Blog
This article on CNN’s website has some interesting views about Qualcomm’s recent announcement about MU-MIMO (multi-user-multiple input, multiple output) for tripling Wi-Fi speeds for patrons of coffee shops. However, I noticed some information in the article that might set false expectations about how quickly these speeds are coming and how soon people will be able to take advantage of them. Therefore, I wanted to paint a more accurate and realistic picture for you here.
- Since most consumer devices only operate at the 2.4 GHz frequency band, which does not support the mentioned MU-MIMO technology, many of the folks who bring their devices to coffee shops will not be able to take advantage of the new speeds. Yes, starting with the iPhone 5, there is support for 5 GHz 802.11n, but not for MU-MIMO (802.11ac, Wave 2).
- The majority of low cost laptops do not even have support for the 5 GHz frequency band of service, therefore, the MU-MIMO discussion is completely irrelevant for these people. Some simple advice for attaining better Wi-Fi speeds would be to upgrade to newer devices that support 5GHz. You can do this now and no MU-MIMO is needed.
- MU-MIMO end user devices that are eluded to in the article are not even available yet. The first of these devices will most likely start to become available in 2015.
- However, even with new technology build-in to new devices and laptops, right now, the Wi-Fi speed at your favorite Starbucks is 90% defined by the wired internet connection, not the Wi-Fi, and this internet connection speed is usually too slow to serve you well. Wired, common, shared internet connection speed may be 1.5 to 3 Mbit/s at best. Did you notice that Google Fiber is taking over the Wi-Fi connectivity at Starbucks? They are significantly adding bandwidth to wired internet speed to improve Wi-Fi performance. It will be clearly faster once they convert over. The SBUX website tells where Google Wi-Fi is available.
- In dense areas, like shopping malls, Wi-Fi protocol does indeed impact Wi-Fi speeds. The issue is the complete lack of control in the 2.4 GHz radio signal environment. It's a crowded, noisy space. But if 5GHz support is available, then you will get your needed speed without MU-MIMO. Even 802.11n at 5GHz can deliver several 10's of megabits per second Wi-Fi speeds, which is likely capped by your available wired internet connection speed in most locations.
- MU-MIMO is certainly relevant in dense enterprise environments. Once the majority of devices are actually able to support MU-MIMO, then this will have an impact on public Wi-Fi as well. However, legacy Wi-Fi slows everybody down and this will linger for a long time, meaning the full promise of MU-MIMO will not be delivered in mixed environments.
The true problem with Wi-Fi is in the robustness and reliability of over the air traffic, not maximum theoretical speed. Standardization to address this has started. It’s called 802.11HEW or likely later to be called 802.11ax.
My final advice: While we are all waiting to get ax’ed by this new standard, upgrade your device to get more Wi-Fi speed. Wi-Fi can be difficult to understand and so we want to help by giving you as much information and knowledge that we can. Check out our Wi-Fi Learning Center to learn more.