Lab – Where did the 6 GHz band of the Deco XE75, TP-Link’s 6E mesh wifi system, go?

Currently being tested, TP-Link’s 6E Deco XE75 mesh wifi system has three frequency bands: 2.4 GHz, 5 GHz and 6 GHz. It is the presence, among other things, of this 6 GHz band that allows the Deco XE75 to be compatible with the 6E wifi standard. However, after installation and configuration, it remains invisible to our devices, which are compatible with the standard.
You have to go to the wifi options of the Deco application to find out where the 6 GHz frequency band of the Deco XE75 has gone. In the options, the 6 GHz band is by default in “Dedicated Backhaul”. Which means, TP-Link having reserved it for exclusive communication between the modules of its mesh system, that it is invisible to our compatible devices.

As a reminder, the backhaul — or “backhaul network” for our Canadian friends — is an intermediate network that allows communication between the modules. It can be on the same wifi frequency band, in which case the available bandwidth for the devices is halved when they are connected to the satellite modules. By cable (Ethernet backhaul), all the modules are connected with an Ethernet cable, thus freeing the wifi bandwidth for the connected devices or via a dedicated wifi band as on the high-end tri-band or quad-band mesh kits, for example on the Netgear Orbi RBKE963 that we were able to test.

In the case of the Deco XE75, TP-Link offers the possibility of performing the backhaul of the modules with the 6 GHz band or of making the 6 GHz band available for the devices, but, in this case, each of the bands performs its own backhaul and therefore theoretically halves the available bandwidth for the devices. There are therefore two possibilities for the user: either keep the original configuration, especially if you do not have 6E wifi compatible devices, or activate the 6 GHz band if you have 6E wifi devices and your environment is saturated with 5 GHz wifi.

Thus, depending on the choice of backhaul type, performance may vary on so-called “satellite” modules. Regarding the Deco XE75, when the backhaul is provided by a Gigabit cable link, we reach an average speed of 865 Mb/s in download and 775 Mb/s in upload during our file transfer. In this case, it is not uncommon to reach the practical limit of Gigabit with 114 Mb/s peak, i.e. 912 Mb/s. If the backhaul is provided exclusively by the 6 GHz frequency band, the our satellite module goes to 826 Mb/s in download and 547 Mb/s in upload. Finally, if we remove the 6 GHz frequency band for the backhaul, the satellite speeds are 539 Mb/s in download and 509 Mb/s in upload. The logic is thus respected, the backhaul by Ethernet cable proves to be faster and more stable. The 6 GHz frequency band ensures, but offers lower speeds than cable. And, as expected, without dedicated backhaul, performance is almost halved, well almost, since the Gigabit port is limiting in the case of Ethernet backhaul, as we will explain in the full test.

You will be able to find very soon on the site the complete test of the 6E Deco XE75 mesh wifi system from TP-Link.