Amazing, happy birthday GSM! Feels like yesterday since you've launched (and I joined in 1993). As Nokia has posted, on July 1, 1991, former Finnish Prime Minister Harri Holkeri made the world's first public GSM call, using Nokia equipment (for sure). However, what Nokia forgot to mention is, that the GSM standard was significantly developed by German Siemens and French Alcatel because the standard goes back to a very early initiative of Germany and France. Anyway, Nokia jumped the bandwagon pretty early as well and was one of the key developers of GSM technology as we know it today.
The Global System for Mobile communications (GSM what initially stood for Groupe Spécial Mobile) was adopted in 1987 as the European standard for digital mobile technology. This second generation mobile technology could carry data as well as voice traffic and was designed to allows easy international roaming across Europe. It even added layers for new new services like text messaging (SMS).
It took some more years before GSM networks became broadly available but the definite starting shot was today - 20 years ago! So happy birthday GSM! And I'm really looking forward what Nokia will be able to do for Windows Phone now - or vice versa.
Cheers ~ Arne