Numbering, addressing and identification
The present document defines the principal purpose and use of different naming, numbering, addressing and identification resources (i.e. Identifiers (ID)) within the digital cellular telecommunications system and the 3GPP system.
IDs that are covered by this specification includes both public IDs, private IDs and IDs that are assigned to MSs/UEs. Many of the IDs are used temporary in the networks and are allocated and assigned by the operators and some other IDs are allocated and assigned on either global, regional and national level by an administrator. See ITU-T Recommendation E.101 [122].
NOTE:	Allocation means the process of opening a numbering, naming or addressing resource in a plan for the purpose of its use by a telecommunication service under specified conditions. The allocation in itself does not yet give rights for any user, whether an operator, service provider, user or someone else, to use the resource. Assignment means authorization given to an applicant for the right of use of number, naming or addressing resources under specified conditions.
The present document defines:
0)	the principal purpose and use of International Mobile station Equipment Identities (IMEI) within the digital cellular telecommunications system and the 3GPP system
a)  an identification plan for public networks and subscriptions in the 3GPP systems;
b)	principles of assigning telephone  numbers to MSs in the country of registration of the MS;
c)	principles of assigning Mobile Station (MS) roaming numbers to visiting MSs;
d)	an identification plan for location areas, routing areas, and base stations in the GSM system;
e)	an identification plan for MSCs, SGSNs, GGSNs, and location registers in the GSM/UMTS system;
f)	principles of assigning international mobile equipment identities;
g)	principles of assigning zones for regional subscription;
h)	an identification plan for groups of subscribers to the Voice Group Call Service (VGCS) and to the Voice Broadcast Service (VBS); and identification plan for voice group calls and voice broadcast calls; an identification plan for group call areas;
i)	principles for assigning Packet Data Protocol (PDP) addresses to mobile stations;
j)	an identification plan for point-to-multipoint data transmission groups;
k)	an identification plan for CN domain, RNC and service area in the UTRAN system.
l)	an identification plan for mobile subscribers in the WLAN system.
m)	addressing and identification for IMS Service Continuity
n)	an identification plan together with principles of assignment and mapping of identities for the Evolved Packet System; and
o)	addressing and identification for Proximity-based (ProSe) Services.
p)	an identification for Online Charging System (OCS).
q)	an identification plan together with principles of assignment and mapping of identities for the 5G System.
The present document specifies functions, procedures and information which apply to GERAN Iu mode. However, functionality related to GERAN Iu mode is neither maintained nor enhanced.