Opus Codec Appears in Broadcast STL System

Today’s news dump included an article on GatesAir, now a freestanding entity, it was once the transmission division of what was then known as Harris Broadcast. The company makes radio and TV transmitters, as well as related equipment, which includes studio-to-transmitter (aka STL) links. According to the Broadcast Beat article they have sold and installed one of their Intraplex IP STLs to WRLY-LP, a low power radio station in Raleigh, NC.

A broadcaster with a transmitter that is not located right at their main building (not co-sited) needs an extremely reliable means of sending their broadcast signal from the studio to the transmitter location. They also need some way to get some transmitter telemetry back from the remote location so that they can monitor the health of the transmitter. Their on-air presence via the transmitter is, after all, their bread and butter.

The STL is most usually an RF link, typically some form of licensed point-to-point microwave system. However, as IP networks have matured, and broadcast margins slimmed, an IP-based STL have come to present a cost-effective alternative to a wireless link.

What makes this GatesAir IP-STL interesting is that they trumpet is use of the Opus audio codec to deliver superior audio quality over the IP transport. The device includes Linear, AAC-LC, Opus & G.722 as standard audio codecs. Other codecs are optionally available, but why bother when Opus can do that job so very well.

Surveying the press releases, it seems that the Intraplex IP devices were introduced earlier this year at NAB2104. This is one of the first times that I’ve seen Opus making waves in dedicated hardware products completely outside of telephony, video conferencing, WebRTC, et al.

Incidentally, Polycom co-founder and otherwise VoIP luminary Jeff Rodman was once Director of Engineering at Harris Video Systems, a precursor to Harris Broadcast.