Late last month the US Patent & Trademark Office published a patent application from Apple that relates to future iPhones being equipped with device-to-device (D2D) communication and efficient power management.

If an iPhone user happens to get hurt while hiking or is in a disaster like a hurricane, they may either be out of cellular range or in an area where cellular towers cease to function in order to successfully call for emergency services.

With a D2D system integrated into future iPhones, a user will still be able to send out an emergency text or audio message that could be received by groups of devices/people that are out of cellular communications range so that they could call for emergency services for you. This could very well be a lifesaving feature in the future.

Device-to-device (D2D) communication may be referred to as direct communication between two mobile devices without traversing a base station or core network (e.g., a cellular network). There are some situations in which a mobile device user may be outside of coverage areas of cellular communications.

For example, in an emergency situation (e.g., an injury during hiking), a user may want to be able to send out emergency signals to people who are near. As another example, in a natural disaster (e.g., a hurricane), it may be advantageous to be able to send out messages to a large group of mobile device users in order to coordinate evacuation or rescue efforts.

In such situations, it may be desirable for a mobile device, such as a smart phone, to communicate with other mobile devices in a D2D communication network.

In some situations, D2D communication may be preferred even if there is cellular coverage. For example, in a sports stadium or in a mall, the cellular signals may be congested. A user may want to turn off cellular communication, and instead communicate with friends using D2D communication. Therefore, there is a need to improved methods of D2D communications.

Apple's invention covers enhanced procedures of sending emergency messages using D2D communications are provided that may alleviate collisions and reduce overhead.

An alternative radio service (ARS) is one type of radio access technology (RAT) for D2D communication. The D2D communications may include text messages as well as voice messages. The communication range can be as far as several tens of kilometers.

An ARS may operate in any unlicensed frequency or frequencies, such as 900 MHz, 2.4 GHz, 5 GHz, or the like. Different countries may have different unlicensed frequency bands.

Apple's patent FIG. 1 below illustrates schematically an example device-to-device (D2D) communication group involving a primary device and multiple secondary devices; FIG. 5 is a flowchart illustrating a method of broadcasting emergency messages via D2D communication; FIG. 8 illustrates example communication ranges for different transmit powers.

Apple's patent FIG. 14 above illustrates different example coverage scenarios of a D2D communication.

Apple's patent application was originally filed in Q4 2018 published late last month by the U.S. Patent Office. Considering that this is a patent application, the timing of such a product to market is unknown at this time.

Some of Apple's Inventors

Sanjeevi Balasubramanian: Strategic Sourcing Manager

Shiva K Narra: Sr. Manager. Previous employers include Motorola and Samsung

Tarik Tabet: Wireless Architecture