The GSM Memorandum of Understanding (GSM MoU)
The GSM MoU was driven by Stephen Temple (UK DTI). After the agreement on the basic parameters of the GSM standard in the first half of 1987, the GSM MoU was designed in order to ensure a commitment of the Network Operators to complete the GSM standard and to introduce GSM networks from 1991 onwards. The GSM MoU played a key role in creating a hug momentum for GSM in Europe.
The original document was signed in September 1987.
When countries outside Europe wanted to introduce GSM an extension was necessary. This was signed in 1991.
More information in the book ‘GSM and UMTS, the Creation of Global Mobile Communication (see section reference books): chapter 2 section 4, chapter 6 and chapter 22.