A ton of stuff is done on mobile terminals. Computer aided dispatch including status and location of a unit, report writing, identity checks, etc. Scanners were useful because a cop would ask the dispatcher for a license check on Joe Blow, age 34, of Smithville - or registration check on a certain license plate number. These days by the time an officer flips on his lights to pull someone over, they probably already know the registration/insurance status, license status of the registered owner, their photo, etc.

Then there's email and other messaging for lower priority things, and phone calls for stuff that is sensitive.