This week marks the twentieth anniversary of the first text message sent via a mobile phone.The message, which simply said "Merry Christmas", was sent by Neil Papworth, an engineer at a company called Sema Group, using an Orbitel 901 handset.

The recipient of that text in 1992 was Richard Jarvis of the UK mobile phone network Vodafone. However, it still took a few years before the technology, widely known as Short Message Service (SMS), actually took off.

Back in the early 1990s, companies were still heavily investing in pagers but by the middle of the decade, texting became increasingly popular among the young because it was usually free and didn't require an intermediary.

However, unlike now, where users enjoy the full alphabet on touchscreen phones with intelligent software that can predict the words you are trying to say, phones at the time could only type by selecting one of three letters above each number on the handset. This proved to be a laborious process to write anything substantial, and with texts limited to only 160 characters, the phenomenon of text speak - or txt spk - soon grew.

From those humble beginnings, networks put a greater focus on providing better text services, developing T9 and other predictive text system to make the experience faster and more fluid and introduced Multimedia Messaging Service (MMS), allowing users to send pictures across different networks.

Today, more than 5.9 trillion texts are sent a year with around 15 million passing between mobile phones every minute. However, experts are already predicting that the format has hit its peak and is now on the decline.

As more customers have switched to smartphones, with better access to the Internet and hundreds of thousands of apps, people are increasingly using e-mail, social networks like Facebook and Twitter, and instant messengers such as Skype, to communicate.

"SMS is in a fight for its life in some markets as it finds its role as a mobile communications service is usurped by free messaging services, such as WhatsApp, iMessage, Viber, KakaoTalk and Facebook Messenger," said Pamela Clark-Dickson at research company Informa Telecoms & Media. "The concern for mobile operators is that the malaise that SMS faces in countries such as the Netherlands, Spain, China, South Korea and the Philippines - where SMS traffic and revenues are in decline - will inevitably spread, as the penetration of smartphones and mobile broadband grows."

Still, there's a long way to go before we begin to write the obituary for SMS. Informa also predicts that texts will continue to grow in the short term, with traffic totaling 9.4 trillion messages in 2016; generating $127 billion in revenues for mobile phone companies.