It’s been a couple of years since I came face-to-face with location based services (LBS). I had been at a Microsoft conference where a very early version of what was to become the MapPoint Location Service was demoed. There seemed to be quite a few applications that would have benefited from this, but there seemed to be some issues around who owned location information and how privacy came into the whole equation.
Today I came across TruePosition who seem to be quite dominant in the sector. They have end-to-end solutions for LBS and have a pretty informative website which I used to come up to speed on the technology. There’s a number of techniques used to locate someone, namely
- U-TDOA : Highly accurate and able to work with any phone, existing or future, this provides the performance needed for mission critical location-based services and works by using three or more cell towers and triangulating on a signal by measuring the time it takes for signals from the cell phone and to get to each tower. (The acronym means: Uplink Time Difference of Arrival)
- A-GPS: This makes use of GPS technology to pinpoint a phone, and supplements this with other technology to make location quicker and more efficient. This requires GPS-enabled phones but can be rolled out with minimal network infrastructure. (The acronym means: Assisted Global Positioning System)
- E-CID: Cell Identification is the process of using the network’s knowledge of the phone within the controlling cell site and communicating the sector information. Using the geographical center of this area provides a rough estimate of the location of the caller, regardless of the type of phone. E-CID is an improvement on this process by using additional signal information to narrow the location. (The acronym means: Enhanced Cell Identification)
- AOA: This method uses an antenna containing a multiple element array in which the exact location of each AOA element is known precisely. Each element is small and capable of receiving a separate signal. By measuring signal strength, time of arrival, and phase at each element of the array, it is possible to calculate the line-of-sight path from transmitter to receiver. Placing another receiver with the same antenna configuration in a different location allows you to repeat the process and figure out an intersaction point. (The acronym means: Angle of Arrival)
As you can see, there’s quite a bit of choice in terms of technology and most solutions will use one or a hybrid of these techniques. There are multiple business applications that can benefit from this, from marketing, location services, individual identification and tracking and many many more. I’m sure this industry will be looking at substantial growth in the near future.