In which year, SMS was tested?

The correct answer is 1992:

Key Points

• SMS:
  • S​hort Message/Messaging Service, commonly abbreviated as SMS, is a text messaging service component of most telephone, Internet, and mobile device systems.
  • The first SMS message was sent over the Vodafone GSM network in the United Kingdom on 3 December 1992, from Neil Papworth.
  • The text of the message was "Merry Christmas.
  • According to Matti Makkonen, the Nokia 2010, which was released in January 1994, was the first mobile phone to support composing SMSes easily
  • The first commercial deployment of a short message service center (SMSC) was by Aldiscon part of Logica (now part of CGI) with Telia (now TeliaSonera) in Sweden in 1993 followed by Fleet Call (now Nextel) in the US, Telenor in Norway and BT Cellnet (now O2 UK) later in 1993.