1. A method of a user equipment, the method comprising: a) sending a first Non Access Stratum (NAS) message to an Access mobility Management Function (AMF) via a first untrusted non-3GPP access network and a first Non- 3gpp access Inter-Working Function (N3IWF); b) receiving an Authentication Request message from the AMF; c) determining, based on the Authentication Request message, whether the AMF has failed the authentication check or not; d) sending an Authentication Failure message to the AMF if the user equipment has determined that the AMF has failed the authentication check, and repeating b) and c) until the user equipment has determined in two consecutive times that the AMF has failed the authentication check; and e) selecting a second untrusted non-3GPP access network or a second N3IWF for making another NAS signalling connection if the user equipment has determined in two consecutive time that the AMF has failed the authentication check.

2. The method according to claim 1, wherein the user equipment determines that the first untrusted non-3GPP access network or the first N3IWF is barred for a NAS signalling connection if the user equipment has determined in two consecutive times that the AMF has failed the authentication check.

3. The method according to claim 2, wherein the user equipment determines that: the first N3IWF is not barred if the user equipment has determined that the first untrusted non-3GPP access network is barred; or the first untrusted non-3GPP access network is not barred if the user equipment has determined that the first N3IWF is barred.

4. A user equipment comprising: 23 a transceiver circuit; and a processor configured to perform a method via the transceiver circuit, wherein the method comprises: a) sending a first Non Access Stratum (NAS) message to an Access mobility Management Function (AMF) via a first untrusted non-3GPP access network and a first Non- 3gpp access Inter-Working Function (N3IWF); b) receiving an Authentication Request message from the AMF; c) determining, based on the Authentication Request message, whether the AMF has failed the authentication check or not; d) sending an Authentication Failure message to the AMF if the user equipment has determined that the AMF has failed the authentication check, and repeating b) and c) until the user equipment has determined in two consecutive times that the AMF has failed the authentication check; and e) selecting a second untrusted non-3GPP access network or a second N3IWF for making another NAS signalling connection if the user equipment has determined in two consecutive times that the AMF has failed the authentication check.

TECHNICAL FIELD
[0001] The present disclosure relates to handling authentication procedure by a user
equipment (UE) and a network, more specifically handling authentication procedure of
a UE with an access point, when the UE authentication procedure fails at the UE end.
BACKGROUND
[0002] The 5G system supports mutual authentication between the UE and the network
supporting both 3GPP access and non-3GPP access. When the UE receives the
Authentication Request message, it will validate the AUTN (Authentication Token) and
SQN (Sequence Number). If the UE determines, two times in a row, that either the
AUTN verification fails or that or the sequence number is out of range, the UE bars the
cell where this authentication happens in case of 3GPP access. The UE never considers
the cell as suitable cell.
[0003] When the UE is connected to untrusted non-3GPP access (e.g. WiFi) and the
authentication procedure fails then the UE behavior is not defined whether the UE will
connect to WiFi access point or N3IWF again to access a 5GS service.
[0004] A UE determines that a cell is fake based on two times failure of authentication
procedure at the UE e.g. when the MAC failure happens in the first authentication
procedure at the UE and followed by SYNC failure at the UE. However, the UE cannot
always be sure after two consecutive authentication procedure failure at the UE that the
cell is a fake cell or a valid cell.
SUMMARY
[0005] The following presents a simplified summary of the subject matter in order to
provide a basic understanding of some aspects of subject matter embodiments. This
summary is not an extensive overview of the subject matter. It is not intended to identify
key/critical elements of the embodiments or to delineate the scope of the subject matter.
[0006] Its sole purpose is to present some concepts of the subject matter in a simplified
form as a prelude to the more detailed description that is presented later.
3
[0007] According to an embodiment of the present disclosure, a method of a user
equipment is disclosed. The method comprises sending a first Non Access Stratum
(NAS) message to an Access mobility Management Function (AMF) via a first
untrusted non-3GPP access network and a first Non-3gpp access Inter-Working
Function (N3IWF), receiving an Authentication Request message from the AMF,
determining, based on the Authentication Request message, whether the AMF has
failed the authentication check or not, sending an Authentication Failure message to the
AMF if the user equipment has determined that the AMF has failed the authentication
check, and repeating b) and c) until the user equipment has determined in two
consecutive times that the AMF has failed the authentication check, and selecting a
second untrusted non-3GPP access network or a second N3IWF for making another
NAS signalling connection if the user equipment has determined in two consecutive
time that the AMF has failed the authentication check.
[0008] Further, according to an embodiment of the present disclosure, the user
equipment determines that the first untrusted non-3GPP access network or the first
N3IWF is barred for a NAS signalling connection if the user equipment has determined
in two consecutive times that the AMF has failed the authentication check.
[0009] Yet, in another embodiment of the present disclosure, the user equipment
determines that: the first N3IWF is not barred if the user equipment has determined
that the first untrusted non-3GPP access network is barred; or the first untrusted non-
3GPP access network is not barred if the user equipment has determined that the first
N3IWF is barred.
[00010] In an embodiment of the present disclosure, a user equipment is disclosed. The
user equipment comprises a transceiver circuit and a processor configured to perform
a method via the transceiver circuit, wherein the method comprises: a) sending a first
Non Access Stratum (NAS) message to an Access mobility Management Function
(AMF) via a first untrusted non-3GPP access network and a first Non-3gpp access
Inter-Working Function (N3IWF); b) receiving an Authentication Request message
from the AMF; c) determining, based on the Authentication Request message,
whether the AMF has failed the authentication check or not; d) sending an
4
Authentication Failure message to the AMF if the user equipment has determined that
the AMF has failed the authentication check, and repeating b) and c) until the user
equipment has determined in two consecutive times that the AMF has failed the
authentication check; and e) selecting a second untrusted non-3GPP access network or
a second N3IWF for making another NAS signalling connection if the user equipment
has determined in two consecutive times that the AMF has failed the authentication
check.
[00011] These and other objects, embodiments and advantages of the present disclosure
will become readily apparent to those skilled in the art from the following detailed
description of the embodiments having reference to the attached figures, the disclosure
not being limited to any particular embodiments disclosed.
BRIEF DESCRIPTION OF FIGURES
[00012] The foregoing and further objects, features and advantages of the present subject
matter will become apparent from the following description of exemplary embodiments
with reference to the accompanying drawings, wherein like numerals are used to
represent like elements.
[00013] It is to be noted, however, that the appended drawings along with the reference
numerals illustrate only typical embodiments of the present subject matter, and are
therefore, not to be considered for limiting of its scope, for the subject matter may admit
to other equally effective embodiments.
[00014] FIGURE 1(a)-(c) illustrate about the performance of a user equipment in
an event of authentication failure at the UE, according to an embodiment of the present
disclosure.
[00015] FIGURE 2 illustrates various examples of conditions of barring a UE and
related examples according to an embodiment of the present disclosure.
5
[00016] FIGURE 3 shows a block diagram for a user equipment in accordance with
the present disclosure.
[00017] FIGURE 4 shows a block diagram for an (R)AN node in accordance with
the present disclosure.
[00018] FIGURE 5 shows a block diagram for a core network node in accordance
with the present disclosure.
DETAILED DESCRIPTION
[00019] Exemplary embodiments now will be described with reference to the
accompanying drawings. The disclosure may, however, be embodied in many different
forms and should not be construed as limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will be thorough and
complete, and will fully convey its scope to those skilled in the art. The terminology
used in the detailed description of the particular exemplary embodiments illustrated in
the accompanying drawings is not intended to be limiting. In the drawings, like
numbers refer to like elements.
[00020] It is to be noted, however, that the reference numerals in claims illustrate only
typical embodiments of the present subject matter, and are therefore, not to be
considered for limiting of its scope, for the subject matter may admit to other equally
effective embodiments.
[00021] The specification may refer to “an”, “one” or “some” embodiment(s) in several
locations. This does not necessarily imply that each such reference is to the same
embodiment(s), or that the feature only applies to a single embodiment. Single features
of different embodiments may also be combined to provide other embodiments.
[00022] As used herein, the singular forms “a”, “an” and “the” are intended to include
the plural forms as well, unless expressly stated otherwise. It will be further understood
that the terms “includes”, “comprises”, “including” and/or “comprising” when used in
this specification, specify the presence of stated features, integers, steps, operations,
elements, and/or components, but do not preclude the presence or addition of one or
6
more other features, integers, steps, operations, elements, components, and/or groups
thereof. It will be understood that when an element is referred to as being “connected”
or “coupled” to another element, it can be directly connected or coupled to the other
element or intervening elements may be present. Furthermore, “connected” or
“coupled” as used herein may include operatively connected or coupled. As used
herein, the term “and/or” includes any and all combinations and arrangements of one
or more of the associated listed items.
[00023] Unless otherwise defined, all terms (including technical and scientific terms)
used herein have the same meaning as commonly understood by one of ordinary skill
in the art to which this disclosure pertains. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be interpreted as having a
meaning that is consistent with their meaning in the context of the relevant art and will
not be interpreted in an idealized or overly formal sense unless expressly so defined
herein.
[00024] The figures depict a simplified structure only showing some elements and
functional entities, all being logical units whose implementation may differ from what
is shown. The connections shown are logical connections; the actual physical
connections may be different. It is apparent to a person skilled in the art that the
structure may also comprise other functions and structures.
[00025] Also, all logical units described and depicted in the figures include the software
and/or hardware components required for the unit to function. Further, each unit may
comprise within itself one or more components which are implicitly understood. These
components may be operatively coupled to each other and be configured to
communicate with each other to perform the function of the said unit.
[00026] In reference with Figure 1, a UE connects to an untrusted non-3GPP access
network and it is assigned an IP address (Step 1a). Any non-3GPP authentication
method can be used here, e.g. no authentication (in case of a free WLAN), EAP with
pre-shared key, username/password, etc. When the UE decides to attach to 5GC
network, the UE selects an N3IWF in a 5G PLMN (Step 1b), as described in TS 23.501
[2] clause 6.3.6.
7
[00027] The UE proceeds with the establishment of an IPsec Security Association (SA)
with a selected access point e.g. N3IWF (N3IWF-1) by initiating an IKE initial
exchange according to RFC 7296 [6]. After the IKE initial exchange, all subsequent
IKE messages are encrypted and integrity protected by using the IKE SA established in
this step.
[00028] The UE shall initiate an IKE_AUTH exchange by sending an IKE_AUTH
request message. The AUTH payload is not included in the IKE_AUTH request
message, which indicates that the IKE_AUTH exchange shall use EAP signalling (in
this case EAP-5G signalling). If the UE supports a service, it shall include a Notify
payload in the IKE_AUTH request, as specified in RFC 4555 [7], indicating that the
service is supported. In addition, as specified in TS 33.501 [5], if the UE is provisioned
with the N3IWF root certificate, it shall include the CERTREQ payload within the
IKE_AUTH request message to request the N3IWF's certificate.
[00029] The N3IWF responds with an IKE_AUTH response message, which includes
an EAP-Request/5G-Start packet. The EAP-Request/5G-Start packet informs the UE
to initiate an EAP-5G session, i.e. to start sending NAS messages encapsulated within
EAP-5G packets. If the N3IWF has received a CERTREQ payload from the UE, the
N3IWF shall include the CERT payload in the IKE_AUTH response message
containing the N3IWF's certificate.
[00030] The UE sends an Initial NAS message to an access point, such as AMF. The
initial NAS message is one of following message:
i) Registration Request message,
ii) Service Request message,
iii) Deregistration Request message.
[00031] The AMF initiates the authentication procedure to the UE by sending an
Authentication Request message with 5G authentication challenge data (RAND, AUTN
and ngKSI (Key Set Identifier in 5G)).
[00032] The UE shall check the 5G authentication challenge data (RAND, AUTN and
ngKSI) received in the AUTHENTICATION REQUEST message to verify
authenticity of the 5G core network. If the authentication checks fails, then the UE
returns the Authentication Failure message containing cause of failure (GMM cause
8
#5GMM cause #20 "MAC failure", the 5GMM cause #26 "non-5G authentication
unacceptable",5GMM cause #71 "ngKSI already in use"; or with the 5GMM cause #21
"synch failure") and a re-synchronization token AUTS provided by the USIM. The UE
stores the 5G authentication challenge data (RAND, AUTN and ngKSI), reason for
failure and AUTS. After the transmission of the Authentication Failure message, the
UE starts timer T3520.
[00033] The AMF initiates the authentication procedure to the UE by sending an
Authentication Request message with 5G authentication challenge data (RAND, AUTN
and ngKSI).
[00034] The UE shall check the 5G authentication challenge data (RAND, AUTN and
ngKSI) received in the AUTHENTICATION REQUEST message to verify
authenticity of the 5G core network. If the authentication checks fails, then the UE
returns the Authentication Failure message containing cause of failure (GMM cause
#5GMM cause #20 "MAC failure", the 5GMM cause #26 "non-5G authentication
unacceptable",5GMM cause #71 "ngKSI already in use"; or with the 5GMM cause #21
"synch failure") and a re-synchronization token AUTS provided by the USIM. The UE
stores the 5G authentication challenge data (RAND, AUTN and ngKSI), reason for
failure and AUTS. After the transmission of the Authentication Failure message, the
UE starts timer T3520.
[00035] The UE shall deem that the network has failed the authentication check or
assume that the authentication is not genuine and proceed as described above if any of
the following occurs:
- the timer T3520 expires;
- the UE detects any combination of the 5G authentication failures: 5GMM causes
#20 "MAC failure", #21 "synch failure", #26 "non-5G authentication
unacceptable" or #71 "ngKSI already in use", during three consecutive
authentication challenges. The 5G authentication challenges shall be considered
as consecutive only, if the 5G authentication challenges causing the second and
third 5G authentication failure are received by the UE, while the timer T3520
started after the previous 5G authentication failure is running.
[00036] The UE performs at least one of the following action.
9
i) The UE bars the N3IWF-1 i.e. the UE does not select the N3IWF -1 to
connect to the 5GC network, but the UE does not bar the untrusted non-
3GPP access.
[00037] In one example, the UE bars N3IWF-1 temporarily for a certain period of time
and after the certain period, the UE starts using the N3IWF. The period may be
indicated by the network (e.g. N3IWF, AMF). The period may be included in at least
one of the above mentioned messages (e.g. AUTHENTICATION REQUEST
message).
[00038] In one example the UE starts using N3IWF-1 after the UE switches off and on
the phone.
ii) The UE does not bar the N3IWF-1 i.e. the UE selects the N3IWF-1 to connect
to the 5GC network. The UE bars the untrusted non-3GPP access network. The UE
may connect to another untrusted non-3GPP access network and selects the
N3IWF-1 and connects to the 5GC network.
[00039] In one example the UE bars untrusted non-3GPP access network temporarily
for a certain period of time and after the certain period the UE starts using the N3IWF.
The period may be indicated by the network (e.g. N3IWF, AMF). The period may be
included in at least one of the above mentioned messages (e.g. AUTHENTICATION
REQUEST message).
[00040] In one example, the UE starts using untrusted non-3GPP access network after
the UE switches off and on the phone.
[00041] The UE executes above steps i) or ii) irrespective of the scenario where the UE
got N3IWF-1 certificate or not.
iii) if the UE did not request N3IWF-1 to send N3IWF-1 certificate in step 3 then
the UE bars the N3IWF-1. The UE selects another N3IWF node i.e. N3IWF-2. The
N3IWF-2 may be found by a new service information in the DNS query in order to
except the N3IWF-1, failed N3IWF, to be chosen again.
[00042] In one example the UE bars N3IWF-1 temporarily for a certain period of time
and after the certain period the UE starts using the N3IWF. The period may be indicated
10
by the network (e.g. N3IWF, AMF). The period may be included in at least one of the
above mentioned messages (e.g. AUTHENTICATION REQUEST message).
[00043] In one example the UE starts using N3IWF-1 after the UE switches off and on
the phone.
iv) if the UE requested the N3IWF-1’s Certificate and N3IWF-1 sent it’s certificate
and the UE determines that N3IWF-1’s certificate is valid then the UE bars the
untrusted non-3GPP access network but does not bar the N3IWF-1.
[00044] In one example, the UE bars untrusted non-3GPP access network temporarily
for a certain period of time and after the certain period the UE starts using the N3IWF.
The period may be indicated by the network (e.g. N3IWF, AMF). The period may be
included in at least one of the above mentioned messages (e.g. AUTHENTICATION
REQUEST message).
[00045] In one example, the UE starts using untrusted non-3GPP access network after
the UE switches off and on the phone.
[00046] The UE may also bar the N3IWF in case it got a certificate, but for example the
certificate’s validity could not be verified because the UE does not possess the
necessary root key or because the UE did not have a valid time at the time of validating
the certificate. In order to do so, the UE will keep the following information about the
certificate:
[00047] -Whether the certificate’s validity could be verified.
[00048] -If yes, whether the certificate was valid or not.
[00049] Even in the case of an invalid certificate, the UE may continue to connect
because if the subsequent authentication procedure proceeds without errors, there is no
reason to bar the N3IWF. However, if the certificate was invalid and the authentication
procedure produces errors, the UE can bar the N3IWF.
[00050] v) in one example in all above cases, when the USIM is removed from the UE
then the UE unbar the N3IWF-1 or untrusted non-3GPP access.
11
[00051] vi) in one example in all above cases, the UE maintain a barred list of N3IWF
or a barred list of untrusted non-3GPP access in the ME memory. The UE shall not use
a N3IWF present in the barred list of N3IWF or an untrusted non-3GPP access present
in the barred list of untrusted non-3GPP access, for any UICC (i.e. any USIM of the
UICC or USIM of any UICC) inserted in the UE.
[00052] In one example, the UE shall deem that the network has failed the authentication
check or assume that the authentication is not genuine when a single authentication
procedure fails at the UE due to the reason mentioned previously.
[00053] In one example, the UE shall deem that the network has failed the authentication
check or assume that the authentication is not genuine when an authentication
procedure fails more than two consecutive times at the UE due to the reason mentioned
previously.
[00054] In the above, a number of actions that the UE can take are explained herein.
[00055] Figure 2 shows how some of the above can be combined in one decision tree to
be used by the UE. After the UE has detected the second authentication failure, the UE
will first check whether it has requested a certificate from the N3IWF.
[00056] If no, the UE goes on to step iii) of the above and ends up in the “OR” block of
the main diagram, barring either the N3IWF or the non 3GPP access. In the “OR” block,
the UE may retrieve a list of known N3IWFs from storage and use the list of element
of step iv) in the above to decide whether there is any N3IWF on that list that is not
barred. If so, the UE may bar the N3IWF and connect to another one. In case, the UE
does not have any further N3IWFs, it may decide to bar the non-3GPP access instead
and find another non-3GPP access network according to action in step ii).
[00057] In case, the UE did request a certificate and the UE could validate the certificate,
the UE will bar the N3IWF according to iv) in the above. In case the certificate was not
valid, it will also bar the N3IWF according to iv) in the above. In case the UE could not
verify the validity of the certificate, the UE ends up in the “OR” block and will bar
either the N3IWF or the non-3GPP access network according to the steps in the “OR”
block.
12
[00058] Other variations of the decision tree are possible and even each UE may be
configured with a different decision tree, for example by the operator.
[00059] The UE sends an Initial NAS message to the 5GC network via another access
point e.g. N3IWF-2. The 5GC network performs the Authentication procedure.
[00060] After the Authentication procedure is performed successfully, the UE sent the
debug information of failure of authentication procedure in the first NAS message. The
debug information element includes at least one of the following information element:
i) N3IWF node information address (IP address),
ii) reasons for failure of authentication procedure in both steps 6 and 9,
iii) 5G authentication challenge data (RAND, AUTN and ngKSI), and
iv) Certificate of N3IWF.
[00061] The first NAS message can be one of the following NAS message:
i) a new NAS message, and
ii) any existing NAS message (e.g. Registration Request, UL NAS transport
message, Service Request message etc.).
[00062] The 5GC network analyses the reason of failure of authentication procedure
based on the received debug information. If the network determines that the N3IWF or
untrusted non-3GPP access is fake, it indicates to this to the UE in a second NAS
message. If the network determines that the N3IWF is not fake, it indicates that the
N3IWF-1 is a valid N3IWF in a second NAS message. In the same way, if the network
determines that untrusted non-3GPP access node is not fake, it indicates that the
untrusted non-3GPP access is a valid untrusted non-3GPP access in a second NAS
message. In one case the NAS message is security protected i.e. ciphering or integrity
protected or both ciphering and integrity protected.
[00063] In one example, when the 5GC network determines that the N3IWF-1 or
untrusted non-3GPP access node is fake then the 5GC network deletes the N3IWF-1 or
untrusted non-3GPP access node from the UE configuration.
[00064] When the UE receives the second NAS message, the UE takes at least one of
the following options:
13
i) if the N3IWF-1 is indicated as valid then the UE may select N3IWF-1 to
connect to the 5GC network,
ii) if the N3IWF is indicated as fake then the UE shall not select the N3IWF-1
to connect to the 5GC network. The UE marked it as barred,
iii) if the untrusted non-3GPP access node is indicated as valid then the UE may
connect to the untrusted non-3GPP access node, and
iv) if the untrusted non-3GPP access node is indicated as fake the UE shall not
connect to the non-3GPP access node.
[00065] The second NAS message can be one of the following:
i). a new NAS message, and
ii) an existing NAS message (e.g. Registration Accept message, service Accept
message etc.).
[00066] In the first embodiment, in scenario when the UE is camped on a 3GPP access
cell and the UE determines that the network fails the authentication check, then the UE
stores the cell information (e.g. Global Cell Identity, Physical Cell Identifier (PCT))
and reasons for the authentication failure.
[00067] When the UE selects another cell and is registered to the PLMN successfully
(i.e. Authentication procedure is executed successfully) then the UE sends a first NAS
message containing the cell information and the reasons for the authentication failure
as stored to the network (e.g. AMF). The first NAS message containing the cell
information and the reasons for the authentication failure may be sent upon reception
of any request for reporting the cell information and the reasons for the authentication
failure.
[00068] The network analyses the information received in the first NAS message and
determines whether the reported cell is valid or fake. The network then informs the UE
if the cell is valid or fake in a second NAS message.
[00069] When the UE receives the second NAS message and if the cell is indicated as
valid then the UE will treat the cell as non-barred cell i.e. the cell will be a suitable cell
for cell selection. If the network indicates the UE is fake, the UE will mark this cell as
barred and will store the information in the non-volatile memory (UE memory) and
consider this cell as barred cell.
14
[00070] In one example when the 5GC network determines that the cell is fake then the
5GC network broadcasts the cell is barred or fake in a System information block. When
the UE does not consider the cell as suitable for camping i.e. treat it as barred cell.
[00071] In the second embodiment, in scenario when the UE is camped on a 3GPP
access cell and the UE determines that the network fails the authentication check then
the UE stores the cell information (e.g. Global Cell Identity, Physical Cell Identifier
(PCT)) and reasons for the authentication failure.
[00072] When the UE selects another cell and is registered to the PLMN successfully
(i.e. Authentication procedure is executed successfully) then the UE transmits a first
RRC message containing the cell information and the reasons for the authentication
failure as stored to the network (e.g. NG-RAN node) The first RRC message containing
the cell information and the reasons for the authentication failure may be sent upon
reception of any request for reporting the cell information and the reasons for the
authentication failure.
[00073] The network (e.g. NG-RAN node) analyse the information received in the first
RRC message and determines whether the reported cell is valid or fake. The network
then informs the UE if the cell is valid or fake in a second RRC message.
[00074] When the UE receives the second RRC message and if the cell is indicated as
valid then the UE will treat the cell as non-barred cell i.e. the cell will be a suitable cell
for cell selection. If the network indicates the UE is fake, the UE will mark this cell as
barred and will store the information in the non-volatile memory (UE memory) and
consider this cell as barred cell.
[00075] According to third embodiment, when a UE determines that the network fails
the authentication check and if the UE supports a 3GPP access (NG-RAN or E-UTRAN
access or UTRAN or GERAN) then the UE may perform registration procedure to the
3GPP access and a 3GPP access is available.
[00076] Similarly if the UE determines that the network fails the authentication check
on an 3GPP access (e.g. gNB) and the UE supports a non-3GPP access then the UE
may performs registration procedure to the 5GC network via non-3GPP access.
15
[00077] The User Equipment (or “UE”, “mobile station”, “mobile device” or “wireless
device”) in the present disclosure is an entity connected to a network via a wireless
interface.
[00078] It should be noted that the UE in this specification is not limited to a dedicated
communication device, and can be applied to any device, having a communication
function as a UE described in this specification, as explained in the following
paragraphs.
[00079] The terms "User Equipment" or "UE" (as the term is used by 3GPP), "mobile
station", "mobile device", and "wireless device" are generally intended to be
synonymous with one another, and include standalone mobile stations, such as
terminals, cell phones, smart phones, tablets, cellular IoT devices, IoT devices, and
machinery.
[00080] It will be appreciated that the terms “UE” and “wireless device” also encompass
devices that remain stationary for a long period of time.
[00081] A UE may, for example, be an item of equipment for production or manufacture
and/or an item of energy related machinery (for example: equipment or machinery such
as: boilers; engines; turbines; solar panels; wind turbines; hydroelectric generators;
thermal power generators; nuclear electricity generators; batteries; nuclear systems
and/or associated equipment; heavy electrical machinery; pumps including vacuum
pumps; compressors; fans; blowers; oil hydraulic equipment; pneumatic equipment;
metal working machinery; manipulators; robots and/or their application systems; tools;
molds or dies; rolls; conveying equipment; elevating equipment; materials handling
equipment; textile machinery; sewing machines; printing and/or related machinery;
paper converting machinery; chemical machinery; mining and/or construction
machinery and/or related equipment; machinery and/or implements for agriculture,
forestry and/or fisheries; safety and/or environment preservation equipment; tractors;
precision bearings; chains; gears; power transmission equipment; lubricating
equipment; valves; pipe fittings; and/or application systems for any of the previously
mentioned equipment or machinery etc.).
[00082] A UE may, for example, be an item of transport equipment (for example
transport equipment such as: rolling stocks; motor vehicles; motor cycles; bicycles;
16
trains; buses; carts; rickshaws; ships and other watercraft; aircraft; rockets; satellites;
drones; balloons etc.).
[00083] A UE may, for example, be an item of information and communication
equipment (for example information and communication equipment such as: electronic
computer and related equipment; communication and related equipment; electronic
components etc.).
[00084] A UE may, for example, be a refrigerating machine, a refrigerating machine
applied product, an item of trade and/or service industry equipment, a vending machine,
an automatic service machine, an office machine or equipment, a consumer electronic
and electronic appliance (for example a consumer electronic appliance such as: audio
equipment; video equipment; a loud speaker; a radio; a television; a microwave oven;
a rice cooker; a coffee machine; a dishwasher; a washing machine; a dryer; an electronic
fan or related appliance; a cleaner etc.).
[00085] A UE may, for example, be an electrical application system or equipment (for
example an electrical application system or equipment such as: an x-ray system; a
particle accelerator; radio isotope equipment; sonic equipment; electromagnetic
application equipment; electronic power application equipment etc.).
[00086] A UE may, for example, be an electronic lamp, a luminaire, a measuring
instrument, an analyzer, a tester, or a surveying or sensing instrument (for example a
surveying or sensing instrument such as: a smoke alarm; a human alarm sensor; a
motion sensor; a wireless tag etc.), a watch or clock, a laboratory instrument, optical
apparatus, medical equipment and/or system, a weapon, an item of cutlery, a hand tool,
or the like.
[00087] A UE may, for example, be a wireless-equipped personal digital assistant or
related equipment (such as a wireless card or module designed for attachment to or for
insertion into another electronic device (for example a personal computer, electrical
measuring machine)).
[00088] A UE may be a device or a part of a system that provides applications, services,
and solutions described below, as to “internet of things (IoT)”, using a variety of wired
and/or wireless communication technologies.
17
[00089] Internet of Things devices (or "things") may be equipped with appropriate
electronics, software, sensors, network connectivity, and/or the like, which enable these
devices to collect and exchange data with each other and with other communication
devices. IoT devices may comprise automated equipment that follow software
instructions stored in an internal memory. IoT devices may operate without requiring
human supervision or interaction. IoT devices might also remain stationary and/or
inactive for a long period of time. IoT devices may be implemented as a part of a
(generally) stationary apparatus. IoT devices may also be embedded in non-stationary
apparatus (e.g. vehicles) or attached to animals or persons to be monitored/tracked.
[00090] It will be appreciated that IoT technology can be implemented on any
communication devices that can connect to a communications network for
sending/receiving data, regardless of whether such communication devices are
controlled by human input or software instructions stored in memory.
[00091] It will be appreciated that IoT technology can be implemented on any
communication devices that can connect to a communications network for
sending/receiving data, regardless of whether such communication devices are
controlled by human input or software instructions stored in memory.
[00092] It will be appreciated that IoT devices are sometimes also referred to as
Machine-Type Communication (MTC) devices or Machine-to-Machine (M2M)
communication devices or Narrow Band-IoT UE (NB-IoT UE). It will be appreciated
that a UE may support one or more IoT or MTC applications. Some examples of MTC
applications are listed in the Table 1 (source: 33GPP TS 22.368 [3], Annex B, the
contents of which are incorporated herein by reference). This list is not exhaustive and
is intended to be indicative of some examples of machine type communication
applications.
[00093] Table 1: Some examples of machine type communication applications.
Service Area MTC applications
Security
Surveillance systems
Backup for landline
Control of physical access (e.g. to buildings)
Car/driver security
Tracking & Tracing Fleet Management
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Order Management
Pay as you drive
Asset Tracking
Navigation
Traffic information
Road tolling
Road traffic optimisation/steering
Payment
Point of sales
Vending machines
Gaming machines
Health
Monitoring vital signs
Supporting the aged or handicapped
Web Access Telemedicine points
Remote diagnostics
Remote
Maintenance/Control
Sensors
Lighting
Pumps
Valves
Elevator control
Vending machine control
Vehicle diagnostics
Metering
Power
Gas
Water
Heating
Grid control
Industrial metering
Consumer Devices
Digital photo frame
Digital camera
eBook
[00094] Applications, services, and solutions may be an MVNO (Mobile Virtual
Network Operator) service, an emergency radio communication system, a PBX (Private
Branch eXchange) system, a PHS/Digital Cordless Telecommunications system, a POS
(Point of sale) system, an advertise calling system, an MBMS (Multimedia Broadcast
and Multicast Service), a V2X (Vehicle to Everything) system, a train radio system, a
location related service, a Disaster/Emergency Wireless Communication Service, a
community service, a video streaming service, a femto cell application service, a
VoLTE (Voice over LTE) service, a charging service, a radio on demand service, a
roaming service, an activity monitoring service, a telecom carrier/communication NW
selection service, a functional restriction service, a PoC (Proof of Concept) service, a
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personal information management service, an ad-hoc network/DTN (Delay Tolerant
Networking) service, etc.
[00095] Further, the above-described UE categories are merely examples of applications
of the technical ideas and exemplary embodiments described in the present document.
Needless to say, these technical ideas and embodiments are not limited to the abovedescribed
UE and various modifications can be made thereto.
[00096] Figure 3 is a block diagram illustrating the main components of the UE. As
shown, the UE includes a transceiver circuit which is operable to transmit signals to
and to receive signals from the connected node(s) via one or more antenna. Although
not necessarily shown, the UE will of course have all the usual functionality of a
conventional mobile device (such as a user interface) and this may be provided by any
one or any combination of hardware, software and firmware, as appropriate. Software
may be pre-installed in the memory and/or may be downloaded via the
telecommunication network or from a removable data storage device (RMD), for
example.
[00097] A controller controls the operation of the UE in accordance with software stored
in a memory. For example, the controller may be realized by Central Processing Unit
(CPU). The software includes, among other things, an operating system and a
communications control module having at least a transceiver control module. The
communications control module (using its transceiver control sub-module) is
responsible for handling (generating/sending/receiving) signalling and
uplink/downlink data packets between the UE and other nodes, such as the base station
/ (R)AN node, a MME, the AMF (and other core network nodes). Such signalling may
include, for example, appropriately formatted signalling messages relating to
connection establishment and maintenance (e.g. RRC messages,), NAS messages such
as periodic location update related messages (e.g. tracking area update, paging area
updates, location area update) etc.
[00098] Figure 4 is a block diagram illustrating the main components of an exemplary
(R)AN node, for example a base station (‘eNB’ in LTE, ‘gNB’ in 5G, ‘untrusted non-
3GPP access’ for non-3GPP access, N3IWF (Non-3GPP Interworking Function) for
non-3GPP access). As shown, the (R)AN node includes a transceiver circuit which is
20
operable to transmit signals to and to receive signals from connected UE(s) via one or
more antenna (in case N3IWF, it may not include the transceiver circuit) and to transmit
signals to and to receive signals from other network nodes (either directly or indirectly)
via a network interface. A controller controls the operation of the (R)AN node in
accordance with software stored in a memory. For example, the controller may be
realized by Central Processing Unit (CPU). Software may be pre-installed in the
memory and/or may be downloaded via the telecommunication network or from a
removable data storage device (RMD), for example. The software includes, among
other things, an operating system and a communications control module having at least
a transceiver control module.
[00099] The communications control module (using its transceiver control sub-module)
is responsible for handling (generating/sending/receiving) signalling between the
(R)AN node and other nodes, such as the UE, the MME, the AMF(e.g. directly or
indirectly). The signalling may include, for example, appropriately formatted signalling
messages relating to a radio connection and location procedures (for a particular UE),
and in particular, relating to connection establishment and maintenance (e.g. RRC
connection establishment and other RRC messages), periodic location update related
messages (e.g. tracking area update, paging area updates, location area update), S1 AP
messages and NG AP messages (i.e. messages by N2 reference point), etc. Such
signalling may also include, for example, broadcast information (e.g. Master
Information and System information) in a sending case.
[000100] The controller is also configured (by software or hardware) to handle related
tasks such as, when implemented, UE mobility estimate and/or moving trajectory
estimation.
[000101] Figure 5 is a block diagram illustrating the main components of the AMF. The
AMF is included in the 5GC. As shown, the AMF includes a transceiver circuit which
is operable to transmit signals to and to receive signals from other nodes (including the
UE) via a network interface. A controller controls the operation of the AMF in
accordance with software stored in a memory. For example, the controller may be
realized by Central Processing Unit (CPU). Software may be pre-installed in the
memory and/or may be downloaded via the telecommunication network or from a
removable data storage device (RMD), for example. The software includes, among
21
other things, an operating system and a communications control module having at least
a transceiver control module.
[000102] The communications control module (using its transceiver control sub-module)
is responsible for handling (generating/sending/ receiving) signalling between the AMF
and other nodes, such as the UE, base station/(R)AN node (e.g. “gNB” or “eNB”,
‘untrusted non-3GPP access’ for non-3GPP access, N3IWF (Non-3GPP Interworking
Function) for non-3GPP access) (directly or indirectly). Such signalling may include,
for example, appropriately formatted signalling messages relating to the procedures
described herein, for example, NG AP message (i.e. a message by N2 reference point)
to convey an NAS message from and to the UE, etc.
[000103] As will be appreciated by one of skill in the art, the present disclosure may be
embodied as a method, and apparatus. Accordingly, the present disclosure may take the
form of an entirely hardware embodiment, a software embodiment or an embodiment
combining software and hardware aspects.
[000104] It will be understood that each block of the block diagrams, can be implemented
by computer program instructions. These computer program instructions may be
provided to a processor of a general purpose computer, special purpose computer, or
other programmable data processing apparatus to produce a machine, such that the
instructions, which execute via the processor of the computer or other programmable
data processing apparatus, create means for implementing the functions/acts specified
in the flowchart and/or block diagram block or blocks.
[000105] In the drawings and specification, there have been disclosed exemplary
embodiments of the disclosure. Although specific terms are employed, they are used in
a generic and descriptive sense only and not for purposes of limitation, the scope of the
disclosure being defined by the following claims.

We claim:
1. A method of a user equipment, the method comprising:
a) sending a first Non Access Stratum (NAS) message to an Access mobility
Management Function (AMF) via a first untrusted non-3GPP access network and a first Non-
3gpp access Inter-Working Function (N3IWF);
b) receiving an Authentication Request message from the AMF;
c) determining, based on the Authentication Request message, whether the AMF has
failed the authentication check or not;
d) sending an Authentication Failure message to the AMF if the user equipment has
determined that the AMF has failed the authentication check, and repeating b) and c) until
the user equipment has determined in two consecutive times that the AMF has failed the
authentication check; and
e) selecting a second untrusted non-3GPP access network or a second N3IWF for
making another NAS signalling connection if the user equipment has determined in two
consecutive time that the AMF has failed the authentication check.
2. The method according to claim 1, wherein the user equipment determines that the
first untrusted non-3GPP access network or the first N3IWF is barred for a NAS signalling
connection if the user equipment has determined in two consecutive times that the AMF has
failed the authentication check.
3. The method according to claim 2, wherein the user equipment determines that:
the first N3IWF is not barred if the user equipment has determined that the
first untrusted non-3GPP access network is barred; or
the first untrusted non-3GPP access network is not barred if the user
equipment has determined that the first N3IWF is barred.
4. A user equipment comprising:
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a transceiver circuit; and
a processor configured to perform a method via the transceiver circuit, wherein the
method comprises:
a) sending a first Non Access Stratum (NAS) message to an Access mobility
Management Function (AMF) via a first untrusted non-3GPP access network and a first Non-
3gpp access Inter-Working Function (N3IWF);
b) receiving an Authentication Request message from the AMF;
c) determining, based on the Authentication Request message, whether the
AMF has failed the authentication check or not;
d) sending an Authentication Failure message to the AMF if the user
equipment has determined that the AMF has failed the authentication check, and repeating b)
and c) until the user equipment has determined in two consecutive times that the AMF has
failed the authentication check; and
e) selecting a second untrusted non-3GPP access network or a second N3IWF
for making another NAS signalling connection if the user equipment has determined in two
consecutive times that the AMF has failed the authentication check.