20 Years of SMS Interoperability

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How we Got Here and What it Meant, and Still Means for Messaging

Text messaging through Short Message Service (SMS) is now ubiquitous and universal. Today, virtually every subscriber in the world has access to simple text messaging. Some say that it is old and out of date, but this simple messaging concept has been and still is the most widely penetrated medium in the history of humankind.

In 2020, the Unites States exchanged more than 2.2 trillion SMS and MMS messages – 119 billion more than 2019 according to the CTIA 2021 Annual Survey. Texting each other via SMS/MMS is now a daily part of our lives and will continue to be for the foreseeable future. Additionally, this communications channel has long been the leader as an outreach channel for brands and businesses to engage with consumers.

But it wasn’t always that way.

It is, indeed, a 20-year story that began to come to fruition in the late autumn of 2001.

SMS first came to full functionality after the December 3rd, 1992 message from Neil Papworth to Richard Jarvis that said “Merry Christmas.” Throughout that decade, SMS grew within European and Asian mobile operators’ GSM networks. Finally, starting in 1999, SMS could be sent between GSM networks. But that was only single network interoperability.

Twenty years ago, you couldn’t send an SMS message between mobile operators in the United States, Canada, and many other markets. This was because of the incompatibility of the underlying network infrastructure. Network technology was not consistent among the operators with some using TDMA, CDMA, and iDEN in addition to GSM. Networks in Europe and Asia were mostly all GSM and SMS usage across GSM networks was growing and becoming quite popular.

It’s hard to believe that it’s been 20 years since true hub-based messaging interoperability was first announced, as so much in the industry has happened. Many believe that we’ve always been able to text anywhere we can call across the mobile ecosystem, but that was not always true.

The actual anniversary is a bit obtuse, in that quite a bit happened in November 2001. First, a company called CMG Wireless Data Solutions[i] announced  on November 6, 2001 that four Canadian mobile operators:  Bell Mobility, Rogers AT&T, Microcell and Telus Mobility would offer SMS interoperability in the near future.  This was using a product called the CMG Inter-SMSC Router (or ISR), which was previously announced as a product on July 12, 2001. I was fortunate to be in the right place at the right time and conceived of the concept of an inter-SMSC router / hub or SMS Gateway in early 2001. This was after I was motivated by speech given my colleague Steven van Zanen at a GPRS conference in Atlanta where he outlined amazing success stories of SMS in Europe and Asia. GSM network interconnectivity was key. After that initial conception, the idea was formally defined and designed and the ISR was quickly born. I began evangelizing the ISR and the concept of hub-based SMS interoperability extensively during the first half of 2001. Someone must have listened, because in late spring 2001, the Canadian mobile operators, under the CWTA umbrella launched an RFP for SMS interoperability across the four primary Canadian carriers. CMG subsequently won that RFP, resulting in the November 6th announcement.

Soon after that, on the 19th of November, a Virginia based company called InphoMatch[ii] announced a 1-carrier agreement with AT&T Wireless to provide a variation of messaging interoperability. By beginning of April 2002, CMG and the Canadian operators were live. In early 2002, InphoMatch added Voicestream (now T-Mobile USA) to its interoperability nest with AT&T Wireless, with Verizon following at the end of March.  By the end of April 2002, InphoMatch’s intercarrier traffic grew to over 31 million messages.

Thus, the rise of truly interoperable SMS was off.

As 2002 proceeded, more mobile operators joined InphoMatch. A handful of other messaging hubs also got into the interoperability game and by the end of the year, the first peering agreement was signed. Messaging peering agreements are quite important in that there is no one company serving all the mobile operators regionally or globally. Each messaging hub must exchange messages with other messaging hub providers so provider A’s customers can exchange SMS with provider B’s customers. Peering is an important concept within the telecommunications ecosystem, such that it is a requirement to create a ubiquity for messaging, networks (e.g. GRX/IPX), and more.

Due to true, cross-carrier interoperability, spanning multiple network technologies, US SMS traffic grew exponentially. In 2003, I had made my way into InphoMatch and I’ve remained in this group to this date. By 2003, SMS usage in North America had exceeded everyone’s expectations. At the end of that year, a research firm noted that over 30 million US subscribers were active SMS users – a penetration rate of only 19%! There was so much potential and by the end of 2005, Mobile 365 (formerly InphoMatch) processed over 19.2 billion SMS messages. In 2006, after Mobile 365 became Sybase 365, traffic doubled to over 39.3 billion cross-carrier SMS messages processed. Messaging traffic continued to grow and by June 2010, Sybase 365 crossed over 1 trillion lifetime messages processed since 2001. For the total of the United States, by 2010, over 2.05 trillion messages were exchanged per the CTIA Annual Survey for 2011.

In the 2nd decade of the 2000’s, Sybase 365/SAP Digital Interconnect (now Sinch) continued to march through 1 trillion message milestones, topping 5 trillion messages processed in 2020.

Referring to cumulative messaging traffic, we project Sinch will cross 6 trillion in 2023.  We should emphasize that these are cross-carrier messages that we process — not all messages generated by all mobile operators around the world. 

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In the last 10 years, SMS traffic growth has diminished somewhat. In fact, we can pinpoint the peak of SMS messaging: October 2011. After that point, SMS began a slow decline and reached stabilization of national and global messaging. Initially, this was due to from iMessage launching and taking the iOS to iOS traffic; however, other non-carrier messaging ecosystems now also contributed to this decline. WhatsApp came to app stores in 2010; but, it didn’t start to push out SMS/MMS in some markets until 2013. In many markets of the world, as WhatsApp grew to over 2 billion subscribers, it is now the predominant P2P messaging channel in use – but not everywhere. For example, WhatsApp is illegal in China where WeChat is the predominant messaging ecosystem.

As we noted earlier, SMS now ubiquitous.  It’s on every handset. All mobile operators support it. It is many times, the only communications medium that’s available to millions if not billions of subscribers. And it’s used.  A lot.

Despite all of the other messaging / social channels that are available today – from Instagram to Telegram, Apple Messages for Business to WhatsApp, Snapchat, and WeChat and all the other “chats” – we all still use SMS.  Maybe not for every conversation, as well as for numerous use-cases for business engagement. 

Today, hub-based messaging interoperability is the foundation of international messaging exchanges that enable every single mobile operator in the world to exchange messages. Certainly, quite a few mobile operators worldwide still use bilateral GSM network routes (over SS7 no less!), but this continues to diminish as most of the P2P international traffic is now exchanged through messaging hubs. The United States, Canada, and a handful of other countries use messaging hubs for some or all their national traffic, either through a single messaging hub provider or multiple providers who are interconnected via peering agreements.

Call it what you will, but global, ubiquitous P2P mobile operator messaging was born 20 years ago and we should take some time to acknowledge this medium’s amazing rise. From that single idea of a hub-based messaging clearinghouse, spawned many of the messaging channels on the market today – most will boast hundreds of millions of monthly users, but none of them can boast that they reach every active mobile handset in the world. SMS may have reached its pinnacle in terms of traffic ten years ago, but its usefulness as a business engagement channel and a personal communications channel is long from over.

[i] CMG Wireless Data Solutions was a subsidiary of the Netherlands based company CMG, which later merged with Logica to become LogicaCMG. Later, LogicaCMG spun out the mobile services and products business (LogicaCMG Wireless Networks) to become Acision. Acision was acquired by Comverse and renamed Xura in 2015. In December 2016, Xura acquired Mitel Networks Corporation’s mobility unit and was renamed Mavenir (the “new” Mavenir as the “original Mavenir” was acquired in March 2015 by Mitel Networks Corporation).

[ii] InphoMatch merged with the French company Mobileway in 2004 and was rebranded as Mobile 365. Mobile 365 was acquired by Sybase in late 2006, and rebranded as Sybase 365.  Sybase itself was acquired by SAP in 2010 with the business unit rebranding as SAP Mobile Services and then SAP Digital Interconnect a few years later. In November 2020, Sinch completed the acquisition of SAP Digital Interconnect.