A Radio World ebook explores best practices in streaming for radio organizations. This is an excerpt.

Jan Bläsi is software architect for Qbit.

Internet streaming is evolving rapidly and is increasingly important to radio broadcasters. Here are some of the trends we’ve observed.

All-IP architecture

As broadcasters move away from legacy analog and AES3 links to modern IP-based solutions such as Ravenna, Livewire+ or Dante, common off-the-shelf hardware can be used to host modern encoding solutions, such as our Q8V codec system, that may run on everything from our own hardware or COTS hardware to private or public cloud.

When the encoding should be done in public clouds, technologies such as SRT or RIST may be leveraged to facilitate contribution of source audio signals over the public internet without losing any packets.

Importance of redundancy

As internet radio streaming becomes an increasingly important distribution path, broadcasters look for solutions to increase the resiliency of their streaming solutions. 

Encoders are deployed redundantly, leveraging the PTPv2 timing of AES67 to output a synchronized stream from both systems, without needing a control link between them. This allows seamless switchover, even in the event of hardware outages.

On the source side, ST2022-7 seamless redundancy switching can be used to receive a single audio stream over multiple interfaces, without interruptions to the signal in case one of the links fails.

In the unlikely case that all input sources fail, a file backup may be used to ensure that there always is a signal on air.

Another practice that is increasingly common is the use of multiple CDNs for distribution to avoid depending on a single party and to assure competitive pricing. 

Our Q8V solution is engineered to facilitate such setups by allowing the user to send the same stream to multiple CDNs, while ensuring that a failure of one CDN does not bring the stream delivery to a halt. This can even be extended to some hybrid solutions, where a public CDN is combined with an in-house CDN as a backup.

Shiny new technologies

While many broadcasters still rely on long-established technologies such as Icecast or SHOUTcast, the advantages of modern, adaptive streaming technologies such as HLS and MPEG-DASH have led to their widespread adoption in recent years.

Those standards allow devices switching between bitrates to adjust to network conditions and allow the listener to jump back in time if he or she missed a segment of the stream. MPEG-DASH can be used in conjunction with HbbTV to allow adding radio programs to their television bouquets.

In addition to new streaming technologies, broadcasters extend their streaming offerings with modern codecs, such as xHE-AAC by Fraunhofer IIS, which allows for good-sounding audio at bitrates of down to 12 kbps (in stereo) while also ensuring seamless switching to bitrates to up to 500 kbps. 

It also includes dynamic range control (MPEG-D DRC), allowing listeners to apply different loudness profiles depending on their location. Listeners may use a more compressed DRC profile when sitting on a train or in the car, and another profile with more dynamics in their homes, where better speakers are available and there is less noise.

Additionally, new standards such as E-AC-3 and AC-4 Joint Object Coding by Dolby can be used for experiences that are more immersive than ever.

Modern encoding systems combine more features into a single solution. Comprehensive audio processing solutions integrated in the encoding system eliminate the need for extra processors in the chain, reducing costs and making operations more streamlined. Also, all metadata processing is concentrated in the encoding solution, leveraging integrations with playout systems.

Secure and monitored

The importance of security-hardening devices is more and more evident. Locked-down firewalls and detailed access control, for example using LDAPS, ensure that no unauthorized party can adjust settings and cause issues. Management access is restricted to using HTTPS, avoiding man-in-the-middle attacks.

With an increasing number of streams, monitoring is getting more challenging. Thankfully, modern monitoring solutions allowing for continuous download monitoring and visualization with control room views, like our own QAMOS, are available. Even when the system is not actively monitored by an operator, comprehensive alarming ensures that they are notified of any outages via mail or text message.

Customers can keep an overview of all of their streams, ensuring there are no issues and keeping listeners happy.

Read the Radio World ebook on streaming best practices.

The post In Streaming, Resiliency and Monitoring Grow in Importance appeared first on Radio World.