[tlug] Portable private wifi lan

["Stephen J. Turnbull" <stephen@example.com>]

Dave M G writes:

 > I had an idea today for a fun sort of interactive stage performance.
 > What exactly happens in the performance could vary a lot depending on
 > what the performers want to do, but the key thing is that it rests on
 > having a wireless network in the theatre that people with wifi devices
 > on hand.

A variant of this idea is already exploited by Japanese TV.  All those
audience participation shows where audience members hold up maru/batsu
cards, you know?  The more modern ones give the audience members a
button at their seats.

 > I can sort of see it all in my head, but I don't know exactly what it
 > takes to do it. I know little about how WiFi works. I only really know
 > how a web page is delivered over the internet, not so much over
 > LANs.

The beauty of the Internet (as a concept) is that you don't need to
care how the LAN works.  Any home wireless base station/firewall can
do the trick: just don't plug it into the Internet.  It will use DHCP
to assign private IP network addresses, and it will take care of
coordinating all the devices in the neighborhood that want to connect.

 > Would one need Apache or something like that somewhere on the
 > network in order to serve up a local web page?

That's one way to do it, but you might find that web is a bit
heavyweight from the user's point of view.  See below for some
suggestions about similar UIs.

 > Could that be handled by a laptop on the network, so that the show
 > could be portable to any venue that had Wifi?

The server needs can be handled by a laptop, certainly.  And why not
just take your Wifi with you?  Either a cheap base station or a
wireless card for the laptop that does all the wireless modes (I
forget the technical names, but there's "ad hoc", "base station", and
"client"; many cards for laptops won't do "base station", which is
what you need to set up a network automatically).

 > Can someone maybe give me some pointers on what requirements I need to
 > meet in order to set this system up? When I look up setting a private
 > network, I get information about how to secure a regular home or
 > business network with internet access. But that's not what I'm after.

I don't think you need more information.  You just need a cheap home
wireless router that does DHCP to assign IP addresses, and to remember
to not plug it in to the Internet. :-)

Regarding Apache: I'm sure you've got the skills to design appropriate
interfaces, and the devices can handle the load.  But you might want
to look at "software for experimental economics/political science/
social science" for something that matches your spec quite exactly.
Or "voting software", although that will probably land you in heavy
security territory (ie, software for handling general elections and
the like).  Also, perhaps MUD (multi-user dungeon) software would be
of use.  Not the games themselves, but the servers.

Both the experiment software and the MUDs would allow very flexible
communication if you want it, but they're also capable of very
efficient communication.  The UIs might give you ideas.  (Experiment
servers are mostly implemented on top of a LAMP stack these days, as
are the popular global MUDs like World of Warcraft AFAIK.)