your
internet transfers but transfers between computers on your
network will be much slower compared to 802.11g, 802.11a or
wired Ethernet. 802.11b is a half duplex protocol – it can
send OR receive, but not both at the same time. The range
for this type of device is about 250ft indoors. Some people
have used directional antennas to get some serious range out
of their 802.11b products – miles!
A new emerging
standard is the 802.11g devices which operate at a
maximum of 22Mbps but can communicate at up to 54Mbps, also
on the 2.4 GHz spectrum and reverse compatible with 802.11b,
this makes it a great choice for anyone. Like 802.11b,
802.11g is subject to the same interference and security
issues and also the same range. When an 802.11g product
communicates with an 11Mbps 802.11b product, it drops down
to 11Mbps or less depending on signal strength. In other
words, if you purchase an 802.11g product for use with an
802.11b access point, expect only 11Mbps. The 802.11g
standard has not been widely adopted because of the
emergence of 802.11a.
802.11a
is a 54Mbps wireless standard that is completely
incompatible with 802.11b or g but has a greater overall
throughput. 802.11a operates in the 5 GHz frequency range
and can transfer data at the rate of 54Mbps! That is over
4X the transfer rate of 11Mbps 802.11b and although it is
another form of Wireless Ethernet, 802.11a is incompatible
with 802.11b products because of the different frequencies
they operate at. 802.11a network adapters can operate in two
modes, infrastructure and ad-hoc. In infrastructure mode,
all network adapters talk to each other THROUGH a central
'Access Point'. This access point grants permission to each
device, determines the frequency to communicate on, and
relays data between network adapters. Since 802.11a products
communicate in the 5 GHz frequency range, they do not cause
problems with cordless phones like most 802.11b products
do. Unfortunately, 802.11a also has a range limitation in
comparison to 802.11b - often 1/3 the range. 802.11a can
communicate at a maximum rate of 72Mbps but due to FCC
frequency restrictions, it is currently limited to 54Mbps.
If these regulations change, a simple firmware upgrade will
update your equipment.
All three of
these wireless technologies need what is called an Access
Point referred to as an AP. Access points are
stand alone devices that can 'bridge' wireless computers to
wired Ethernet computers. They may also be built into other
devices like network routers, especially in the home
consumer market.
Access points
come in three varieties: bridge, NAT router and NAT router +
bridge.
A
bridge type connects a wireless network to a wired
network transparently. Communication is possible between
both networks in both directions.
A NAT
router type routes traffic from your wireless
network to an Ethernet wired network, but it will not route
traffic back. This type can be used to share an Internet
connection.
Lastly, there
are hybrid
NAT router + Bridge devices that bridge both, your
wired and wireless networks, then route them both to the
internet using a single IP address. This is good for sharing
an Internet connection when you have both wired and wireless
computers in your home. These are often called Cable/DSL routers with
wireless.
