Télécoms sans Frontières took the data transmitter and laptops it had used to track food aid during a famine in Niger in 2005 and adapted them to store facts about disease prevalence afterwards.

Powerbeam's solution is to fit a small fluorescent bulb to the receiving device so that a camera on the transmitter can track the light and steer the laser beam accordingly.

However, the Q-track technology does not use signal strength to measure the distance between transmitter and receiver or time of flight like GPS.