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

[Holger Wirtz]

On Thu, Jan 10, 2008 at 11:08:55AM +1300, Clive Nicolson wrote:
> 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.

Thanks for this hint! If I write such an app I think I only do this for
one kind of modulation.

Regards, Holger

> 
> Clive
> 
> 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
> >
> 
> _______________________________________________
> --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

-- 
#####  #### ##  ##   Holger Wirtz         Phone : (+49 30) 884299-40
##  ## ##   ### ##   DFN-Verein           Fax   : (+49 30) 884299-70
##  ## #### ######   Stresemannstr. 78    E-Mail: wirtz at dfn.de
##  ## ##   ## ###   10963 Berlin
#####  ##   ##  ##   GERMANY              WWW   : http://www.dfn.de
GPG-Fingerprint: ABFA 1F51 DD8D 503C 85DC  0C51 E961 79E2 6685 9BCF