| 摘要 |
<p>A method of establishing an emergency call includes: if a P-CSCF detects the emergency call carrying an IMPU of the TELURI format sent by a UE, then it generates an IMPU of SIP URI format according to the IMPU of the TEL URI format, and sends the two IMPU to a PSAP; the PSAP initiates an emergency callback to the UE according to one of the two IMPU; a system of establishing an emergency call includes: a UE, a P-CSCF and a PSAP; otherwise, there is a P-CSCF, which includes: an IMPU receiving and detecting module and an IMPU transferring the formats module. The PSAP can always obtain the IMPU of the TEL URI format and the IMPU of the SIP URI format of the UE at the same time, when the PASP does not support the ENUM function, it can send emergency callback to the UE according to the IMPU of the SIP URI format of the UE saved by itself, thus improves the success probability of the emergency callback sent by the PSAP; simultaneously, when the PASP supports the ENUM function, it does not need to look up the IMPU of the SIP URI format of the UE through the ENUM function, thus reduces the time of establishing the emergency call.</p> |
