[Asterisk-Users] WI FI IP phones??

[Jonathan Moore]

Not sure if my other message got through. Wifi limitations with voip are a
function of # of concurrent active calls per access point (in addtion to which
codecs used). A single floor of the hospital might have many many access points.
If you just need a way to contact nurses on call, my guess is you would never
have all 30 phones active at once. This would be in your favor, since just
having a phone on and in standby is not going to eat up much bandwidth. Howeve
since peoples lives may be on the line the network would need to be really well
engineered and coverage would need to be designed with concurrent calls in mind
rather than the usual testing for signal strength.

In addition to the generel active calls/AP issue there are protocols like SVP,
Spectra Link Protocol, that provide for some type of quality of service for
Wifi. I don't really recomend Spectra link, mainly because they wanted a $5000
commitment just to demo their product. 

There is a qos spec for qos on wifi in the works, this won't magically make you
able to have more calls per AP, but it might help calls in session from being
starved out. I am pretty sure that what you want to do can be done at least with
the Spectra stuff, since I have talked to tech director of a new middle school
that is using this for their phone system. Every classroom teacher has one of
these and I think most of the other phone users in the building.

Another little trick floating around is for the Linksys APs. Again not
necessarily recommending but there are custom firmware images (since they run
Linux) that provide QOS, I think there may even be an image with a builtin SIP
proxy.
-- 
Jonathan Moore
Director of Technology
Winfield Public Schools
Office 620.221.5100
Fax 620.221.0508


Quoting James Moran <jmoran at potentialtech.com>:

> No I'm not but it's a hospital that nurses are on call and need to have
> a way to contact them.  On Fri, 2004-05-07 at 09:52, John Fraizer wrote:
> > James Moran wrote:
> > 
> > > We need to have about 30 phones on one floor
> > > 
> > 
> > And you really think that WiFi phones are suited for this application? 
> > Not an RF engineer, are ya?
> > 
> > John
> > _______________________________________________
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> -- 
> James Moran <jmoran at potentialtech.com>
> Potential Technologies
> 
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