GSM roaming-practical experiences

On the 7 September 1987, mobile network operators within Europe signed a Memorandum Of Understanding, MoU, to produce a mobile telephony system that would be standard across Europe. This became known as GSM-Groupe Speciale Mobile. One ability of the GSM system is to make and receive calls on any other GSM network using the same number. This feature is known as roaming, or in more precise terms: Article 1 of the MoU provides for the establishment of international roaming services whereby a subscriber provided with a service in one country by one of the network operators can also gain access to the service of any other network operator in their respective countries. This is seen as being the main advantage of GSM over the analogue systems. The author explains how roaming works and discusses practical experiences