Arduino IDE code to enter and exit Modem sleep.

[rin67630]

Hi,
sorry to bother you, but I need some help.
Call me stupid, but I just could not find any clear instructions on how to do that simple thing:
enter and exit modem sleep for less than 1 second?

I have been searching for hundreds of sites which all mainly go directly into light sleep or digressing pages of theory...

I just would need the code to be used within the Arduino IDE to:
-disable Bluetooth that I don't need (if it runs by default?)
-disable Bluetooth-LE that I don't need (if it runs by default?)
-enter the modem sleep mode (for ~900mS each second)
-resume from the modem sleep mode (just to perform one JSON fetch every second and to resync NTP time once a day) and then return to modem sleep letting me doing other tasks as e.g. monitoring an IR remote.

Additionally I'd like to know how fast the resume performs and if I need a delay after the resume instruction before I can go on with the JSON fetch.

Thank you for your assistance!