LOS ANGELES — We’ve previously covered virtualization of DAB mux encoders. A recent article from worlddabeureka.org has provided a little more detail, which should be of interest to those of us in the U.S. as well. Let’s take a look at it.
According to VMware, “Virtualization is the process of creating a software-based (or virtual) representation of something rather than a physical one.” Virtual machines, which run on a larger server, provide the functionality that was previously provided by a physical computer.
As an example, the IZT DAB ContentServer is based on standard server hardware and can be cost-effectively operated in virtual machines.
“Traditional DAB head-ends were designed using several dedicated devices for different purposes. In contrast, now we can incorporate audio encoding, data service handling and multiplexing in one entity — including configuration and monitoring capabilities. The software system is installed on a standard IT server, saving rack-space and energy costs as well as facilitating the replacement of defective or obsolescent hardware. The use of standard hardware and integrated audio encoding bring the benefits of lower hardware costs, cost-efficient maintenance and a significantly lower risk of failure,” according to the same article.
IZT recommends using VMware ESXi as hypervisor for the set up a virtualized DAB head-end. Each DAB service or ensemble multiplexer requires a separate ContentServer instance; the ContentServer software system includes and integrates an operating system (Linux Ubuntu-based). Additional virtual machines can also be installed--for example, software to analyze the EDI output streams of the multiplexers, which ultimately reach the actual MUX transmitters.
Use of VMware ESXi allows for configuration of physical and virtual network interfaces via a web interface. Each multiplexer system in the setup can be accessed via its primary IP address; however, each multiplexer can also be accessed via different VLAN interfaces, such as those transporting Audio over IP (AoIP) from different service providers, and outbound links to transmitter sites. The host system and VMs can be monitored using SNMP.
“Broadcasters and network operators can benefit from building DAB head-ends based on virtualization – especially in case of complex setups, such as multi-regional DAB networks. However, virtualization requires careful system planning and monitoring. Accordingly, a system supplier should involve the operator’s technical experts and system architects for the integration of the system into the IT infrastructure,” according to the same article.