When a customer subscribes to a company’s phone service, that company must validate the address using the Location Validation Function before it is entered as a record in the LIS. The changes are being developed through the technical standards committees and are taking into consideration the modifications that the LVF function will require. The NENA i3 documentation has been the catalyst for these discussions and provides the framework for how the routing of the information will occur.
NG9-1-1 and LIS also resolve location confusion from voice over internet protocol (VoIP) calls whereby a person can be placing a VoIP call from a mobile device but the call is delivered to a 9-1-1 PSAP based on the the home address that was registered at the time of service initiation. For example, a call may be routed from the caller’s home when he or she actually is attending a business meeting or vacationing in another city. The NG9-1-1 network will operate with the functions as identified in i3 that will allow for legacy, mobile and VoIP calls to capture their location within the accessed network to place the call from the mobile device’s current location and then route the call.
Another important change in call handling with NG9-1-1 systems is that all calls will be routed through a state or regional emergency services IP network (ESInet). There the call data is processed by an emergency call routing function (ECRF) database server, which stores precise location data and—by communicating with yet another server that uses Location to Service Translation (LoST) protocol—determines the best PSAP to which the call should be routed. By sending the call first to the area-wide ESInet, the system ensures compatibility for calls from a wide variety of devices—handsets, wireless, computers, text messages and other sources.
With an entire new set of databases, servers and acronyms, NG9-1-1 phases out the current ALI and MSAG technology. Addresses now will be pre-validated through LIS, and calls will arrive at the PSAP with a civic address or coordinate attached. At that point the GIS data in the ECRF will be used to route the call.