Understanding MU-MIMO Wireless (2024)

If you're in charge of your company's IT infrastructure and network monitoring, you've likely encountered the term "Multiuser Multiple Input/Multiple Output" (MU-MIMO). But for those who aren't networking experts, especially if you've got those experts asking you to spend some bucks on it, it's worth understanding MU-MIMO because not only can it radically speed up your wireless networking throughput, but it can potentially decrease the number of routers and access points you need. Put simply, MU-MIMO technology enables the simultaneous transfer and receipt of network data across multiple devices. In this piece, I'll explain what MU-MIMO is, how it works, and how it benefits you—and I'll try to put it in terms that don't require an advanced degree from the Massachusetts Institute of Technology (MIT).

Traditional routers, which operated with "Single User Multiple Input/Multiple Output" (SU-MIMO) technology, helped to propel the wireless data industry by sending information over a network to one device at a time. The routers were able to accept and send data similarly to how humans inhale oxygen and exhale carbon dioxide. Oxygen comes in and carbon dioxide goes out. Following this metaphor, MU-MIMO technology would enable a human being to inhale and exhale simultaneously, without stopping or slowing either process. In real terms, MU-MIMO helps routers and access points maintain a steady flow of data to multiple devices at once, without stopping.

Here's another way to look at it: Rather than sending data to devices in bursts (otherwise known as "packets"), MU-MIMO-enabled devices send a steady stream of content to multiple devices within your network, without pause or delay. Each device (up to four devices) receives its own independent stream so it's not sharing bandwidth with other devices on the network.

With traditional SU-MIMU routers, multiple machines receive packets in shifts, which works well enough when bandwidth requirements are low. But, similar to the I Love Lucy episode in which Lucy and Ethel unsuccessfully gather chocolate balls off of a factory's conveyor belt as the speed increases, if your bandwidth requirements grow, then your traditional router isn't able to properly distribute the data fast enough to maintain steady operations.

How MU-MIMO Impacts You
MU-MIMO routers and access points distribute bandwidth into separate, steady streams that give each device the priority it needs to properly function. MU-MIMO routers offer 2x2, 3x3, or 4x4 stream varieties, which means you can run two, three, or four different streams for four separate devices without suffering any bandwidth congestion.

If your home or office uses the 802.11ac wireless protocol, then you can pick up a MU-MIMU router or access point for about $75 more than a SU-MIMO device. This is especially useful for spaces with more than three devices running simultaneously where latency issues are a hindrance to work or hardcore gaming.

Two-thirds of households with three or more persons have at least five devices simultaneously connecting to the internet, according to an IDC report. Most of these devices are streaming movies, games, and music—all while gobbling up precious bandwidth. The same report revealed that 42 percent of respondents suffered performance issues when playing video games, and 34 percent struggled to stream movies and TV shows. These issues will continue to worsen as homes adopt smart technology in traditional appliances such as refrigerators, washing machines, and thermostats.

IDC estimates that MU-MIMO routers can improve performance by 300 percent for all of the devices on your network, even if you're running more than 2, 3, or 4 devices. That's because each of the devices is receiving data simultaneously rather than waiting for individual packets to arrive. So, even though they're not receiving individual bursts of data, they're never not receiving data from the router.

What's Next for MU-MIMO?
Today's MU-MIMO routers don't allow downlink connections so you'll only see a difference in network performance when you're receiving data from the internet as opposed to network uploads. In the future, you'll likely see standards developed that allow MU-MIMO routers to, at the very least, aid in the upload process to improve uplink speed.

Additionally, MU-MIMO works better on devices such as TVs, desktops, and gaming consoles. That's because movement befuddles MU-MIMO devices. Your smartphones and smartwatches will likely be relegated to SU-MIMO technology if you're too active within the network's boundaries. Don't be too alarmed by this as most smart devices that have been built since the beginning of 2016 support MU-MIMO, so it's likely that this issue will be resolved in short order.