A mobile network operator (MNO), also known as carrier service provider (CSP), wireless service provider, wireless carrier, or cellular company, or mobile network carrier is a telephone company that provides services for mobile phone subscribers.
One essential characteristic that defines a mobile network operator is that they must have acquired a radio spectrum license from the government before they can clear cell phone service within a country. The precise spectrum obtained does depend on the type of mobile phone technology the operator intends to deploy. For example, a Global System for Mobile Communications (GSM) network operator will require a GSM frequency range. The government allocates spectrum using whichever method it chooses, although the most common method is an auction. Recent allocation of 3G and WiMax licenses in Europe and India (only 3G in India) have been auctioned.
However the operator must also deploy essential equipment in order to offer the services, most notably the radio transmitter network and the core network. In addition, other service platforms such as voicemail and short message service center will be deployed as well as billing and customer relationship management (CRM) systems.