How to Accrue Revenues for a Pay In Advance situation.

How do you recognize revenue, for pay in advance industry like pagers, long distance one year up front contract kind of situations.

Lets say , you offer pager services for $120/Year in advance, and the customer paid you in advance. Oracle Projects believes you have invoiced, and recognizes revenue immediately. how can you receognize 1/12 every month. without entering any transactions in the system, just by running the revenue generation process.