In a new series of features, WorldDAB members review the latest transmission technologies and trends. The first is from Paneda and looks at Cloud DAB. How does it work and what are some of the benefits?
Lars-Peder Lundgren, Sales Manager, Paneda
In recent years there has been great progress in the DAB head-end market with DAB multiplexing systems. Today, for example, a DAB Head-End system can be delivered according to the customer’s specific needs.
DEDICATED HARDWARE: Traditionally dedicated hardware with physical interfaces, the development has been improved and today a complete system today can be installed in a very compact setup. For example, a DAB multiplexer and 16 audio encoders with associated metadata management and management can be installed in a single 1U piece of hardware. Today most systems on the market use a standardized web interface for managing the complete system.
SERVER HOSTED: A complete system can be installed in a server platform enabling a great number of independent systems to be installed in the very same server infrastructure. The system normally uses virtualization and can host up to 10 different DAB head-end systems with hundreds of encoders. The system can be installed in the customers’ existing server infrastructure or be offered as a turn-key solution with a pre-installed server.
CLOUD: The most dramatic development has been in cloud computing, where a complete system can be installed without any hardware and offered where the entire system is installed as a cloud service. In a Cloud solution, the entire system of the DAB multiplexer and DAB Encoders are installed virtually in a data centre. The customer will be granted access to the system via a web interface, where each user of the system has its own login. A cloud based system offers several benefits: it’s easy and quick to get started, requires no special skills and no hardware that can break or grow old.
TECHNICAL OVERVIEW CLOUD SETUP:
The broadcaster provides audio in various formats as standard web streams, HQ web streams, linear audio or alternatively a DAB encoder can be used locally. The complete DAB stream is transported over IP to the transmission point.
A challenge in the development has been that, with the standard protocol EDI, it is not possible or feasible to transport the DAB output stream over the internet in a robust and secure way, and a new protocol has been required. The complete DAB stream is then received by a Cloud Connector which converts the signal to standardized protocols (EDI) at its output to the transmitters.
Having a broadcast system on the internet requires a focus on security and the latest developments comply to the highest security requirement available as HTTPS, SSL, Certificates and 2 factor authentications. Before, access to the DAB headend system was often more or less unrestricted. Now, you communicate over TLS in your web browser with the same encryption used for connecting to your bank and passwords are reinforced with the same two factor authentication techniques that protect your Google account. Everyone has their own account to ensure changes are trackable and accountable. The servers have built in firewalls to complement the external ones.
If there are several different players in the same DAB multiplexer who independently manage and monitor their own as services, as well as using all the features DAB offers, this meant a system called Service Multiplexers, which means that the system contains a common Ensemble multiplexer and several corresponding sub-multiplexers (Service Multiplexers) who each sends the data stream to the common ensemble mux. This type of installation requires many components and different interfaces.
Today, this is handled in a much better, simpler and more cost-effective way. The latest development offers a built-in function for handling “Virtual providers” and means that in the DAB system it’s possible to connect a certain group of users (or individuals) to a certain range of capacity, service ID and sub channels. Each radio station with its users has its own web interface and can handle its system completely independent of others. Furthermore, the setup offers an improved business model as once the platform is set up, the multiplexer operator can offer capacity in the system.
Even in redundancy there have been a lot of exciting changes. A traditional system with 1 + 1 redundancy means that you usually have 2 identical systems, and after each system you use a redundancy switch that simply selects the best system of the two.
This has had a major disadvantage, that if a radio channel in the main system is faulty (silent or broken) then this switch will select the backup system, forcing all channels to use their backup channels. Many users also want the ability to use web streams as backup, and when all channels are forced to switch over to this, it has not been acceptable.
A new system has now been developed that enables two DAB streams (one from each MUX) to be combined to create a completely correct and error free output without switching. This is possible since the new switch is “content aware” and can combine two faulty streams and combine these, given that the errors are not identical in both multiplexers, in that case there is normally no switching change.
The smart logical switch is installed as a built-in function in the multiplexers and doesn’t require any hardware.
The technology has evolved when it comes to integration with third party tools such as content management servers. Traditionally, integrating with a DAB headend system has not always been easy. First you needed to spend days to get the communication up and running. This could include implementing proprietary protocols or requiring a DLL from the manufacturer. More than often this meant that the third party had to adjust their environment to the DAB systems.
Go back 5 years and it was almost mandatory for an on-site visit for upgrading or bigger maintenance. In the best case you could provide a client PC with teamviewer. Now some systems have built in remote-assistance support. With just a click on a button you can give the manufacturer direct access to the system as if they were sitting next to it. The initial deploying can be done remotely, meaning quicker response times and lower costs. Of course, all access is done securely over links with strong encryption.
The DAB headend systems are moving to a leaner working style. This means no more fixed releases once or in best case twice a year. Using modern techniques such as continuous integration and automated testing, a new release is always present. This means you don’t have to wait for a feature to be included in a major release to get it, instead it is available as soon as it is implemented and tested.