Fans of Star Trek would know the USS Enterprise as a disc-shaped flying aircraft and UFOs have mostly been circular in shape. Maybe that is why Airbus is envisioning a ring-shaped aircraft for the future that should possibly give more onboard space for passengers and make it more resistant to loads, thus reducing the need for heavy duty materials. This could possibly make for lighter planes and thus lowering ticket prices.
According to the abstract mentioned in the patent application filed by Airbus:
The present invention proposes an aircraft wherein the structure delimiting passenger cabin extends over 360 degrees around a space defined outside structure. The invention allows structure to be more resistant to loads induced by the cabin pressurization, while allowing to reduce or even to avoid the need for a sealed bottom, and while allowing to increase the space available for passengers
Anyway here is one illustration of what is to come in the future:
For those keen to read more on the patent filing, you can read more about it here.