RIP ISDN

In the words of the Fitzy and Wippa song, why don’t you F****ing work!

Well it seems from 2018 it will stop working for a few different Telstra products.

DDS Fastways is not common in broadcast, Frame relay which is not common but still used for some broadcasters and ISDN 2, 10,20,30 will all be exited with a stop sell date of January 31^st 2018 and a shutdown starting from the June 2019 with a complete shutdown to be completed by 2022.

This was bound to happen as ISDN was first invented in 1979 and is switched thru the “AXE” exchanges made by Ericsson which started operating in  Australia in 1982 and with the NBN coming its definitely time to turn them off.

The concern for broadcasters is that ISDN2, commonly used for outside broadcasts and for backup transmitter links in Australia

This will cause issues for broadcasters in regional markets as there is no product that can reliably replace these old technologies. Frame Relay and ISDN are such great products because they are able to be used on such long cable runs from the exchange.

ISDN is especially robust as Telcos can use digital repeaters to extent services and being a circuit switched network which means if you put a packet of audio or voice in 1 end there is a 99.9999% chance it will come out the other end.

I know you’re thinking “oh the NBN will save us” well no it won’t! And this is for a few reasons.. Firstly most transmitter sites are situated often 10+ kilometres out of town or on top of mountains that have very little infrastructure and the NBN will not drag an optic fibre cable out and commission a node for 3-4 users.

And even if they did, There is no COS (class of service) or “priority” on NBN services. Not to mention that AM transmitters and ADSL don’t mix very well as ADSL/ADSL+ uses 138khz to 2.2mhz for signalling.. In most cases it works but not reliably and with a great reduction in speed.

Secondly, The NBN fixed wireless or satellite is not good enough for reliable broadcast audio path due to these services have High Jitter rates  and high contention rates which is not suitable for broadcast technology.

And a double whammy for the industry is the eventual shutdown of the 850mhz STL band.. Information from reliable sources have hinted to a complete shutdown starting around 2022.

This leaves the industry with a problem we all need to solve, the saving grace is we have a few years to find a solution.

About: 

Dale Sharp is a 2015 Acra Winner for Engineering Excellence and the Chief Engineer at EON Broadcasters 92.7 MIX and 91.9 SEA FM on the Sunshine Coast.