This design is a combination of three different concepts: the world, wifi, and a light bulb.
While thinking of ways to combine a light bulb and the Earth, I've thought of the concept of "lighting up the world" and probably one of the better ways to show it is to illustrate it literally. The contrast of yellow shows brightness while the blues helps convey the earthy feel. The use of the world also gives an instant recognition that the company is global.