Download Booster: combine ethernet and WiFi bandwidth (load-balancing internet connections)

I'd like to know and how I can use **simultaneously** two (or more) internet connections, *i.e. Ethernet, WiFi, but also 3G/LTE, ...* For example, I would use Ethernet from my ADSL router and WiFi from an Android phone used as 4G router; how do I **merge** them in order to get a single internet connection? This is a bleeding-edge request but after some search I found at least the right keyword: *load balancing*, but it looks like a server-only feature or needs a dedicated hardware *i.e. Ubiquiti router* A feature that mimics download booster, called *Turbo Mode* if I well remember, has been found in some Android smartphones (I remember early Samsung S-series models...); in this case, the phone combines 4G with WiFi. Thus, being android Linux-based, is there a way to do it on my Arch Linux laptop?