SOS was first transmitted in the U.S. in 1909 from the Arapahoe vessel and was later used alongside CQD when the Titanic was sinking. The U.S. officially adopted the signal after Titanic .

Thousands of customers woke up Thursday morning to an SOS symbol at the top of their iPhones and no service due to a nationwide telecommunications outage. The outages were impacting AT&T customers ...

Mutexes and semaphores in .NET. A mutex is used to synchronize access to a protected resource or a “critical section” of code. (A critical section is code that must not be run by multiple ...

Is your iPhone showing an SOS indicator in the status bar? Don't panic. Here's what that means and how to get rid of it.

If SOS is showing up on your iPhone's status bar, it means there's no cellular connectivity for your phone. Here are two quick ways to troubleshoot the problem if you think you should have a ...