RTLS, or Real Time Location System, is the combination of software and hardware used to monitor the location of objects and people inside of buildings.  The objective for using a system like this is to continually analyse the location of mobile equipment you need to track.

There are three components to an RTLS system:

First, are active asset tags and employee badges that transmit a unique number at a specific signal strength.

Second, antennas are installed at fixed reference points.  The antennas listen for the signal from the tags and badges.  Since the signal strength decreases over distance it is possible to judge the distance between antennas and tags.

Third, is a Location Engine that compares the signal strength readings from multiple antennas.  Since the antennas are installed at known locations the system can use distance calculations to determine the location of the tags.

How Bluetooth antennas communicate with Wifi

There are several types of signals being used by RTLS systems being implemented by various suppliers.  Primarily the technologies are:

Wi-Fi

These system and take advantage of existing Wi-Fi networks and leverage signal strength readings however the signal strength is too loud for room level accuracy.  A secondary signal and sensor network is required.

Optical Based (Infrared)

The building is outfitted with infrared transmitters in areas of interest such as patient rooms.  These transmitters excite tags on objects as they pass near them which transmit their information to the server.  This technology requires line-of-site between the tag and transmitter preventing employee tags being under lab coats or asset tags being placed under equipment.

Acoustic Based (Ultrasound)

Ultrasound locating technologies work similarly to infrared systems only they use ultrasound transmitters deployed in locations of interest.  They can pinpoint the location of tags in their areas but cannot judge distances.

Bluetooth

Bluetooth Low Energy tags emit a signal strong enough to pass through equipment but not through floors or concrete walls.  The signal strength is also low enough to accurately determine distance between the antennas and tag resulting in a higher degree of accuracy.

All of these systems must have a pathways to send information back to the Location Engine software.  Generally this is done by wi-fi, but some may require hard-wired ethernet cables.