(covers information from several alternate timelines)
A cell phone playing video in 2024
A woman texting on her cellular phone
A cellular phone, also known as a cell phone or mobile device, was a portable telephone communications device used by Humans in the 20th and 21st centuries, as well as by some Humans in the alternate reality created in the year 2233.
In 1996, four officers from the USS Voyager – Kathryn Janeway, Chakotay, Tom Paris, and Tuvok – were walking near the Santa Monica pier, when Janeway's combadge beeped and many people near them thought their cellular phones were ringing. (VOY: "Future's End")
Tuvok used Rain Robinson's cell phone while at the Griffith Observatory to send a report to Janeway on Voyager. He was able to do this by modifying the satellite transmitter to carry and receive Voyager's frequencies, although with a poor connection. Not long after, Robinson used her own phone to call Henry Starling, telling him that she was afraid someone was after her, but this was just a ruse planned by the away team from Voyager. (VOY: "Future's End, Part II")
In 2022, Sera, a Romulan agent masquerading as a contemporary human in Toronto, claimed she was using her cellular phone to live stream video of a time-travelling James T. Kirk's arrest by Toronto City Police officers over the Internet. This persuaded them to release him. (SNW: "Tomorrow and Tomorrow and Tomorrow")
In 2024, Pedro used his cell phone to send someone a text message after he was rescued from ICE by Seven of Nine and Raffaela Musiker. (PIC: "Fly Me to the Moon")
While at the Europa Mission gala, Jean-Luc Picard couldn't help but notice that Renée Picard was paying a great deal of her attention to her mobile device. Tallinn then told him "we all do that." (PIC: "Two of One")
At 10 Forward Avenue, FBI Agent Martin Wells showed Jean-Luc Picard and Guinan some CCTV footage on his cellular phone that showed Picard materializing out of thin air. (PIC: "Monsters")
That same year, Detective Preston of the SFPD spoke on a cellular phone to the Governor of California, Robert Chen on the state of the Bell Riots. While talking, Chen advised her to move in with a SWAT team. (DS9: "Past Tense, Part II")
In 2241 of the alternate reality, James T. Kirk's stepfather's Corvette was equipped with a Nokia mobile telephone. His stepfather used this to contact Kirk when he took the car out for a joyride. (Star Trek)
In 2255 of the alternate reality, at a bar in Riverside, Iowa, a woman used her cellular phone to send a text message when Kirk got into a fist fight with some Starfleet cadets. (Star Trek)