Amazon has filed a patent for beehive-like depots which could one day be used to dispatch drone deliveries.

The retail giant has already trialed using drones for deliveries as part of its futuristic "Prime Air" service, which would send small packages by drone in under 30 minutes.

The US patent application proposes using the nine-storey facilities to recharge and house drones. They are designed to use up less space in towns and cities and cut congestion on roads.

While Amazon has more than a dozen fulfillment centres in the UK, where tens of thousands of packages are stored, sorted and shipped, the patent suggests these traditional warehouses could be replaced by multilevel facilities with landing pads for delivery by air.

Amazon's drones would be restocked by human workers inside the multilevel delivery hub

The patent describes how "unlike traditional fulfillment centres, the multilevel fulfillment centres may include many levels" with "one or more landing locations and one or more deployment locations to accommodate UAVs [unmanned aerial vehicles]".

Last year, the online retail giant tested its drone service in the UK, making its first ever package delivery in 13 minutes to a house in Cambridge.

This is not the first experimental patent Amazon has filed for its fleet of drone delivery vehicles. Amazon has also filed proposals for "airborne fulfillment centres" that would be used as flying bases for aerial home deliveries.

Flying at 45,000 feet, the warehouses would hang from zeppelin-style airships and be stocked with popular items, with drones swooping down to earth before returning to the mothership.

Amazon's airborne delivery centre proposal

Amazon has led much of its airborne delivery testing from the UK, where special permissions from the Civil Aviation Authority have made it easier to run the pilot.