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Episode 12 – So You Think You Know USB?
In the last decade of pro AV, USB has exploded from a protocol for keyboards and thumb drives, to a critical part of AV infrastructure. Cameras, microphones, and speakers regularly connect via USB to provide the “bring your own meeting” experience. But how much do you really know about USB? Is USB3 just faster USB2, or something more? What the heck is USB-C? And why is USB so hard to extend? Our guest Tavis Sparrow comes from Icron, the leaders in extending and switching solutions for USB, and he will shed light on answers to these questions and more.
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Sr. Technical Business Manager, Icron Technologies
Tavis is a Sr. Technical Business Manager at Icron Technologies, a world leader in USB extension technology, supporting customers in North America and Europe with applications assistance. Tavis brings 25 years of analog and telecommunications engineering experience, helping to bridge gaps between unique design challenges and reliable connectivity solutions.
Justin Kennington (00:09):
Hello and welcome everyone to SDVoE LIVE! I’m your host, Justin Kennington, and this is TV for pro AV. We’re going to talk about something a little bit different this week. We’re going to talk about USB. What started out, now 25 years ago if you can believe it, as a simplified way to hook up your mouse and keyboard, and maybe your printer, has really turned into something very different that now affects pro AV in a big way. Today we’re going to try and dissect things a little bit. We’re going to talk about USB 2, USB 3, USB 4 and how USB-C fits into all of that. Our guest is Tavis Sparrow. He’s a technical business manager with Icron. I hope many of you know Icron already. They’re a member of the SDVoE Alliance, but they’re also leading experts in the field of USB extension and switching.
We’re also going to dive into why that is a challenging field that deserves to even have a leader. Just use a longer cable, can’t you? It’s not that simple. Tavis will explain a little bit about why. Before we jump into the rest of the show, a couple of agenda items to cover. I want all of you to join us for our aftershow. That’s exclusive content inside SDVoE Academy where you can log in for free.
Without much further ado, we’re going to go to my co-host Matt Dodd over in our classroom to talk you through our next segment.
Matt Dodd (02:32):
Hello, everybody. Here’s a snippet from the latest course in SDVoE Academy, “So You Think You Know USB?”
Tavis Sparrow (03:24):
We’ve all seen USB ports on equipment, and we’re all pretty familiar with them. But how much do you know about how USB works? Are you able to explain to a customer the relationship between USB types, payload and data throughput to allow them to make an informed decision about which USB type to choose? This short course will lay out the building blocks to give you more confidence in making sure your customers are furnished with the facts they need to know. The universal serial bus has been a familiar friend since 1996, offering a much simpler way to connect with devices such as keyboards, mice, and printers. In those early years, USB 1.1 gave us up to 12 megabits per second of bandwidth to work with, also known as Full Speed, plenty for those tabletop human interface devices commonly referred to as HID devices. By 2001, USB 2.0 came on the scene with 480 megabits of bandwidth, also known as High Speed, and ushered in a new era of convenient-to-connect, sophisticated products such as mass storage devices, thumb drives, high-speed network adapters, external displays and of course, streaming cameras.
Starting back in 2011, USB 3 has been adopted by the vast majority of contemporary host devices, including PCs, laptops, tablets, smartphones, and gaming consoles, to name a few. Within the USB 3 standard we’ve arrived at version 3.2 and break down bandwidth into Gen 1, which is five gigabits per second, also known as SuperSpeed, Gen 2 which is 10 gigabits per second, also known as SuperSpeed Plus, and Gen 2.2, which is 20 gigabits per second, also known as SuperSpeed Plus Plus. Put simply, we now benefit from much richer experiences beyond what USB 2 bandwidth can provide.
Is USB 3, just a faster flavor of USB 2? How host hubs and devices communicate with one another has also evolved. Prior to USB 3, it used to be 2.0 and 1.1 were half-duplex systems meaning data could only be transmitted in one direction at a time, just like speaking on a walkie-talkie. You only need one pair of wires for the job, which is why those familiar type-A connectors have four pins on them, two for communication and two for power and ground. USB 3 introduces full duplex communication whereby both sides of the USB network can transmit to each other at the same time. We go from the walkie-talkie experience to a phone call. For this full-duplex mode of communication, we need more wires to work with. So the next time you look at those blue-colored, type-A connectors, you may notice the second row of five pins buried in the connector. Two pins for transmit, two pins for receive and another ground pin that’s tied to the shield of the cable. The takeaway, USB 3 traffic runs across a different communication path than USB 2.0 and 1.1.
Matt Dodd (06:43):
We just published that course in SDVoE Academy. After that section, it goes into the pin outs – from the type-A connector moving into the type-C connector – very much worth going and checking that out.
Matt Dodd (07:29):
Let’s go straight into the news. (Visit “Resources” on the episode 12 page in SDVoE Academy for links to the articles.)
First up, you gave me some reading to do here. This was very interesting – the North American USB device market forecast. What was your takeaway on this?
Justin Kennington (07:57):
Two things I thought were interesting. One is how much the automotive industry has an impact on USB devices. They’re predicting a 10% annual growth rate for the next six or seven years for USB devices, much of that driven by the automotive market. If you think about it, people do like plugging USB things into their cars these days, but more relevant to pro AV was the effect the pandemic had on USB devices. It was twofold. It was on the supply side. They mentioned, as in many electronic industries, a crunch on factories being able to produce devices and this having a negative impact on sales of course. On the other hand, as people are staying home more, working from home more, they want to upgrade their home office setups. A lot of this is those streaming cameras, those USB attached microphones, maybe more mass storage devices for transferring all the work that they’re doing. That’s driving an increased demand for USB devices. That’s driving that overall growth.
Matt Dodd (09:01):
It’s clear that there’s going to be huge growth and that leads us to the second piece of news – a real eye opener for me – the whole USB-C/USB 3 piece.
Justin Kennington 10:49):
First of all, we should clarify the difference is USB-C is a type of connector. USB 3 is a protocol that defines how fast and how the things operate. USB-C might carry a USB 2 signal, or it might carry a USB 4 signal or one of the USB 3 signals, of course, but connector types versus protocol standards are different elements.
That’s the difference between these two, but then the article gets into all of the extra features that a USB-C cable can bring, which is not only carrying USB signals, but carrying native video signals. It has extra pins set aside so that you could move DisplayPort or HDMI over this cable, not as a USB signal, but as a DisplayPort, as an HDMI signal. You can carry a lot of power over these cables, the a hundred watts to charge your laptop and yet different devices have different capabilities, different cables, and support different versions of those features. It becomes a real challenge for the folks in charge of communicating that to the broader audience. Remember, this is not just a pro AV audience. Here in pro AV we’re all relatively sophisticated when it comes to technology and understanding these things, but USB is after a mass market of a lot of folks that don’t live their lives inside the technology bubble. Being able to communicate all these things is a challenge that I’m glad isn’t on my plate, frankly.
Matt Dodd (12:22):
Absolutely. And it’s worth mentioning as well, that there’s a piece about Thunderbolt in there, just the type of USB-C cable. You don’t just assume that one cable is going to serve all purposes because it doesn’t. In fact, towards the end of the article, it really makes your eyes open. When you think in the earliest stages of USB-C, a cable was able to draw potentially too much from a machine it was connected to and fry it. That’s not the case now, it’s very quickly been resolved as the Gen 1 and Gen 2 have increased. You can’t just plug it into any USB-C and it will serve all purposes. Lots to think about there. Thankfully, Justin, we’ve got the right guy to help us think it through haven’t we?
Justin Kennington (13:25):
If anyone can clear this up for us, Travis will be the guy to help.
Tavis Sparrow (13:36):
Justin Kennington (13:42):
This is a hot topic these days, and we’re very happy to have someone who lives and breathes it every day to tell us about it. So first, tell us a little bit about yourself, Tavis. I told them you’re a technical business manager, but what do you do day-to-day besides just plugging and unplugging USB devices?
Tavis Sparrow (14:02):
My responsibilities at Icron are multifaceted, as most of us have many hats. In North America, I’m responsible for our OEM partners so I deal a lot in embedded applications, but I also have a field applications engineering responsibility here in North America, as well as in Europe. I spend a lot of time talking to engineers, system designers, specifiers, installers, if you will, on the front side of things to help them navigate their plans and their courses of action. Then they are eventually handed off to our internal tech support team for the deep stuff, they start getting on the front lines with them.
Justin Kennington (14:48):
Sure. Give us a little intro to Icon for anybody who doesn’t know.
Tavis Sparrow (14:55):
Icron Technologies has been around for almost as long as USB has been around. Our founders immediately recognized, back in those days, being limited to five meters of cable length might be an issue for some and that was well ahead of the curve of where we are right now with the consumption of high-speed video in these conference venues. We would like to think of ourselves not only as a product company, but as a technology supplier as well, especially to our embedded customers. What we do every day, and the only thing we do, is USB extension. It’s such a simple statement to make, but the devil’s in the details, and it’s hard to do.
Justin Kennington (15:40):
Can you give us a little flavor of that? I mean, 20 years ago and we needed to extend our VGA signal, you buy a longer cable, maybe the picture gets a little fuzzy, but it works. How is there a whole company built around the idea of extending USB? What’s the challenge?
Tavis Sparrow (15:59):
USB, fundamentally, if you had to distill it all down, is extremely sensitive to its timing constraints. When you send information from one side of the USB network to the other, there’s a small window of time that something has to be communicated back. Think of it in terms of an ACK packet or something like that – very, very small windows of time. The standard, even until today, has never been designed to embrace long transmission lines or the concept of extension.
You recall that USB was basically to connect your computer – a laptop or PC – to something that was probably going to be an arm’s length away: a keyboard, a mouse and a printer. That high-speed information didn’t have to travel very far down a wire so timing maybe wasn’t so hard to achieve. Now when you want to take that six-foot distance of your arm’s length away and turn that into 330 feet, you have some physics in the way. That’s the challenge on the extender companies. How do you accommodate added latency and delay in the communication path without having USB fall over, because again, USB is not designed for it?
Justin Kennington (17:17):
How much of your extension marketplace is focused in pro AV then? However you want to quantify that is fine, but I’m thinking that probably pro AV must be a lot of the places where people want to do extension. Is that correct?
Tavis Sparrow (17:37):
Yeah, absolutely. Our customer engagement in the field is going to be dominated by people doing things with cameras and audio devices. That is definitely the lion’s share of it, but the comfortable legacy stuff is always going to be there too. Even though we’re focusing on USB 3 and beyond today, USB 1.1 even is still important for our people doing KVM applications where you’re extending mice and keyboards and things of that sort to multiple consoles. But yeah, definitely it’s high quality video we’re getting involved with most of the time.
Justin Kennington (18:18):
It sounds like you’re already touching on the answer to my next question, but what’s hot around USB and pro AV? What’s the interesting, new, or just the dominant application that’s challenging and taking up your time?
Tavis Sparrow (18:35):
It’s how far behind the leading edge of technology does it take industry to catch up to what’s available? A couple of years ago we released our flagship USB 3-2-1 extension technology and it’s still growing very, very well. Back then, it was a fancy device to extend USB 3 Gen 1 signals up to 330 feet point-to-point. It was impressive, but it seemed to be more of a Cadillac solution in a luxurious application. As time has moved on, people’s expectations for collaboration systems is that they have a USB 3 camera that’s delivering all this data into these fancy algorithms that our UCC clients can provide – digital backgrounds or automatic framing, all these other things that really, really benefit or work better with USB 3 resolution and frame rate.
Those optional, luxurious, it’d be nice to haves, become into a state of we have to have USB 3 extension. Now we’ve got this critical mass where the industry has accepted our USB extender as something that is viable and something to strongly consider on these new contracts. We’re getting asked for what’s next, meaning how do I get this USB 3 extension over a LAN now? Getting away from point-to-point, and putting this onto a network, that’s the next big push that we’re working on.
Justin Kennington (20:17):
That will be an interesting challenge. We’re talking about some very high bandwidths to push over a network. What kinds of applications?
Tavis Sparrow (20:32):
It’s a very important thing and worth mentioning right now, that as we learn more and more about these evolving technologies, it’s good to have that stuff filed all the way in the back of your mind. “Oh, this USB 3 can deliver this payload, this bandwidth,” for instance. But if I intend to integrate that with other data sources, video, audio, or otherwise, and push that through a common LAN, you start running out of pipe pretty quick.
Justin Kennington (20:59):
Things add up. I can understand applications for extending a high bandwidth USB. Simple stuff, right? I’ve got a Zoom room, I’ve got a camera on one end and I’ve got a PC on the other end of the room. I need to extend it. What kind of applications are people looking into where they want to switch USB? They want to move it over the network in those high bandwidth ways.
Tavis Sparrow (21:23):
Some of the larger venues will like to use some sort of a matrix switch – either something that’s a conventional matrix switch, or maybe something that’s using the LAN as your switch, or some are using AV bridges to be those switching locations. It’s usually serving multiple camera angles in larger venues, in academia, for instance, where you might have to move across four or five different cameras throughout a given session. There are obviously professional producers on hand to do all that so there’s a real demand to switch cameras that way. There are many applications. Another popular one is if you’re in a multi-function space, say at a conference center or a hotel ballroom, and you’re dealing with one large shared space that can be repartitioned or reconfigured on the fly and there’s a variety of AV drops scattered throughout the venue. The idea is you use the LAN as your switch to set up shop where these nodes need to come out of the floor and be in a specific location. Switching is very important there as well.
Justin Kennington (22:35):
That makes a lot of sense. In that large venue case you mentioned it almost feels like that’s a place where broadcast cameras and SDI cameras used to be the thing. Do you see USB cameras encroaching on other more traditional cameras as we move ahead?
Tavis Sparrow (22:54):
I think it’s possible. I guess in our world, when we’re dealing with our pro AV customers as one entity and our broadcast customers as a different entity, I think one common thing in the video domain and audio domain is the concept of a time sync. In USB, there is no timing management system built into the protocol. In order to get accurate time syncing, you have to do more things, whereas in the broadcast world, through SMPTE standards, it’s baked into everything. I think there’s a cost benefit to USB 3 based devices compared to broadcast equivalents or similar broadcast-type equipment. It’ll be interesting to see what happens with the USB 4. I’m not part of any of these groups to help define this stuff but the thing that I picked up on in USB 4 is we now have a timing management system in the USB 4 standard. It is conceivable that we can exploit that for accurate time sync now in the USB domain that we never had before.
Justin Kennington (24:07):
That’s interesting. Let me pause you there, because I wanted to talk a little bit about USB 2, 3, and 4, but right now I need to go check with Matt. So let’s save it for the aftershow and we’ll see you there, Tavis.
Matt Dodd (26:18):
Before we go into the aftershow, let’s just get from you a little bit about what to expect next time in episode 13 “Digital Canvas: the Modern Classroom”.
Justin Kennington (26:53):
Lucky episode 13! Our friend Gary Kaye is going to join us. Gary has been talking for a long time about the concept of a digital canvas, the idea that content should be thought of as content that can be laid out somewhere in this vast array of pixels, rather than displayed on this one screen.
Imagine if everything behind me were a whole world of pixels and I could put some content here, some content there, a little list down here. I’ll let him explain it better than I do, but it’s a really interesting topic for us because SDVoE offers a really flexible way to implement this concept. In fact, you’ll see in a recent article “ZeeVee Delivers on Gary Kayye’s Digital Canvasing Concept with new AV-over-IP Management Platform”, one of our founding members ZeeVee has actually put together a function of their software controller for SDVoE that enables this digital canvas concept. It’s something really important for the industry going forward.
Totally setting aside SDVoE, just the idea of displays being defined by a number of pixels on a wall rather than by the size and shape of this particular piece of glass, that’s really where we’re headed in terms of big trends. This is going to be our first chance to dive in with Gary and talk about that. So it should be exciting.