Setting up a WiFi Hot Spot
               by Mike - K5HUM

A company called LinkSys (i.e. Cisco) manufactures a
nifty gadget called a range Expander, Model number
WRE54G.

This signal expander works in conjunction with Cisco's
Wireless Router (the WRT54G) but will work with many
other models's of wireless routers as well.

The typical install of a WRT54G Wireless router
provides an open air or native range of under 150 feet.
This native range can be greatly extended by using gain
antennas but more on that later. Inside a typical house
or structure the native range of a WRT54G can be
severely attenuated by the composition of walls, floors
etc.

Solution, enter the WRE54G Expander. This is nothing
more than a digital repeater in Ham parlance. It
connects to the WRT54G's signal, and acts as a relay.
In other words the Expander is the access point for
something like a wireless laptop. The laptop asks for a
web page, the expander forwards the request to the
router and sends back the information to the laptop.

In most cases the expander is geographically in between
the user's device (laptop in this case) and some modest
distance from the gateway to the internet (the wifi
router). However, depending on the layout or geometry
of your situation, there are two possible ways to
configure the setup of an expander for best use.

The common setup method when only one expander is used
is to give the expander a unique IP address. By default
the WRE54G is set to use 192.168.1.240 which in most
cases is acceptable, then set the gateway IP to that of
the router (typically 192.168.1.1). The Net Mask is
always 255.255.255.0

However before I digress more, I strongly recommend
obtaining the latest model LinkSys WRE54G expander (a
Version 3) that comes with a CAT5 jack mounted on top
the case to allow connection to either the PC's NIC or
a free node on the router. This allows you to setup the
device without having to have your overall wireless
system operational (the older versions are setup using
an existing wireless signal and are a bit more
troublesome to configure - especially if your wireless
router is already using data encryption). Like many
such devices, you use your Web Browser to connect to
the Expanders built in setup web server. The default
address of a new WRE54G is usually 192.168.1.240

In addition to obtaining an expander with the LAN
jack, I would also recommend buying an older WRT54G
router (older is fine if you remember to up grade the
firmware). WRT54G Version 3 thru 6 has replacable
antennas. Version 8, the latest, no longer has
replacable antennas, they are hard wired. Or, buy any
quality Router with replaceable antennas. Just be
mindful of the style (manufacturers part number
designation) of the coax sockets and plugs so if you
buy gain antennas, you buy the right styles. Frequently
a change in the antennas, to ones of extra gain (up to
9db or higher) can greatly improve range such as the
yagi can antennas for long unidirectional ranges. BTW,
the antennas should be changed in like pairs, not just
one. The antennas work in a diversity system, with the
one getting the best r/t at any instant being used. If
you are lucky, a change in antennas alone might provide
you with the extra range you need.

In a complicated geographical structual situation, a
2nd expander could be used. In this case you can
optionally have the 2nd expander using the gateway
address of the router or daisy chain it. Just remember
to give it another IP such as 192.168.1.241 instead of
192.168.1.240. This diagram illustrates two expangers
giving aprox 200 feet radius of coverage:

                            100f
                           out to
100f<-(E1-090d)..100feet..[Router]..100feet..(E2-180)->100f
                           out to
                            100f

By connecting the Expanders in a Daisy chain, wherein
the 2nd Expander uses the 1st as its gateway (i.e the
gatway address of the 2nd would be the IP of the 1st)
the range of coverage would look like:

[Router]...100f to...(E1)...100f to...(E2)...->100f

This setup is more unidirectional giving more range in
one direction but would suffer from a bigger loss of
signal bandwidth.

I would also suggest setting the router and expanders
to G mode only, as most modern WiFi receivers can use G
mode. B is much lower bandwidth.  I realize the newer N
mode is already out and seems to provide better
coverage and higher bandwidth, so this article is
intended to take advantage of older, cheaper equipment
that can be found on places like E-Bay.

Finally, a few words on security.  First and foremost
its advisable to change your router and expander
passwords from the default of "Admin" to something more
secure. Next its highly suggested that you employ some
form of data encryption. Although WEP (wireless
encryption protocol) is not theoretically as secure as
more robust types I suggest it in ordinary home and
office surroundings.

WEP will take an english passphrase and hash it into a
string of hexadecimal numbers which become the entry
key to anyone using your hotspot.

I wish someone had written this article when I was
getting my wireless feet wet, it would have saved me a
lot of time. So, Im offering this to anyone else
considering creating a small home or office HotSpot.

73s
Mike K5HUM