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VIRTUALIZATION IN RADIOHow Broadcasters Are Leverag-ing Computing Power to Minimize Costs, Rack Space & Complexity

Over the past 10 years, the art of building radio stations has changed dramatically thanks to the wide adoption of AoIP networking. But the change isn’t finished: broad-casters are again looking to the IT industry, and their use of Virtual Machines — envisioning the virtualization of hardware as the next logical step in broadcasting’s infrastructure revolution.

Virtualization

Virtualization has been the hot topic in the IT world for the past several years. Everybody’s talking about “the cloud”, and everybody’s trying to virtualize everything. Why? Vir-tualization provides business operations with higher IT ef-ficiency, improved reliability, and simplified IT operations.

In computing, virtualization refers to the creation of a virtual version of something – a version that exists only in computer memory. Virtualization can include virtual computer hardware platforms, virtual operating systems, virtual storage devices, and even virtual computer network resources.

Broadcasters are talking about virtualization, too. But in most cases, when broadcast equipment companies refer to “virtualization,” they aren’t describing broadcast devices that exist in digital form; they’re talking about old-fash-ioned remote control of hardware – a way of using PCs to connect to physical devices they already make. It’s plain that this is not really virtualization in the modern sense.

The reason virtualization is so popular in the IT world is that virtual software devices running on server hardware are much more scalable, serviceable and upgradable than their physical counterparts. In the IT world, building server farms or data centers is not an easy task when you are working with 100,000 physical computers – but having their equivalent in virtual machines enables them to diag-nose, fix, and scale easily, with a central point of control.

One of the benefits of virtualization is that commercial, off the shelf hardware (referred to as COTS) and software can easily be used to build these virtual machines. This is why IT professionals think virtualization is cool. Now let’s examine the reasons Radio engineers might think so.

First, we could replace dedicated hardware devices (audio processors, mixing consoles, codecs, etc.) with software applications. It’s much easier to update software than to update a hardware box. Sure, we can update firmware – but when the hardware runs out of memory or DSP horse-power, its capacity to add new features is diminished. This is not true in the PC world; computers get more powerful

all the time. Replacing the computer you installed a few years ago with a new computer that costs the same (or maybe less) instantly doubles, or even triples, the power you had before. This ongoing increase of computing power allows software apps to continually evolve, improve, and offer more functionality.

Second, software reduces cost and complexity. Software apps eliminate the need for collections of cabling and boxes, but they also eliminate real, hard costs – the costs of power supplies and sheet metal and DSP chips and color displays. And software apps themselves often cost less than their hardware equivalents, with savings in the realm of 50% (or perhaps more).

Third, software allows the use of commercial, off-the-shelf (COTS) hardware and software as a platform for originat-ing and producing Radio broadcasts, again reducing cost compared to dedicated, single-purpose equipment.

Finally, software apps enable cloud architectures, some-thing broadcasters are dreaming and talking about. They’re asking: if there’s a data center out there, like an Amazon Cloud Services, why can’t I use that to create radio from anywhere? Migrating from boxes to software allows this.

So why are broadcasters interested in virtualizing the de-vices they use to create radio programming? For the same reasons as IT: lower cost to implement, higher reliability, a scalable architecture, and increased flexibility - for ex-ample, the ability to design and administer radio studios company-wide from a regional or central office.

Unfortunately, the way radio studios are built today requires racks full of hardware. Most of these – audio processors, codecs, phone systems, etc., are based on Digital Signal Processing technology. All of them send their audio to the mixing console, which in modern terms is also a box with DSP inside. Often, studio computers use sound cards for audio playout, and those cards often rely on DSP as well.

Notice the common element to all of these items just named: DSP. All of these devices performing their work in the digital domain; mixing, compressing, levelling, con-

VIRTUALIZATION IN RADIO

HOW BROADCASTERS CAN LEVERAGE COMPUTING POWER TO MINIMIZE COSTS, RACK SPACE & COMPLEXITY

necting, sweetening, editing and more — yet all housed in separate pieces of hardware.

To state it plainly: the entire ecosystem of today’s radio studio is really just a series of boxes wired together. Even though we’ve migrated to digital audio from analog, the digital implementation looks and behaves and connects just like the old analog equipment it replaced. What if all of those devices became software applications instead?

Dematerialization

The terminology may be unfamiliar, but the experience is not: Your smartphone is an excellent example. Think back to the old days and you’ll remember carrying a briefcase filled with the things you needed to accomplish your daily work: notepad, calculator (perhaps a slide rule!) voice re-corder, camera, pocket dictionary, electrical engineer’s ref-erence book and more. Literally hundreds of functions have been absorbed into our smartphones, and we now have one device that does many things. That’s dematerialization in a nutshell: replacing hardware devices with software apps — which usually do a better job.

Even though it seems revolutionary, dematerialization has actually occurred in radio before. Back in the analog days, we played audio from records, magnetic tape and cart ma-chines. In larger stations, it wasn’t unusual to have three or more turntables, four tape decks and six or eight cart machines, each tied to a dedicated channel on the console – which made for very big consoles!

Then, we added digital. Unfortunately. these new devices didn’t replace analog; we simply added a couple more fader strips for CDs. Then, we toyed with magnetic DAT tape and MiniDiscs, thinking these would replace cart machines. But instead, they added to the proliferation of audio devices within the studio.

Then came the turning point: personal computers powerful enough to record, edit and play broadcast-quality audio. Within a few short years, audio applications replaced all of those devices. It’s very difficult now to find a cart machine or a reel-to-reel tape deck in a radio station, or even a CD player — because their functions have all migrated to the

studio PC, which is now used for playback of music and recorded program elements, audio production and editing, automation for unattended audio playout, plus program logging and other audio functions.

This is why radio longs for dematerialization: we’ve already seen it happen, observed its benefits — and we want more of it. So, you may ask, why did dematerialization stop at audio playout?

The short answer: we didn’t have enough power to go fur-ther at the time. The fastest computer then was a Pentium IV, running at 3 GHz. In order to play audio and perform the other functions previously discussed, a computer of that class was stretched to its limit — often, 90% of system resources (or more) were consumed just in order to play four audio files simultaneously. There simply wasn’t enough headroom left in that machine to allow running virtual equivalents of other broadcast hardware devices.

But computer technology marches on. Today, for less than the price you paid for that old P4, you can get a computer with a CPU that’s at least 30 times more powerful.

Although the PC’s power has changed dramatically, the resource requirements for those apps are essentially unchanged. It’s like using your Xbox to play Pong: it’ll do the job alright, but it’s sure capable of so much more. Your shiny new PC is barely breathing.

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How Many MIPS?

We have tons of excess capacity going to waste; power we could use to convert even more boxes into software. This is where it gets really interesting!

Dematerialization, Part II

Let’s examine the contents of a typical modern radio stu-dio. Common equipment includes mixing consoles, remote codecs, telephone hybrids, voice processors, final audio processors, streaming encoders and sound cards. These are expensive items — which is why the price of building a typical radio studio is so high.

These products can all be built as software apps installed on our studio playout PC. We can turn dedicated hard-ware into software, and run it on the same computer that handles the playout software.

This obviously eliminates complexity, since all of the rout-ing and control are now running on the same PC. This is much easier to manage; reduces a lot of cabling, and finally unlocks the power of your PC.

Of course, we can’t virtualize everything. We still have mics, headphones and speakers. And though we’ve moved audio compression, playout, phone hybrids, mixing and such into the computer, we still have to get audio in and out. So we still need some sort of a PC sound card.

Since mixing is now performed inside the computer, the number of inputs and outputs needed is greatly reduced. But we still need some — a USB or AoIP interface to connect to mics, speakers, etc. With our analog gear con-nected to our computer, we’re ready to get virtual.

Where Will The Apps Come From?

Believe it or not, many of the individual apps we need for our virtual studios already exist. Just as with smartphones, various companies have developed PC apps that work inside a virtual radio studio environment – apps that elimi-nate or reduce the need for physical boxes.

Codecs

Codecs for remote broadcast are a common part of many radio operations. One such company, Source Elements, makes a broadcast-oriented codec app called Source Connect Pro for live remotes and voice-over work. Using AAC-LD MPEG-4, this program can transport full-fidelity 20 kHz. audio over standard IP connections, eliminating the need for costly ISDN lines. AudioCompass is another such offering. Programs such as these have become the heirs-apparent to ISDN; voice-over artists have come to rely on them. All of these codecs run in the PC environ-ment.

Phones

Likely you’re already familiar with Skype. In fact, many broadcasters already use Skype very effectively.

There is, however, a professional multi-line phone system from Broadcast Bionics, This is a complete VoIP talk show, with call screening, line switching, and even DSP hybrids contained within its sophisticated software.

VIRTUALIZATION IN RADIO

HOW BROADCASTERS CAN LEVERAGE COMPUTING POWER TO MINIMIZE COSTS, RACK SPACE & COMPLEXITY

Program Processing

One of radio’s most hotly-debated topics concerns final program processing. Much discussion, and money, is ap-plied to determining which hardware will make your station stand out amongst the crowd. Arguments about which is best can easily reach the same fevered pitch found in political debates, or football discussions.

And prices for premium processors can reach $10,000 or more; much of the cost comes from the hardware plat-forms used to run the audio-shaping algorithms.

But those algorithms are already coded in software, so logi-cally there should be no barrier to using COTS computing platforms to run those algorithms. In the recording world, mastering processors have been available as software plugins for some time now – and some of them are not so different from the final audio processors we use in radio.

In fact, there are already some powerful broadcast audio processors written just for PC environments. For instance, Orban, the company that practically invented modern radio processing, is enthusiastic about virtualization. Their PCn 1600 software shown below brings the suite of Optimod sound-shaping tools, and distinctive Orban sound, to the PC world.

Another program, Thimeo Avant, comes from Stereo Tool creator Hans Van Zutphen. Avant is a full-featured final au-dio processor for radio which features a very sophisticated

declipping algorithm that can actually undo the damage produced by overaggressive audio mastering.

Stream Encoding

Many, if not all, broadcasters now deliver programming to the consumer via Internet as well as over-the-air. Since the programming is delivered via Internet livestream, it’s only natural that a large number of livestream encoders are natively PC-based.

Shown below is StreamS from Modulation Index, a pro-fessional HLS/MPEG-DASH streaming encoder software named nCode. This software employs multiple adaptive MPEG AAC and HE-AAC encoders, so that a single input can be translated into output streams of multiple bit rates suited to the receiver’s device.

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Virtual Mixing And Routing

Mixing is a huge part of virtualization. After all, the mixing console is still the center of the studio, be it physical or virtual — something has to mix incoming signals, control gain, create mix-minuses, generate program feeds, etc.

Lawo has developed a family of virtual radio mixing prod-ucts called RƎLAY, with all of the familiar capabilities and controls you would expect to see in a physical console, albeit optimized for multi-touch control using a laptop, tablet or a properly-equipped desktop. Faders, headphone and monitor controls, trim, balance and so forth can be adjusted on-screen with a touch, and DSP plug-ins provide compression, expansion, noise gating, equalization, etc.

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OnAir4

Newer generations of operators have even expressed a preference for touchscreens versus traditional faders and controls. In fact, virtualizing the mixing console can make it even easier to produce flawless shows with minimal interaction.

For instance, RƎLAY operators can choose hands-free mix-ing with AutoMix, an intelligent algorithm that dynamically adjusts the gain on multiple faders in response to input levels. Another function, AutoGain, calibrates mic input gain automatically while talent speaks.

For audio routing applications, RƎLAY Virtual Patch Bay emulates the familiar patch panels found in nearly every TOC rack. It can save complex configurations as presets for fast recall, making quick work of routing scene changes.

Virtual Patch Bay comes with a variety of DSP signal pro-cessing modules. It also works with VST plugins, such as

those used in recording studios, which makes it something much more interesting than just a routing switcher — it’s middleware that can host studio-quality signal process-ing and effects, enabling further virtualization of hardware functions.

What Shall We Build?

Now that nearly all our broadcast tools have become soft-ware, we can think about the broadcast studio in a differ-ent way.

Instead of the traditional radio plant built with racks of specialized hardware, we might now think of a broadcast studio built utilizing generic DSP resources running on commodity computing platforms. With the increasing power available in desktop and laptop PCs, and the rich selection of software apps to run on them, the possibilities are wide open.

For instance, we can easily build a stream server. Imagine a powerful, off the shelf PC running an AES67 networking driver. We install audio processing and stream encoding, and a single audio input can be replicated using multiple bit rates and encoding methods – a multi-format stream server.

VIRTUALIZATION IN RADIO

HOW BROADCASTERS CAN LEVERAGE COMPUTING POWER TO MINIMIZE COSTS, RACK SPACE & COMPLEXITY

Or how about a multi-channel audio processor? This might be comprised of 6 (or 16) of the stereo audio processing apps we discussed earlier. Each processor is fed with a unique source, which is processed and sent to a broadcast destination — transmitter site, stream server, or individu-ally tailored headphone feeds for all your studio guests.

An IP-codec server could be built using the same idea. Reporters in the field, equipped with smartphones running off-the-shelf codec client apps, can connect back to a cen-tral codec server for distribution inside a broadcast facility, or to a number of clients or affiliates.

What about a multi-touch console? It’s quite possible now. Install your console app on an off-the-shelf 2-in-1 PC or tablet, add some or all of the other software we’ve dis-cussed, and you’ve built an entire virtual radio studio.

We can scale this geographically, too. Broadcast software apps running on a central IT server, with distant clients connecting to the core using, for example, an MPLS connection with enterprise-level QoS. This allows us to concentrate our resources in one location for maintenance, while users on the edge have all the tools they need in a thin-client installation, with little local hardware required.

Apps In The Cloud

Engineers are often asked “When are we going to be in the cloud?” Of course this provokes laughter, because it’s a rather open-ended question. But we’ve already seen how services performed by dedicated hardware can be virtualized, run on commodity PCs, and scaled upward as needed. So let’s take it a step further: let’s move some of those apps onto Web-based servers, to be accessed from nearly anywhere and scaled on-demand.

In the illustration above, a generic server (or farm of servers) runs virtual machines. The virtualization layer (or “hypervisor”) creates and manages the virtual machines on the host hardware. These virtual machines act just like physical Windows- or Linux-based computers, which run our apps.

Using this method you can now build for $10,000, using virtual server space, what would have cost $25,000 using physical hardware — plus the cost of supporting infra-structure, cabling, switching, electricity, and installation & maintenance labor. That’s a lot of money saved for other things.

The key to making this happen, as we’ve already noted, lies in converting the boxes we now have into software apps.

The Virtual Radio Studio

The sum of these pieces – a COTS computer or tablet run-ning the apps, perhaps also sending livestreams to a cloud-based streaming server – equals a complete radio studio at half the cost, without very much hardware.

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But there’s still the question of how to get audio into and out of the PC. Recording studios long ago moved from sound cards to USB, Thunderbolt and FireWire interfaces. But here, broadcast is way ahead of the recording industry: we have AoIP.

Here’s an example system using AoIP for audio interface. Microphones, headphones and speakers connect to an AoIP I/O device and standard Ethernet switch, plus the PC-based DSP farm previously discussed. The PC is equipped with an AoIP driver (Lawo’s RƎLAY VSC Virtual Sound Card) to produce and consume AES67 / RAVENNA network streams. A stereo generator could be connected to the switch to feed the transmission chain.

This compact setup makes it possible to perform audio mixing, routing, mic processing, final audio processing etc., completely within the computer environment. Though the illustration here shows a radio transmission chain, most applications will include a software stream encoder generating Internet audio. The need to maintain separate hardware boxes, or worry about middle-of-the-weekend power supply failures, is gone.

Let’s condense this concept even further: we can put an entire virtual studio inside a common laptop computer.

For example, Lawo’s RƎLAY VRX Virtual Radio Mixer soft-ware runs on a COTS computer. No external mixing engine is needed; all mixing happens inside the PC using native resources. With the laptop connected to a RAVENNA net-work, the VRX application can mix any AoIP stream.

The RƎLAY AoIP interface provides the audio I/O as well as another key piece of the broadcast environment: ultra-low-latency monitoring.

Ever since radio embraced real-time DSP processing in the 2000s, live monitoring latency has been an issue. Non-live program elements have a few milliseconds of latency, but they are not the issue; it is mic-to-headphone delay that derails talent, and any virtual mixer will necessarily have such delay.

We solve this by including a low-latency monitoring side-chain inside our audio interface. This allows the creation of an instant “pseudo-mix” whenever talent’s mic is opened. The virtual mixing software can continue its mixing, processing and other DSP-based tasks, and while it does so, the I/O interface can mirror control input and provide low-latency monitoring for mic sources.

Since it contains no DSP processing, this dedicated moni-toring sidechain has very little latency. Using it, we can mix live mic audio with non-live sources so that talent can hear the mix without being distracted by their own voices slap-ping back. This completely mitigates the mic-to-headphone latency problem. Clever, yes?

Scaling The Virtual Studio

Not everyone is comfortable using a PC as a broadcast ap-pliance – folks often prefer “big iron” IT hardware. These

VIRTUALIZATION IN RADIO

HOW BROADCASTERS CAN LEVERAGE COMPUTING POWER TO MINIMIZE COSTS, RACK SPACE & COMPLEXITY

facilities have already virtualized their broadcast hardware; in fact, some very large broadcasters utilize blade servers just like these to run generic hardware equivalents within virtualized environments as the basis of their entire broad-cast operation.

Using a hypervisor like VMWare, blade servers can host 10, 20, or 50 PC equivalents. There’s no reason a blade server loaded with virtualized broadcast apps can’t take the place of traditional broadcast hardware.

These hypervisors are built for high-availability applica-tions, such as banking, air travel, and electronic com-merce. In the IT world, a failed blade results in an alert dispatched to the engineer – who is also told that the job of the failed blade has been automatically taken over by a redundant blade. It’s almost as though hypervisors were created expressly to serve the 24/7 needs of broadcasting.

Using IP for audio also means that we can move audio around at will, as data packets, inside the IT environment. We can send audio into the blade server by way of an AoIP connection to a standard NIC, using a hypervisor which can produce a virtual Ethernet switch (software-defined networking, or SDN). Our many virtual audio devices now connect and pass audio to each other by way of this virtual network.

And all of this can be scaled up on demand. Why not? Our devices are all virtual now — everything from the mixing console to the AoIP switch.

Summary

In the IT world (and in the recording industry), virtualiza-tion has replaced the old-fashioned “one box per function” model with apps that run on commodity hardware.

Broadcasters can use this technology in the same way, to lower the cost of building broadcast studios – just as recording studios have – while maintaining quality and increasing reliability.

With those lower costs come benefits which positively impact the ease of maintaining and upgrading facilities. Remote upgrades and diagnostics, a difficult operation with legacy hardware, are suddenly very easy.

Virtualization also makes the broadcast plant instantly scalable in terms of capability and capacity. Since comput-ing platforms are essentially large DSP resource pools, the need for another codec, another phone bank, more audio processing channels, or nearly any other audio device you can think of can be satisfied, not with the purchase of another expensive discrete box, but by launching a new VM and loading another instance of software.

Best of all, the capabilities of commodity computing hardware will continue to rise, and cost-per-MIPS to fall following Moore’s Law, as they have done reliably since PCs first came into wide use. In this way, the transition to virtualization nearly guarantees regular, incremental up-grades to broadcast plants in a cost-effective manner that could never be accomplished with the old hardware-based model.

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About LawoLawo designs and manufactures pioneering network, control, audio and video technology for broadcast and post production, as well as live performance and theatrical applications. Products include control and monitoring systems, digital audio mixing con-soles, routers, video processing tools as well as solutions for IP-based A/V infrastructures and routing systems. All products are developed in Germany and manufactured according to highest quality standards at the company’s headquarters in the Rhine valley town of Rastatt, Germany. For additional information, please visit the company online at www.lawo.com.

www.lawo.com

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© 2016 Lawo AG. All rights reserved. Windows is a registered trademark of Microsoft Corporation. Other company and product names mentioned herein may be trademarks of their respective owners. Product specifications are subject to

change without notice. This material is provided for information purposes only; Lawo assumes no liability related to its use. As of July 2016.