F/NAV messages are used within the Open Service (OS) and they are transmitted in E5a frequency band (1176.45 Mhz). The complete navigation message data are transmitted as a sequence of frames. A frame is composed of several sub-frames, and a sub-frame is composed of several pages. The page is the basic structure for building the navigation message.F/NAV navigation message is transmitted on channel E5a at a rate of 25 bps.
F/NAV message structure
How many frames does F/NAV and I/NAV consists ?
Like GPS navigation message has 25 frames.