This reference point shall allow the MSC Server/VLR to report the mobility management related events to the Network Agent (such as attach/detach/location area update) and may allow the MSC Server/VLR to report call related events (such as call setup with the bearer information and call release).
This reference point may allow the MSC Server/ VLR to report Mobility States (such as Detached, Idle and Connected) and Call States (such as Busy with Bearer information and Idle).
The PC2 reference point is used to define the
interaction between ProSe Application Server and ProSe functionality provided by the 3GPP EPS via
ProSe Function (e.g. name translation) for EPC-level ProSe discovery.
See also RFC 6733
for Diameter Base Protocol, and
for 3GPP-specific Diameter codes and identifiers.
PC3 relies on EPC user plane for transport
(i.e. an "over IP" reference point). It is used to authorise ProSe Direct Discovery and EPC-level ProSe
Discovery requests, and perform allocation of ProSe Application Codes corresponding to ProSe
Application Identities used for ProSe Direct Discovery. It is used to define the authorisation policy per
PLMN for ProSe Direct Discovery (for Public Safety and non-Public Safety) and communication (for
Public Safety only) between UE and ProSe Function.
The PC4a reference point is used to provide subscription information
in order to authorise access for ProSe Direct Discovery and ProSe Direct Communication on a per PLMN
basis. It is also used by the ProSe Function (i.e. EPC-level ProSe Discovery Function) for retrieval of
EPC-level ProSe Discovery related subscriber data.