Feb 7, 2020

Wi-Fi LBS For Occupancy Sensing In Buildings: A Technical Overview

Lester Shen, Di Sui


Location-based services (LBS) have been used successfully in a variety of applications in healthcare, retail, and hospitality buildings to track and in some cases interact with individuals. These services include wayfinding, asset tracking, marketing, information, and push notifications. Specific applications include:

  • Wayfinding in shopping malls and in the office,

  • Asset tracking applications in manufacturing retail, and healthcare, 

  • Proximity marketing in stores where advertising content such as coupons or offers is provided wirelessly through apps to shoppers when they stand near specific items and brands in the aisle, 

  • Information provided in self-guided museum tours, and

  • Location-based push notifications.

LBSs use real-time locating systems (RTLS) that identify and track the location of objects and people through the use of wireless technology. Within the defined space, fixed reference points (a “beacon” also sometimes called a reader, or access point (AP)) receive signals transmitted by the devices or tags that the object or person is carrying. Signal strength of the tag to a specific reference point is a measure of proximity and, using multiple beacons, the location of the tag can be determined through trilateration.

A number of technologies have been used for real-time locating such as RFID (radio frequency ID), Bluetooth Low Energy (BLE) beacons, and Wi-Fi. Each system has advantages and disadvantages when applied to occupancy sensing and building operation-related LBS.

This report was funded in part by the U.S. Department of Energy, Building Energy Efficiency Frontiers & Innovation Technologies.