IT/AV

Getting Up To Speed For An AVoIP Future, Part 1

An idealized scenario teases out the potential benefits.

Information on AV-over-IP is everywhere you look these days. So, why should you read yet another article on the subject? Well, I’m an audio guy—not a network engineer—and part of my job is to help people understand and implement AV-over-IP solutions. I find there is so much to know, and there’s almost too much information out there. Some resources are overly network-centric, some materials appear as marketing jargon and some information is too broad to benefit the average AV integrator. As such, I’ve decided to sort through the noise to try to help other AV folks (like me) figure out what they need to know to start embracing AV-over-IP.

After this short series, of which this is Part 1, you should be able to do the following:

  • Identify the benefits and challenges of IP-based systems from end users’ and IT managers’ perspectives.
  • Propose IP-based solutions to customers with increased confidence and effectiveness.
  • Discuss and appraise the impact of a proposed IP-based solution with a client’s IT stakeholders.

In no way will we attempt to cover all subjects related to IT/IP, nor will we suddenly make you understand the intricacies of network engineering. Instead, I seek to share my current understanding of this ever-evolving subject—AV person to AV person—and offer tools to engage relevant stakeholders, including vendors, IT managers and end users. In this part, we’ll start with a sample system similar to what we frequently see in a best-case scenario. In upcoming installments, we will drill down into the underlying technologies, potential challenges and alternate options.

Recently, I received a call for a house of worship (HoW) that wanted the worship leader’s image shown on a large screen in the main room for image magnification (IMAG) as well as local sound reinforcement. The HoW also had overflow rooms on the same campus, where it wanted to share the audio and video. In addition, the HoW asked to share the service with homebound parishioners via the internet. Similar scenarios apply in a city hall where municipalities require local AV reinforcement for council proceedings, while also sharing content within the building and streaming via a local-access Public Education and Government (PEG) cable TV channel or via a website. The type of end user in an idealized scenario is almost irrelevant; the principles apply across multiple vertical markets. The key is that there are three different needs—potentially benefiting from three different methodologies—within the same project.

In our simplified scenario, we could take multiple audio, video and control outputs from a conventional AV system and connect them to encoders. The encoders connect to a network switch. Network-connected decoders provide audio, video and control outputs ready to wire into playback systems at the receiving locations. A computer connected to the same network runs the configuration software. Alternatively, a web browser accesses administrator functions running on the network devices. The software or browser-based tools automatically recognize all connected devices and provide easy access to routing between devices. (Remember, this is an idealized scenario. Your mileage will vary.)

The number of AV inputs and outputs are infinitely expandable just by adding encoders and decoders when needed. Many AV devices have the encoder or decoder built in, allowing direct connection to the network. In the near future, a single RJ45 connector might make all other connectors on AV devices obsolete.

Do you want IMAG video in a dozen remote locations and digital signage in 12 others? Click a few boxes. Do you want one camera to record a lecture and stream to all 24 places the next day? Click another box. Want to add more cameras and share with the new building wing? Plug the cameras into encoders, decoders into displays, log into the configuration tool, click a mouse and, voilà!, it’s done.

All things being equal (which they never are), IP-based systems provide easier cable pulls, fewer and faster terminations, simplified expandability and reconfiguration, flexible control and management, and connectivity across greater distances as compared to conventional methods. In addition, IP-enabled solutions often offer features that end users now expect in everyday products, such as remote access or control from their smart devices.

In some situations and configurations, AV-over-IP provides plug-and-play simplicity—an ideal scenario if ever one existed. However, in many cases, the perceived learning curve and the details of interfacing with an existing network infrastructure are among the most significant integration challenges. Bandwidth requirements, working with end-user IT managers and potential latency issues also affect our idealized solutions.

Speaking of bandwidth and latency, those are two of the most significant factors impacting the selection of an AV-over-IP methodology. For example, IMAG requires real-time distribution to minimize the time difference between what appears on the screen and a presenter who is visible within the same space. However, zero-latency distribution often increases the bandwidth requirements, because the processing necessary for signal compression might take too much time. In situations such as those, an uncompressed JPEG 2000 or SDVoE option might be suitable.

On the flip side, several seconds or more of latency might be perfectly acceptable for the outside streaming portion of our hypothetical system, allowing time for signal compression to adhere to bandwidth restrictions. H.264 or H.265 might provide the best option in this case. In between, we have our on-campus rooms with different bandwidth and latency requirements, where we might consider other Layer 2 or Layer 3 solutions.

But what are JPEG 2000, SDVoE, H.264, H.265, “Layers” and all this other stuff, anyway?In our next installment, we will dive into the technical terms and methodologies, identifying where the responsibilities of AV professionals end and where the world of IT managers begins.

By developing vocabulary, we will help build the skills necessary for AV integrators to communicate with end-user IT representatives on customers’ terms. We will also separate terminology into what AV people need to know versus what it’d be nice to know, and we’ll translate typical marketing-speak into everyday language.

In subsequent installments, we will cover some pitfalls and challenges, followed by potential resolution methods.

Benefits Of Network Distribution

Distributing audio, video and control across a network provides significant benefits to stadiums, arenas and other large venues. The savings in materials, installation, maintenance, and upgrades or reconfiguration is frequently sizeable. A few fiberoptic or Catx cables replace thousands of feet of multicore cables and signal extenders. IP solutions often allow remote monitoring or adjustments of devices throughout a vast complex, enabling faster resolution of system issues. In the old days of matrix switches, you either had to prepay for potentially unused switch capacity or had to risk outgrowing the switch in the future. With many IP solutions, the network serves as a virtual switch, providing an unlimited number of endpoints and infinite expandability, reducing the need to forklift expensive equipment during an upgrade or reconfiguration. In most cases, the larger the venue, the more significant the benefits of an IP solution.

Mayor Shelbourne of Swallow Falls probably sums it up best: “Blah blah blah. Science science science. Bigger…and bigger is better!” (see www.sndcom.us/mayorshelbourne).

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