This TS specifies the procedures used by the protocols for mobility management and session management
between UE and MME in the EPS. These protocols belong to the non-access stratum (NAS).
The EPS Mobility Management (EMM) protocol provides procedures for the control of
mobility when the UE is using the E-UTRAN.
The EMM protocol also provides control of security for the NAS protocols.
The EPS Session Management (ESM) protocol provides procedures for the handling of
EPS bearer contexts. Together with the bearer control provided by the access stratum, this protocol is used for the control of user plane bearers.