Local area wireless networking,
generally in the form of WiFi (also known as 802.11b and 802.11g)
is a hot topic. Companies, universities and home users
are setting up wireless access points and running notebook computers
without network wires. Even Starbucks, other coffee houses, airports,
hotels and some small towns are installing WiFi for
visitors. 80211hotspots.com has
a listing of many sites around the US where you can access public
wireless networks. So why not go wireless with your PDA? It makes
perfect sense to free the most portable of all computers from
wires. All you need is a fast Internet connection (DSL, cable model
or wired Ethernet) and a WiFi access point to get started. Many
PDAs and notebooks come with built-in WiFi, and if not, you can
always buy an add-on card.
What
is WiFi?
WiFi is the "friendly" term
for the 802.11b (as well as 802.11a and 802.11g) Ethernet standard. It's the cousin to standard
802.11 wired networking and runs at a maximum of 11 megabits/second.
That's plenty fast enough for most computer users, and more than
fast enough for PDA users. It runs in the 2.4 gigahertz spectrum
and shares that spectrum with microwave ovens, Bluetooth, some
satellites and 2.4 gigahertz cordless phones. WiFi has a range
of approximately 150 feet. Plenty enough range for the household
(even good if you want to take a stroll in the back yard) and it
can even penetrate walls. In corporate and university settings,
several base stations and antenna amplifiers are installed to cover
the large spaces and even courtyards of the average large business.
It won't cost you an Arm and
a Leg
Base stations are now very affordable,
with reliable brands such as D-Link, Apple and Linksys selling
for around $100 or less. Wireless 802.11b SD network cards for Pocket
PCs run around $60 to $100 and notebook PC cards cost even less. MostWindows Mobile
Pocket PCs,Pocket PC phones, some MS Smartphones and several Palm models such
as the LifeDrive and Tungsten
T|X have
built-in WiFi, while other Palms such as the Zire
72, Tungsten E2 and Tungsten
T5 can use
Palm's SD WiFi card which
is sold separately. If you're interested in a Windows Mobile Pocket
PC with WiFi, check out our comparison
tables which list models
with built-in WiFi.
Security
There
have been articles published discussing security flaws
in 802.11a/b/g. That doesn't mean it's a totally insecure medium.
Transmitted data is scrambled. And if you choose to use encryption,
the data is even harder to read. Encryption is available in two
strengths: 64 bit (which really runs at 40 bit) and 128 bit encryption
being the strongest available. You can tell your base station
who's allowed to connect and who isn't. If a hacker is using
a wireless network device to listen in on your traffic and she's
good at hacking, she might be able to intercept and read your
data as it's transmitted over the air. However, she'd had to
be within range of your network, yet manage to not be noticed
by others. Not all that easy, after all. However, if you're setting
up a WiFi network in a corporate environment, take care that
additional security measures (use WPA or VPN) are used whenever sensitive data
is being transmitted over the airwaves!
What
about 802.11a and 802.11g?
802.11a
access points and cards are still on the market now, though they've
become less common because they run at on a different
radio band and are not backward compatible with 802.11b networking
products so you'll have to upgrade everything if you're an existing
802.11b user. For now, the 802.11a network cards are 32 bit cardbus,
which modern notebooks can use, but not PDAs because their expansion
card bus is 16 bit. So don't hold out for the faster 802.11a if
you're a PDA user!
802.11g,
which is now prevalent, does
run on the same band as 802.11b and is available
in 16 bit card format. It took a few years, but 802.11g
cards and integrated 802.11g are available for Windows Mobile PDAs and phones and Nokia
S60 smartphones and handhelds. Keep in mind that PDAs don't transfer
network data all that fast through their expansion card slots, so
running at 802.11g's 54 megs vs. 802.11b's 11 megs won't make much of a
difference to you. You will see a few hundred k increase in data
transfer, and more importantly, your WiFi access point won't have to
slow down to "b" speeds thereby slowing down your entire wireless
network. You see, WiFi access points are both b and g compatible, but
the access point will drop down to the slower b mode if even one
802.11b client (device) connects. So it's better to keep things at g if
you can. That said, if you're running a 10baseT, DSL or cable modem
network, you're limited to less than 11 megs, even in your wired
network. The real advantage is sharing files between computers on the
same network, say in your home or office, where data can move at 54
megs between these "local" machines, even though the outside connection
speed to the Internet is limited by your DSL, cable modem or 10baseT
network.
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