Wi-Fi

Wi-Fi was a method of wirelessly connecting electronic devices to each other via the internet, for purposes of communication or entertainment. It could also be used as a method of dispersing energy. It had varying qualities of reception.

When about to be incarcerated in the Tower of London with two of his other incarnations in 1562, the Eleventh Doctor jokingly asked if there would be Wi-Fi. (TV: The Day of the Doctor)

Nikola Tesla had the idea of Wi-Fi in 1900s. (TV: Nikola Tesla's Night of Terror)

In 2009, the transformation of humanity into the Master Race was blamed on hallucinations caused by faulty Wi-Fi. (TV: The End of Time)

By 2013, Wi-Fi was practically omnipresent on Earth - the Eleventh Doctor described humanity as "living in a Wi-Fi soup." The Maitland family could access Wi-Fi in their home, using the password rycbar123. The Great Intelligence used an organisation run by Miss Kizlet to upload peoples' souls through Wi-Fi into the data cloud in order to feed its form; this plan was enacted by disguised robots called Spoonheads. (TV: The Bells of Saint John)

In the 21st century, a Fliis used Wi-Fi to telepathically control people. (COMIC: Fashion Victims)

In the underwater base the Drum in 2119, the Twelfth Doctor tuned his sonic sunglasses into the base's Wi-Fi, providing an audio-visual feed to the base's computers to let the base crew get a closer look at the ghosts haunting them. He also used the sunglasses to generate holograms, first of Clara Oswald and later of himself, which were projected using the base's Wi-Fi. (TV: Under the Lake, Before the Flood)

In the 50th-51st century, the Library had Wi-Fi. When Miss Evangelista was killed, her data ghost was caught in the Wi-Fi and reconstructed by CAL in her hard drive. (TV: Forest of the Dead)

In the 52nd century, the Seventh Transept had decent Wi-Fi, despite being a tomb. Dorium Maldovar was able to use his media chip to access the Wi-Fi after he was decapitated and brought to the Seventh Transept. (TV: The Wedding of River Song)