Emergency Call Support Using Notruf

Notruf is an single emergency line for German networks that uses geolocation to collect and store a caller's information. The information collected includes party location and call center location/numbers. Notruf uses Ribbon SBC call processing to collect information from the caller. 

Within this context, the primary objectives of this feature is to insert calling party location information, and to provide a dialed emergency number translation (if needed) for emergency calls within German networks.

The SBC is deployed in customer networks as a Centralized Policy Server (CPS). The SBC Core supports the mandated German emergency call concept requirements, as follows:

• Location database for all subscriber numbers in the customer network.
• Association of the stored location information with an emergency call setup and generate the location information signaling parameter in the egress emergency call request. The SBC uses an ISUP UUI parameter encoded in accordance with ITU-T Recommendation Q.763/Q.931 and “TR Notruf” Technical Directive on Emergency Calls to carry the location information to the Public Safety Answering Point (PSAP).
• Translates dialed emergency number 110 or 112 to the corresponding PSAP address.
• Routes the call accordingly through the customer network.

The Access and Interconnect deployment models are considered for the German market, which requires support for both Notruf 1.0 and 2.0 specifications for emergency call handling by the Ribbon SBC.

• Access deployments require the Ribbon SBC to support SIP calls from the UEs and add the configured location information and route the calls to respective PSAPs. 
• Interconnect deployments where the Ribbon SBC may not add the location information on its own, but will relay the information provided by the access nodes. It may be required to interwork the Notruf formats based on the protocol towards PSAP.