Low latency IP Audio streaming for remote base?
Moderator: Global Moderator Team
Low latency IP Audio streaming for remote base?
I'm helping my club out on setting up Kids Day on the Air this June 19th. Unfortunately, the site we pretty much have to work from has a S7 noise floor, with interfering signals as high as -60dBm! - not exactly conducive to HF contacts. The plan is to operate a remote base for receive, somewhere with a lower noise floor, and just transmit from the site.
So the problem is "how to get audio from the remote base to the site?" One way would be to do an HF to VHF or UHF link, but that really requires a control operator at the remote base. The other would be to remote control the radio over the Internet via a secure tunnel - that moves the "control point" to the site and removes the need for a remote operator (also the remote site isn't transmitting). I've done a bit of playing around with Icecast2 + Ices2, but I really cannot get the latency below about 2 seconds here on my local network. That seems a bit high for 2 way communications, and I'd like to see if anybody else has a better suggestion for a solution.
So the problem is "how to get audio from the remote base to the site?" One way would be to do an HF to VHF or UHF link, but that really requires a control operator at the remote base. The other would be to remote control the radio over the Internet via a secure tunnel - that moves the "control point" to the site and removes the need for a remote operator (also the remote site isn't transmitting). I've done a bit of playing around with Icecast2 + Ices2, but I really cannot get the latency below about 2 seconds here on my local network. That seems a bit high for 2 way communications, and I'd like to see if anybody else has a better suggestion for a solution.
These opinions are mine, not Aeroflex's - if you want service info, manual, or other official support please contact Aeroflex directly.
- motorola_otaku
- Cock Block
- Posts: 6671
- Joined: Mon Nov 29, 2004 8:53 pm
- Location: Stinkadena, TX
Re: Low latency IP Audio streaming for remote base?
I saw an ad for these guys in CQ yesterday but don't know a thing about them: http://www.glentekcorp.com/
Their solution to IP latency is to use a POTS line for audio back to the operator with the IP side handling radio control.
I don't guess the remote base site will be close enough to use point-point fixed devices, like Canopy?
Their solution to IP latency is to use a POTS line for audio back to the operator with the IP side handling radio control.
I don't guess the remote base site will be close enough to use point-point fixed devices, like Canopy?
And the sign says you got to have a membership card to get inside.
Re: Low latency IP Audio streaming for remote base?
Not even close - no line of sight.motorola_otaku wrote:I saw an ad for these guys in CQ yesterday but don't know a thing about them: http://www.glentekcorp.com/
Their solution to IP latency is to use a POTS line for audio back to the operator with the IP side handling radio control.
I don't guess the remote base site will be close enough to use point-point fixed devices, like Canopy?
And POTS would be difficult given the circumstances.
This is a one-day event, not an on-going set up.
These opinions are mine, not Aeroflex's - if you want service info, manual, or other official support please contact Aeroflex directly.
Re: Low latency IP Audio streaming for remote base?
Well, I've been doing a bit of experimentation, so I'll share:
Experiment #1: icecast2 + ices2 (http audio streaming)
Verdict: Unsatisfactory - buffering adds a minimum of 2 seconds latency. If the system is configured to use a low bitrate then it is even worse, as many clients insist upon buffering 64KB which is over a MINUTE of audio.
Experiment #2: Ekiga
Verdict: Possible - Low latency on LAN. However, will require registration of the radio with an Internet visible SIP server to set up the connection. I'll either have to use ekiga.net + insure the base SHALL NOT accept calls save from known sources OR use a private SIP on a non-standard port (:= difficult to do with standard clients). Also there needs to be a way to force Ekiga to accept the incoming call.
Future experiments:
MAST - RTP only server, no SIP needed. Requires JACK audio interface (grrr.)
Eliminated:
Echolink - pretty much Windows only, which rules it out.
IRLP - Requires Redhat, requires their audio interface board, hard to make a private link.
Experiment #1: icecast2 + ices2 (http audio streaming)
Verdict: Unsatisfactory - buffering adds a minimum of 2 seconds latency. If the system is configured to use a low bitrate then it is even worse, as many clients insist upon buffering 64KB which is over a MINUTE of audio.
Experiment #2: Ekiga
Verdict: Possible - Low latency on LAN. However, will require registration of the radio with an Internet visible SIP server to set up the connection. I'll either have to use ekiga.net + insure the base SHALL NOT accept calls save from known sources OR use a private SIP on a non-standard port (:= difficult to do with standard clients). Also there needs to be a way to force Ekiga to accept the incoming call.
Future experiments:
MAST - RTP only server, no SIP needed. Requires JACK audio interface (grrr.)
Eliminated:
Echolink - pretty much Windows only, which rules it out.
IRLP - Requires Redhat, requires their audio interface board, hard to make a private link.
These opinions are mine, not Aeroflex's - if you want service info, manual, or other official support please contact Aeroflex directly.
-
- 102480-000000-3
- Posts: 138
- Joined: Tue Jan 18, 2005 6:48 pm
- Location: Hiding on the roof
- Contact:
Re: Low latency IP Audio streaming for remote base?
Any of your guys have a Kenwoody TS-480? It has some remote base capabilities that may do what you want.
http://www.kenwood.com/i/products/info/ ... nual_E.pdf
http://www.kenwood.com/i/products/info/ ... nual_E.pdf
Re: Low latency IP Audio streaming for remote base?
Not that I am aware of: likely, the radios will be my IC7000, and a SDR5000 borrowed from work - Which one I use for receive and which one I use for transmit is still open for debate, but I am leaning toward the SDR doing RX at home and my 7000 doing TX.
These opinions are mine, not Aeroflex's - if you want service info, manual, or other official support please contact Aeroflex directly.
Re: Low latency IP Audio streaming for remote base?
Have you tried Skype yet? I have a friend who remoted am MP-1000 with ham radio deluxe and Skype with decent results.
IRLP Node 2410
Echolink Node 152298
Icecast Server
They call it PMS because Mad Cow Disease was already taken.
Echolink Node 152298
Icecast Server
They call it PMS because Mad Cow Disease was already taken.
- motorola_otaku
- Cock Block
- Posts: 6671
- Joined: Mon Nov 29, 2004 8:53 pm
- Location: Stinkadena, TX
Re: Low latency IP Audio streaming for remote base?
There's also Allstar (http://www.allstarlink.org) but I don't think you're going to like the latency with them either.
And the sign says you got to have a membership card to get inside.
Re: Low latency IP Audio streaming for remote base?
I'm not sure Skype gives me anything Ekiga doesn't - both need a central server to set up the call, and at least with Ekiga I can think about running my own SIP server that I control access to.
These opinions are mine, not Aeroflex's - if you want service info, manual, or other official support please contact Aeroflex directly.
Re: Low latency IP Audio streaming for remote base?
Again, a bit heavy - I'd looked at Asterisk, but that's a lot to set up for one day.motorola_otaku wrote:There's also Allstar (http://www.allstarlink.org) but I don't think you're going to like the latency with them either.
These opinions are mine, not Aeroflex's - if you want service info, manual, or other official support please contact Aeroflex directly.
-
- 142490-000000-7
- Posts: 305
- Joined: Sun Jan 23, 2005 10:13 pm
- Location: I sold my soul for a Saber.
Re: Low latency IP Audio streaming for remote base?
Crossband repeat and ham radio deluxe =D
Pass me my Saber -- it's the one marked 'Bad Motherf***er'.
Re: Low latency IP Audio streaming for remote base?
Sorry, HRD has one failing from my perspective - it requires an invasive, stability robbing virus to be installed on your computer.slimbob wrote:Crossband repeat and ham radio deluxe =D
These opinions are mine, not Aeroflex's - if you want service info, manual, or other official support please contact Aeroflex directly.
- smokeybehr
- 98247E-211491-4
- Posts: 3241
- Joined: Thu Apr 19, 2007 12:58 am
- Location: In the muthaf***in' forest, bitch! Where else?
- Contact:
Re: Low latency IP Audio streaming for remote base?
You mean Windows?Wowbagger wrote:Sorry, HRD has one failing from my perspective - it requires an invasive, stability robbing virus to be installed on your computer.slimbob wrote:Crossband repeat and ham radio deluxe =D
mong wrote: If you are a chick, show us your tits
If you're a dude, show rayray your tits
Re: Low latency IP Audio streaming for remote base?
Who said IRLP needs to use their boards?
There's nothing that exciting about IRLP boards. Some LEDs, an 8870 for DTMF decoding (which is fed to the parallel port I/O lines), and some logic-level stuff for PTT and Aux outputs from the parallel port I/O lines.
The whole damn thing runs off of a bunch of binaries written in C, an open-source voice-conferencing program, BASH scripts, netcat, pgp, and cron jobs.
Take a look at the scripts sometime. Starting with the install script.
It's a giant kludge on wheels, but there's nothing stopping you from modifying it, other than perhaps Dave Cameron's IP rights.
Interesting link: http://www.irlp.net/new-install/
There's nothing that exciting about IRLP boards. Some LEDs, an 8870 for DTMF decoding (which is fed to the parallel port I/O lines), and some logic-level stuff for PTT and Aux outputs from the parallel port I/O lines.
The whole damn thing runs off of a bunch of binaries written in C, an open-source voice-conferencing program, BASH scripts, netcat, pgp, and cron jobs.
Take a look at the scripts sometime. Starting with the install script.
It's a giant kludge on wheels, but there's nothing stopping you from modifying it, other than perhaps Dave Cameron's IP rights.
Interesting link: http://www.irlp.net/new-install/
- smokeybehr
- 98247E-211491-4
- Posts: 3241
- Joined: Thu Apr 19, 2007 12:58 am
- Location: In the muthaf***in' forest, bitch! Where else?
- Contact:
Re: Low latency IP Audio streaming for remote base?
I found a schematic for an IRLP interface board that I could easily fab up on a breadboard and transfer it to one of those breadboard PCBs. I just need to order the ICs from one of the usual sources, and whip it up for testing in an evening.
mong wrote: If you are a chick, show us your tits
If you're a dude, show rayray your tits