It might be hard to believe, but there is a better chance of getting lost inside a building than outside in the woods. Do you remember the last time you were heading to a new destination without the use of GPS? If you are a millennial driver, born after 1982, the chances are very slim. Those who were born before may have some vague memories of using an old-school paper map or printing out directions from Google Maps or MapQuest. Whatever the case, we now feel pretty confident in our ability to navigate when out and about. But what about finding a destination indoors? How do we navigate a particular location when entering a public indoor space, such as a store in a mall? What about a room in a hospital? Or a seat in a stadium?
Challenges when searching for specific locations in buildings
Whether you’re visiting a sick relative or undergoing a medical procedure yourself, visiting a hospital is never a pleasant experience. Hospital buildings are tough to navigate — in fact, most buildings are. If you’re not familiar with the structure, you’ll likely need some direction from staff. The problem is hospital staff are usually extremely busy and unapproachable.
Parking lots, too, are mission impossible, especially when your phone has no service or WiFi. You can try memorizing your license plate number, parking near a colorful sign, or identifying landmark you won’t forget, but it’s challenging. Google Maps, for example, developed a feature that automatically saves your parking location. But what happens when you’re underground with no service?
Airports are another perfect example of how hard is to locate places indoors. If you’re picking someone up, you need to figure out exactly where to wait for their arrival. If you’re the one traveling, you need to allocate precious time to find your check-in area and departure gate. Imagine if you could use your phone to find your airline check-in counter, gate, or any service you need as easily as following your GPS while driving. How come no one has come up with a solution for these issues to date?
Technical challenges of using indoor positioning
Indoor positioning or indoor way finding have come with enormous technical challenges. Unfortunately, GPS technology that uses satellite positioning cannot function indoors because GPS signals cannot reach indoor receivers. Smaller places require more accuracy because, well, every aspect of the space is smaller and denser. BT and WiFi are not able to pinpoint specific locations, while sound waves are perfectly capable of doing so. Additional technical challenges come from the movement of people and the random effects of signal propagation.
Wi-Fi fingerprinting is a well-established indoor positioning technique based on the Received Signal Strength (RSS) transmitted by nearby Wi-Fi access points. However, the system performance depends on an elaborate training process and ongoing maintenance efforts.
Bluetooth beacons have been used for indoor navigation since they were introduced by Apple in 2013. Once beacons are placed at several positions in the building, Bluetooth signals are sent to mobile devices to continuously determine its position, making indoor navigation feasible.
The Gatwick airport in London, for example, has recently installed a way finding system supported by an augmented reality (AR) tool that uses beacons to direct customers around the building using their smartphones. The beacons have been installed across the North and South terminals. Beacons show where the passenger is located via mobile apps with a blue dot for indoor navigation. It’s important to note that radio frequencies cause interference within environments, such as hospitals that have electromagnetic fields, which could damage the Bluetooth signal. Additionally, intensified densities of Bluetooth beacons can cause radiation.
The fundamental problem with most of these solutions is the physical nature of how radio waves function. Radio waves travel through walls, meaning they need a lot of calibration and numerous beacon installations as they don't naturally detect boundaries made up of walls, ceilings, or floors. The ability to identify on which floor you’re located in a building, what hall way you may be walking through, or which room you are in, is a quality reserved for sound waves. In addition, all radio frequency (RF) wave technologies emit electromagnetic radiation. When using the numerous beacons needed to calibrate positioning, these radiation waves are emitted, making it difficult to impossible to use in environments that are sensitive to electromagnetic radiation, such as mines, certain factories, electric substations, and hospitals. An additional benefit of sound waves for use in applications is proximity marketing, when indoor spaces in a store change, the entire network setup needs to be recalibrated, and all the beacons need to be reinstalled.
Indoor Navigation is an exciting challenge for those trying to come up with the next big technological solution that could change our everyday lives. There are a few exciting developments worth mentioning. NASA‘s “Pointer,” for example, can track firefighters as they navigate through burning buildings, by relying on magneto quasi-static fields. The technology is completely different from cell phones, wireless internet, radar, and GPS, all of which rely on electromagnetic waves to allow communication over long distances. However, Pointer only works over short distances and requires users to carry special equipment, but it could enable accurate indoor positioning.
Last but not least, sound waves are an example of a technology that can be applied to indoor navigation, offering an alternative to GPS (that can’t be used indoors), WiFi, or Bluetooth. With many different players joining the space and leveraging innovation, we can expect to see this type of technology flourish and help us get around and navigate more efficiently.
Maybe, the future of indoor navigation will be a combination of all these amazing technologies. Until then, let’s make sure to keep allocating some extra time when going to the airport, just in case we get lost.