Re: Outdoor Wireless Access Point

[Joel Maslak <jmaslak () antelope net>]

On Mar 31, 2012, at 3:38 AM, Shahab Vahabzadeh <sh.vahabzadeh () gmail com> wrote:

> As I look for maps we need at least 3 or 4 outdoor radio, I think in these
> networks the best solution is to have only one SSID in whole network to
> give mobility for the network, is this called ad-hoc? or it has an other
> name?

No, it's still infrastructure mode, not ad-hoc.

Ad-hoc means "no access point".

All you need to do is set the APs up to use the same SSID and authentication methods, keys, etc.  It's pretty simple 
and can even be done with consumer gear (with less stable performance of course).  If you don't put the APs all on the 
same layer 3 LAN (same subnet), you'll need some sort of controller-based solutions so that a user's IP address still 
makes sense to their computer when they move from one AP to another.  If you can keep all the APs on one subnet, you 
won't need that.

It gets a bit more complex if you are using radio to link buildings together and/or backhaul to the access point.  
There's plenty of good references on the internet.

Note that the wireless handoffs aren't perfect on basic 802.11 gear.  Your laptop might not pick the best AP if it can 
hear multiple APs.  And you might lose a few packets when you hand-off between APs, but it's typically no big deal.   
Your ssh session would stay connected across those hand-offs just fine.

If you plan on doing VoIP on the wireless, it gets more complex yet - you have to worry about the time it takes 
handoffs and that can be more complex.  You have to implement WMM and DSCP.  You need to worry about low-speed users 
(1mbps, 2mbps, etc) on the same link.  It's a lot harder to build a VoIP wireless solution than a web browsing wireless 
solution, but still plentty possible to do without expensive equipment.

In summary: you probably should find a guide on how to build wireless networks, preferably a vendor agnostic one.  You 
will either be the hero of your organization or the enemy, depending on how well your network works.