OTP autentication to a mobile phone (sometimes called mobile TAN/mTAN)

Hello, we would like to have captive users(authentication portal) authenticated with a one time password (OTP). After entering the user-account at the captive login page, preferably a/the RADIUS server should send the unique autentication number (sometimes called mobile TAN/mTAN or OTP) to the users mobile phone in order to gant access. Is something like that possible with freeradius? Thank's for any feedback. John