Apple has filed a patent for a service that could transform iPhones and iPads into secure walkie-talkies.

iPhone users could use the service to find one or more friends nearby and chat to them without having to connect to a mobile phone network.

The service for establishing what Apple calls ‘ad-hoc point-to-point voice communication’ is the subject of the patent, published today.

Apple suggests multiple reasons why people might want to communicate in this way.

One scenario it suggests, is where two people need to talk to each other from opposite sides of a crowded, noisy room and need to be free to move independently.

“Such ambient noises may require both individuals to approach within a certain proximity of each other, which can hinder freedom of movement of one or both users for the duration of the direct communication,” it states.

Users could use a graphical interface on a touchscreen to pick the people nearby they wanted to establish a direct voice link with, the patent suggests, as shown below.

The patent argues that picking people from this interface would be simpler and quicker than working out who was nearby, finding them in a contacts list and ringing them.

Also, when people on a call can directly see each other, the latency of routing that call over a cellular system, over the internet via Voice over IP or other indirect communication channel, can create a jarring mismatch between what the user is saying and what they’re doing, the patent contends, making a lower latency, direct voice link preferable.

Apple suggests this point-to-point network link could be established using Bluetooth or local wi-fi connections and that the link would work providing users stayed within a certain proximity to each other.

Such a communication method could be secure and discreet, relative to phone calls, using unsecured walkie-talkies or talking to someone face-to-face, the patent posits.

“As wireless ad hoc network links can include signal encryption, discreetness of the voice communication between users via the wireless ad hoc network link can be enhanced,” it states.

The patent lists the iPhone and the iPad among the examples of electronic devices the service could be used with, though doesn’t single them out. In another possible hint, the filing also refers to a “wireless communication device” used for direct voice comms as running the GUI on an iPhone or iPad-like touchscreen.

A sketch in the patent shows the service being used by two people wearing headsets plugged into smartphones, as seen at the top of the story. The patent also includes a drawing showing a point-to-point voice link being directly established between two wireless headsets.

Bizarrely, the patent even suggests the system could be handy where two people want to meet up while avoiding people nearby who smell unpleasant or who are discharging bodily fluids.

“For example, the users may desire to maintain a minimum distance between each other for cultural reasons, lack of familiarity with each other, a desire to avoid impinging upon each other’s personal space, a desire to minimize contact with bodily odors and discharges of other individuals,” the patent states.