The Revolutionary Technology Behind Deeyook
Interferometry is based on wireless propagation
Wireless propagation in space is very useful for location tracking - RADAR is a good example. However, RADAR is, by definition, a two-way propagation paradigm, A to B to A, measuring propagation time at the speed of light. Since the speed of light is enormous, even the slightest timing errors are catastrophic.
Interferometry measures angles, not distances.
The Physical Model
Measuring the phase difference between different antenna elements in the array is a patented method, specific to OFDM modulation e.g., IEEE802.11n/ac/ax Wi-Fi. The constellation of many such interference pattern-generating transmitters can be modeled. The model dictates expected phase difference readings at arbitrary locations, without ever reading signals there beforehand. The model is then reversed, using numerical methods, to predict the location, given the readings.
Access Point Interferometry
Wi-Fi access points use two or more antennas to substantially improve the service they provide to connected mobiles. The antennas, in combination with smart digital signal processing (DSP) in the AP, make the transmission robust, eliminating 'black spots' leading to poor reception in some random spots near the AP.
Our innovation exploits the given DSP and antenna configuration in the AP to extract the (angular) direction from the AP to individual mobiles. The mobile is merely receiving Beacon packets that the AP sends repeatedly, at constant intervals of one tenth of a second. The receiving omni directional antenna in the mobile, is orientation insensitive. All 802.11n/ac/ax protocols are supported in 5GHz, 6GHz and 2.4GHz.
Our patents teach how to passively extract Direction of Departure from standard based MIMO signals that were designed to be direction insensitive. Our direction estimation is dead reckoning free, meaning readings do not degrade over time.
The mobile extracts the interferometric data out of ordinary Wi-Fi chipsets, already populating mobile devices. Since Interferometry has no dead reckoning, power can be turned off completely between operations to save power with no 'warm up' costs. Further, Beacons are received as part of the normal operation of the Wi-Fi chip, so the extra cost of tracking is marginal.
Solving the Real Location Problem
Given the direction at which many APs view the tracked mobile, the geometrical problem is solved, providing real-time location estimation of individual mobiles. In order to save power at the mobile, actual calculation is performed in the cloud, results pushed into a database and made available through software API to location-based apps such as 3rd party warehouse management systems (WMS), geofencing systems, chain of custody systems, navigation tools etc. The measurements taken by the mobile are sent over the available backhaul channel, be it cellular or Wi-Fi, regardless of which wireless signal is used for location estimation. The geometrical model used to estimate mobile locations is perpetually updated in software, using mobile readings. The AP model comprises AP location, AP orientation etc.
01
INTERFEROMETRY
Measure phase differential
02
STREAMED TO CLOUD
Deploy machine learning algorithms
03
DETERMINE THE ANGLE
04
DETERMINE THE ANGULAR SPACE
Translate and anchor the position
05
GEOGRAPHIC POSITION
Within a known map
*Mobile being a non-stationary IoT device, i.e., cellphone, tablet, laptop, etc., any trackable object