According to GlobalWebIndex in early 2016, digital consumers worldwide own an average of 3.64 devices per person, with the top 25% in terms of income skewing even higher to 4.40 per person. We aim to be always on, always ready to be productive or entertained. Every connected device generates data and network traffic, even when not in active use. Not surprisingly, Cisco forecasts that IP traffic growth will continue its phenomenal ascent, realizing 19% compounded annual growth through 2020. To keep pace, fixed broadband rates will “nearly double from 24.7 Mbps in 2015 to 47.7 Mbps by 2020.”
In that same period, Cisco predicts, 71% of total IP traffic will stem from non-PC devices, including smartphones, tablets, smart TVs, and surveillance cameras. What can we anticipate will comprise most of that traffic? In the short-term, video will continue to clobber our data pipes, both wired and wireless. Cisco expects that business video will comprise 66% of business Internet traffic by 2020, and consumer video will fill 82% of all consumer traffic in that time. Beyond that, look for virtual reality to push bandwidth boundaries even further, with VR traffic expected to skyrocket an unbelievable 61x between 2016 and 2020.
OK, you get it: more gadgets, more data, and no end in sight. So what?
Most of those gadgets rely on Wi-Fi, and if you haven’t glimpsed the real problem yet, envision a corporate meeting room with eight or ten workers gathered around a table. Everyone pulls at least one HD video stream as the group conferences with two remote offices. A couple members transfer multi-gigabyte project folders. At any given time, someone runs a multimedia presentation to the group. And so on. In 2017, it doesn’t take many workers to generate hundreds of megabits per second (Mbps) of traffic load on an access point.
Alternatively, consider a suburban home in the startlingly near future. A couple stream a 4K movie to the living room big screen. Junior #1 sits in his gaming chair with a VR headset strapped to his face, streaming 1920 x 2160 at 120 Hz to each eye. Junior #2 has four video chat sessions going on as her study group tackles a communal, cloud-hosted engineering project. Meanwhile, the home’s HVAC system, three digital assistants, and four streaming security cameras keep the Wi-Fi loaded, even without any help from the humans.
Now, keep in mind that, today, the average U.S. home with broadband can’t stream even a single 4K video, but that’s just one service provider upgrade away from reality. And when that upgrade arrives, the home’s (or office’s) access point may likely be the Achilles’ heel that cripples everyone’s experiences.
A few years ago, the 802.11n W-Fi standard dominated home and business networks. However, most mainstream product implementations topped out at a raw data rate of 300 Mbps that might be somewhere north of 100 Mbps under real world conditions. Now, 802.11n, just like today’s 802.11ac (Wave 1), uses a multiple input, multiple output (MIMO) system for a single user. Without getting deep in the tech weeds, this means that the access point uses multiple data streams concurrently to boost the performance of one connected client at a time. Yes, multiple clients can be connected simultaneously to an 802.11n access point, but, like multiple tables being assigned to one waiter, they each get served individually in turn.
So, 802.11n had multiple issues hampering its performance. At best, its wireless channels were limited to a width of only 40 MHz. (Think of channel width as being like the number of lanes on a freeway able to move rush hour traffic.) Also, being a single-user system built in inherent lags and inefficiencies from client switching. The resulting 100 to 140 Mbps of total throughput common to most 11n access points was sufficient in 2008 — and wholly insufficient in 2017.
Fortunately, 802.11ac Wave 1 filled some of the need, which is why IDC shows that 11ac “now accounts for 67.1$ of dependent access point unit shipments.” With improved modulation, channels up to 80 MHz in width, and other improvements, 11ac Wave 1 delivered a raw (theoretical) data rate of 1.3 Gbps, but still under a single-user design. A Wave 1 access point will satisfy a small group of users today, but it won’t accommodate the sorts of scenarios we outlined above that are expected tomorrow. Moreover, the 1.3 Gbps of Wave 1 access points already outstrip the 1 Gbps data rate of the Gigabit Ethernet routers into which they plug.
802.11ac Wave 2 blows channel width all the way to 160 MHz, increases the number of concurrent (spatial) data streams from three to four, and finally builds in true multi-user MIMO (MU-MIMO). The upshot is raw data rates up to 3.47 Gbps — nearly triple that of Wave 1. If the bandwidth of Wave 1 could make a Gigabit Ethernet router stumble, Wave 2 will crush it into the floor. Products bearing Wave 2 capability, such as Samsung’s Galaxy S7 and S7 Edge, are already trickling into the market. Expect that trickle to become a floor as Wave 2 chipsets propagate through more access point offerings. Cisco illustrates how Wave 2 smartphones can yield raw data rates of up to 563 Mbps and laptops can pull up to 1.69 Gbps.
Again, it won’t take many users to swamp an access point with those numbers, but the entire proposition depends on getting the wired infrastructure supporting those access points to deliver sufficient bandwidth. We all know what happens at rush hour when enough traffic for four lanes only has one lane to use.
The industry saw this problem coming. Aquantia, Cisco, and others formed the NBASE-T Alliance to help promote Aquantia’s 2.5 Gbps and 5.0 Gbps Ethernet technology, which operates up to 100 meters over traditional Cat5e or Cat6 twisted pair copper cabling. The IEEE adapted NBASE-T’s technology into the 802.3bz specification, which is now at the heart of next-generation PCs, workstations, routers, and other networking infrastructure.
In short, every home and business that wants to enable media-rich, many-user wireless capabilities is going to need 802.11ac Wave 2 (or whatever succeeds it). But to make Wave 2 practical, useful, and able to fulfill all of its users’ expectations, adopters will want to leverage 2.5 or 5 Gbps wired Ethernet solutions to give those wireless networks the bandwidth they demand.