3GPP TSG-SA WG3-LI Meeting #43 SA3LI11_121
San Francisco, 15. - 19. Nov. 2011.
Title: Discussion on IMEI triggered LI on IMS
Document for: Discussion
Work Item / Release: Rel-12 and next releases (at least)
As it is designed in 3GPP specifications, IMS network elements don’t have access on IMEI id, or any UE identity, that uniquely identifies a specific device among all other devices (MEID or any reliable UE identifier if 3GPP standards evolve…), by itself.
In CS domain, IMEI (except case of faked or absent IMEI in the UE) based LI are possible. This document is to create a discussion on the opportunity and the different solutions that can fulfill the need to keep compatibility on LI with IMS based switches…
2.1 IMEI and privacy
Some protection can be used to protect the privacy of any user of a 3GPP phone. Some argument may be raised that the IMEI information is considered as an information that is not available or not transmitted from PS domain to IMS or CS domain. However, IMEI information is needed as well for emergency call, it is required that IMEI-URN as the instance ID in the ‘+sip.Instance” header field parameter in the Contact header of the SIP Invite (ie. 3GPP TS 23.237 and 3GPP TS 24.237). This is required to support access transfer of emergency calls to the PSAP.
Some development may be made in order to transfer such information, outside emergency call in the header of some SIP message in order to let IMS elements (to be defined) trigger the interception and send at least, HI2 messages to LEMF or if the proposal to vendor to study services based LI is accepted, that CC of IMS is handled as well.
At least, two solutions may exist:
A solution based on reverse dynamic triggering
A Trigger inside the P CSCF looking inside the contact header message of during a SIP register phase.
It is proposed to discuss the above details and more about a IMEI base triggered LI in the IMS domain. If there are positive reaction, it is recommended to take them into account during the definition of future IMS LI architecture.