CA 02691502 2016-10-07
Attorney Docket No. P28235CA1
CONTROLLING A PACKET FLOW FROM A USER EQUIPMENT
BACKGROUND
The present invention relates to radio telecommunication systems. More
particularly, and not by way of limitation, the present invention is directed
to a method,
device, and node for controlling a packet flow from a User Equipment (UE) in a
radio
telecommunication system.
Today, several actors are involved in managing the software and hardware of
a UE, such as a mobile telephone or other communication device in a wireless
communication system. The software can be applications, services, and modules,
including the operating system stored in and used by the UE. The UE's
manufacturer
typically installs a collection of software in the UE at the time the device
is
manufactured. Later, an end user may modify the UE's software by downloading
to the
UE, applications and the like from different sources via, for example, the
Internet. The
UE's manufacturer, the operator of the communication system to which the UE is
subscribed or in which the UE is visiting, and/or an authorized third party,
depending on
business agreements, may also remotely modify part or all of the UE's
software.
After such modifications and in other instances, the UE may behave
improperly. From a system operator's point of view, for example, improper
behavior
may include the UE's diminishing the capacity of the communication system by
increasing the number of control or other messages exchanged with the system.
Improper UE behavior can arise in a number of ways, such as unexpected
interactions
between software modules in the UE, malicious software modules, and the like.
A user
might download a malicious or malformed application such as a Java
application, which
interacts with the network-protocol stack through open Application Programming
Interfaces (APIs) in the UE. As a result, the UE may repeatedly send service
requests
to an operator's network.
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Techniques for dealing with improper UE behavior by disabling services to a
UE have been discussed in standardization organizations such as the Third
Generation
Partnership Project (3GPP). The 3GPP promulgates specifications for the GSM
telecommunications system and its enhancements such as Enhanced Data Rates for
GSM Evolution (EDGE), the universal mobile telecommunications system (UMTS),
the
Long Term Evolution (LTE) access network, and systems employing wideband code-
division multiple access (WCDMA).
The Third Generation Partnership Project Technical Specification, 3GPP TS
24.305, describes procedures for managing settings of the UE for remotely
disabling
selected UE capabilities, used over a 3GPP access, i.e., a circuit-switched
(CS) and
packet-switched (PS) domain over GERAN/UTRAN radio access.
The Open Mobile Alliance (OMA) has developed specifications for Device
Management (DM) of communication devices, and versions 1.1.2 and 1.2 of those
specifications define a protocol for managing configuration, data, and
settings in
communication devices. OMA standards and other information are available at
http://www.openmobilealliance.org. OMA DM can be used to manage the
configuration
and Management Objects (MOs) of UEs from the point of view of different DM
Authorities, including setting initial configuration information in UEs,
subsequently
updating persistent information in UEs, retrieving management information from
UEs,
and processing events and alarms generated by UEs. An MO is generally a
software
object that may be written, for example, according to SyncML, which is a mark-
up
language specification of an XML-based representation protocol,
synchronization
protocol, and DM protocol, transport bindings for the protocols, and a device
description
framework for DM. Using OMA DM, third parties can configure UEs on behalf of
end
users. A third party, such as a network operator, service provider, and
corporate
information management department can remotely set UE parameters and install
or
upgrade software through suitable MOs in the UE.
The Evolved Packet System (EPS) has been defined since 3GPP release-8
as a system for mobile communication using packet data over an evolved GPRS
network. The core network is an evolved UMTS packet core network and the radio
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access network may be an evolved UTRAN (E-UTRAN), a non-3GPP access network
(for example WLAN), or a combination of both. The 3GPP Technical
Specifications,
3GPP TS 23.401 and 3GPP TS 24.301, describe the GPRS enhancements for E-
UTRAN access.
To stay registered in the EPS, an EPS bearer must be retained, as otherwise
the EPS mobility procedures will be rejected by the EPS network, as described
in 3GPP
TS 23.401. Also, as described in 3GPP TS 24.305, the OMA DM server controlling
the
Selective Disabling of a 3GPP UE Capabilities Management Object (SDoUE MO)
needs
to be able to push down updates of the MO to the UE. The push of MO updates
using
SMS cannot always be assumed to be available unless both the UE and the
network
support SMS using CS Fallback capabilities described in 3GPP TS 23.272, and
even
then a PS access is required to be open. Thus, the MO update may need to be
sent
over the PS access. Therefore, the PS access open in the UE needs to be
accessible
by the OMA DM server. Consequently, an EPS bearer towards a Packet Data
Network
(PDN) needs to be retained until the software in the UE has been updated. This
may
imply a risk of flooding the network with malicious traffic if the UE has been
hacked.
BRIEF SUMMARY OF THE INVENTION
The present invention solves or at least mitigates the risk of flooding the
radio
access network and core network with malicious UE-initiated traffic. The
invention
enables the UE to retain a PDN connection with an EPS bearer open that enables
the
OMA DM server to communicate with the UE and ensure the EPS mobility procedure
works. In one embodiment, the invention provides the operator with the ability
to
provision an Access Point Name (APN) and a Traffic Flow Template (TFT) to be
used
until the operator has enabled UE-initiated EPS services again.
Thus, in one embodiment, the present invention is directed to a method in a
UE for limiting packet flow from the UE to a communication network. The method
includes the steps of receiving from the network, an instruction to activate a
logic
parameter for controlling the packet flow from the UE to the network;
requesting
configuration of a network connection for transmitting packets to the network
according
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to the logic parameter; and requesting deactivation of all other network
connections.
The logic parameter may be in a management object, and may be pre-stored in
the UE,
or may accompany the instruction.
In another embodiment, the present invention is directed to a UE that includes
means for receiving from a communication network, an instruction to activate a
logic
parameter for controlling a packet flow from the UE to the network; means for
requesting configuration of a network connection for transmitting packets to
the network
according to the logic parameter; and means for requesting deactivation of all
other
network connections.
In another embodiment, the present invention is directed to a device
management server in a communication network for remotely controlling a packet
flow
from a mobile communication device. The server includes means for storing a
management object that includes at least one of: a flag, a defined Access
Point Name
(APN), and a logic parameter for controlling the packet flow from the mobile
communication device to the network; and means for downloading the management
object to the mobile communication device. The flag, when downloaded to the
mobile
communication device, causes the device to activate the logic parameter in the
management object or to activate a stored logic parameter in the device. The
defined
APN, when downloaded to the mobile communication device, causes the device to
send
a request to establish a new connection to the network on which packet flow
from the
device is controlled according to the logic parameter.
In another embodiment, the present invention is directed to a Packet Data
Network (PDN) Gateway. The PDN Gateway includes means for receiving from a UE,
a
PDN connectivity request to establish a new PDN connection; and means for
limiting a
packet flow from the UE on the new PDN connection according to defined
parameters.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
In the following section, the invention will be described with reference to
exemplary embodiments illustrated in the figures, in which:
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FIG. 1 is a tree diagram of an enhanced Selective Disabling of 3GPP UE
Capabilities Management Object (SDoUE MO+) in an exemplary embodiment of the
present invention, with nodes added by the present invention indicated in
boldface type;
FIG. 2 is a flow chart illustrating the steps of an exemplary embodiment of
the
method of the present invention; and
FIG. 3 is a simplified block diagram of a User Equipment (UE) and associated
nodes in a network in an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
For economy of explanation, this application focuses on wireless
communication systems that comply with specifications promulgated by the 3GPP,
but it
should be understood that the principles described in this application can be
implemented in other communication systems. It will also be understood that
this
description is written in terms of OMA DM, but this description should not be
interpreted
as being limited to OMA DM. Independent of the mechanism used to disable or
enable
services in a UE, it is advantageous for the UE to be selectively controllable
in a
standardized way.
The present invention updates 3GPP TS 24.305 procedures to handle the
difference between EPS (3GPP TS 24.301) and GPRS (3GPP TS 24.008). The
disabling of EPS is different than for GPRS. In EPS, the UE can request
procedures for
EPS contexts, but only the network can initiate them (this, in normal cases,
includes the
case of deactivation). Therefore, in exemplary embodiments of the present
invention,
the operator is provided with the ability to disable mobile-requested EPS
Session
Management (SM) procedures. In one embodiment, a logic parameter is downloaded
to the UE, causing the UE to request a new PDN connection towards the network
with
either a defined APN or no APN if the defined APN is not available for the UE.
The UE
requests deactivation of all previously existing PDN connections, and utilizes
a
particular traffic flow mapping for an EPS context that provides the network
operator
with control of packet access from UE applications.
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In another embodiment, the logic parameter causes the UE to send the
defined APN in the request for a new PDN connection. The defined APN causes
the
network to establish the new PDN connection with a particular PDN GW,
configured to
control the traffic flow from the UE in accordance with the particular traffic
flow mapping.
Optionally, the PDN GW may push traffic flow mapping parameters to the UE.
It should be noted that in different configurations of the 30PP network
architecture, the gateway may utilize either the GPRS Tunneling Protocol (GTP)
or the
Proxy Mobile IF (PM IF) protocol as a network mobility protocol. When GTP is
utilized, it
is the PDN GW that may push traffic flow mapping parameters to the UE. When
PMIP
is utilized, the Serving GW may provide this part of the PDN GW functionality.
Thus,
when the PDN GW is referred to herein, the term is intended to include the
functionality
of pushing traffic flow mapping parameters to the UE, whether the push is made
by the
PDN GW or by the Serving GW.
In another embodiment, the logic parameter causes the UE to utilize an
existing PDN connection towards the network rather than establishing a new
connection. Again, the UE requests deactivation of other PDN connections, if
any, and
utilizes a particular traffic flow mapping for an EPS context that provides
the network
operator with control of packet access from UE applications.
In another embodiment, the OMA DM server may know that the UE includes
an internal application to ensure that only the application(s) controlling the
connection
towards the OMA DM server, and potentially emergency calls, are allowed access
to
use the PS connection. In such case, the OMA DM server does not have to
download
any APN or logic parameter to the UE. Instead, the OMA DM server may send only
a
flag instructing the UE to activate the internal application.
Once the network operator has control of packet access from UE
applications, the operator can prevent a misbehaving UE from flooding the
network with
malicious or erroneous traffic. As part of the correction process, a device
management
server such as an OMA DM server can push corrective software to the UE to
correct or
replace a corrupted application causing the misbehavior. In addition, the
logic
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parameter may also limit the packet flow to a maximum data rate or a maximum
packet
size.
FIG. 1 is a tree diagram of an enhanced Selective Disabling of 3GPP UE
Capabilities Management Object (SDoUE MO+) in an exemplary embodiment of the
present invention, with nodes added by the present invention indicated in
boldface type.
Those skilled in the art will understand that the modified SDoUE MO+ is a
software
module that includes parameters that can be used to manage settings of the UE
for
remotely disabling and enabling selected capabilities of the UE. The
identifier for an
existing SDoUE MO is "urn:oma:mo:ext-3gpp-sdoue:1.0". The OMA DM Access
Control List (ACL) property mechanism as standardized (see Enabler Release
Definition
OMA-ERELD-DM-V1 2 [8]) may be used to grant or deny access rights to OMA DM
servers in order to modify nodes and leaf objects of the SDoUE MO.
In an exemplary embodiment of the present invention, the existing SDoUE
MO is enhanced to support the case of EPS with the addition of the following
new
nodes: EPS _ SM _EPS, APN, TrafficMappingInfo, Number0fPacketFilters, and
PacketFilterList. When downloaded to the UE, the enhanced SDoUE MO+ adds at
least the following capabilities to a device management server such as an OMA
DM
server:
1. The capability to separately disable UE-initiated EPS procedures such
as UE-requested PDN connectivity, UE-requested bearer resource modification,
and
UE-requested PDN disconnect, as well as to provide restriction to EPS
services.
2. The capability to provision a special APN to which the UE can set up a
=
PDN connection. This enables the PDN Gateway (PDN GW) to restrict the UE
traffic to
only traffic necessary for communication with the OMA DM server and
potentially IP
Multimedia Subsystem (IMS) emergency calls.
3. The capability to locally install the essential Uplink Traffic Flow
Template
(UL TFT) parameters in the UE to restrict the UE's ability to send IP packets
other than
those allowed by the operator, for example those required towards the OMA DM
server.
If an APN is provided in the SDoUE MO+, the PDN connection may be
established with a PDN GW that is pre-configured with TFT-type information
that can be
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set on the EPS bearer. However, if no APN is provided, the operator may
establish the
PDN connection to another PND GW utilizing a default APN.
With continuing reference to FIG. 1, the following paragraphs describe
additions required to the indicated sections of 3GPP TS 24.305 in order to
describe the
new nodes and leaf objects of the enhanced SDoUE MO+ management object:
/<X>/EPS_SM_EPS
The EPS Session Management (SM) procedures for EPS contexts
(EPS SM EPS) interior node 11 is a flag indicating an operator's preference to
enable
_ _
or disable mobile-requested EPS SM procedures for EPS contexts, i.e., UE-
requested
PDN connectivity, UE-requested bearer resource modification, and UE-requested
PDN
disconnect, as well as to provide restriction to EPS services.
The EPS SM procedures for EPS contexts are specified in 3GPP TS 24.301
[5A].
- Occurrence: ZeroOrOne
- Format: bool
- Access Types: Get
- Values: 0, 1
0 ¨ Indicates that mobile-requested EPS SM procedures for EPS contexts
are enabled and no restriction to EPS services applies.
1 ¨ Indicates that mobile-requested EPS SM procedures for EPS contexts
are disabled and restriction to EPS services applies.
/<X>/APN
The APN leaf object 12 provides the information of an access point name.
- Occurrence: ZeroOrOne
- Format: chr
- Access Types: Get
- Values: <Access point name>
The format of the APN is defined by 3GPP TS 23.003 [2A] in clause 9.
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EXAMPLE: mycompany.mnc012.mcc340.gprs
/<X>/TrafficMappingInfo
The TrafficMappingInfo interior node 13 is used to enable configuring the
minimum acceptable traffic flow template (TFT) parameters (packet filters) for
EPS
context according to the operator's preference.
- Occurrence: ZeroOrOne
- Format: node
- Access Types: Get
- Values: N/A
The information provided by the TrafficMappingInfo interior node is used by
the UE only when the EPS_SM_EPS leaf value is set to "1".
/<X>/Number0fPacketFilters
The Number0fPacketFilters leaf object 14 indicates the number of traffic
filters contained in the PacketFilterList leaf 15.
- Occurrence: One
- Format: int
- Access Types: Get
- Values: <Number of packet filters>
The Number0fPacketFilters is an unsigned 8-bit integer, and the value range
is defined as the number of packet filters parameter in the traffic flow
template
information element (see subclause 10.5.6.12 in 3GPP TS 24.008 [3]).
EXAMPLE: 3 (packet filters)
/<X>/PacketFilterList
The PacketFilterList leaf object 15 provides the information of a variable
number of traffic filters.
- Occurrence: One
- Format: int
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- Access Types: Get
- Values: <Packet filter list information>
The PacketFilterList is an unsigned 64-bit integer. The bit pattern shall be
encoded as the packet filter list parameter in the traffic flow template
information
element (see subclause 10.5.6.12 in 3GPP TS 24.008 [3]) with the least
significant bit in
the rightmost position of the integer. For example, if the parameter is
encoded into bits
6, 7, and 8 in 3GPP TS 24.008 [3], then it must be encoded into bits 1, 2, and
3 in this
leaf.
FIG. 2 is a flow chart illustrating the steps of an exemplary embodiment of
the
method of the present invention. When the value of the EPS_SM_EPS leaf 11 is
set to
"1", the method proceeds as follows:
At step 21, the OMA DM server sends the modified SDoUE MO+ to the UE.
At step 22, the UE initiates a new UE-requested PDN connectivity procedure
toward the
network as described in 3GPP TS 24.301 [6A]. At step 23, it is determined
whether the
APN leaf 12 exists in the modified SDoUE MO+. If the APN leaf 12 does not
exist, the
method moves to step 24 where the UE sends a PDN CONNECTIVITY REQUEST
message without including any APN in the message, and the network utilizes a
default
APN for establishing an EPS context with a PDN GW at step 25. However, if the
APN
leaf exists, the method moves instead to step 26 where the UE sends the PDN
CONNECTIVITY REQUEST message and includes the value defined in the APN leaf as
the APN in the message. At step 27, the network utilizes the defined APN for
establishing an EPS context with a PDN GW associated with the defined APN.
After successful completion of the UE-requested PDN connectivity procedure
at step 27, it is determined at step 28 whether the TrafficMappingInfo
interior node 13
exists in the modified SDoUE MO+. The TrafficMappingInfo interior node, as
shown in
FIG. 1, provides at least one logic parameter for controlling the packet flow
from the UE.
If the TrafficMappingInfo node does not exist, the method moves to step 29
where the
UE transmits packets on the new PDN connection without filtering the packets.
At step
31, the PDN GW associated with the defined APN may optionally be configured to
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control the traffic flow from the UE or to download to the UE, a logic
parameter for
controlling the traffic flow from the UE. At step 32, the UE utilizes the
logic parameter
(i.e., traffic mapping information filters) to limit packet transmissions on
the EPS context
established by the UE-requested PDN connectivity procedure. Returning to step
28, if it
is determined that the TrafficMappingInfo interior node does exist in the
SDoUE MO+,
the method moves directly to step 32.
Furthermore, the UE continues to limit packet transmissions on the EPS
context in accordance with the logic parameter until the EPS_SM_EPS leaf value
is
reset to "0". The UE is however allowed to temporarily stop using the traffic
mapping
information in the following cases:
- upon receipt of an OMA DM notification message indicating that the UE
shall initiate an OMA DM session to the OMA DM server that either had set the
disable
value of the EPS SM EPS leaf or is the one stored in the AlertServerlD leaf;
and
_ _
- when
the UE wishes to either establish an emergency call over IMS (if the
IMSEmergencyCalls value is set to "0") or send an OMA DM generic alert message
according to sub-clause 5.17A of 3GPP TS 24.305.
At step 33, the UE initiates the signaling procedure for UE-requested PDN
disconnection as described in 3GPP TS 24.301 [6A] of all previously existing
PDN
connections, thus leaving only the new one, which was established by the
successful
completion of the UE-requested PDN connectivity procedure. At step 34, the EPS
context provides the network operator with control of packet access from UE
applications. As noted above, in EPS, the UE can request procedures for EPS
contexts, but only the network can initiate them (for normal cases, this
includes the case
of deactivation). Therefore, in this exemplary embodiment of the present
invention, the
operator is provided with the ability to disable mobile-requested EPS Session
Management (SM) procedures.
It should be noted that the invention is not restricted to a specific order of
the
PDN connectivity request procedure and the deactivation of existing bearers;
the only
restriction is that the UE always need to keep at least one PDN connection to
avoid
getting detached from the EPS. A different order may be required in case the
UE
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and/or EPS is currently using the maximum number of EPS bearers supported by
the
UE and/or the EPS (e.g., Mobility Management Entity (MME), Serving GW, or PDN
GW). For example, the UE may receive a rejection of an initial PDN
connectivity
request, and in response, first deactivate one of the available PDN
connections to free
up resources before initiating the PDN connectivity procedure for the PDN
connection to
be used towards the OMA DM server.
FIG. 3 is a simplified block diagram of a UE 41 and associated nodes in a
network 42 in an exemplary embodiment of the present invention. For
simplicity, only
those components in the UE and those nodes in the network that are associated
with
the present invention are shown. The network includes a device management
server
such as an OMA DM Server 43, the operation of which may be controlled by a
processor 44. A memory 45 may store management objects such as the SDoUE MO+
of the present invention. An MO downloading unit 46 downloads the SDoUE MO+ 47
to
the UE 41.
Receipt of the SDoUE MO+ in the UE causes a PDN connectivity request unit
48 to initiate a new PDN connectivity procedure by sending a PDN CONNECTIVITY
REQUEST message 49 to the network 42. The network establishes a new EPS
Context 51 between the UE and a PDN GW. Upon establishment of the new EPS
Context, a previous PDN connections deactivation unit 53 sends a PDN
disconnection
request 54 to the network to disconnect any previously established PDN
connections.
This leaves only the new EPS Context in place between the UE and the network,
and
packet transmissions from the UE over this context are controlled by the logic
parameter (packet filters) in the SDoUE MO+. Thus, the network has control of
packet
access through a packet filtering unit 55 as controlled by a processor 56 and
applications 57.
In this manner, the present invention solves or at least mitigates the risk of
flooding the radio access network and core network with malicious UE-initiated
traffic.
The invention enables the UE to retain a PDN connection with an EPS bearer
open until
the software in the UE has been updated.
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As will be recognized by those skilled in the art, the innovative concepts
described in the present application can be modified and varied over a wide
range of
applications. Accordingly, the scope of patented subject matter should not be
limited to
any of the specific exemplary teachings discussed above, but is instead
defined by the
following claims.
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