The research team from University of Washington (UW) recently discovered a new way of communication between mobile devices and other special devices like credit cards, contact lenses, and brain implants. A recent showcase of this technology demonstrated a Bluetooth signal transmitted from a Smartwatch interacting with smart contact lenses that were fitted with the antenna. The process followed by this team mainly depends on a communication technology known as backscatter, it permits the instruments to exchange information by reflecting back the existing signals. One of the research associates, Vamsi Talla explains "Instead of generating Wi-Fi signals on your own, our technology creates Wi-Fi by using Bluetooth transmissions from nearby mobile devices such as smartwatches."
Figure 1: Interscatter communication enables implanted devices to talk
For all kinds of communications, Interscatter uses ZigBee, Wi-Fi or Bluetooth transmissions in one single tone signal. This one can be transformed and modified easily. The backscattering of these single tone signal allows encoding of data by contact lens in form of an ideal Wi-Fi packet. This can always be used in collection of health information that can be read by any regular electronic device such as laptop, tablet, or smartphone. Assistant professor Shyam Gollakota further adds, "Bluetooth devices randomise data transmissions using a process called scrambling. We figured out a way to reverse engineer this scrambling process to send out a single tone signal from Bluetooth-enabled devices such as smartphones and watches using a software app."
The prime challenge faced by the team with respect to backscatter is that it leads to creation of a completely useless mirror signal copy that eats up most part of bandwidth and comes in the way of networks over the mirror copy of the Wi-Fi channel. To counter this, the team has developed another special technique called 'single sideband backscatter' that removes the undesired by-products and frees up the bandwidth.