Description
Title of Invention: CONTROL OF SMALL DATA
TRANSMISSION IN A MOBILE RADIO COMMUNICATIONS
NETWORK
Technical Field
[0001] The present invention relates to a mobile radio communications network and related
network device and methods of operation offering network communication by way of a
Small Data Transmission (SDT) feature.
Background Art
[0002] Communication procedures within mobile radio communications network can
involve amounts of data of various signals and recent discussion within 3GPP (3rd
Generation Partnership Project) documentation in particular has focused on the
transmission of small amounts of data by way of SDT features and services.
[0003] Many Machine Type Communication (MTC) applications send or receive small
amounts of data. 3GPP Services and Systems Aspects (SA1) Working Group has
already identified SDT as one possibly attractive feature for MTC. According to
Technical Specification document TS22.368, s7.2.5, the MTC Feature 'Small Data
Transmission' is intended for use with MTC Devices that send or receive small
amounts of data and the size of many of the instances of data exchange is on the order
of lk (1024) octets.
[0004] Also, 3GPP Services and System Aspects (SA2) Working Group has considered
Small Data Transmission optimisation as part of the MTCe-SDDTE (Small Data and
Device Triggering Enhancements) Work Item, as discussed in particular as section 5.1
of the Technical Report TR23.887. One key issue identified is the desire to 'Efficient
Small Data transmission' and the following functional requirement for Small Data
transmission has been determined, i.e. systems should support transmissions of small
amounts of data efficiently with minimal network impact such as signalling overhead,
network resources and delay for reallocation.
[0005] 3GPP SA2 Working Group has already agreed several suggested solutions for such
efficient transmissions are known from TR23.887.
[0006] Also, during its last meeting (SA2#98, July 2013) SA2 recommended 'Standalone
Small Data Service with T5/Tsp and generic NAS (Non-Access Stratum) transport' for
standardisation and identify a protocol for SDT to carry small data units of various
users of that small data service was agreed and which spans between service accesses
points in the User Equipment UE device and the SCS/AS (Service Capability Server/
Application Server). As discussed further below with reference to Fig. 1, any service
data exchange between the UE and Application Server (AS) is intended to go through
the MTC-IWF (Machine Type Communication - Interworking Function) and the SCS.
The small data transfer can be provided as confirmed or unconfirmed delivery service.
[0007] An Illustration known from TR23.887, of uplink Small Data Transmission (SDT)
through control plane channel on T5 and Tsp interfaces is also discussed further below
with reference to Fig. 2.
[0008] However, such suggested protocol details are not fully defined and so are incomplete.
[0009] Although an existing protocol could be adopted for the SDT protocol, there are many
new and specific requirements that would make simple adoption of current protocols
inappropriate. One such specific issue is how to control the use of SDT at the both
sides, the UE and the network. Indeed an Editor's Note in the TR23.887 confirms that
the manner of ensuring that the application correctly uses the Service Request
procedure and does not abuse this 'Small Data' NAS procedure is an open issue.
However the MME's (Mobile Management Entity) ability to release the connection
provides a control point.
[0010] Yet further in its Liaison Statement (LS) answer to (R2- 133033) SA2, RAN 2
Working Group has suggested that it is essential to ensure that only traffic matching
small data feature characteristics can use SDT solution since the use with other traffic
patterns would result in deterioration in capacity and performance.
[001 1] It is also noted that, while with the normal data transmission there is an initial PDP/
PDN (Packet Data Protocol / Packet Data Networks) connection establishment that
could be rejected, with a SDT service there is no PDP/ PDN connection establishment
that occurs before sending the SDT.
Summary of Invention
Technical Problem
[0012] Although this all suggests the need for tighter control in the use of SDT services and
features, and requires means for rejection of the SDT service if not compliant with the
requirements or for any other reason like subscription, traffic, deployment, equipment
failure and etc, no effective solutions exist.
[0013] The present invention seeks to provide for a mobile radio communications network, a
network device and associated methods of operation having advantages over known
such networks, devices and methods.
[0014] In particular, the present invention seeks to provide for the control of the use of SDT
features in an advantageously efficient manner and, particularly, through the efficient
and reliable rejection of an SDT service request/attempt through appropriate control
and restriction.
Solution to Problem
[0015] According to a first aspect of the present invention, there is provided a mobile radio
communications network within which a mobile radio communications device is to
operate with access to a Small Data Transmission feature and including a first network
device arranged to receive Small Data Transmission signalling initiated by the mobile
radio communications device, a second network device arranged to receive signalling
from the first network device as part of an establishment procedure for attempted
Small Data Transmission communications for the mobile radio communications device
within the network, the first network device being further arranged to determine if
Small Data Transmission should be prevented for the mobile radio communications
device and to initiate a Small Data Transmission rejection message for use in the
control of the mobile radio communications device if Small Data Transmission is to be
prevented.
[0016] Preferably, the first network device is arranged to determine if the Small Data
Transmission should be prevented responsive to its signalling exchange with the
second network device.
[0017] Advantageously, the first network device includes a SGSN/MME (Serving GPRS
(General Packet Radio Service) Support Node / Mobile Management Entity).
[0018] Further, the second network device can include a server device such as, for example,
a Home Subscriber Server (HSS).
[0019] Advantageously, the signalling exchange between the first network device and
second network device as part of the establishment procedure includes an interrogation
signal sent from the first network device to the second network device preferably for
identification of a Small Data Transmission Receiver Id.
[0020] In one particular exemplary embodiment, the network arrangement is such that the
Small Data Transmission rejection message is sent directly from the first network
device to the mobile radio communications device.
[0021] In an alternative arrangement, the first network device can include a MTC/IWF
device.
[0022] In this manner, the second network device can again include a server device such as,
for example, a Service Capability Server/ Application Server (SCS/AS). Also, the
signalling exchange arising within the network, can be arranged such that the
signalling exchange between the first and second network devices includes au
thorizing/authentication signalling between the MTC-IWF and the SCS/AS.
[0023] As a further option, and with the network device including the MTC-IWF, the second
network device can include an HSS and the network can be arranged such that the
signalling exchange between the first and second network devices includes inter
rogation signalling directed to the HSS as discussed above.
[0024] Advantageously, the Small Data Transmission rejection message from the MTC-fWF
is delivered to the mobile radio communications device by way of a further network
device, and advantageously the further network device can include a SGSN/MME.
[0025] Advantageously, the Small Data Transmission rejection message can include an in
dication of the cause of rejection. Further, the mobile radio communications device can
be arranged upon receipt of the Small Data Transmission rejection message to generate
a transfer rejection signal for delivery to an application operating therein and seeking
network access by way of a Small Data Transmission feature.
[0026] Further, the network can be arranged such that a Small Data Transmission rejection
message received at the mobile radio communications device includes time-period in
formation serving to control a length of time for which a mobile radio communications
device cannot access the Small Data Transmission feature.
[0027] According to another aspect of the present invention, there is provided a method of
controlling use of a Small Data Transmission feature within a mobile radio commu
nications network within which a mobile radio communications device is to operate
with access to a Small Data Transmission feature, the method including the steps of
receiving at a first network device Small Data Transmission signalling initiated by the
mobile radio communications device, receiving at a second network device signalling
from the first network device as part of an establishment procedure for attempted
Small Data Transmission communications for the mobile radio communications device
in the network, by determining at the first network device if Small Data Transmission
should be prevented for the mobile radio communications device and initiating a Small
Data Transmission rejection message for use in the control of a mobile radio commu
nications device if Small Data Transmission is to be prevented.
[0028] Preferably, the method includes determining if the Small Data Transmission should
be prevented responsive to its signalling exchange with the second network device.
[0029] Again, the invention proves advantages in providing improved control of em
ployment of a Small Data Transmissions service and with a mobile radio commu
nications network having the functionality, by way of one or more devices, to reject a
Small Data Transmission service request/attempt, in certain circumstances.
[0030] The first network device employed within the method can includes a SGSN/MME.
[0031] Further, the second network device employed within the method can include a server
device such as, for example, a Home Subscriber Server (HSS). Advantageously, the
signalling exchange between the first network device and second network device as
part of the establishment procedure can includes an interrogation signal sent from the
first network device to the second network device for seeking a Small Data
Transmission Receiver Id.
[0032] In one particular exemplary embodiment, the method includes sending the Small
Data Transmission rejection message directly from the first network device to the
mobile radio communications device.
[0033] In an alternative arrangement, the first network device employed by the method can
include a MTC/IWF device.
[0034] In this manner, the second network device employed by the method can again
include a server device such as, for example, a Service Capability Server/Application
Server (SCS/AS).
[0035] The signalling exchange arising within the network as part of the establishment
procedure can include authorizing/authentication signalling between the MTC-IWF
and the SCS/AS.
[0036] As a further option, and with the network device including the MTC-IWF, the second
network device can include a HSS and the network is arranged such that the signalling
exchange forming part of the establishment procedure includes interrogation signalling
directed to the HSS as discussed above.
[0037] Advantageously, method includes delivering the Small Data Transmission rejection
message from the MTC-IWF to the mobile radio communications device by way of a
further network device.
[0038] The further network device employed by the method can include a SGSN/MME.
[0039] Advantageously, the Small Data Transmission rejection message can include an in
dication of the cause of rejection. Further, the mobile radio communications device can
be arranged upon receipt of the Small Data Transmission rejection message to generate
a transfer rejection signal for delivery to an application operating therein and seeking
network access by way of a Small Data Transmission feature.
[0040] Further, the network can be arranged such that a Small Data Transmission rejection
message received at the mobile radio communications device includes time-period in
formation serving to control a length of time for which a mobile radio communications
device cannot access the Small Data Transmission feature.
[0041] According to yet another aspect of the present invention, there is provided a mobile
radio communications network device arranged to receive Small Data Transmission
signalling from a mobile radio communications device and to send signalling to a
second mobile radio communications network device as part of an establishment
procedure for attempted Small Data Transmission communication for the mobile radio
communications device within the network, the mobile radio communications network
device further being arranged to determine if a Small Data Transmission should be
prevented for the mobile radio communications device and to initiate a Small Data
Transmission rejection message for use in the control of the mobile radio commu
nications device if Small Data Transmission is to be prevented.
[0042] Preferably, the mobile radio communications network device is arranged to
determine if the Small Data Transmission should be prevented responsive to its
signalling exchange with the second network device.
[0043] As above, the mobile radio communications network device can include a SGSN/
MME.
[0044] Further, the network device can be arranged to send an interrogation signal to the
second network device as part of the signalling exchange.
[0045] In one particular exemplary embodiment, the mobile radio communications network
device is arranged to send the Small Data Transmission rejection message directly to
the mobile radio communications device.
[0046] In an alternative arrangement, the mobile radio communications network device can
include a MTC/IWF device.
[0047] In this manner, the signalling exchange between the mobile radio communication
network devices can include authorizing/authentication signalling between the MTCIWF
and a SCS/AS.
[0048] As a further option, the signalling exchange between the mobile radio commu
nications network devices can include interrogation signalling directed to an HSS
within the network.
[0049] According to yet another aspect of the present invention, there is provided a method
of operating a mobile radio communications network device to receive a Small Data
Transmission from a mobile radio communications device operating within the
network and with access to a Small Data Transmission service, the method including
the step of receiving Small Data Transmission signalling initiated by the mobile radio
communications device, sending, as part of a signalling exchange, signalling to a
second mobile radio communications network device as part of the establishment
procedure for attempted Small Data Transmission communication for the mobile radio
communications device determining if the Small Data Transmission should be
prevented for the mobile radio communications device and initiating a Small Data
Transmission rejection message for use in the control of the mobile radio commu
nication device if Small Data Transmission is to be prevented.
[0050] Preferably, the method includes determining if the Small Data Transmission should
be prevented responsive to its signalling exchange with the second network device.
[0051] Advantageously, the signalling exchange within the method between the network
devices can include an interrogation signal sent from the mobile radio communications
network device to the second mobile radio communications network device.
[0052] Preferably, the interrogation signal can include one seeking to obtain Small Data
Transmission Receiver Id data.
[0053] In one particular exemplary embodiment the method of control is one such that the
Small Data Transmission rejection message is sent directly from the first network
device to the mobile radio communications device.
[0054] Alternatively, the signalling exchange arising in relation to the method within the
network can include an authorizing/authentication signalling exchange.
[0055] Further, the signalling exchange can include interrogation signalling directed to an
HSS.
[0056] It will of course be appreciated that the present invention provides for a mobile radio
communications device arranged for receiving control signalling relating to access to a
Small Data Transmission feature and as originating within a mobile radio commu
nications network, and from a mobile radio communications network device, as
outlined above. It should be appreciated that methods and devices of the present
invention, and related network, can be arranged to include cause of rejection within the
rejection signalling and including and indication of at least one of a subscriber-related
cause or a non-subscriber related cause.
Advantageous Effects of Invention
[0057] The invention proves advantages in providing efficient and adaptable control of the
employment availability of a Small Data Transmissions service by/for a mobile radio
communications device; the device having the functionality to reject a Small Data
Transmission service request/attempt if appropriate.
Brief Description of Drawings
[0058] [fig.l]Fig. 1 is a schematic illustration of protocol stack structures for network nodes
within a mobile radio communications network arranged for adopting a Small Data
Transmission service.
[fig.2]Fig. 2 is a signalling diagram illustrating one example of a proposed uplink
Small Data Transmission procedure.
[fig.3]Fig. 3 is a signalling diagram illustrating control signalling in accordance with
one exemplary embodiment of the present invention.
[fig.4]Fig. 4 is a signalling diagram illustrating control signalling in accordance with
another exemplary embodiment of the present invention.
[fig.5]Fig. 5 is a signalling diagram illustrating control signalling in accordance with a
yet further exemplary embodiment of the present invention.
[fig.6]Fig. 6 is a schematic diagram of a mobile radio communications network device
according to an exemplary embodiment of the present invention.
[fig.7]Fig. 7 is a schematic illustration of a mobile radio communications device for
operation in accordance with one exemplary embodiment of the present invention.
Description of Embodiments
[0059] Exemplary embodiments of the invention will be described further hereinafter, by
way of example only, with reference to the accompanying drawings.
[0060] Turning first to Fig. 1, there is provided a schematic illustration of nodes within a
mobile radio communications network 10 and including a User Equipment (UE)
device 12, a Mobile Management Entity (MME) 14, a Machine Type Communication -
Interworking Function (MTC-IWF)16, a Service Capability Server (SCS) 18 and Ap
plication Server (AS) 20.
[0061] The MTC-IWF 16 is arranged to interface with the MME 14 by way of a T5 interface
protocol 22, and to interface with the SCS 18 by way of a Tsp interface protocol 24.
[0062] For ease of reference not all layers of the protocol stacks within each of the devices
12-20 are identified but, as a generality, the protocol stack of the UE 12 includes ap
plication layer 26, SDT user layer 28, SDT layer 30 and Non-Access Stratum (NAS)
layer 32.
[0063] The relaying function of the MME 14 is provided by way of an NAS layer 34, T5
interface Application Protocol layer 36. The MTC-rWF relaying functions are
achieved by way of T5 interface Application Protocol layer 38 and also a Tsp interface
Application Protocol layer 40 connecting, by way of the Tsp interface 24 to a Tsp ap
plication protocol layer 42 within the SCS 18. The SCS 18 includes a Transmission
Control Protocol (TCP) layer 44 and also a SDT layer 54 and Transport Layer Security
(TLS) layer 56.
[0064] The protocol stack of the AS 20 includes an application layer 48, HTTP (Hyper Text
Transport Protocol) layer 50, TLS layer 52 and TCP layer 46.
[0065] As will be appreciated, the SDT protocol is arranged to span 58 between service
access points in the UE 12 and the SCS 18/AS 20. As also illustrated, any service data
exchanges between the UE 12 and the AS 20 are required to pass through the MME
14, MTC-IWF 16 and the SCS 18 as indicated and the small data transfer can be
provided as a confirmed or unconfirmed delivery service.
[0066] By way of further illustration of the proposed protocol for SDT service features
reference is now made to Fig. 2 which illustrates uplink SDT through a control plane
channel on the T5 and Tsp interfaces and as proposed in 3GPP Technical Report
TR23.887. Details of Radio Resource Control (RRC) and NAS security handling are
not specifically shown but should be considered as an implicit part of the procedure
shown.
[0067] The signalling illustrated is within a network environment 60 including a mobile
radio communications device such as a User Equipment (UE) 62 with its associated
Application(s) 64, a SGSN/MME 66, MTC-IWF 68 and SCS/AS 70.
[0068] First, an application 64 of the UE 62 requests 72 the transfer of an SDT-PDU (Packet
Data Unit) and performs any desired security functions, such as integrity protection of
the PDU.
[0069] A SDT-PDU is sent in an NAS message 74 to the SGSN/MME 66 and the protocol
type of the NAS PDU is set to "SDT". The SDT-PDU includes header and payload
data. Within the header, if not already done by the application, the UE 62 fills the
"SENDER" field with its MSISDN (Mobile Station International ISDN Number) (if
known) or External ID (if known) and places SCS/AS ID in the "RECEIVER" field.
The sub address field can include the identity of the application and the UE 62 can
perform any required security functions, i.e. integrity protection and/or encryption, if
not already done by the application.
[0070] Upon receiving the SDT-PDU, the SGSN/MME 66 verifies the sender ID. If the
SDT-PDU contains no sender ID, the SGSN/MME 66 adds a sender ID and if the sub
scription doesn't require home-routing, the SGSN/MME 66 (not shown) determines the
destination for the SDT-PDU by interrogating the Home Subscriber Server (HSS) for
the SDT Receiver ID and thereby determines the appropriate MTC-IWF. If the sub
scription requires home-routing, the SGSN/MME 66 determines the appropriate MTCIWF
from the UE's IMSI (International Mobile Subscriber Identity) or sender ID. The
SGSN/MME 66 then sends 76 the SDT-PDU to the MTC-IWF 68 over T5 interface
using the T5-AP protocol.
[007 1] The MTC-IWF 68 then determines the SCS/AS 70 using the 'RECEIVER ID' field in
the SDT-PDU header, and forwards 78 the SDT-PDU or SDU to the SCS/AS 70 using
Tsp-AP. Before forwarding the message, however, the MTC-IWF 68 replaces IMSI (if
indicated as sender ID) with MSISDN or External ID as 'SENDER ID'.
[0072] Upon receiving the SDT-PDU the SCS/AS 70 may verify the message integrity. The
SCS/AS 70 then returns an appropriate response 80, i.e. a Tsp-AP-PDU-Ack to
confirm the Tsp transfer of the SDT-PDU or the SDU, if an acknowledgment is
requested.
[0073] If such an acknowledgement is requested, the MTC-IWF 68 sends a T5-PDU-Ack 82
to the SGSN/MME 66.
[0074] The SGSN/MME 66 then sends an NAS-PDU-Ack 84 to the UE 62 and the UE 62
confirms 86 the SDT-PDU or the SDU transfer to the application 64.
[0075] However, and as already discussed above, the proposed protocol illustrated with
reference to Figs. 1 and 2 is still lacking in detail and there are disadvantages identified
as discussed above in considering the adoption of existing protocols.
[0076] It is important to achieve, in a reliable and efficient manner the appropriate level of
control and restriction as regards the employment of SDT by a UE within a network so
as, not least, to avoid loss of network capacity and network performance that might
arise with a mismatch between network traffic and SDT features.
[0077] Turning now to Fig. 3, there is provided a signalling diagram illustrating signalling
arising within a network relating to the control of use of a SDT feature by way of an
SGSN/MME network node and according to one exemplary embodiment of the present
invention.
[0078] Here a network environment 88 including a UE 90 and associated application(s) 92 is
illustrated along with a SGSN/MME 94 and HSS 96.
[0079] The signalling commences with an application 92 of the UE 90 requesting 98 the
transfer of an SDT-PDU. The application 92 can perform any wanted security
functions, e.g. integrity protection such as suggested by 3GPP Technical Report TR23,
887.
[0080] The SDT-PDU is then sent in a NAS message 100 to the SGSN/MME 94 and the
protocol type of the NAS-PDU is set to "SDT".
[008 1] Upon receiving the SDT-PDU, the SGSN/MME 94 determines the destination for the
SDT-PDU by interrogating 102 the HSS 96 for the SDT Receiver Id and so as to
identify the appropriate MTC-IWF (not shown). However, there is a possibility that the
SDT service is not allowed by the PLMN (Public Land Mobile Network) (for example,
during roaming the visiting PLMN may not allow SDT service) or that the SDT service
is barred (for reasons like pending payment or abuse of the service). If so, the SGSN/
MME 94 would be updated with this information during the HSS interrogation 102.
[0082] As a result of the HSS interrogation 102 the SGSN/MME 94 can reject the SDT
service by sending back a NAS-PDU-Reject message 104, ideally with one of the
following service reject causes:
Service option not supported - This reject cause can be used by the SGSN/MME 94
when the UE 90 requests a SDT service which is not supported by the PLMN. On
receiving NAS-PDU-Reject message 104 with reject-cause = 'Service option not
supported', the UE 90 shall deactivate the SDT procedure (by entering an SDT transfer
inactive state, for example) and shall not trigger another SDT service while on this
PLMN. The UE 90 may indicate the result to the SDT Application by sending Transfer
Reject message and include inside the reject cause.
Requested service option not subscribed - This reject cause can be sent by the SGSN/
MME 94 when the UE requests a SDT service for which it has no subscription. On
receiving NAS-PDU-Reject message with reject cause = 'Requested service option not
subscribed', the UE 90 shall deactivate the SDT procedure and shall not allow for
another SDT service from that SDT Application. The UE 90 may indicate the result to
the SDT Application by sending Transfer Reject message and include inside the reject
cause.
Operator Determined Barring -This reject cause is used by the SGSN/MME to
indicate that the SDT service was rejected due to Operator Determined Barring. On
receiving NAS-PDU-Reject message with reject cause = 'Operator Determined
Barring', the UE 90 shall deactivate the SDT procedure and shall not allow for another
SDT service from that SDT Application until the barring is lifted. The UE 90 may
indicate the result to the SDT Application by sending Transfer Reject message and
include inside the reject cause.
[0083] Finally, the UE 90 can indicate the SDT procedure rejection to the Application 92
that has initiated the SDT request by sending a Transfer Reject message 106 including
the reject-cause, the sdt-back-off-timer (if any) and the sdt-pdu-id in case there are
multiple active SDT procedures by that Application 92.
[0084] It is also possible that the SGSN/MME 94 can employ the new NAS-PDU-Reject
message 104 to also reject for other, non-subscription related reasons with the
following reject causes:
Insufficient Resources - This reject cause is used to indicate that the requested SDT
service cannot be provided due to insufficient resources.
Service option temporarily out of order - This reject cause is sent when the network
cannot service the request SDT service because of temporary outage of one or more
functions required for supporting the service.
Network failure - This reject cause is used to indicate that the requested SDT service
was rejected due to an error situation in the network.
[0085] One possible UE 90 reaction when receiving the reject indication 104 could be as
follows:
On receiving NAS-PDU-Reject message with one of the above reject causes, the UE
90 deactivates the SDT procedure (by entering an SDT transfer inactive state, for
example). If the SGSN/MME 94 included a value for the sdt-back-off-timer, the UE 90
shall not trigger another SDT procedure for the duration of this timer. Also, the UE 90
shall send Transfer Reject message to the SDT application for which the service was
rejected and include in it the reject-cause, sdt-back-off-timer (if any) and the sdt-pdu-id
(if multiple SDT procedures by that Application).
[0086] It should also be appreciated that any other, either new or existing, messages such as
UPLINK NAS TRANSPORT REJECT for SDT service rejection can be included as
part of exemplary embodiments such as that discussed above.
[0087] Turning now to Fig. 4, there is provided a signalling diagram for signalling arising
within a network environment 108 in which a UE 110 and its associated Application
112 and according to another exemplary embodiment of the present invention in which
SDT service rejection is initiated by the MTC-IWF. Other network elements illustrated
therefore are a SGSN/MME 114 and MTC-IWF 116. The signalling again commences
with a transfer request 118 from the Application 112 to the UE 110, and then a NAS
message 120 from the UE 110 to the SGSN/MME 114, which in turn sends the SDTPDU
122 over the T5-AP interface to the MTC-IWF 116.
[0088] As part of this exemplary embodiment, it should be appreciated that upon receiving a
T5-AP-PDU message, a MTC-IWF determines the SCS/AS using the Receiver Id field
in the SDT-PDU header and forwards the SDT-PDU or SDU to the SCS/AS using the
Tsp_AP. Before forwarding the message, the MTC-IWF replaces IMSI (if used as a
sender Id) with MSISDN or external Id as Sender Id on the Tsp interface as discussed
above in relation to Fig. 2. However, some problems can arise in the selection of the
SCS/AS by the MTC-IWF. In 3GPP Technical Specification TS23.682, Annex A it is
noted that the deployment of a SCS may be inside or outside the operator domain.
When the SCS/AS node is part of the operator domain, the SCS/AS is considered a
mobile operator internal network function, is operator controlled, and may provide
operator value-added services. In this case, security and privacy protection for commu
nication between the MTC-IWF and SCS/AS is optional.
[0089] However, when the SCS/AS is deployed outside the operator domain the SCS is
MTC Service Provider controlled. In this case, security and privacy protection for
communication between the MTC-rWF and SCS/AS is needed. The above-mentioned
TS23.682 emphasises that MTC-IWF shall authorise the SCS/AS before commu
nication is established.
[0090] Accordingly, and having regard to this further exemplary embodiment of the
invention, if the authentication of the SCS/AS (not shown) fails, it is proposed that the
MTC-IWF 116 rejects the SDT service by returning a T5-AP-Reject message 124 with
a new reject-cause = SCS-authentication-failure, to the SGSN/MME 114.
[0091] On receiving the T5-AP_Reject message 124 with reject-cause = SCS-au
thentication-failure, the SGSN/MME 114 forwards the reject-cause to the UE 110 in a
NAS-PDU-Reject message 126. The SGSN/MME 114 may also provide sdtback-
off-timer in the NAS-PDU-Reject message 126 and the SGSN/MME 114 may
start SCS identification procedure for resolving any SCS access security issues. The
UE 110 can send a Transfer Reject message 128 to the Application 112.
[0092] On receiving an SCS-authentication-failure, one possible UE reaction can be as
follows:
the UE 110 shall deactivate the SDT procedure and if the sdt-back-off-timer is
provided, the UE 110 shall not trigger another SDT procedure before expiry of the sdtback-
off-timer.
[0093] Of course, it is appreciated that the SCS/AS node selection could fail for other
reasons as well, such as for technical or congestion reasons in which case the same
message T5-AP-PDU_Reject message 124 could be used with general service failure
causes, like:
Insufficient resources - This reject cause is used by the SCS to indicate that the
requested SDT service cannot be provided due to insufficient resources.
Service option temporarily out of order - This reject cause is sent by the SCS when
the network cannot service the request SDT service because of temporary outage of
one or more functions required for supporting the service.
Network failure - This reject cause is used by SCS node to indicate that the requested
SDT service was rejected due to an error situation in the network.
[0094] As yet a further example of the present invention, reference is made to Fig. 5 which
illustrates signalling arising in connection with SDT service rejection by the MTCIWF
but, this time, with HSS interrogation similar to that as discussed in relation to
Fig. 3 above.
[0095] The network environment 130 as illustrated according to this further exemplary em
bodiment includes a UE 132 and associated Application 134, and also SGSN/MME
136, MTC-IWF 138 and HSS 140 network nodes.
[0096] The initial signalling again includes transfer request 142, NAS 144 and SDT-PDU
146 signalling.
[0097] In this exemplary embodiment, and with the Small Data Transfer security offloaded
by the SGSN/MME 136 and the related functionality moved to the MTC-IWF 138, the
MTC-IWF 138 could be connected to the HSS 140. During an SDT procedure
triggered by the UE 132, the MTC-IWF 138 would interrogate 148 the HSS 140 for
latest subscription information related to the on-going SDT. In this case the MTC-IWF
138 would also be capable of rejecting the SDT service for subscription failures. As a
result of such HSS interrogation 148 the MTC-IWF 138 would be able to reject the
SDT service by sending back a T5-AP-PDU-Reject message 150 with one of the
following previously described service reject causes: Service option not supported,
Requested service option not subscribed, Operator Determined.
[0098] When the SGSN/MME 136 receives T5-AP-PDU-Reject message 150 the SGSN/
MME 136 rejects the SDT service by sending a NAS-PDU-Reject message 152 to the
UE 132 (behaviour on receiving NAS-PDU-Reject message 152 with one of the above
reject causes can be as described above in relation to Fig. 3). The UE 132 can send a
Transfer Reject message 154 to the Application 134.
[0099] Now turning to Fig. 6, there is provided a schematic illustration of one example of a
mobile radio communications network device 156 such as, but not limited to, the
SGSN/MME and the MTC-IWF as discussed above.
[0100] The device 156 includes standard transmission/reception circuitry 158 operatively
connect to interface functionality 160. The device 156 also includes authentication/inter
rogation functionality 162 and a SDT objection message initiator 164 both of which
are under the control of control functionality 166.
[0101] It will be appreciated that either one of the authentication or interrogation func
tionality can be provided in element 162 upon the manner in which the second mobile
radio communications network device is to exchange signals with the device 156 so as
to lead to generation of the SDT rejection message by way of 164 and under the
control of controller 166.
[0102] With regard to Fig. 7, there is provided a schematic diagram of a UE device
including a mobile radio communications device 167 embodying the present invention.
[0103] The UE device 167 includes standard transmission/reception functionality 168 operatively
connected to an antenna functionality 170. As standard, the UE device 167
includes a memory 172, controller 174, processor 176 and user interface 178. In this
exemplary embodiment however, the controller 174 includes an SDT controller
arranged to be responsive to signalling messages received from a network device such
as that illustrated in Fig. 6 and so as to inhibit access to an SDT feature within the
network. The controller 174 can include means for communicating with an Application
attempting to run within the device 167 there is to provide a transfer reject signal as
discussed above. Also, the SDT controller 174 can include timer functionality r e
sponsive to timing information provided in the signalling from the network device and
so as to limit the SDT inhibition for a particular time period.
[0104] As will be appreciated from the above, the present invention provides for the
generation of control/restriction signalling within the network and for onward delivery
to a mobile radio communications device so as to effectively and efficiently control the
employment of a SDT feature by the mobile radio communications device when
seeking network access for data transmission.
[0105] The invention can advantageously also allow for the analysis of possible failure cases
in the newly defined by 3GPP SDT procedure and how to respond to such failures in
the network and the UE.
[0106] For this, the invention advantageously provides for:
A message in the T5 interface between SGSN/MME and MTC-IWF -
T5-AP-PDU-Reject;
A message between the UE and SGSN/MME - NAS-PDU-Reject;
A message between the UE and the SDT Application - Transfer-Reject;
A rejection cause 'SCS-authentication-failure' in the T5-AP-PDU-Reject and NASPDU-
Reject messages;
Use of existing rejection causes in the new messages T5-AP-PDU-Reject and NASPDU-
Reject;
A sdt-back-off-timer in the new messages NAS-PDU-Reject and Transfer Reject;
A sdt-pdu-id parameter in the NAS-PDU-Reject and Transfer- Reject messages; and
SGSN/MME behaviour at rejection of SDT service by the MTC-IWF.
[0107] However, it should be appreciated that, although discussed above primarily in
relation to 3G Radio Access Technology (RAT), the present invention is not limited to
application in relation to any particular RAT. For example, the inventive concept is
equally applicable to 2G RATs such as GSM systems and devices. In this manner it
will be appreciated that the above mentioned references to the various mobile and
network devices could likewise include references to related mobile and network
devices of such alternative RATs. For example, as an alternative to the above
references to MME/SGSN, reference to a Mobile Switching Centre (MSC) can be
considered, and as an alternative to references to an HSS, reference to a Home
Location Register (HLR) can be considered.
[0108] Note that the present invention is not limited to the above-mentioned exemplary em
bodiments, and it is obvious that various modifications can be made by those of
ordinary skill in the art based on the recitation of the claims.
[0109] This application is based upon and claims the benefit of priority from United
Kingdom Patent Application No. 1318901.4, filed on October 25, 2013, the disclosure
of which is incorporated herein in its entirety by reference.
Reference Signs List
[0110] 10 mobile radio communications network
12, 62, 90, 110, 132 UE
14 MME
16 MTC-IWF
18 SCS
20 AS
26 application layer
28 SDT user layer
30, 54 SDT layer
32, 34 NAS layer
36, 38 T5 interface Application Protocol layer
40, 42 Tsp interface Application Protocol layer
44, 46 TCP layer
48 application layer
50 HTTP layer
52, 56 TLS layer
60, 88,108, 130 network environment
64, 92, 112, 134 application
66, 94, 114, 136 SGSN/MME
68, 116, 138 MTC-IWF
70 SCS/AS
96, 140 HSS
156 device
158 transmission/reception circuitry
160 interface functionality
162 authentication/interrogation functionality
164 SDT objection message initiator
166 controller
PCT7JP2014/005350
Claims
A mobile radio communications network within which a mobile radio
communications device is to operate with access to a Small Data
Transmission feature and comprising a first network device arranged to
receive Small Data Transmission signalling initiated by the mobile
radio communications device, a second network device arranged to
receive signalling from the said first network device as part of an estab
lishment procedure for attempted Small Data Transmission commu
nications for the mobile radio communications device within the
network, the first network device being further arranged to determine if
Small Data Transmission should be prevented for the mobile radio
communications device and to initiate a Small Data Transmission
rejection message for use in the control of the mobile radio commu
nications device if Small Data Transmission is to be rejected .
The mobile radio communications network as claimed in Claim 1 and
wherein the said first network device comprises a SGSN/MME.
The mobile radio communications network as claimed in Claim 1 or 2,
wherein the said second network device comprises a server device.
The mobile radio communications network as claimed in Claim 3,
wherein the server comprises a Home Subscriber Server.
The mobile radio communications network as claimed in any one of
Claims 1 to 4, wherein the first network device is arranged to determine
if Small Data Transmission should be prevented responsive to its
signalling exchange with the said second network device.
The mobile radio communications network as claimed in Claim 5 and
arranged such that the said signalling exchange between the first
network device and second network device as part of the said e stab
lishment procedure comprises an interrogation signal sent from the first
network device to the second network device.
The mobile radio communications network as claimed in any one of
Claims 1 to 6 and arranged such that the Small Data Transmission
rejection message is sent directly from the said first network device to
the mobile radio communications device.
The mobile radio communications network as claimed in Claim 1 and
wherein the said first network device comprises an MTC/IWF device.
The mobile radio communications network as claimed in Claim 8 and
wherein the said second network device comprises a server device.
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[Claim 10] The mobile radio communications network as claimed in Claim 9 and
wherein the server comprises a Service Capability Server/ Application
Server.
[Claim 11] The mobile radio communications network as claimed in any one of
Claims 8, 9 and 10, wherein the first network device is arranged to
determine if Small Data Transmission should be prevented responsive
to its signalling exchange with the said second network device.
[Claim 12] The mobile radio communications network as claimed in Claim 11 and
arranged such that the signalling exchange between the first and second
network devices comprises authorizing/authentication signalling
between the MTC-IWF and the SCS/AS.
[Claim 13] The mobile radio communications network as claimed in Claim 11 or
12 and wherein, the said second network device comprises a Home
Subscriber Server.
[Claim 14] The mobile radio communications network as claimed in Claim 13 and
arranged such that the said signalling exchange between the first and
second network devices comprises interrogation signalling directed to
the Home Subscriber Server.
[Claim 15] The mobile radio communications network as claimed in any one of
Claims 8 to 14 and arranged to deliver the Small Data Transmission
rejection message from the MTC-IWF device to the mobile radio com
munications device by way of a further network device.
[Claim 16] The mobile radio communications network as claimed in Claim 15,
wherein the said further network device comprises an SGSN/MME.
[Claim 17] The mobile radio communications network as claimed in any one of
Claims 1 to 16 and arranged such that the Small Data Transmission
rejection message includes an indication of the cause of rejection.
[Claim 18] The mobile radio communications network as claimed in Claim 17 and
arranged such that the cause of rejection indication indicates one of
subscription related cause or a non-subscription related cause.
[Claim 19] The mobile radio communications network as claimed in any one of
Claims 1 to 18 and arranged such that the said Small Data
Transmission rejection message received at the mobile radio commu
nications device includes time-period information serving to control a
length of time for which a mobile radio communications device cannot
access the Small Data Transmission feature.
[Claim 20] The mobile radio communications network as claimed in any one of
Claims 1 to 19, and arranged such that the Small Data Transmission
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rejection message received at the mobile radio communications device
includes a Small Data Transmission identifier to differentiate between
different Small Data Transmission procedures within an application.
The mobile radio communications network as claimed in any one of
Claims 1 to 20, and arranged such that a transfer reject message is
initiated in the mobile radio communications device, responsive to the
said Small Data Transmission rejection message, and for control to an
Application within the mobile radio communications device.
The mobile radio communications network as claimed in Claim 21,
wherein the transfer reject message includes at least one of an in
dication of cause of rejection, time-period information serving to
control a length of time of preventing access of the mobile radio com
munications device to the Small Data Transmission feature, and a
Small Data Transmission identifier.
A method of controlling use of a Small Data Transmission feature
within a mobile radio communications network within which a mobile
radio communications device is to operate with access to a Small Data
Transmission feature, the method including the steps of receiving at a
first network device Small Data Transmission signalling initiated by the
mobile radio communications device, receiving at a second network
device signalling from the said first network device as part of an estab
lishment procedure for attempted Small Data Transmission commu
nications for the mobile radio communications device in the network,
by determining at the first network device if Small Data Transmission
should be prevented for the mobile radio communications device and
initiating a Small Data Transmission rejection message for use in the
control of a mobile radio communications device if Small Data
Transmission is to be rejected .
The method as claimed in Claim 23, wherein the said first network
device employed within the method comprises an SGSN/MME.
The method as claimed in Claim 23 or 24 and wherein the said second
network device employed within the method comprises a server device.
The method as claimed in Claim 25 wherein the server device
comprises a Home Subscriber Server.
The method as claimed in any one of Claims 23 to 26, wherein the first
network device is arranged to determine if Small Data Transmission
should be prevented responsive to its signalling exchange with the said
second network device.
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The method as claimed in Claim 27wherein the said signalling
exchange between the first network device and second network device
as part of the said establishment procedure comprises an interrogation
signal sent from the first network device to the second network device.
The method as claimed in any one of Claims 23 to 28 and including
sending the Small Data Transmission rejection message directly from
the said first network device to the mobile radio communications
device.
The method as claimed in Claim 23 and wherein the said first network
device employed by the method comprises an MTC/IWF device.
The method as claimed in Claim 23 and wherein the said second
network device employed by the method comprises a server device.
The method as claimed in Claim 31 wherein the said server device
comprises a Service Capability Server/Application Server (SCS/AS).
The method as claimed in any one of Claims 30, 31 and 32, wherein the
first network device is arranged to determine if the Small Data
Transmission should be prevented responsive to its signalling exchange
with the said second network device.
The method as claimed in Claim 34 and wherein the said signalling
exchange arising within the network as part of the said establishment
procedure comprises authorizing/authentication signalling between the
MTC-IWF and the SCS/AS.
The method as claimed in Claim 33 or 34 and wherein the said second
network device comprises a Home Subscriber Server.
The method of controlling use of a Small Data Transmission feature
within a mobile radio communications network as claimed in Claim 35
wherein the signalling exchange forming part of the said establishment
procedure comprises interrogation signalling directed to the Home
Subscriber Server.
The method of controlling use of a Small Data Transmission feature
within a mobile radio communications network as claimed in any one
of Claims 30 to 36 and including the step of delivering the Small Data
Transmission rejection message from the MTC-IWF to the mobile
radio communications device by way of a further network device.
The method as claimed in any one of Claims 30 to 37 wherein the
Small Data Transmission rejection message includes an indication of
the cause of rejection.
The method as claimed in Claim 38 and including a cause of rejection
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comprising and indication of at least one of a subscriber-related cause
or a non-subscriber related cause.
The method as claimed in any one of Claims 30 to 39 wherein Small
Data Transmission rejection message received at the mobile radio com
munications device includes time -period information serving to control
a length of time for which a mobile radio communications device
cannot access the Small Data Transmission feature.
The method as claimed in any one of Claims 30 to 40, wherein the
Small Data Transmission rejection message received at the mobile
radio communications device includes a Small Data Transmission
identifier serving to differentiate different Small Data Transmission
procedures within an application.
The method as claimed in any one of Claims 30 to 41, and including
the step of producing a transfer reject message in the mobile radio com
munications device, responsive to the said Small Data Transmission
rejection message, and for control of an Application within the mobile
radio communications device.
The method as claimed in Claim 42, wherein the transfer reject
message includes at least one of an indication of cause of rejection,
time-period information serving to control a length of time of
preventing access of the mobile radio communications device to the
Small Data Transmission feature, and a Small Data Transmission
identifier.
A mobile radio communications network device arranged to receive
Small Data Transmission signalling from a mobile radio commu
nications device and to send signalling to a second mobile radio com
munications network device as part of an establishment procedure for
attempted Small Data Transmission communication for the mobile
radio communications device within a network, the said mobile radio
communications network device further being arranged to determine if
a Small Data Transmission should be prevented for the mobile radio
communications device, and to initiate a Small Data Transmission
rejection message for use in the control of the mobile radio commu
nications device if Small Data Transmission is to be rejected .
The mobile radio communications network device as claimed in Claim
44 and comprising a SGSN/MME.
The mobile radio communications network device as claimed in Claim
44 or 45,and arranged to determine if Small Data Transmission should
PCT7JP2014/005350
be prevented responsive to its signalling exchange with the said second
mobile radio communications network device.
The mobile radio communications network device as claimed in Claim
46 and arranged such that the said signalling includes an interrogation
signal to the second network device as part of the said signalling
exchange.
The mobile radio communications network device as claimed in Claim
46 or 47 and arranged to send the Small Data Transmission rejection
message directly to the mobile radio communications device.
The mobile radio communications network device as claimed in Claim
46 and comprising an MTC/IWF device.
The mobile radio communications network device as claimed in Claim
49 and arranged such that the said signalling exchange between the
mobile radio communication network devices comprises authorizing/
authentication signalling between the MTC-IWF and a SCS/AS.
The mobile radio communications network device as claimed in Claim
49 and arranged such that the said signalling exchange between the
mobile radio communications network devices includes interrogation
signalling directed to a Home Subscriber Server within the network.
The mobile radio communications network device as claimed in any
one of Claims 44 to 51, and arranged such that the Small Data
Transmission message includes at least one of an indication of cause of
rejection, time-period information serving to control a length of time of
preventing access of the mobile radio communications device to the
Small Data Transmission feature, and a Small Data Transmission
identifier.
A method of operating a mobile radio communications network device
to receive a Small Data Transmission from a mobile radio commu
nications device operating within a network and with access to a Small
Data Transmission service, the method including the step of receiving
Small Data Transmission signalling initiated by the mobile radio com
munications device, sending, as part of a signalling exchange,
signalling to a second mobile radio communications network device as
part of the establishment procedure for attempted Small Data
Transmission communication for the mobile radio communications
device, determining if the Small Data Transmission should be
prevented for the mobile radio communications device and initiating a
Small Data Transmission rejection message for use in the control of the
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mobile radio communication device if Small Data Transmission is to be
rejected .
The method of operating a mobile radio communications device as
claimed in Claim 53, wherein the said determination if Small Data
Transmission should be prevented occurs responsive to the said
signalling exchange.
The method of operating a mobile radio communications device as
claimed in Claim 54 wherein the said signalling exchange within the
method between the network devices comprises an interrogation signal
sent from the said mobile radio communications network device to the
said second mobile radio communications network device.
The method of operating a mobile radio communications device as
claimed in Claim 54 and wherein the said signalling exchange can
comprise interrogation signalling directed to an HSS.
The method of operating a mobile radio communications device as
claimed in any one of Claims 53 to 56 and wherein the said Small Data
Transmission rejection message is sent directly from the said first
network device to the mobile radio communications device.
The method of operating a mobile radio communications device as
claimed in Claim 54 wherein the said signalling exchange arising in
relation to the method within the network comprises an authorizing/
authentication signalling exchange.
The method of operating a mobile radio communications network
device as claimed in any one of Claims 53 to 58, wherein the Small
Data Transmission message includes at least one of an indication of
cause of rejection, time-period information serving to control a length
of time of preventing access of the mobile radio communications
device to the Small Data Transmission feature, and a Small Data
Transmission identifier.
A mobile radio communications device arranged to receive a Small
Data Transmission rejection message from the mobile radio commu
nications network device of any one of Claims 44 to 52.
A mobile radio communications network substantially as hereinafter
described with reference to any one or more of Figs. 3 to 7 of the ac
companying drawings.
A method of controlling use of a Small Data Transmission feature
within a mobile radio communications network substantially as
hereinafter described with reference to any one or more of Figs. 3 to 7
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of the accompanying drawings.
[Claim 63] A mobile radio communications network device substantially as
hereinafter described with reference to any one or more of Figs. 3 to 7
of the accompanying drawings.
[Claim 64] A method of operating a mobile radio communications device sub
stantially as hereinafter described with reference to any one or more of
Figs. 3 to 7 of the accompanying drawings.