MIMO (multiple-input multiple-output) is a technology that uses multiple antennas to transmit different data streams at the same time in the Wi-Fi network. MIMO increases the stability and data throughput in the Wi-Fi network.

Many current FRITZ!Box models already support the new MU-MIMO (Multiple-User-MIMO) technology. Whereas the older SU-MIMO (single-user MIMO) technology could only transmit data to a single wireless device at a time, MU-MIMO can transmit data to several wireless devices simultaneously.

MIMO multi-antenna technology

One single antenna can only transmit or receive one data stream at a time. Several antennas can transmit or receive several data streams simultaneously, according to the number of antennas.

Using multiple antennas in conjunction with MIMO technology means that data can be transmitted in several simultaneous data streams between a wireless router and a wireless device instead of transmitting it separately in sequence.

To use all of the advantages the MIMO technology has to offer, both the wireless router and the wireless device must support MIMO and ideally have the same number of antennas (for example 4x4, 3x3).

The presence several antennas also makes it possible to use so-called beamforming. With beamforming, the antennas on the wireless router transmit directly towards the wireless devices, which increases the range and stability of the Wi-Fi connection. Beamforming thus ensures optimal alignment with the wireless device, regardless of where the wireless router is positioned.

SU-MIMO (single-user MIMO)

With the older SU-MIMO technology, a wireless router can only transmit data to several wireless devices one after the other. This means the speed achievable in the entire Wi-Fi network is reduced when several wireless devices are used at the same time.

For example, when a wireless router with 4x4 MIMO transmits data to a smartphone with only one antenna (1x1), three fourths of the wireless router's maximum bandwidth remain unused for the duration of this transmission.

MU-MIMO (multi-user MIMO)

With the new MU-MIMO technology, a wireless router can transmit data to several wireless devices at the same time, thus reducing the waiting time for wireless devices and increasing data throughput in the entire Wi-Fi network.

This means that a wireless router with 4x4 MU-MIMO can simultaneously transmit data to four different smartphones with only one antenna (1x1) that do not support MIMO. By reducing the waiting time when transferring data, they can switch back to power-saving mode more quickly, which in turn has a positive effect on battery runtime.

On the other hand, wireless devices with 4x4 MIMO can use the full bandwidth of a wireless router with 4x4 MU-MIMO within a transmission interval.