iPhone XS and iPhone XS Max include 4 × 4 MIMO for cellular data connections. 19659004] MIMO is an integral part of today's wireless communications technology, whether it's 802.11ac Wi-Fi or 4G LTE mobile data.
Traditionally, a device had only a single antenna in the device. One would call this a 1 × 1 MIMO device because it has one antenna and can support one data stream at a time.
However, there are also devices with multiple antennas. A 2 × 2 MIMO device has two antennas for two simultaneous data streams, a 3 × 3 MIMO device has three antennas for three data streams and a 4 × 4 MIMO device has four antennas for four data streams.
Each device antenna is used to both receive data and send data. The more antennas your device has, the more data can be transferred at one go – and that means faster download and upload speeds for the WLAN.
Imagine driving on a highway. If you have a four-lane highway, more traffic can flow at the same time than on a two or one lane highway.
Changing from 1 × 1 MIMO to 4 × 4 MIMO means quadrupling the theoretical maximum data transfer rate. This is because each antenna supports a separate data stream up to a theoretical maximum. The exact limit varies depending on the state of the wireless networks that use them.
These higher speeds require you to be connected to a mobile network that supports 4 × 4 MIMO. It does not work anywhere on any network operator, but mobile operators have been introducing this feature into their entire US networks for several years.
More MIMO also means a better signal
Only the iPhone XR supports 2 × 2 MIMO.
Recent tests have shown that increasing 2 × 2 MIMO to 4 × 4 MIMO can also improve wireless signal strength. PC Magazine had Cellular Insights run a series of tests comparing the iPhone XR with the iPhone XS. The iPhone XR and iPhone XS have the same wireless modem. The main difference should therefore be that there are fewer antennas on the iPhone XR compared to the iPhone XS – 2 × 2 MIMO on the XR compared to 4 × 4 on the XS.
When both phones were connected to a 4 × 4 MIMO LTE network, the 4 × 4 iPhone XS reached a download speed of almost 400 Mbps. The 2 × 2 MIMO iPhone XR reached the same signal strength right under 200 Mbit / s.
That is to be expected and demonstrates the advantages of 4 × 4 MIMO compared to 2 × 2 MIMO: data can be transmitted twice as fast.
However, the tests also showed that the iPhone XS has better signal strength than the iPhone XR in the 4 × 4 MIMO network. Surprisingly, the iPhone XS had better signal strength than the iPhone XR, even if it was connected to a mobile network that supported only 2 × 2 MIMO.
This does not matter if you have a fixed connection and are downloading your iPhone XR speeds are good enough for you. However, if you have a weak cell signal, it looks as if the additional 4 × 4 MIMO antennas could lead to an improved radio signal. 4 × 4 MIMO is not just about speed – it also seems to improve the overall signal strength.
Cellular Vs. Wi-Fi
MIMO technology is used for both cellular and Wi-Fi connections. However, mobile radio and WLAN have separate antennas.
4 × 4 MIMO is common today in high-end phones such as Apple's iPhone XS and iPhone XS Max. Samsung's Galaxy S9 and S9 + also support 4 × 4 MIMO, as do the Pixel 3 and Pixel 3 XL from Google. You can support all four separate streams simultaneously when connected to a mobile network that offers them.
However, this only applies to the mobile connection. For example, the iPhone XS and Pixel 3 have 4 × 4 MIMO LTE (cellular), but 2 × 2 MIMO wireless LAN. Even if you are connected to a 4 × 4 MIMO router, you will only get 2 × 2 MIMO WLAN speeds. The mobile and WLAN antennas are separated.
What is 4 × 4 MU-MIMO?
Some newer wireless routers also support MU-MIMO. This refers to "Multi-User Multiple Input, Multiple Output". A 4 × 4 MU MIMO router has four antennas on which it can communicate at the same time. If you had multiple 4 × 4 MIMO devices connected to this router, they would all have four data streams at the same time.
Or, if you have a laptop with 3 × 3 MIMO like Apple's newer MacBook Pros, you can connect to a 4 × 4 MIMO access point with three streams simultaneously.
However, if you have a 2 × 2 MIMO wireless phone or a 3 × 3 MIMO laptop and connect it to one A legacy router that does not support MIMO at all will only receive a single stream. When you connect a 3 × 3 MIMO device to a 2 × 2 MIMO router, only two data streams are used.
RELATED: What is MU-MIMO and do I need to do this on my router? I Need 4 × 4 MIMO
Samsung's Galaxy S9 and S9 + support 4 × 4 MIMO, like many other flagship Android phones.
The more MIMO, the better. If all other things are the same, you should prefer 4 × 4 MIMO over 2 × 2 MIMO and 2 × 2 MIMO before any MIMO (or 1 × 1 MIMO, in other words.).
Devices with more antennas are generally more expensive but often pay for them. It's just more hardware. Modern flagship phones usually have 4 × 4 MIMO. The iPhone XR is a bit unusual with just 2 × 2 MIMO in its price range. Hopefully, Apple will next year 4 × 4 MIMO in the successor of the iPhone XR record.
This extra wireless hardware consumes a bit more energy, so 4 × 4 MIMO could reduce battery life by a factor of 2 × 2 MIMO. But we doubt that this is a big factor compared to anything else that costs power to a mobile device.
Overall, the faster wireless speed and improved signal strength are always good. For devices with this feature, you may only pay extra.
Credit: GobyOneKenobi / Shutterstock.com, Apple, Apple, Samsung