The US Patent and Trademark Office has awarded technology giant Google a patent for an aerial drone delivery concept that includes a system for lowering items to the ground on a tether but also a “bystander communication module”.

Google applied for this patent in July 2014 and the USPTO granted the patent, publishing the news on its website on Tuesday 26 April.

A number of other companies have patented systems for lowering parcels to the ground on a tether and the system is not very new – indeed, this seems to be a direction of travel for the drone delivery systems of the future. The “bystander communication module” however makes this concept a little more interesting than the others.

The new gadget would generate an “avoidance cue” that would warn bystanders that it is lowering the package to the ground and this could “also be further configured to generate the retrieval cue”.

Safety is a major issue that technology companies are addressing as they develop systems that will both do the job and be acceptable to regulators. This is one of the issues that makes it incredibly hard for such systems to come from concept to reality.

Google has been granted a number of other patents associated with drone delivery systems and looks to be one of the major players that will enter the fray when the first drones come online (whenever that will be…).

A number of factors stand in the way of drone delivery. They will require a lot of power to hover when they lower their goods and may not have a great range per delivery so will only be able to work in densely populated areas. Weather is another problem – the UK frequently sees winds in excess of 30mph that will significantly dampen the range of these vehicles not to mention the amount of time they will be able to fly every year!