M/493 -

The present document describes the protocol specifications for emergency service caller location determination and
transport architecture as specified in ETSI ES 203 178 [1].

Stage 3 specifications for Emergency Service Caller Location determination and transport architecture as specified in ES 203 178

Considering TS 102 650 and architectures from other standardisation organisations a single functional architecture to support European requirements on emergency caller location determination and transport needs to be developed in particular for the case where VoIP service provider and one or several network operators  - all serving the customer in the establishment of an emergency call -  are independent enterprises needing to co-operate to determine the location of the (nomadic) caller. The architecture shall identify all necessary interfaces, which are needed to fulfil the requirements outlined in EC Mandate M/493, and provide a basis for possible protocols to be used on those interfaces. Environmental aspect comments: 1) The establishment of emergency calls and the provision of location information about the caller shall not be hampered by high service or network loads or partial service or network outages. (2) The location information shall be provided to the PSAP in a manner that it is easily associated with the respective incoming voice call. (3) Location related information accurate enough to allow routing of the call must be constrained to those entities that require it in order to deliver the call to the correct PSAP. (4) Accurate location information shall be obtained from at least a trustworthy source. A CPE may not be  considered trustworthy. User /Consumer Aspects comments: 1) The location should be determined as fast as possible. (2) Should the location determination fail for any reason, the emergency call is still to be setup without delay. (3) The access to and the provision of location information shall be strictly limited to emergency calls only. (4) The architecture shall not be based on location information provided by an entity controlled by the user. Security Aspects  (1) The access to location information shall be strictly limited to cases of an emergency call. (2) Location information sufficiently detailed to dispatch personnel and resources shall only be provided to the PSAP handling the emergency call.

DES/E2NA-00001-M493-stage2