Apple has envisioned a way to see whether a fellow iPhone user is free to talk before you even complete the call.
Published Thursday by the U.S. Patent and Trademark Office, a patent appropriately called "Methods to determine availability of user based on mobile phone status," describes just that process.
How many times do you call someone only to get dumped into voice mail? Maybe the person isn't available or is in a dead zone or has just turned on Airplane mode. Apple's proposed invention seeks to eliminate that uncertainty by alerting you to the person's status right off the bat.
To accomplish this feat, a person's iPhone would talk to Apple on the backend to report its status and call preferences. Such settings as location, signal strength, battery life, and mode (Normal, Airplane, or Vibration) would be sent to Apple's servers. A fellow iPhone user who attempts to call that person would see the status of the callee's phone on the screen and can then decide whether to complete the call.
In essence, your phone would borrow a key feature from instant messaging in which you can see if someone is online, offline, free, or busy.
As Apple describes it in typical patent language:
A command is received at an operating system of a first mobile phone for displaying contact information of a remote user having a mobile phone number of a second mobile phone. In response to the command, a request is transmitted to a remote server from the first mobile phone over a cellular network requesting an operating status of the second mobile phone. The operating status of the second mobile phone is received from the remote server over the cellular network. The operating status of the second mobile phone is displayed on a display of the first mobile phone as a part of contact information of the remote user associated with the second mobile phone, where the operating status includes current locality of the second mobile phone.
Such an invention does bring up privacy issues. What if you don't want Apple and other people to know your status? Assuming this feature ever even sees the light of day, Apple would presumably offer you a way to simply turn it off.