Multi-user, multiple-input, multiple-output technology—better known as MU-MIMO or Multi-User MIMO promises wireless transfers up to four times faster than traditional wireless routers.
Wireless routers that do not support MU-MIMO use the so-called SU-MIMO method to transmit data over a wireless radio channel. SU-MIMO comes from Single-User Multiple Input Multiple Output and means that a wireless stream can send and receive data to and from a single client at a particular time.
SU-MIMO comes from Single-User Multiple Input Multiple Output and means that a wireless stream can send and receive data to and from a single client at a particular time.
The SU-MIMO is part of the 802.11n standard that was developed in October 2009. All wireless routers supporting the 802.11n standard version can use SU-MIMO to transfer data. When using this method, routers are able to send and receive data only in one direction, to one customer per line.
Assume you have three users, each with its wireless device, connected to the router’s network. The router can receive and transmit data only from/to the first user. When it ceases with the first, he moves to the second and then to the third.
The number of simultaneous data streams is limited by the number of antennas used. In SU-MIMO we can have up to four streams for simultaneous data transfers if the router has four antennas. For example, a wireless router that transmits and receives data using two antennas can handle two clients simultaneously. A four-antenna router can handle four simultaneous transfer streams with four clients. Wireless networks are often composed of a large number of customers, each requesting its own data transfer. In this situation, the router works like a machine gun mounted on a rotating carousel. Send bit data very quickly to each device in a row. Each device awaits the turn to receive and send data, and when a new device connects to the network, waiting becomes even longer. As a result, the more devices you connect to a wireless router that uses SU-MIMO, the latency increases and the transfer rate decreases for each device.
MU-MIMO, Multi-User MIMO or Multi-User Multiple Input Multiple Output is the ability to transmit and receive data to/from multiple clients simultaneously, not just one, or to send data to a customer using multiple simultaneous streams, thus increasing the transfer speed. With this method, the wireless router can “talk” with more than one user on a single wireless channel or a single user using multiple streams on the same channel.
There are several types of implementations for MU-MIMO transfers that we can find on routers and wireless devices:
1. 2×2 MIMO – provides two spatial streams for transmitting and receiving data on the same channel or frequency. For this setup, you only need two antennas, and you can simultaneously connect a maximum of two clients, each with a separate stream.
2. 3×3 MIMO – provides three spatial streams and requires three antennas. Can simultaneously manage a maximum of three clients.
3. 4×4 MIMO – provides four spatial streams and requires four antennas. A maximum of four clients can be connected at a time.
4. 8×8 MIMO – Offers eight spatial streams on the same channel or wireless frequency to connect a maximum of four clients (yes, only four). For this setup, you need eight antennas. 8×8 MIMO is not yet a widespread implementation.
What are the advantages of MU-MIMO?
If you buy a wireless router or WiFi mesh system with support for MU-MIMO transfers, you get the following benefits:
1. Decreasing the waiting time for each wireless device when it needs to receive data.
2. Increase data download speed for all devices that can use MU-MIMO streams.
3. Both devices with MU-MIMO support and devices that don’t support it will benefit from improved wireless connections.
4. Increases the network capability and the number of devices that can be managed simultaneously by the router.
Disadvantages of MU-MIMO
There are also some drawbacks for MU-MIMO wireless routers or systems:
1. MU-MIMO only works on wireless networks that use the 802.11ac standard and the 5 GHz frequency. You can not benefit from MU-MIMO on the 2.4 GHz wireless frequency or on older standards like 802.11n. The 2.4 GHz frequency is bound to use SU-MIMO.
2. MU-MIMO only increases download speed, not upload data.
3. You need both an MU-MIMO router and MU-MIMO devices so you can feel all the benefits. When you buy a laptop, phone, or other gadgets, make sure it supports 802.11ac wireless networks and MU-MIMO transfers.
If you have smartphones, computers, and gaming consoles, then the benefits of an MU-MIMO router are growing exponentially. We recommend that if you have eight or more wireless devices in your home, consider buying a wireless router with MU-MIMO.