CAPTURE: Cooperatively Applied Positioning Techniques Utilizing Range Extension

  • Gary Cullen

Student thesis: Doctoral Thesis


Access to location-based information in mobile devices, is now ubiquitous. This has been mostly possible in the outdoor arena via the Global Positioning System (GPS) providing near global coverage, barring some natural obstacles and manmade obstructions. The provision of accurate position estimations and broad coverage in the indoor environment has however proven somewhat more problematic to deliver.

The most commonly implemented Indoor Positioning Systems (IPSs) use existing Wi-Fi network components and infrastructure to locate devices. This technique offers obvious economic rewards, utilizing a preinstalled infrastructure. These topologies however were typically designed to provide network coverage, rather than deliver an indoor location-based solution.

Large areas without coverage are common in these networks, because network designers were not typically concerned with providing 100% coverage for mobile data. Hallways, toilet areas or other general-purpose areas that ordinarily would not require network coverage, were not provided with dedicated Wireless Access Points (WAPs). Transient users, navigating these areas of the network were therefore, un-locatable using this infrastructure. Furthermore, the indoor arena is an especially noisy radio atmosphere as it hosts other wireless devices such as Bluetooth Headsets, Cordless Phones and Microwave Ovens which operate at the same frequency as a Wi-Fi signal. Considering users spend more time in an indoor environment, the need for a solution is clear.

The hypothesis of this research is that mobile devices at the boundaries of IPSs which have themselves been located by an IPS, can assist in a cooperative fashion, to locate mobile devices beyond the range of the IPS but within range of the cooperating devices. The primary research question is whether the range of indoor positioning solutions can be extended using cooperative devices at their extremities.

To solve the hypothesis, this work designed and implemented a framework using cooperative techniques using range extension (CAPTURE) which works with any IPS irrespective of the technology it utilised to locate. The framework can plug into existing solutions to extend their range into areas of indoor environments that cannot be reached without the need for any additional infrastructure. Results show CAPTURE can extend the range of an existing IPS by up to 180m using Wi-Fi and Bluetooth.
Date of AwardMay 2019
Original languageEnglish
SupervisorJose Santos (Supervisor) & Kevin Curran (Supervisor)


  • Indoor Positioning Systems
  • Cooperative Positioning

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