It was almost two and a half years ago that Amazon.com Inc. first put forward the idea of using drones to deliver packages to its customers via its “Prime Air” service. But while the Federal Aviation Authority (FAA) has been dragging its feet to create legislation that would legally delivery drones to operate, Amazon has been busy working out the practicalities necessary to get its airborne fleet into the skies.

Amazon is generally viewed as one of the most secretive of technology companies, but its wall of silence crumbles away when it comes to patents. And so, it can now be revealed that the retail giant has just been granted a new one, which depicts “drone docking stations” that will become an essential part of the infrastructure for Prime Air.

The patent reveals that these docking stations can be either standalone structures built exclusively for that purpose, or else attached onto existing structures such as power poles, street lights, cell phone towers and other tall buildings. These docking stations would be useful for a number of reasons, as Amazon helpfully explains:

“The docking stations can include package handling facilities and can act as a final destination or as a delivery hub. The docking stations can extend the range of UAVs by providing recharging/refueling stations for the UAVs. The docking stations can also include navigational aid to guide the UAVs to the docking stations and to provide routing information from the central control.”

While it may be a bit surreal to imagine fleets of drones buzzing around over our heads, parking atop of street lights and other structures, the drone docking stations do seem to be necessary, as they solve the problem of limited battery life that would make deliveries impossible to many further flung locations.

“The range provided by current UAV technology, however, makes deliveries over a wide area — e.g., throughout a city, or even a portion of a city – difficult,” Amazon says in the patent.

Amazon hopes its Prime Air service will be able to deliver all manner of goods and groceries to consumers in the near future, effectively doing away with the need to pop by the local store (for those who can afford it anyway), but it remains to be seen when its drones will take to the skies. The FAA recently published regulations allowing the commercial use of drones for the first time, but the new rules are not very helpful in Amazon’s case.

At present, the rules require that drone operators keep the drone within their line of sight at all times, and until that restriction is lifted, Amazon’s drones will remain grounded.