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Enabling reliable indoor localization can facilitate several new applications akin to how outdoor localization systems, such as GPS, have facilitated. Currently, a few key hurdles remain that prevent indoor localization from reaching the same stature. These hurdles include complicated deployment, tight time synchronization requirements from time difference of arrival protocols, and a lack of mechanism to allow a pan-building seamless solution. This work explores ways in which these key hurdles can be overcome to enable a more pervasive use of indoor localization. We propose a novel passive ranging scheme where clients overhear ongoing two-way ranging wireless communication between a few infrastructure nodes, and compute their own relative location without transmitting any signals (preserving user privacy). Our approach of performing two-way ranging between infrastructure nodes removes a crucial timing requirement in traditional time-difference-of-arrival methods thereby relaxing the synchronization requirements imposed by previous techniques. We use ultra-wideband wireless (UWB) radios that can easily penetrate building materials so that spanning an entire floor of a large building with just a few infrastructure nodes is possible. We build working prototypes, including the necessary hardware, and demonstrate the plug-and-play nature of our proposed solution. Our evaluation in three indoor spaces shows 1–2 meter-level localization accuracy with areas as large as 2241sq.m. We expect our explorations to re-trigger interest in novel applications for indoor spaces based on fine-grained indoor location knowledge. 

Location-based services have the potentials to change how we interact with the places and things around us. UWB indoor localization is one of the most successful enabling technologies that has achieved decimeter accuracy with robustness against complex indoor multipath environments. In this work, we demonstrate a system that not only achieves high localization accuracy, but also supports infinite scalability, full user privacy, and plug-and-play infrastructure deployment, which brings localization closer to a universal and pervasive technology. 

In this work, we explore ways to make hybrid conferences appear seamless and natural by merging the virtual- and the real-worlds. We use ultra-wideband UWB localization to insert “avatars” of real participants in the virtual space, and holographic projections to make virtual participants appear present in the real-world. 

This demonstration presents the Location-Specific Public Broadcast system, in which localization and wireless broadcasts are combined to deliver a scalable, privacy preserving, and generic solution to location-based services. Other interactive location-based systems either preload information on the user devices, which are usually bulky, difficult to update and have to be custom-made for each venue, or fetch information from cloud based on location, which sacrifices user privacy. In our system, a wireless access point continuously broadcasts information tagged by locations of interest, and the mobile devices performing passive localization select and display the information pertinent to themselves. In this case, the location-specific information is stored only on the WiFi AP, and the phone app would be ultra lightweight with only the location calculation and information filtering functionalities, which can be used in any space. We envision our solution being adopted in public places, such as museums, aquariums, etc., for location-specific information delivery purposes, like enhancing interactive experience for visitors.