Choose one word from the word list below to fill in the blank in each of the following sentences. Change the form of the word where necessary: enhanced feature, mobile network, International Roaming ability, mobile communication infrastructure , digital, cheap handset, users, analogue system, spectrum efficiency, cellular market 1. GSM is one of the leading in the world with over 250 million subscribers and over 60% of the world . 2. One major decision was to an ________ rather than a . 3. The digital system would offer improved , better quality transmission and new services with including security. 4. It the mainstay of the plans for Europe’s for the 1990s. 5. The main features of GSM were to be , good sound quality, small and ability to handle high volumes of ________.