[Jack-Devel] Network Transmission

Hi,

 

I work as a volunteer technical officer at a not-for-profit FM radio
broadcaster.

 

I'm writing mainly for advice in solving issues that will soon be an issue
in the future as there doesn't seem to be any software based solutions.

 

Typically a radio broadcaster will have a studio and a remote transmitting
site and will use microwave or telephone carrier based connectivity to send
audio to the transmitter site. This is called STL. Radio stations often
broadcast time information and therefore want low delay transmissions. There
is an increased use of what the radio broadcast industry is calling STL-IP
or Studio to Transmitter Links over IP networks. With the adoption of
digital broadcasting such as DAB+, STL-IP is becoming the norm and appears
to be a requirement to gain access to DAB+ transmitters in many cases.

 

Typically STL-IP is used with a dedicated hardware device that uses AAC
codecs, has an Ethernet port, supports multicast, and has a routing table
capable of failing over to alternate IP pathways. The transmission standard
is open and Wikipedia has details on this at
http://en.wikipedia.org/wiki/Audio_over_IP

 

STL-IP devices are inherently expensive. The lowest cost installations I
know of cost around $4,000 AUD for hardware. There is the potential for a
developer implementing a software based solution to seek substantial funding
from radio broadcasters.

 

There have been efforts in the JACK project to produce network based
operation, so I thought I'd open discussion here on how STL-IP could be
implemented on Linux. Such an implementation should outperform any existing
network based solution in JACK by far.

 

Regards,

Peter Hoskin

1317471744.14307_0.ltw:2,a <02c801cc8034$af1eae60$0d5c0b20$ at 10mbit dot biz>