- Case Studies
June 21, 2021 - This month’s column paraphrases a Doobie Brothers album from 1974, "What Were Once Vices Are Now Habits." Frankly, that title could have worked just as well when considering this month’s topic - Wi-Fi 6, the latest iteration of wireless connectivity.
At its inception 22 years ago, Wi-Fi (short for Wireless Fidelity) was largely a curiosity. Data could be sent from a computer to a network connection over short distances with burst of signals in the 2.4 GHz radio band. This first iteration, formally known by its IEEE designation 802.11b, was painfully slow with a maximum speed of 11 megabits per second (Mb/s) - and that was assuming no other devices were competing to use the channel.
Industry veterans will recall with a laugh all the demonstrations of "wireless projector connectivity" back then at InfoComm. We watched and waited as Word documents and PowerPoint frames sent to a projector over 802.11b connections took forever to build and appear on the screen. And those were small files, typically less than 50 kilobytes per frame! Streaming video and audio were out of the question with these speed bumps.
Over time, Wi-Fi kept evolving, but it still wasn’t fast enough to be dependable. Frequency-hopping techniques and other methods to preserve shared wireless bandwidth while ensuring connectivity were developed, tried, and often tossed. More radio bands were added at 5 GHz and 60 GHz (very short-range). Orthogonal frequency division multiplexing (OFDM) was adopted to "squeeze" through bits of data. Channel bonding was implemented to increase bandwidth.
Along the way, the conventional wisdom was to rely on wired network connections for both dependability and security. Video streaming was in its infancy in the late 2000s when the fourth iteration of Wi-Fi, 802.11n, made its debut. All of a sudden, people realized that Wi-Fi was actually becoming a practical communication medium - it had gotten fast enough to stream standard-definition video with efficient codecs like H.264 AVC. (Audio was never an issue, as it usually streamed in the low hundreds of kilobits per second).
With the launch of Netflix streaming, viewers everywhere wanted in on the action. The first wireless presentation-sharing devices began coming to market. Those laughable wireless projector demos from a decade earlier were quickly forgotten, and homes, schools, and businesses began installing Wi-Fi access points everywhere. Terms like "mesh networks" became part of the lexicon. Having wired Ethernet connections everywhere in a building didn’t seem so important anymore.
Today, the tables have turned completely. Wi-Fi is an essential part of our everyday lives. Streaming video, once seen as impractical, is an afterthought now. In fact, streaming video is by far the largest revenue generator for the movie industry, having surpassed optical disc years ago. With fast Wi-Fi, we can communicate anywhere from any device.
Today’s appliances depend on it, as do our personal health devices. Entire categories of "smart" gadgets have sprung up in recent years; some of them rather silly like connected pet food dispensers. When we travel, we can use fast Wi-Fi on trains, airplanes, and subways. When we check into a hotel, our room key holder includes a Wi-Fi password. Internet telephony, once an obscure, "out there" way of getting around expensive long-distance calling, is now a standard feature of mobile phone service plans. Service providers reflect that new reality in their monthly plans - no one charges for minutes or texts anymore, just gigabytes of data.
20 years after its birth, Wi-Fi has matured with version 6, aka 802.11ax. This version has really been turbocharged, using a bunch of tricks to boost speeds. Each Internet frame is denser with more symbols, and the length of each symbol is longer. Channel bonding has gotten more sophisticated to dynamically increase and decrease bandwidth as needed, and each Wi-Fi radio can quickly determine if a channel is in use and move to another, quieter channel to complete a transmission. Wi-Fi is also "green," as access points can tell a user’s radio to "sleep" until a specific time to transmit and receive data.
The MIMO (multiple in, multiple out) technique of using multiple antennas has also matured. With 802.11ac, an access point could talk to multiple connected devices simultaneously, but those devices couldn’t respond in the same way. Now, the multiple-user MIMO in Wi-Fi 6 lets devices respond to the wireless access point at the same time. And an enhanced version of OFDM dynamically chops up wireless channels on the fly to allow more data to flow between more devices, allocating bandwidth as needed and when needed.
The Wi-Fi 6 standard was officially released two years ago, but we’re now seeing a wave of Wi-Fi 6 modems and routers coming to stores, ranging in price from $250 to $450 for individual modems and routers to $600 - $700 for complete systems with mesh transceivers. These products claim speeds of up to 4 Gb/s @ 5 GHz and 1-2 Gb/s @ 2.4 GHz. Of course, those speeds are claimed for optimal conditions over short ranges, but given that Full HD video can be reliably streamed @ 5-6 Mb/s using the H.264 codec, you should have plenty of headroom.
What does this mean for the AV industry as we migrate to AV-over-IT? For one thing, it will accelerate the trend toward software-based signal switching and distribution, particularly where presentation-sharing devices are in operation. Meeting participants won’t need to search for an Ethernet jack or even an HDMI connection. Rather; they’ll just log into whatever wireless presentation sharing system is in use, perform their dog-and-pony show, and log out.
And those presenters won’t need to worry if the Wi-Fi system is fast enough to keep up: Online gamers are using Wi-Fi 6 on a regular basis for their bandwidth-hungry sessions. Wi-Fi 6-based presentation switchers can easily incorporate effects like dissolves, wipes, and picture-in-picture (we’re already seeing tiled images with online platforms like Zoom), but at the same image quality as a wired HDMI connection would provide.
Is our industry headed toward a completely wireless world? Of course not. Permanent infrastructure offers guaranteed bandwidth that no wireless system can ever match. But we’ll see less meeting room interfacing hardware in the future, as pop-up and wall plate access points become history. The addition of high-bitrate, short-range WiFi millimeter radios in mobile devices will accelerate this changeover.
For most of us, Wi-Fi access is becoming as essential as water, food, clothing, and shelter. As history has shown, what were once novelties have indeed become necessities.