Understanding WiFi terms like 1T1R, 2T2R, and MIMO

In antenna and router technology, terms like 1T1R, 2T2R, and so on are used to describe the configuration of antennas and radio chains in wireless communication devices. These terms provide information about the number of transmit (T) and receive (R) antennas or radio chains in a device. Let's break down what these terms mean:

T stands for Transmit: This refers to the number of antennas or radio chains dedicated to sending data from the device to the network or other devices.
R stands for Receive: This refers to the number of antennas or radio chains dedicated to receiving data from the network or other devices.

Now, let's look at a few examples:

1T1R: This configuration has one transmit antenna and one receive antenna. It's a simple setup commonly found in older or budget wireless devices, or long range repeaters that are designed to have all power allowed by FCC on one transmit radio instead of divided among multiple ones. With only one transmit and one receive path, the device can communicate with the network but may have limited speed vs a device with more antennas.
2T2R: This configuration includes two transmit antennas and two receive antennas. It's a common setup in many consumer-grade wireless routers and devices. The additional antennas help improve performance, especially in terms of signal strength and throughput.
3T3R or 4T4R: These configurations have three or four transmit antennas and three or four receive antennas, respectively. These setups are often found in higher-end routers and wireless access points. They offer even better performance, increased capacity, and improved coverage compared to 2T2R configurations.
MIMO (Multiple-Input, Multiple-Output): These terms are often associated with these antenna configurations. MIMO technology uses multiple antennas for both transmission and reception to enhance wireless performance by increasing data throughput, improving signal quality, and reducing interference.

Another way to look at it is like lanes on a highway. If you are the only user of a WiFi router or computer, 1T1R may be sufficient, because you will only be streaming one video, or downloading one file at a time. If you are the only driver on a road, one lane is fine. But when there is more traffic, more lanes help. If multiple users are using the network, this increases traffic, and more antenna streams may be desired.