My guess is a comm center is dispatching for multiple towns. Where I live, the local pd handles the dispatching of calls for three towns on two seperate frequencies (All three towns can switch to the others primary frequency). All three towns patrol cars call the comm center by "control from " xx-yy where xx is the two digit code assigned to thier municipality and yy is the number assigned to their car. This tells dispatch the town and car that is calling (I guess in case 2 or 3 of the towns all have a car 01, 02, etc.)