[aprssig] APRN news from Dayton!

Gregg Wonderly gregg at wonderly.org
Mon May 23 19:09:23 EDT 2011

On 5/23/2011 5:43 PM, Stephen H. Smith wrote:
> On 5/23/2011 2:17 PM, Bill V WA7NWP wrote:
>>> However, there is an alternative.
>>> IP-Sound is a Free application for audio exchange client to client over a
>>> TCP/IPv4 network (Lan/Internet). The main purpose for the existence of
>>> IP-Sound is to provide low quality audio 8-16kHz, with low latency for use
>>> together with remote control software for "ham" radio amateur equipment.
>>> IP-Sound is developed by SM5VXC.
>>> It can be used to transport the audio part of a ham remote-control setup
>>> (i.e. the mike and speaker audio) end-to-end over a network or Internet
>>> connection. The advantage of IP-Sound over systems like Skype, MS Netmeeting
>>> or Echolink is that it can use lossless codecs that won't mangle the
>>> phase/amplitude integrity of audio signals received by the sound card. This
>>> is critical to operating modes like PSK31 and SSTV.
>> If an alternate tool is going to be used for the images, why not just
>> send the picture as digital data instead of analog data on top of an
>> VOIP audio system...
> Because we persist in using analog FM radios, intended for voice, on the RF
> links. As long as we want RF<-->Internet<-->Rf links to be transparent to analog
> radios, the Internet links need to use this kind of analog kludge.

I am not convinced.  The transport only needs to be "modemized" when it is going 
across RF.  Anything that can receive a TCP connection should be able to encode 
it into an appropriate modulation if it can go from TCP to audio.

Gregg Wonderly

More information about the aprssig mailing list