[asterisk-dev] Simulation of radios with something like MeetMe()

Clive Nicolson clive at baby.bedroom.gen.nz
Wed Jan 9 16:08:55 CST 2008

AM radios are used in aircraft, so the received volume is the sum of the 
signals (which are signal path related). If using FM radios the received 
volume is affected by signal strength capture effects! ie you only hear 
the strongest signal.


On Wed, 9 Jan 2008, Alexander Lopez wrote:

> Reverse your thinking...
> The Player 'knows' where they are in relation to the others.  Have the
> game's radio 'client' lower its 'receiver' by adjusting the gain coming
> from the IAX client.  Radio was half-duplex back then (and now for the
> most part) so all you have to do is find out who is talking and adjust
> it.
> That would not require any changes to Asterisk and would almost
> guarantee that you would not need to maintain your own asterisk code and
> you would gain from the improvements in Asterisk as a project.
>> -----Original Message-----
>> From: asterisk-dev-bounces at lists.digium.com [mailto:asterisk-dev-
>> bounces at lists.digium.com] On Behalf Of Steven S. Critchfield
>> Sent: Wednesday, January 09, 2008 11:39 AM
>> To: Asterisk Developers Mailing List
>> Subject: Re: [asterisk-dev] Simulation of radios with something like
>> MeetMe()
>> ----- "Holger Wirtz" <wirtz at dfn.de> wrote:
>>> Hi,
>>> I hope this is not too much OT. I am currently working on a
>>> simualtion
>>> of radio equipment for the open sorce flightsimualtor FlightGear. It
>>> works with Asterisk and the client is based on iaxclient (see
>>> http://wiki.flightgear.org/flightgear_wiki/index.php?title=FGCOM)
>>> Actually it works but there are some problems. For more realistic
>>> radios
>>> there should be an application like app_meetme with more features:
>>> For the outgoing audio stream to each client there has to be a mixup
>>> of
>>> the stream based on the distance between the partners. I know that
>>> this
>>> would use more cpu cycles than the normal conference.
>>> But the real problem is:
>>> how do I get the coords of the plane from the client to the Asterisk
>>> application? My idea was to send them once or twice a minute with a
>>> SendText() on the channel.
>>> Now my questions:
>>> - Can this be realized with an advanced app_meetme?
>>> - Is it possible to work with text informations in an application
>>> like
>>>   app_meetme?
>> While thinking about this, meetme would probably be the wrong
> application
>> to host this. Specifically, as I understand it, meetme currently
> creates
>> one mix audio stream and then distributes this to the various parties.
>> What you need is a different stream per user mixed based on relative
>> distances. Also the need to be able to wipe certain signals out as
> they
>> are overpowered b y closer strong signals.
>> I think what you need is going to be a fairly complex problem and well
>> beyond usefull in the telephony world where we want to make this all
> the
>> best quality sound possible.
>> You also might want to consider how realistic you want your radio
>> simulator to work. For instance, if you are flying below the peak of a
>> mountain range, your quality over the range is going to be affected by
>> where your receiver is and what kind of signal bounces you might get.
>> --
>> Steven Critchfield critch at basesys.com
> _______________________________________________
> --Bandwidth and Colocation Provided by http://www.api-digital.com--
> asterisk-dev mailing list
> To UNSUBSCRIBE or update options visit:
>   http://lists.digium.com/mailman/listinfo/asterisk-dev

More information about the asterisk-dev mailing list