Do you mean the Mobile Data indicator? It's always there... If you have mobile data active and have a connection on your network, it will always appear next to the signal bars showing the connection type (2G, 3G or 4G depending on your phone and network).
If you mean the button to toggle mobile data on and/or off, it should also be there but this does depend on which version of Android you're running...
Welcome to the forum at Android Central! If you're on the stock ROM I'm surprised its not already there or are you looking for the "switch" to turn it off and on? What carrier are you with?
Yes I am looking for mobile data indicator
It doesn't appear when I swipe the screen downwards, I have to switch it on or off from settings/more settings/mobile network
What radio are you looking for? There is no FM radio built-in.
Are you looking for the version information for the radios? That's under Settings -> About phone, under Baseband version.
It sounds like your carrier has removed the 'Mobile data' toggle - unless you root your phone and modify SystemUI there's no way to get it back. In another thread I did suggest some widgets that would provide that functionality.
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