With a 20 MHz LTE channel it's quite easy now to fully load a Wi-Fi network. When I recently tested Wi-Fi tethering with an LTE smartphone I noticed that the maximum data rate was caped at around 45 MBit/s despite the LTE network supporting higher speeds. That's about as much as a single 20 MHz 802.11n Wi-Fi channel can transport in a real environment on the IP layer without MIMO. Many access points these days also support the optional bundling of two 20 MHz channels. My Layer 1 Chanalyzer tool showed, however, that my smartphone was not using the option. Not that this is too much of an issue but we've reached a point where the cellular network can be faster than what can be provided locally by the phone to other devices over Wi-Fi.