Inkwell: Authors and Artists

    
It makes perfect sense in an environment like a college campus, but it does
create some security issues. But it's really no different from providing
free access on wired computers in the library.

There's nothing "inherently open" about WiFi. The owner of the network can
decide whether they want to make it open to the public or limit it to
authorized users.
  

    
> (jonl), I don't understand your question in #18. When WiFi/802.11 works
> properly, it's a wireless extension of a LAN that looks just like a LAN
> with ethernet cables.

My question in #18 was about the origin of WiFi - why did it emerge in the 
first place, and how (or how well) does it extend the capabilities of 
LANs?
  

    
As I understand it, WiFi was intended to be "wireless Ethernet". It replaced
was intended to extend existing LANs to wireless links. So, for example, a
user with a laptop could connect to the LAN without a cable tethering her to
an Ethernet port. Or somebody taking inventory in a warehouse could use a
portable device with a barcode reader. That kind of thing.

When it's working right, and the client machine is configured correctly, the
differences between a wired LAN and a wireless LAN are minimal -- the
maximum speed is lower, and the link isn't as secure, but in many
situations, the type of link is invisible to the user.
  

    
Re. the comments on security of WiFi, we should talk more about that later 
in the discussion.

Getting WiFi to work right and getting the client configured correctly is 
what the book's about. What should the average home user consider in 
deciding whether to add WiFi, and in thinking about how to set it up?
  

    
The first decision point is "Can you conveniently connect all your
copmputers and peripherals with ethernet cables?" If they're all in the same
room, and you don't need to add portable devices, then a wired network is
easier, more secure and cheaper. If you're can run cables through the walls,
or through the rafters of the attic or basement, cables might still be
easier. But if you don't want to drill holes through walls, or if you want
to reach places where cables aren't practical (like the back yard) WiFi is
a viable option.

Unless you live in a mansion, the exact location of the access point is
probably not critical. It my opinion that having the access point next to
a computer and a telephone is a better chioce than placing it in the
middleof the house, because you will want to watch the flashing lights on
the accesss point, and maybe connect and disconnect the power plug while
you're entering commands to the access point from a computer, and because
you will want to watch the flashing lights while you're on the phone to tech
support.
  

    
Let's say you do live in a mansion or large building, and you want 
wireless everywhere... might you need more than one access point?
  

    
I have Mac and Windows on my home Wi-Fi network.  Once I got the right
card the Mac was a piece of cake to set up and I had almost no Mac
experience.  The XP machine took a little bit of tech savvy to do the
network settings, which I am fortunate to have.  I would expect the
casual user to need some tech support or face something of a learning
curve on Windows, more so than on the Mac.

Do you have any feelings one way or the other about Mac v. Windows in
a Wi-Fi environment?  
  

    

        I'm interested in the same area, especially regarding
print-serving issues.
  

    
Yeah, you can extend the range of a WiFi network by adding more access
points.

As for the Mac v Windows question, it's entirely possible to create a mixed
network with Mac, Windows, Linux, Unix and even Palm stuff all exchanging
data through the same network.  Apple has done a better job than many others
in providing an easy to use configuration utility, so the Airport package is
a good choice as host for a mixed network.

One of the big shortcomings of the whole WiFi world is that there isn't a
single set of terms that everybody uses. So it's often difficult to know
exactly what settings an access is expecting. That's one of the things I've
tried to address in The Book of WiFi, by including a bunch of step-by-step
instructions and translating the terms that different access points and
network adapters use for the same settings.

Unfortunately, there are stil a bunch of obscure settings that you have to
configure before the network will work properly. Remember ten or fifteen
years ago, when you had to worry about data bits and stop bits every time
you made a connection through a modem? Nobody knew what a stop bit was (it's
a settng that goes back to the days of machanical teletype machines), but
you had to set it properly or the link wouldn't work. WiFi settings are like
that--they have to be set the same at the network card and the access point,
even if you don't know exactly what they mean.
  

    
>That's one of the things I've tried to address in The Book of WiFi,
>by including a bunch of step-by-step instructions and translating >the
terms that different access points and network adapters use for >the
same settings.

That stuff was well done.
  

    
Definitely.

John, you mention extending the network by adding access points... can you 
say more about access points and what they do? Is an access point a 
bridge, a router, or any of the above?
  

    
John, further following up on #34 and #36, do all the added access
points need to be on the wired network? How would one go about
distributing a WiFi network across a fairly large area if only one
access point is directly wired to the network and the others are
wireless, and not all in range of the main access point (as in point to
multipoint scenarios?)

For example, if I had to cover an area that would require three access
points and:

access point 1 is wired to the network,
access point 2 is in wireless range of access point 1,
access point 3 is in wireless range of 2, but *not* 1, etc.
  

    
The access point is the base station of a wireless network. it's the feed
point where the network clients connect to the upstream network. Many access
points come in a single box combined with an Ethernet switch or router, but
they're separate functions.

In other words, each network client exchanges data only with the nearest
access point. If you're doing a file transfer with another client, each
client links to the access point, and not to the other client. So you can
think of the access point as a wireless hub.

It's possible to set up an "ad hoc" point to point network that doesn't use
an access point, but that's pretty uncommon.

If you need more than one access point, you have to connect each access
point to the upstream LAN. Orinoco and some other folks make base stations
that use a separate point-to-point radio link for the upstream connection,
but that's not the same as the kind of daisy chain described in #37. You
can't use Access Point #2 as a client of AP #1.

There are a couple of ways to deal with the large area problem. Easiest is
to just wire all the access points to the same LAN. Or you could wire each
access point to the Internet and set up a vitual private network. Or use a
multi-stage network. Connect Access Point #1 to the backbone LAN, install a
network client (with a directional antenna if necessary) at each remote
site, and connect each client to another Access Point, using a different
non-overlapping channel.

The other option, if you're only concerned about Internet access and not
about local file sharing, is to connect each access point to the Internet,
and assign the same SSID (network name) to each access point. As far as the
network clients are concerned, it's all the same network, so the client will
find the strongest nearby signal. The fact that there's no shared network
between the access points will mean that you might have trouble handing a
live connection from one AP to the other, but as long as you're standing
still (with a laptop on a table or your lap), it ought to work.

In a home or small business, I'd find a way to connect all the access point
with Ethernet cables. Through the rafters, inside the baseboards or the
heating ducts. There's almost always some way to do it.
  

    
How well does 802.11 penetrate walls? If there are several walls between 
the base station and the client, does each wall diminish the signal 
appreciably?
  

    
Depends on what the wall is made of. If it's just wood and plaster/drywall,
it shouldn't make much difference. But rebar or other metal can make a big
impact. When we set up a temporary WiFi network in a hotel ballroom last
spring, the temporary "curtain wall" was enough to cut the signal strength.
  

    <scribbled by jonl Wed 13 Aug 03 19:26>
  

    <scribbled by jonl Wed 13 Aug 03 19:48>
  

    
Okay, getting this right: you don't say much about antennas because 
they're not quite in scope, but could you say a bit about their value - 
where can they be most effective?
  

    
First, every access point and every network adapter must have at least one
antenna connected to it. But most of them have built-in antennas that are
inside the case, or permanently attached.

If you can get a decent signal with the built-in antenna, that's all you
need. But if you're in a situation where you're trying to wrign the last
possible hundred feet of distance between the client and the access point,
an external antenna will help.

A few network cards come with external antenna connectors. The Orinocos have
a connector behind the teeny tiny dot on the edge of the card. But you need
an adaptor cable that goes from the connector to a standard cable, and that
costs more than the network card if you buy it from Proxim. There are some
third-party "pigtail" cables out there for a lot less.

Anyway, the rule of thumb is that an external antenna will boost the signal
strength. If you run it up to the attic or the roof, the line of sight
distance increases, too. So an external antenna (or two--one at each end of
the link) makes sense when you're trying to set up a long-distance link. In
a home or small-office WLAN, I don't think it would make a lot of difference
unless there's some kind of unusual problem like a metal filing cabinet
between the two ends.

As for access to public WiFi hotspots, you're probably using a laptop or
smaller client computer. An external antenna would be just one more piece to
haul around. Not much weight, but more nuisance.

Of course, if you want to pirate somebody's service from outside their
intended coverage area, an antenna might help, but you're on your own for
that kind of thing...
  

    
Changing the subject a bit - you mention the WiFi Alliance several times 
in the book. What does the Alliance do, and how effective are they?
  

    
The WiFi Alliance is the industry group that has promoted interoperability
among all the makers of access points and network adapters. They conduct
periodic "bake-offs" where everybody brings their own gear and proves that
they can connect to everybody else's equipment.

Unfortunately, their interoperability specs don't include the terminology
used in configuration utilities. But other than that, it's a safe bet that
any device that carries the WiFi logo will work in any WiFi network.

There's a new and different logo for the newer wireless ethernet standards
that have appeared since 802.11b--802.11a, 802.11g and so forth. But give
the rigorous testing that the Alliance demands, it's likely that they'll be
compatible across brands, just like the 802.11b stuff.

Before you ask, I don't have any useful opinions about 802.11a or g. I
haven't had a chance to play with the newer gear, so all I know is what I
read in the trade magazines and blogs.
  

    
The WiFi Alliance just moved to Austin, where I live. Spent some time 
talking to Frank Hanzlik, their new director. He pointed out another cool 
thing they offer, a 'zone finder' at their web site... you can search for 
hotsposts around the country, they maintain a list.

Getting back to the book... can you talk a little about the details of 
planning an installation?
  

    
The book has a couple of chapters devoted to planning an setting up a
network. I'd encourage people to read them rather than trying to boil it
down to three or four paragraphs.

It seems like this has turned into a dialog between (jonl) and myself. Does
anybody else have any thoughts about this stuff? I'm fascinated by the
social implications of wireless and how it effects people's lives. Has
anybody seen a change in the way they relate to networking or the Internet
because they've been able to cut the cable? Does it really make any
difference to be able to go online from a Starbucks?
  

    
Does it make a difference?

Perhaps not at Starbucks since you
're suppose to try and socialize a bit.

At a series of meetings in Pasadena we connected all sorts of difference
ways. Wireless was the easiest in a four story building where there were
no network-in-the-wall connections.

The Hilton charged $10 per day per room for a high speed connection at
2M or better.

And the university made us sign all sorts of papers before they would
allow us to use the wall connections but their firewall was a major
bottleneck for our Internet useage.



Wireless is simply the frontier of freedom in information flow. The cost
is minimal if not zero. It's the high tech equivalent of borrowing a cup
of sugar from the neighbor. Your network becomes someone else access
point.

Now, the telcos, the cable folks and anyone else who has made money
living off others may not like the business model. However, the Internet
seems to be the last bastion with the freedom to socialize with no cost.
  

    
No cost? Who's paying for the infrastructure?