Apple has explicitly refuted a recent report that it would create its own virtual network cellular service, or MVNO. The company was said to be in negotiations with carriers in the U.S. and Europe, but it now appears that this was not the case.
BREAKING: Apple says it has not discussed & is not planning MVNO cellular service following reports saying it was planning on doing that.— CNBC Now (@CNBCnow) August 4, 2015
An MVNO service leases cellular bandwidth from carriers like AT&T and Verizon to create a virtual network, often offering less expensive service to the MVNO's customers. According to the report from Business Insider, Apple's service would have featured a SIM that seamlessly switched between networks, which is how Google's Project Fi works.
Source: CNBC (Twitter)