Aubiums

Aubiums are powerful magic slabs of stone that allow magic to permeate an area. They allow for interaction with arcane and otherworldly forces that would otherwise not be able to gain access to this reality.
Aubiums are similar to modern day WiFi and LTE networks. If natural magic users operate with LTE, using an areas bandwidth until it no longer exists, an Aubium is a WiFi point that allows magic to be used without bandwidth issues.