Which system allows devices to determine their location indoors using triangulation from nearby radio sources?

The Indoor Positioning System (IPS) is specifically designed to determine the location of devices indoors, where traditional GPS signals may be weak or unavailable. This system employs various methods, such as triangulation from nearby radio sources, to pinpoint a device’s location accurately.

Unlike GPS, which relies on satellite positioning for outdoor navigation, an IPS leverages the strength of signals from Wi-Fi access points, Bluetooth beacons, or other radio frequency sources to calculate a device's position. By measuring the distance from multiple known sources and using mathematical algorithms, such as trilateration or triangulation, the system can establish the exact location of the device within a given indoor environment, such as buildings or malls.

Although other options like Bluetooth Tracking and Wi-Fi Triangulation could be components of an IPS, the term "Indoor Positioning System" encompasses all the necessary technologies and methodologies for achieving indoor navigation and positioning effectively. This makes it the most appropriate choice for the question regarding how devices locate themselves indoors using triangulation methods.