Definition:

The capability to route a call to the particular PSAP based on the geographical location from which the call originated. Selective routing is achieved by building telephone number/emergency service number translations in the tandem central office. These translations cause the E9-1-1 database to assign the emergency service number to each telephone number based on the customer's address. Service order activity keeps the E9-1-1 database updated. The E9-1-1 database, in turn, generates recent changes to the tandem office to update the telephone number/ESN translations in the tandem database.