A device that provides over-the-air data transmission. The term typically refers to a 3G or 4G modem (see cellular modem). It may also refer to Wi-Fi or Bluetooth. Some of the first wireless data services were CDPD, DataTAC, Mobitex and Ricochet. Also in the past, with the right cables, certain cellphones could become wireless modems for computers, but not often. See wireless glossary, CDPD, DataTAC, Mobitex and Ricochet.