This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
lastKnownMcc is a read-only property that represents the Mobile Country Code (MCC) of the last known network operator.
var dataMCC = navigator.mozMobileConnection.data.lastKnownMcc; var voiceMCC = navigator.mozMobileConnection.voice.lastKnownMcc;
Return a number.
Not part of any specification.