In 2007, Apple’s first iPhone hit the shelf. That same year, the fourth generation of Wi-Fi® technology—802.11n—was introduced as a wireless technology to meet the demand for medium-resolution video such as those found on the then two-year old startup YouTube.

Fast forward to 2012 when the number of smartphone users worldwide broke the one billion mark, tablet sales grew greater than 78% in a single year and video traffic accounted for more than half of all Internet traffic. Certainly, the architects of 802.11n could not have anticipated this explosion of mobile data traffic in such a short amount of time.

By eliminating the physical constraints of wired electronic devices, Wi-Fi has spawned a generation of savvy users who now consume digital content at an ever increasing rate. That’s where IEEE 802.11ac comes in, promising to deliver extraordinary improvements in speed, reliability and range necessary to meet the demands of more users, more devices and more data (Figure 1).

Figure 1. 802.11ac delivers the bandwidth required for streaming high-quality media such as live television broadcasts and streaming HD video.

The 802.11ac protocol, referred to by Broadcom as the fifth-generation of Wi-Fi or 5G WiFi, is essentially the next step in the evolution of Wi-Fi from 802.11n (Figure 2). 802.11ac  represents a dramatic leap forward — up to three times faster and up to six times more power efficient than equivalent 802.11n.

Figure 2. Wi-Fi has evolved through the years to accommodate demands for faster data rates and greater bandwidth to support more feature-rich content and applications.

In addition to its speed, 802.11ac increases reliability, and can achieve up to 4x the bandwidth increase over its predecessor using 160 MHz channels; a critical factor in enabling bandwidth-intensive mobile video and voice applications. In addition, it uses a higher modulation scheme—256 QAM as compared to 802.11n’s 64 QAM—which provides more efficient data transfer and in turn, increased battery life. 802.11ac is also powerful enough to cover a broader range and robust enough to handle more devices transmitting data-heavy content, including high definition video and an array of other new use cases for today’s video-obsessed consumers. And that’s just the beginning.

The protocol operates in the 5 GHz band where it enjoys up to 8x more capacity, faster data rates and broader coverage with fewer dead spots. The band is divided into 24 non-overlapping channels with each having the potential to be used in a single wireless system. By comparison, 802.11n primarily operates in the congested 2.4 GHz band with its 14 channels, only three of which are used in North America due to interference issues.

Because it operates in the 5 GHz band, 802.11ac more efficiently uses the air space shared by all wireless technologies. Essentially, it transmits data through the air at a higher rate, enabling devices to get off the channel faster and leaving air for other devices to transmit and receive. As a result, 802.11ac realizes a dramatic reduction in Wi-Fi network congestion.

As an added benefit, 802.11ac is backward compatible. This is especially important given the huge number of Wi-Fi devices already in use. Having the backward compatibility ensures 802.11ac devices will be able to connect to existing 802.11 protocol networks operating in the same 5 GHz band, albeit at slower speeds.

The performance improvements and functionality possible with 802.11ac translate into a host of benefits for consumers, the enterprise, and service providers alike. For consumers, it means increased bandwidth and battery life to enjoy a much more content-rich multimedia experience, faster throughput that will allow content to be streamed in less time, and the capacity for multiple devices to be simultaneously connected to the network.

In the enterprise, as the number of mobile devices and the deployment of cloud-based enterprise networks continues to scale at a dramatic rate, IT managers must reconsider how they provision, secure and control enterprise computing resources and information access. 802.11ac provides the bandwidth and range required for applications such as video conferencing and customer relationship management (CRM) applications, delivering speeds that rival Gigabit Ethernet and offer compatibility with centralized wired networks. 802.11ac also supports a higher number of users with fewer dead spots.

Service providers, reeling from the network overload caused by increasingly data-hungry devices, will also benefit from 802.11ac. The protocol’s greater capacity for offloading data traffic will enable many more simultaneous connections, offering users a better experience. Moreover, service providers won’t need to deploy the same density of access points to get the same coverage.

Just this year, ABI Research reported that worldwide shipments of consumer Wi-Fi customer premises equipment topped 43.3 million. 802.11n devices constitute the majority of that total; however, 802.11ac access point adoption is gaining traction. Strategy Analytics expects sales of consumer devices with 802.11ac to surpass one billion by 2015. While some may dispute how long it will take for the protocol to become dominant, one thing is certain: more devices, more apps and more multimedia are coming down the pipeline. 802.11ac is well positioned to deliver the performance required to address this impending media explosion head on.

Last week, Boingo launched a new Next Generation Hotspot network at Chicago O’Hare International Airport that is the latest step toward a future of public Wi-Fi as easy to use as your cellphone.

Over the last several years, the Wireless Broadband Alliance, Wi-Fi Alliance, and the GSM Association have worked together on a set of specifications and guidelines to enable seamless roaming over Wi-Fi in much the same way that cell phones today seamlessly roam from city to city and country to country. You turn on your phone, it finds the nearest tower, and they negotiate access without you having to do anything special.

Why is this important?

Six years ago (June 2007) Apple launched the iPhone, and the Internet – and how we use it – changed forever.  No longer the exclusive domain of business travelers lugging laptops from airport to hotel to cafe, public Wi-Fi started to become a more egalitarian resource. Anyone and everyone with a pocket-sized web device now whips out their phone to check their email, update their social network status, scan the latest scores, or prove the actual quote from that movie that everyone tries to quote but always gets wrong.

To date, this has sometimes been complicated, since there are hundreds of different Wi-Fi providers – some large like Boingo and AT&T, some smaller like the individual coffee shops themselves. The user experience as they move from hotspot to hotspot varies. Boingo’s Wi-Finder app eliminates a lot of this complication, but still involves some user interaction to make sure the device selects and logs into right network.

The new standards-based networks – using Passpoint-certified hardware (Wi-Fi Alliance certification based on Hotspot 2.0 specification) and Next Generation Hotspot network configurations (Wireless Broadband Alliance guidelines) – enable the phone to identify and negotiate with the network while it’s still in a user’s pocket. By the time they take the phone out to look at it, it has already connected and authenticated to the network, establishing a secure, WPA2-encrypted connection with the hotspot.

Right now, the Next Generation Hotspot network launched in Chicago is being made available to mobile carriers, hotspot operators and smartphone manufacturers who want to test this functionality as part of their product development process. While only a few phones today can take advantage of these specialty networks, more phones will be coming to market and with them the creation of a critical mass of users who can capitalize on the improved user experience of seamless Wi-Fi access.

In the long run, we believe Next Generation Hotspots will be most widely used by a wide range of service providers who have already added public Wi-Fi access to their existing Internet services or provided as a bonus by hardware manufacturers to entice you to buy their devices.

You see much of the same type of activity today, with companies like Time Warner Cable, Comcast, and Verizon providing public Wi-Fi access for their home broadband customers, and carriers like AT&T using their Wi-Fi hotspots to supplement subscribers’ monthly data usage in places like Starbucks and McDonald’s. Likewise, Samsung has included public Wi-Fi access with their latest lineup of tablets and has previously included public Wi-Fi access with network-enabled cameras, and Nintendo enables DS users to access public Wi-Fi in many popular locations.

With the Next Generation Hotspot networks, and their use of Passpoint-certified equipment, that type of network access can easily be extended more broadly to include roaming agreements with multiple providers through standards-based technologies that will be built into the phone, camera, or other Wi-Fi enabled device, especially devices that lack browser interfaces and are currently unable to access public Wi-Fi. By eliminating custom software solutions and turning to standards-based functionality built right into the Wi-Fi chipset, more users will have access to more networks with more of their devices.

And that seems like a win-win-win-win for network operators, service providers, device manufacturers, and users alike.

This post originally ran on the Aerohive blog where Matthew Gast has his own author blog.

In many ways, spectrum is the wellspring of the Wi-Fi industry. At the time I started working with wireless LANs over a decade ago, most products were built on either the original 2 Mbps 802.11 direct sequence specification, or if you were well-connected (both to a network and to a source that would give you products!), the blazing fast 11 Mbps offered by 802.11b. At the time, 802.11a was emerging, and the value proposition was simple: more spectrum supports more devices.

802.11 began life in the US in the ISM bands, and essentially staked its future on the slim 83 MHz band available around 2.4 GHz. To put 83 MHz in perspective, check out the NTIA’s spectrum allocation chart – it’s tough to see the tiny ISM bands. Back in 2004, 802.11a devices were few and far between.

It’s amazing what the tsunami of mobile internet devices will do for you. Building high-density networks is the order of the day for Wi-Fi infrastructure vendors. Whether it’s a conference room, auditorium, school room with 30 students on iPads, or a temporary meeting site, there are just too many devices crammed into the room to get decent speeds out of a mere 83 MHz.

When the 802.11ac task group was chartered, they were given a wide scope: Develop a gigabit wireless LAN standard using spectrum below 6 GHz. The charter offered the option of building a standard that would use both the existing 2.4 GHz spectrum and the multiple 5 GHz options.

In the end, the task group decided to produce a specification that operated only in the 5 GHz bands. The current 802.11ac drafts are spectrum-hungry. Significant portions of the speed gain come from using wider channels; 802.11ac includes options for both 80 MHz and 160 MHz channels, compared to the 20 MHz and 40 MHz channels we know and love today in 802.11n. Using an 80 MHz channel in the crowded 2.4 GHz band is simply a non-starter. There are so many 2.4 GHz devices in any spot that 802.11ac would be deployed that the odds of being able to see the whole band clear and transmit on it are even lower than the odds of winning the lottery.

As a result, 802.11n is likely to be the capstone technology in the 2.4 GHz band. 802.11n is as good as it gets for 2.4 GHz. New standards will bring higher speeds, but the new standards won’t come to 2.4 GHz. The first wave of 802.11ac products will still be dual-band – it’s just that it will be a dual-radio device with 802.11n (2.4 GHz) and 802.11ac (5 GHz).

This post originally ran in February 2013 on the Aerohive blog where Matthew Gast has his own author blog.

Getting out and talking with customers is one of the activities that keeps me fresh. Some of my best ideas have come directly out of customer conversations, which is one of the reasons you’ll always find me willing to speak at one of our Hive User Group events.

On my last trip out to see customers, I gave my current talk about 802.11ac. At the very last minute at the Philadelphia-area event, I noticed that the restaurant was playing Tony Bennett singing “The Best is Yet to Come,” and I couldn’t resist re-titling my talk and throwing in a picture of Tony to express the same sentiment about Wi-Fi.

While there are many reasons that the best days of Wi-Fi with 802.11ac are yet to come, I’ll focus on one in this post that I haven’t really written about before: improved battery life.

Yes, battery life. 802.11ac will help extend battery life in mobile devices. You read that right. Heck, earlier this week, HTC announced that the HTC One (picture right) is coming with 802.11ac.

The major components of a Wi-Fi interface, in the order that an incoming signal hits them, are:

1. The antenna system. This one is obvious. You can’t receive radio waves without an antenna.
2. Analog processing. The signal that comes off the antenna is very weak. A high-quality amplifier is used o boost the signal off the antenna system to feed to the radio chip. Because the signal is so weak, one of the most important attributes of this first amplifier is that it introduce as little noise into the amplified signal as possible. Amplifiers take some power, but not as much as you might think compared to components further along the chain.
3. The digital signal processing (DSP) stage. There are multiple components here – each antenna’s received signal goes through demodulation and through a Fourier transform, and then multiple spatial streams are pulled apart. The computational power increases dramatically with multiple streams. For a single stream, this step is a straightforward single Fourier transform. With multiple streams, it’s a Fourier transform per stream, possibly with complex applied mathematics to get at each spatial stream.
4. Decoding the recovered bit stream to correct errors and passing the frame to higher software layers.

What kills battery life is not the amplifier in the analog section. Yes, amplifiers do require power, but the real power hog in multi-stream MIMO systems is the digital processing used to recover parallel spatial streams. If you eliminate the requirement to receive multiple spatial streams, the power required in the digital stage drops dramatically.

If you are making a mobile device, the easiest way to reduce power requirements is to build a single-stream device to minimize the power drain in the DSP stage. Not surprisingly, that’s exactly what HTC did with their new phone. Yes, it’s 802.11ac, but it’s single-stream 802.11ac.

With single-stream 802.11ac, the HTC One can reduce the time needed to send or receive data and increase battery. Although the digital stage for 11ac is slightly more complicated than it would be for 11n, that is more than made up for by the savings that come from running the analog amplifier for shorter periods of time.

(Note that my analysis depends on this being single-stream 11ac and single-stream 11n. If you need a complex multi-stream digital stage, all bets are off because you need much more intensive digital processing to make multiple streams work.)

With Mobile World Congress happening next week in beautiful Barcelona, I wouldn’t be surprised to see a number of additional phones announced with 802.11ac.

When power-conserving devices like battery-powered handhelds are being built with 802.11ac, you can tell that we’re on a roll. As the immortal Tony Bennett put it, the best is yet to come …

It’s said that after seven years in a relationship, malaise and discontent can seep in, causing the eye to wander to newer, more exotic objects of desire – it’s called the seven-year itch. As goes love, so goes Wi-Fi. We face this same predicament after seven long and fulfilling years with the 802.11n standard.

But is 802.11ac the one we’re meant to run off with, or just a distraction from a Wi-Fi standard that still meets our needs? If we take our cue from colleges and universities, the earliest adopters of Wi-Fi technology, it’s time for an upgrade.

Many detractors will say that 802.11ac hasn’t yet lived up to its potential, but technically the same could be said about current iterations of 802.11n access points. So instead, let’s look at the top five reasons why universities are flocking to this new standard in its current form, as certified by Wi-Fi Alliance.

Reason #1: More devices, more apps, more multimedia

As any campus IT administrator knows, students bring throngs of gadgetry with them to campus. And these devices behave in elusive ways.

They buffer massive amounts of multimedia and then go silent, stick to APs when they should roam, talk multicast to other personal devices on the network, and transmit low-priority background data at the same time as critical academic traffic. The only certainty of these devices is their uncertainty.

802.11ac can help in the following ways:

• A wider pipe: 802.11ac stitches together more spectrum per client, allowing 80 MHz channel widths. Think about it this way: when a campus moves from 20 MHz to 80 MHz, it automatically receives 4.5X more speed.
• Better modulation: 802.11ac improves modulation to 256 quadrature amplitude modulation, or QAM. In optimum environments, this provides an additional 33% increase in throughput over the 64-QAM used by 802.11n.
• Higher performance APs: New purpose-built 802.11ac APs have faster processors and more memory, improving client performance in high-density environments by more than 20% compared to 802.11n or to 802.11ac APs built on 802.11n hardware. This performance boost exists even in networks that only have 802.11n clients.
• More efficient use of the air: With 802.11ac, data is transmitted at a higher rate, meaning devices get off the channel faster, leaving air for other devices to transmit and receive.

Reason #2: Coverage

Universities need to provide Wi-Fi throughout large buildings and outdoor areas, making adequate RF coverage a must. 802.11ac has some tricks up its sleeve.

First, borrowing from the capacity discussion above, it’s all about rate vs. range. Even though the ability to throw a signal is nearly equivalent between 802.11n and 802.11ac, the new speeds (data rates) can provide twice the capacity at an equivalent range.

This means that users suffering through a slow rate in one coverage area would immediately enjoy faster speeds with 802.11ac.

Even better, now that Explicit Transmit Beamforming is a mandatory part of the 802.11ac standard, radios can focus signal on individual clients for a huge speed improvement. Aruba’s testing has shown that speeds can improve by over 30% per client (2 MCS index levels)!

Finally, purpose-built 802.11ac APs use the newest antenna designs and the full dimensions of the AP to increase wireless signals even further.

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