5GMM States
5GMM main states in the UE
Main States:
5GMM-NULL: 5GS services are disabled in the UE. No 5GS mobility management function shall be
performed in this state.
5GMM-DEREGISTERED: In the state 5GMM-DEREGISTERED, no 5GMM context has been established
and the UE location is unknown to the network and hence it is unreachable by a network. In order to
establish a 5GMM context, the UE shall start the initial registration procedure.
5GMM-REGISTERED-INITIATED: A UE enters the state 5GMM-REGISTERED-INITIATED after it has
started the initial registration procedure or the non-initial registration procedure, and is waiting for a
response from the network.
5GMM-REGISTERED: In the state 5GMM-REGISTERED, a 5GMM context has been established.
Additionally, one or more PDU session(s) may be established at the UE. The UE may initiate the non-
initial registration procedure (including the normal registration update and periodic registration update)
and the service request procedure. The UE in the state 5GMMREGISTERED over non-3GPP access shall
not initiate the periodic registration update procedure.
5GMM-DEREGISTERED-INITIATED: A UE enters the state 5GMM-DEREGISTERED-INITIATED after it
has requested release of the 5GMM context by starting the de-registration procedure and is waiting for
a response from the network.
5GMM-SERVICE-REQUEST-INITIATED: A UE enters the state 5GMM-SERVICE-REQUEST-INITIATED
after it has started the service request procedure and is waiting for a response from the network.
Substates of state 5GMM-DEREGISTERED
5GMM-DEREGISTERED.NORMAL-SERVICE: The substate 5GMM-DEREGISTERED.NORMAL-SERVICE is
chosen in the UE when a suitable cell has been found and the PLMN or tracking area is not in the
forbidden list.
5GMM-DEREGISTERED.LIMITED-SERVICE: The substate 5GMM-DEREGISTERED.LIMITED-SERVICE is
chosen in the UE, when it is known that a selected cell for 3GPP access or TA for non-3GPP access is
unable to provide normal service (e.g. the selected cell over 3GPP access is in a forbidden PLMN or is in
a forbidden tracking area or TA for non-3GPP access is forbidden).
5GMM-DEREGISTERED.ATTEMPTING-REGISTRATION: The substate 5GMM-
DEREGISTERED.ATTEMPTING-REGISTRATION is chosen in the UE if the initial registration procedure
failed due to a missing response from the network or due to the circumstances.
5GMM-DEREGISTERED.PLMN-SEARCH: The substate 5GMM-DEREGISTERED.PLMN-SEARCH is
chosen in the UE, if the UE is searching for PLMNs. This substate is left either when a cell has been
selected (the new substate is NORMAL-SERVICE or LIMITED-SERVICE) or when it has been concluded
that no cell is available at the moment (the new substate is NO-CELL-AVAILABLE). This substate is not
applicable to non-3GPP access.
5GMM-DEREGISTERED.NO-SUPI: The substate 5GMM-DEREGISTERED.NO-SUPI is chosen in the UE, if
the N1 mode is enabled and the UE has no valid subscriber data available (SIM/USIM not available, the
SIM/USIM is considered invalid by the UE).
5GMM-DEREGISTERED.NO-CELL-AVAILABLE: No 5G cell can be selected. This substate is entered
after a first intensive search failed when in substate 5GMMDEREGISTERED.PLMN-SEARCH. Cells are
searched for at a low rhythm. No 5GS services are offered. This substate is not applicable to non-3GPP
access.
5GMM-DEREGISTERED.eCALL-INACTIVE: The substate 5GMM-DEREGISTERED.eCALL-INACTIVE is
chosen in the UE when:
a) the UE is configured for eCall only mode as specified in 3GPP TS 31.102;
b) timer T3444 and timer T3445 have expired or are not running;
c) a PLMN has been selected as specified in 3GPP TS 23.122;
d) the UE does not need to perform an eCall over IMS; and
e) the UE does not need to perform a call to a non-emergency MSISDN or URI for test or terminal
reconfiguration service.
In this substate, the UE shall not initiate any signalling towards the network, except to originate an eCall
over IMS, or a call to a non-emergency MSISDN or URI for test or terminal reconfiguration service. This
substate is not applicable to non-3GPP access.
5GMM-DEREGISTERED.INITIAL-REGISTRATION-NEEDED: Valid subscriber data are available for the
UE and for some reason a registration procedure for initial registration has to be performed as soon as
possible. This substate can be entered if the access is barred due to unified access control, or if the
network rejects the N1 NAS signalling connection establishment.
Substates of state 5GMM-REGISTERED
5GMM-REGISTERED.NORMAL-SERVICE: The substate 5GMM-REGISTERED.NORMAL-SERVICE is
chosen by the UE as the primary substate when the UE enters the state 5GMM-REGISTERED, and for
3GPP access, the cell the UE selected is known to be in an allowed area.
5GMM-REGISTERED.NON-ALLOWED-SERVICE: The substate 5GMM-REGISTERED.NON-ALLOWED-
SERVICE is chosen in the UE, if the cell the UE selected is known to be in a non-allowed area. This
substate is not applicable to non-3GPP access.
5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE: The substate 5GMM-
REGISTERED.ATTEMPTING-REGISTRATION-UPDATE is chosen by the UE if the registration procedure for
mobility and periodic registration update failed due to a missing response from the network, or due to
the circumstances described in TS 24.501. No 5GMM procedure except registration procedure for
mobility and periodic registration update (i.e. the 5GS registration type IE set to "mobility registration
updating" in the REGISTRATION REQUEST message) shall be initiated by the UE in this substate. No data
shall be sent or received.
5GMM-REGISTERED.LIMITED-SERVICE: The substate 5GMM-REGISTERED.LIMITED-SERVICE is chosen
in the UE, if the cell the UE selected is known not to be able to provide normal service.
5GMM-REGISTERED.PLMN-SEARCH: The substate 5GMM-REGISTERED.PLMN-SEARCH is chosen in
the UE, while the UE is searching for PLMNs. This substate is not applicable to non-3GPP access.
5GMM-REGISTERED.NO-CELL-AVAILABLE: 5G coverage has been lost or MICO mode is active in the
UE. If MICO mode is active, the UE can deactivate MICO mode at any time by activating the AS layer
when the UE needs to send mobile originated signalling or user data. Otherwise, the UE shall not initiate
any 5GMM procedure except for cell and PLMN reselection. This substate is not applicable to non-3GPP
access.
5GMM-REGISTERED.UPDATE-NEEDED: This state can be entered if the access is barred due to
unified access control when in 3GPP access, if the network rejects the N1 NAS signalling connection
establishment when in 3GPP access or in non-3GPP access or if the UE in 5GMM-CONNECTED mode with
RRC inactive indication receives an indication from the lower layers that the resumption of the RRC
connection has failed . For 3GPP access, the UE has to perform a registration procedure for mobility and
periodic registration update, but access to the current cell is barred.
5GS update(5U) status in the UE
The 5GS update status value is changed only after the execution of a registration, network-initiated de-
registration, 5GS based primary authentication and key agreement, service request or paging procedure.
5U1: UPDATED: The last registration attempt was successful.
5U2: NOT UPDATED: The last registration attempt failed procedurally, e.g. no response or reject
message was received from the AMF.
5U3: ROAMING NOT ALLOWED: The last registration, service request, or registration for mobility or
periodic registration update attempt was correctly performed, but the answer from the AMF was
negative (because of roaming or subscription restrictions).
5GMM main states in the network
Main States:
5GMM-DEREGISTERED: In the state 5GMM-DEREGISTERED, no 5GMM context has been established
or the 5GMM context is marked as deregistered. The UE is deregistered. The network may answer to an
initial registration procedure initiated by the UE. The network may also answer to a de-registration
procedure initiated by the UE.
5GMM-COMMON-PROCEDURE-INITIATED: The network enters the state 5GMM-COMMON-
PROCEDURE-INITIATED, after it has started a common 5GMM procedure and is waiting for a response
from the UE.
5GMM-REGISTERED: In the state 5GMM-REGISTERED, a 5GMM context has been established.
Additionally, one or more PDU session(s) may be established at the network.
5GMM-DEREGISTERED-INITIATED: The network enters the state 5GMM-DEREGISTERED-INITIATED
after it has started a de-registration procedure and is waiting for a response from the UE.
*Network side has only Main State.
Info
Ref: TS 24.501 V16.1.0
Iman Mohammadi
Aug 2019
E-Mail: iman.mohammadi.telecom@gmail.com
Linkedin: https://www.linkedin.com/in/iman-mohammadi-886b89151
Mobile(WhatsApp,Telegram): +989354019601
