6 Use of IMEI in case of emergency calls
22.0163GPPInternational Mobile station Equipment Identities (IMEI)Release 17TS
Emergency calls can in some PLMNs be made without having to send the subscriber identity (IMSI) to the network. In this case the misuse of MS equipments after placing invalid emergency calls can be restrained by using the equipment identity.
The network request for the equipment identity is sent to the MS after the emergency call has been set-up. The procedure is the same as for normal call set-up.