MVNO is a GSM phenomenon where an operator or company which does not own a licenced sprectrum and generally with out own networking infrastructure. Instead MVNOs resell wireless services under their brand name, using regular telecom operator's network with which they have a business arrangements. Usually they they buy minutes of use from the licenced telecom operator and then resell minutes of usage to their customers of MVNO. Currently MVNOs are emerging in fast pace in European markets and beginning in USA also. Slowly MVNO phenomenon catching up in Asia and other parts of the world also.
An example for MVNO is Virgin Mobile. Virgin Mobile plc is a mobile phone service provider operating in the UK, Australia and Canada, and the US. The company was the world's first Mobile Virtual Network Operator, launched in the UK in 1999. It does not maintain its own network, and instead has contracts to use the existing network(s) of other providers. In the UK, Virgin Mobile uses the T-Mobile network. In the US, the Sprint network is the carrier. In Australia, Virgin Mobile operates on the Optus network. In Canada, it uses the Bell Mobility network. These networks use different technology (GSM in the UK and Australia and CDMA in the US and Canada).
Usually MVNO's do not have their own infrastructure, some providers are actually deploying their own Mobile Switching Centers (MSC) and even Service Control Points (SCP) in some cases. Some MVNO's deploy their own mobile Intelligent Network (IN) infrastructure in order to facilitate the means to offer value-added services. In this way, MNVO's can treat incumbent infrastructure such as radio equipment as a commodity, while the MVNO offers its own advanced and differentiated services based on exploitation of their own IN infrastructure. The goal of offering value-added services is to differentiate versus the incumbent mobile operator, allowing for customer acquisition and preventing the MVNO from needing to compete on the basis of price alone.