The latest wireless LAN specification, 802.11 ac, was finally ratified late last year and the industry is now gearing up for a “second wave” of 802.11ac gear that fully implements the standard. That should come as welcome news for any IT or network manager who has to build infrastructure to support their increasingly mobile workforce– which is to say, pretty much all of them.
While you can already buy 802.11ac WLAN gear, it is likely based on draft versions of the standard and thus doesn’t take full advantage of all the spec has to offer. As PCWorld puts it:
While some newer routers, such as Netgear’s six-antenna Nighthawk X6, are implementing cool tricks to squeeze more performance from that technology, a second wave of 802.11ac routers will hit the beach in early 2015.
Much of the improvement in 802.11ac has to do with its ability to employ multiple wireless data streams simultaneously. As the PCWorld story points out, the initial wave of 802.11ac routers generally supports up to three simultaneous streams and a maximum speed of 1.3Gbps. That’s a big jump from the maximum of 450Mbps that the previous 802.11n routers can support, also via three streams. In fact this single-user multiple input/multiple output (SU-MIMO) technology “was one of the hallmarks” of the 802.11n standard, PCWorld says, because it allowed multiple streams to be transmitted to a single client.
The second wave of 802.11ac routers, expected to arrive sometime in 2015, will allow for even greater capacity. As PCWorld reports:
First, they’ll support a feature called MU-MIMO (multi-user multiple input/multiple output), which allows them to transmit multiple spatial streams to multiple clients simultaneously.Second, they’ll bond multiple channels on the 5GHz frequency band to create a single channel that provides 160MHz of bandwidth. … Third, where 802.11n and Wave 1 802.11ac routers support a maximum of three spatial streams, Wave 2 802.11ac routers will potentially support up to eight spatial streams.
801.11ac: A Video-ready WLAN Spec
When all is said and done, forthcoming 802.11ac networks will be able to support bandwidth in the neighborhood of 7G to 10Gbps. And the ability to support so many spatial streams means the devices can have multiple wireless “conversations” going on at once – maybe a videoconference along with a white board session, for example.
That should be welcome news for companies as they try to deal with the high-bandwidth applications employees are using, including streaming video, high-definition video and IP voice over Wi-Fi. What’s more, the number of devices per user is climbing, as it’s not unusual for a single user to have 2 or 3 devices employing the Wi-Fi network – think smartphone, tablet and laptop.
But taking advantage of that increased capacity will require some planning. For one thing, newer 802.11ac devices will operate on the 5GHz frequency band, vs. the narrower – and more crowded – 2.4GHz where 802.11n and early 802.11ac devices operate. While the new equipment is generally backward-compatible with the 2.4GHz gear, companies will have to plan a phased migration to get to the point where they can take full advantage of the new spec. The migration may well take 3 or 4 years given nobody wants to throw away perfectly good WLAN gear.
High-performance WLANs Require Proper Planning
Justin Ndreu, a Senior IT Architect with IBM Global Technology Services, has a six-step plan for building a WLAN capable of supporting voice, video and location services that makes good sense.
Step 1 is conducting a proper radio frequency site survey to determine how many access points you’ll need and where they should be positioned. It’s a step he says customers routinely skip in order to save money, but wind up regretting when they incur “expensive costs to reposition access points, run new cable and troubleshoot connectivity or performance problems.”
His plan also includes steps for designing the network with high-bandwidth applications in mind, deploying it and then validating the RF coverage is what you expected. The plan then requires monitoring to ensure application performance is as expected and ongoing tuning and adjusting.
I can recall vividly not so many years ago insisting that I have a wired connection from my laptop to the company LAN, as the WLAN just didn’t have good, reliable performance. Those days are long gone and now many users – probably most – employ devices where a wired connection is not even an option. The good news is Wi-Fi technology is more than keeping pace.