CN112205015B

CN112205015B - Method, apparatus and computer readable medium for policy distribution

Info

Publication number: CN112205015B
Application number: CN201880093945.9A
Authority: CN
Inventors: 沈洋; A·卡萨蒂
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2018-05-29
Filing date: 2018-05-29
Publication date: 2023-09-05
Anticipated expiration: 2038-05-29
Also published as: WO2019227313A1; CN112205015A

Abstract

Embodiments of the present disclosure relate to methods, apparatuses and computer program products for policy distribution in a communication system. A method implemented at a network device comprising: receiving at least one of a request for policy synchronization and a device identifier from a terminal device; determining whether policy rules are to be distributed to the terminal device based on the received at least one of the request for policy synchronization and the device identifier; and controlling policy distribution to the terminal device based on the determination.

Description

Method, apparatus and computer readable medium for policy distribution

Technical Field

The non-limiting and example embodiments of the present disclosure relate generally to the field of communications technology and, more particularly, relate to a method, apparatus, and computer program product for policy distribution in a communication system.

Background

This section introduces various aspects that may facilitate a better understanding of the disclosure. The statements in this section are thus to be read in this light, and not as admissions about what is in the prior art or what is not.

With the development of communication technology, more and more services/applications and more methods for accessing a network are provided to users. In order to improve resource utilization efficiency, meet quality requirements of various services and/or allow flexible operator configuration of UEs, the concept of User Equipment (UE) policies has been proposed.

For example, with the introduction of fifth generation (5G) communication technologies, UE policies including UE access selection and policies related to Protocol Data Unit (PDU) sessions, such as TS 23.503 vf10 developed by the third generation partnership project (3 GPP), have been defined in technical specifications. According to the specifications of 3GPP, the 5G core network (5 GC) should be able to provide policy information to the UE through a Policy Control Function (PCF). The UE may use the UE policy rules provided by the PCF and locally pre-configured rules thereof.

Disclosure of Invention

Various embodiments of the present disclosure are generally directed to methods, apparatuses, and computer program products for UE policy distribution in a communication system.

In a first aspect of the present disclosure, a method implemented at a network device for policy distribution in a communication system is provided. The method comprises the following steps: receiving at least one of a request for policy synchronization and a device identifier from a terminal device; determining whether policy rules are to be distributed to the terminal device based on the received at least one of the request for policy synchronization and the device identifier; and controlling policy distribution to the terminal device based on the determination.

In some embodiments, the determining may include: in response to receiving the device identifier, obtaining, from the further network device: information about policy rules for subscribers associated with the terminal device, and a stored device identifier for the terminal device; and in response to the received device identifier being different from the stored device identifier, determining to transmit all available policy rules for the subscriber to the terminal device. In some embodiments, the determining may further comprise: determining a delivery status for the policy rule from the information about the policy rule in response to the received device identifier being the same as the stored device identifier; and determining whether the updated policy rule is to be distributed to the terminal device based on the delivery status of the policy rule. In some embodiments, the device identifier comprises a permanent device identifier (PEI) of the terminal device.

In yet another embodiment, determining whether the updated policy rules are to be distributed to the terminal device may comprise: determining the policy rules as updated policy rules to be distributed to the terminal device in response to a delivery status indicating that the latest version of the policy rules has not been delivered to the terminal device; or in response to the delivery status indicating that the latest version of all policy rules has been delivered to the terminal device, determining that no policy rules are to be distributed to the terminal device.

In some embodiments, the information about the policy rules may also include a rule identifier or a policy segment identifier.

In yet another embodiment, the determining may include: in response to receiving the request for policy synchronization, it is determined to transmit to the terminal device all available policy rules associated with the subscriber.

In some embodiments, controlling policy distribution of a terminal device may include: in response to determining that at least one policy rule is to be distributed to the terminal device, transmitting the at least one policy rule to the terminal device. In some embodiments, the transmitting of the at least one policy rule to the terminal device may comprise: responsive to the determined size of the at least one policy rule exceeding a predetermined threshold, segmenting the determined at least one policy rule into a plurality of pieces of information having a size equal to or less than the predetermined threshold, and transmitting the plurality of pieces of information to the terminal device; alternatively, the determined at least one policy rule is transmitted to the terminal device without segmentation in response to the determined at least one policy rule having a size equal to or less than a predetermined threshold.

In some embodiments, the method may further comprise: maintaining policy rules, device identifiers, and delivery status of policy rules for subscribers associated with the terminal device; and transmitting the PEI, the policy rules, and the delivery status for the policy rules to the further network device in response to the policy association for the terminal device being terminated. In some embodiments, maintaining the delivery state of policy rules may include: in response to receiving a notification from the further network device about updating the policy rules, a delivery status is set for the policy rules to indicate that the latest version of the policy rules has not been delivered to the terminal device. In some embodiments, maintaining the delivery state of policy rules for the terminal device may include: in response to receiving a message from the terminal device regarding successful delivery of the policy rule, a delivery status is set for the policy rule to indicate that the latest version of the policy rule has been delivered to the terminal device.

In a second aspect of the present disclosure, a method in a terminal device for policy distribution is provided. The method comprises the following steps: transmitting, by the terminal device, at least one of a request for policy synchronization and a device identifier to the network device for determining policy distribution; and receiving policy rules from the network device for subscribers associated with the terminal device.

In a third aspect of the present disclosure, a network device is provided. The network device includes: at least one processor; at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device at least to: receiving at least one of a request for policy synchronization and a device identifier from a terminal device; determining whether policy rules are to be distributed to the terminal device based on the received at least one of the policy synchronization request and the device identifier; and controlling policy distribution to the terminal device based on the determination.

In a fourth aspect of the present disclosure, a terminal device is provided. The terminal device comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the terminal device at least to: transmitting at least one of a request for policy synchronization and a device identifier to a network device for determining policy distribution; and receiving at least one policy rule from the network device for a subscriber associated with the terminal device.

In a fifth aspect of the present disclosure, a computer program is provided. The computer program comprises instructions which, when executed by an apparatus, cause the apparatus to perform a method according to the first aspect of the present disclosure.

In a sixth aspect of the present disclosure, a computer program is provided. The computer program comprises instructions which, when executed by an apparatus, cause the apparatus to perform a method according to the second aspect of the present disclosure.

In a seventh aspect of the present disclosure, there is provided a computer readable medium having stored thereon a computer program which, when executed by an apparatus, causes the apparatus to perform the method of the first aspect of the present disclosure.

In an eighth aspect of the present disclosure, there is provided a computer readable medium having stored thereon a computer program which, when executed by an apparatus, causes the apparatus to perform the method of the second aspect of the present disclosure.

In a ninth aspect of the present disclosure, a terminal device is provided. The terminal device includes: means for transmitting at least one of a request for policy synchronization and a device identifier to a network device for determining policy distribution; and means for receiving at least one policy rule associated with the terminal device from the network device.

In a tenth aspect of the present disclosure, a network device is provided. The network device includes: means for receiving at least one of a request for policy synchronization and a device identifier from a terminal device; means for determining at least one policy rule to be distributed to the terminal device based on the received at least one of the request and the device identifier; and means for transmitting the determined at least one policy rule to the terminal device.

Drawings

The above and other aspects, features and advantages of various embodiments of the present disclosure will become more fully apparent from the following detailed description with reference to the accompanying drawings in which like reference numerals are used to designate the same or equivalent elements. The accompanying drawings, which are not necessarily drawn to scale, serve to facilitate a better understanding of embodiments of the disclosure, and wherein:

FIG. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented;

FIG. 2 illustrates an example process for policy distribution according to an embodiment of this disclosure;

FIG. 3 illustrates a flow chart of a method for policy distribution at a network device according to an embodiment of the disclosure;

fig. 4-5 illustrate different example implementations for determining whether policies are distributed to terminal devices according to embodiments of the present disclosure and conventional methods;

Fig. 6 shows a flow chart of a method in a terminal device according to an embodiment of the present disclosure; and

fig. 7 illustrates a simplified block diagram of an apparatus that may be implemented as/in a network device or terminal device.

Detailed Description

Hereinafter, the principles and spirit of the present disclosure will be described with reference to illustrative embodiments. It should be understood that all of these embodiments are given solely for the purpose of those skilled in the art to better understand and further practice the present disclosure and are not intended to limit the scope of the present disclosure. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a further embodiment. In the interest of clarity, not all features of an actual implementation are described in this specification.

References in the specification to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms "first" and "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term "and/or" includes any and all combinations of one or more of the listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "includes," "including," "containing," "includes" and/or "including" when used herein, specify the presence of stated features, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

As used in this disclosure, the term "circuitry" may refer to one or more or all of the following:

(a) Hardware-only circuit implementations (such as implementations in analog and/or digital circuitry only); and

(b) A combination of hardware circuitry and software, such as (if applicable):

(i) Combination of analog and/or digital hardware circuit(s) and software/firmware, and

(ii) Any portion of a hardware processor(s) having software (including digital signal processor(s), software, and memory(s), which cooperate to cause a device such as a mobile phone or server to perform various functions) and

(c) Hardware circuit(s) and/or processor(s) such as microprocessor(s) or a portion of microprocessor(s) that require software (e.g., firmware) to operate, but may not be present when operation is not required.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As yet another example, as used in this disclosure, the term circuitry would also cover an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. For example and if applicable to the particular claim elements, the term circuitry would also cover a baseband integrated circuit or processor integrated circuit for a server, a cellular network device, or a mobile device or similar integrated circuit in other computing or network devices.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as 5G, new Radio (NR), long Term Evolution (LTE), LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), high Speed Packet Access (HSPA), etc. The "communication network" may also be referred to as a "communication system". Furthermore, communication between network devices, between a network device and a terminal device or between terminal devices in a communication network may be performed according to any suitable communication protocol, including but not limited to global system for mobile communications (GSM), universal Mobile Telecommunications System (UMTS), long Term Evolution (LTE), new Radio (NR), 5G, wireless Local Area Network (WLAN) standards such as the IEEE 802.11 standard, and/or any other suitable communication standard currently known or developed in the future.

As used herein, the term "network device" refers to a node in a communication network via which a terminal device receives services and/or service related information. For example, the network device may comprise a network node in a Core Network (CN), such as a PCF, an access and mobility management function (AMF), or a gateway.

The term "terminal device" refers to any end device that may be capable of communicating. By way of example, and not limitation, a terminal device may also be referred to as a communication device, a UE, a Subscriber Station (SS), a portable subscriber station, a Mobile Station (MS), or an Access Terminal (AT). The terminal devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablet computers, wearable terminal devices, personal Digital Assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop computer embedded devices (LEEs), laptop computer mounted devices (LMEs), USB dongles, smart devices, wireless Customer Premise Equipment (CPE), and the like. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

As yet another example, in an internet of things (IOT) scenario, a terminal device may represent a machine or other device that performs monitoring and/or measurements and transmits the results of such monitoring and/or measurements to another terminal device and/or network device. In this case, the terminal device may be a machine-to-machine (M2M) device, which may be referred to as a Machine Type Communication (MTC) device in the 3GPP context. As one particular example, the terminal device may be a UE implementing the 3GPP narrowband internet of things (NB-IoT) standard. Examples of such machines or devices are sensors, metering devices such as power meters, industrial machines or household or personal devices (e.g. refrigerator, television), personal wearable devices such as watches, etc. In other scenarios, a terminal device may represent a vehicle or other device capable of monitoring and/or reporting its operational status or other functions associated with its operation.

Fig. 1 illustrates an example communication network 100 in which embodiments of the present disclosure may be implemented. As shown, the communication network 100 may include an access network 110 and a Core Network (CN) 120.UE111 may receive services from core network 120 via a Base Station (BS) 112 in access network 110. The core network 120 may include one or more network devices such AS PCT 121, AMF 122, unified Data Repository (UDR) 123, and Application Server (AS) 124. It is noted that the communication network 100 may comprise other access networks, terminal devices and/or core network devices not shown in fig. 1 for simplicity.

UEs in a communication network may be provided with various services that may have different quality of service (QoS) requirements with respect to delay or packet error rate. To improve resource utilization efficiency and/or meet quality requirements of various services, UE policy information may be provided to the UE from a CN (e.g., PCF in the CN). Such UE policy information may include Access Network Discovery and Selection Policies (ANDSP) and UE routing policies (urs) defined in 3gpp TS23.503 and TS 23.402.

The UE uses the ANDSP for selecting non-3 GPP accesses and deciding how to route traffic between the selected 3GPP and non-3 GPP accesses. The UE uses the urs to determine how to route outgoing traffic. For example, based on the urs, the UE may route traffic to an established PDU session, offload traffic to a non-3 GPP access outside the PDU session, or trigger the establishment of a new PDU session for the traffic. According to current 3GPP technical specifications, such as ts23.503vf10, each urs contains multiple urs rules and each urs rule contains multiple RSDs and the RSDs are selected in order of their priorities.

The structure of the ANDSP and URSP rules is described in tables 6.6.1-1, 6.6.2.1-1, 6.6.2.1-2 and 6.6.2.1-3 of 3GPP TS23.503vf10, reproduced below.

Table 6.6.1-1: access network discovery & selection policy

Table 6.6.2.1-1: UE routing strategy

Table 6.6.2.1-2: UE routing policy rules

Table 6.6.2.1-3: routing descriptor

The UE policy may be stored in the UDR as a data subset "policy set entry" of the data set "policy data". The Nudr service may be used to provide UE policies from the UDR to the PCF at the UE up-down Wen Jian. The UE policy is then distributed from the PCF to the UE via the AMF in the container over the N15 interface between the PCF and the AMF and the N1 interface between the AMF and the UE. The UE policy is transparent to the AMF.

Since the N1 interface is a control plane interface between the AMF and the UE, distribution of the UE policy needs to consider packet size limitations and signaling efficiency of the N1 interface. The length of the UE policy to be distributed cannot be greater than the N1 size limit and unnecessary signaling overload should be avoided. For example, if the UE policy rules have been installed in the UE, and if there are no updates, then it should not be sent from pass to pass.

The current solution for UE policy distribution is specified in 23.503vf10, replicated below:

the PCF divides the UE policy by the policy clause identifier (i.e., PSI). For example, the PCF may assign the urs as one whole policy part, or may subdivide the information in the urs into multiple policy parts by assigning one or several urs rules to each policy part.

When providing policy rules to the UE, the PCF provides policy item identifier(s) (PSI) policy section(s).

At initial registration, the UE provides a stored PSI list identifying the part of the policies currently stored in the UE, and if no policies are stored in the UE, the UE does not provide any PSI. The UE may trigger an initial registration of UE policy information to request synchronization of UE policies, e.g., when the UE is first powered up and there is no policy;

the PCF receives the UE policy request containing the stored PSI list and then retrieves the PSI list and its contents stored in the UDR for the SUPI. The PCF compares the two PSI lists and, in addition, the PCF checks whether the PSI list and its contents need to be updated according to the operator policy. If the two PSI lists are different or need to be updated, the PCF provides the updated PSI list and corresponding policy contents

The PCF maintains an up-to-date list of UE policies delivered to the UE until the AM policy association is terminated. The PCF then stores the latest PSI list and its contents in the UDR.

The above-described solution specified in the current 3GPP specifications mixes the temporary use (temporal use) of the PSI for identifying policy terms with a permanent identification for policy rules. Some drawbacks of this solution have been identified and will be illustrated by some examples below.

For illustration, assume that the UE is configured with URSP rules 1-12 and the rules are stored in UDRs in 4 segments identified by PSI 1-4, for example:

PSI 1＝URSP 1+URSP 2+URSP 3

PSI 2＝URSP 4+URSP 5+URSP 6

PSI 3＝URSP 7+URSP 8+URSP 9

PSI 4＝URSP 10+URSP 11+URSP 12。

it is assumed that all the urs rules associated with PSI 1-4 are distributed to the UE during initial registration of the UE. If the PCF later modifies the urs 1 and 4 due to operator policy changes or policy control request triggers received from the AMF and the total length of urs 1 and 4 is within the length limit of the N1 interface, one solution for distributing updated urs rules may be to distribute two updated rules in a single segment. However, it is not clear how to identify new segments. Another solution may be to distribute two updated rules in 2 segments identified by PSI 1 and PSI 2, respectively. However, signaling overhead is unnecessarily increased in this solution.

Likewise, if the PCF modifies the urs 1+URSP 4+URSP 7+URSP 10 and can pass four urs rules within 2 segments, one solution, represented as solution 1, can distribute the rules in 2 segments identified by new PSI, e.g., PSI 5 and PSI 6. Another solution, represented as solution 2, may distribute 4 rules among 4 segments identified by original PSI 1, PSI 2, PSI 3, and PSI 4, respectively. If solution 1 is selected, the PSI-URSP association will no longer be unique because the URSP rules are associated with two PSIs. For example, URSP 1 was previously associated with PSI 1 and then with URSP 5 during the update. This may lead to complexity of UE policy management. If solution 2 is employed, each urs rule delivery requires a separate PSI even if no segmentation is required. This means an increase in signaling overhead. Thus, there are some drawbacks in the current solutions for UE policy distribution.

In addition, the inventors of the present disclosure have observed that the PSI must contain PLMN IDs and other information, so it can be very large. The larger overhead may overload the signaling more, especially for non-3 GPP accesses. Thus, unnecessary segmentation should be avoided as much as possible. Further, the PSI is defined to identify policy terms only when the size of the UE policy is greater than the packet size limit of the N1 interface and segmentation is required, and thus, it may not be necessary to permanently associate the PSI with a fixed policy rule. In contrast, the PSI association with the policy rules may be valid only during the lifecycle of the access and mobility management (AM) policy association, within the transaction of the AM policy association, or within the AM policy association update, and does not have to be carried from one AM policy association to another. That is, the PSI will be used to identify another policy term upon initial registration of the next UE.

Further, the inventors of the present disclosure have observed that the PCF may not have to store the latest PSI list and its contents in the UDR during the termination of the AM policy association, as the PCF may record the status of each UE policy rule without having to segment them and identify them with the PSI.

Additionally, in the current solution specified in 3GPP, while the UDR knows the delivery state and version of the UE policy rules, the UE must provide a list of stored PSI identifying the policy segments currently stored in the UE at initial registration. Inconsistencies between the UE and UDR may only occur when some unexpected events occur, such as USIM exchanges, software or hardware problems.

On the other hand, the UE does not know the version of the policy rules, i.e., even if the UE provides the PSI, it may not be the latest version. For example, if the UDR updates the UE policies that have been distributed to the UE after deleting the AM policy association, there may be a version inconsistency between the UE and the UDR. In this case, if the UDR determines a UE policy to be distributed to the UE based on the PSI, a problem may be caused.

To address at least some of the above-mentioned problems and other potential problems, methods, apparatus, and computer-readable media for policy distribution have been presented in this disclosure.

In some embodiments, it is proposed that the PCF maintain the state of the UE policy rules (e.g., one or more urs rules, one or more ands rules, or a subset thereof) during the lifetime of the UE's AM policy association. For example, and without limitation, the state of the UE policy rules may include a delivery state (which may be denoted as "latest version delivery state") indicating whether the latest version of the UE policy rules was successfully distributed/removed, a device identifier (possibly including a permanent device identifier (PEI)) for identifying the UE device to which the policy rules were successfully installed. The status information of the UE policy rules helps the PCF to identify if there is a SIM card exchange on the UE side, i.e. if the user moves the SIM card from one user device to another. When the AM policy association terminates, the PCF may store the latest state and contents of each UE policy rule into the UDR. When the UDR updates the content of the UE policy rules, it will inform the PCF, which then updates the settings of the delivery state of the policy rules.

Fig. 2 illustrates an example process 200 for policy distribution according to an embodiment of this disclosure. As shown in fig. 2, during initial registration, UE 201 may provide (210) PCF 202 with at least one of a device identifier (e.g., PEI) and a request for policy synchronization (e.g., an indication of "UE policy synchronization required"), possibly along with a subscription permanent identifier (SUPI) of UE 201. SUPI is a globally unique identifier that is assigned to each subscriber in the 5G system and is configured (provisioning) in Universal Data Management (UDM)/UDR and can be used to identify UE context policy control subscriptions. PEI is defined for 3GPP UEs accessing the 5G system and may be used to facilitate the PCF in identifying the occurrence of SIM card exchanges and determining the appropriate distribution strategy for the UE policy rules. The UE may notify the PCF with a request for policy synchronization that the UE wants to retrieve all policy rules currently available to the UE. When a local problem (software or hardware problem) occurs on the UE, the UE 201 may send (210) the request, as a result of which the UE will lose some or all of the latest policy rules originally installed. PCF 202 may also use the request to determine the distribution of the UE policy. The UE policy rules may include, but are not limited to, an ands rule and/or a urs rule.

In some embodiments, the above information may be provided to PCF 202 via AMF 203, as shown in fig. 2. Upon receiving this information, AMF 203 may initiate (220) an AMF policy association creation request to PCF 202. The request includes SUPI and at least one of PEI from UE 201 and a request for policy synchronization.

In some embodiments, upon receiving the AMF policy association creation request, PCF 202 may retrieve (230) UE policy rule information and corresponding status from UDR 204 and may compare the received PEI (if any) to the retrieved stored PEI. If they are different, or if "UE policy synchronization is required" is included in the access and mobility management (AM) policy association creation request, PCF 202 may respond by sending (250) all policy rules currently available to UE 201; otherwise, PCF 202 may distribute (250) only the updated/new policy rules to UE 201. PCF 202 may determine (240) updated/new policy rules for UE 201 based on the status of the UE policy rules. This approach avoids unnecessary transmission of unchanged UE policy rules and thus saves network signaling overhead.

In some embodiments, the UE policy rule information to be distributed to the UE may be distributed directly by the PCF or segmented into terms prior to distribution if its size exceeds a predefined size limit (e.g., the packet size limit of the N1 interface).

When the PCF updates the UE policy rules, it may only distribute the updated information to the UE, and the updated information may or may not be segmented depending on the size of the updated policy rules.

Fig. 3 illustrates a flow chart of a method 300 implemented at a network device for policy distribution. The network device may be, for example, PCF 121 shown in fig. 1 or PCF 202 in fig. 2. For ease of discussion, method 300 will be described below with reference to PCF 121 and communication network 100 illustrated in fig. 1. However, embodiments of the present disclosure are not limited thereto.

In block 310, PCF 121 receives at least one of a request for policy synchronization and a device identifier from a terminal device (e.g., UE 111 in fig. 1). In some embodiments, the device identifier may include PEI for UE 111.

In block 320, PCF 121 determines whether to distribute policy rules to UE 111 based on the received information (i.e., at least one of the policy synchronization request and the device identifier). Some example implementations for the determination operations in block 320 are shown in fig. 4 and 5.

In the example 400 shown in fig. 4, if a device identifier (e.g., PEI) is received from the UE 111 in block 410; in block 420, PCF 121 obtains/retrieves information about policy rules for a subscriber associated with UE 111 (e.g., identified by SUPI) and a stored device identifier (e.g., PEI) for UE 111 from another network device (e.g., UDR 123 in fig. 1). If PCF 121 determines in block 430 that the received device identifier is different from the stored device identifier, it may determine in block 440 to transmit to the UE all available policy rules associated with UE 111.

On the other hand, if PCF 121 determines in block 430 that the received device identifier is the same as the stored device identifier, it may also determine in block 450 the delivery status for the policy rule from the retrieved information about the policy rule. In block 460, PCF 121 determines whether to transmit the updated policy rules to UE 111 based on the delivery status of the policy rules. That is, in some embodiments, the information about the policy rules may include a delivery status of the policy rules, and PCF 121 may utilize the delivery status of the policy rules to determine whether and which policy rules to distribute to UE 111. The delivery status may indicate whether the latest version of the policy rules has been delivered to the terminal device. For example, if the delivery status indicates that the latest version of the policy rule has not been delivered to the terminal device, PCF 121 may determine the policy rule as an updated policy rule to be distributed to the terminal device in block 460. On the other hand, if the delivery status indicates that the latest version of all policy rules have been delivered to the terminal device, PCF 121 may determine in block 460 that no policy rules are to be distributed to the terminal device.

In some embodiments, the information about policy rules retrieved from UDR 123 may also include a rule identifier. In this case, the data model of the UE policy in UDR 123 may be defined in the format shown in table 1.

Table 1 example 1 of data model of UE policy in udr

Alternatively, in another embodiment, the information about the policy rules may also include a policy segment identifier. In this case, the data model of the UE policy in UDR 123 may be defined in the format shown in table 2.

Table 2 example 2 of the data model for UE policy in UDR

In addition, a device identifier (e.g., PEI) may be stored in UDR 123 as an Information Element (IE) of UE context policy control subscription information, which may have a data model as shown in table 3.

Table 3 data model of UE context policy control subscription information in UDR

Fig. 5 illustrates another example 500 for determining whether policy rules are to be distributed to UEs 111. As shown in fig. 5, if PCF 121 receives a policy synchronization request from UE 111 in block 510, it may determine in block 520 to transmit to the terminal device all available policy rules for the subscriber associated with the terminal device.

Reference is now made back to fig. 3. In block 330, PCF 121 controls policy distribution for the terminal device based on the determination in block 320. For example, if PCF 121 determines in block 320 that at least one policy rule is to be distributed to UE 111, it transmits the at least one policy rule to UE 111 in block 330.

In some embodiments, to reduce signaling overhead, PCF 121 may determine whether to segment at least one policy rule to be distributed prior to transmission based on the size of the at least one policy rule. For example, if the determined size of the at least one policy rule exceeds a predetermined threshold, PCF 121 may segment the at least one policy rule into a plurality of pieces of information having a size equal to or smaller than the predetermined threshold and transmit the plurality of pieces of information to UE 111. On the other hand, if the size of the at least one policy rule is equal to or less than the predetermined threshold, PCF 121 may transmit the determined at least one policy rule to UE 111 without segmentation.

In some embodiments, method 300 may also include operations in blocks 340 and 350. In block 340, PCF 121 may maintain delivery status of policy rules for subscribers associated with UE 111 and may maintain a device identifier for UE 111 and other information regarding the policy rules. For example, if PCF 121 receives notification from another network device (e.g., UDR 123 in fig. 1) that a policy rule is updated, the delivery status of the policy rule may be set to "no" to indicate that the latest version of the policy rule has not been delivered to the terminal device. Alternatively or in addition, if PCF 121 receives a message from UE 111 that the policy rule was successfully delivered, it may set the delivery status of the policy rule to "yes" to indicate that the latest version of the policy rule has been delivered to the terminal device.

During the lifecycle of the policy association (e.g., AM policy association) of UE 111, PCF 121 may maintain delivery status for the policy rules and possibly other information about the policy rules. For example, if the policy association of the terminal device is terminated, PCF 121 may transmit PEI, UE policy rules, and delivery status of the policy rules to UDR 123, as shown in block 350 of fig. 3. In this case, PCF 121 may remove local information about the UE policy when the AM policy association of UE 111 terminates.

Fig. 6 shows a flow chart of a method 600 implemented at a terminal device for policy distribution. The terminal device may be, for example, UE 111 shown in fig. 1 or UE 201 in fig. 2. For ease of discussion, the method 600 will be described below with reference to the UE 111 and the communication network 100 illustrated in fig. 1. However, embodiments of the present disclosure are not limited thereto.

As shown in fig. 6, at block 610, ue 111 transmits at least one of a request for policy synchronization and a device identifier (e.g., PEI) to a network device for use in determining policy distribution, such as PCF 121 in fig. 1. In some embodiments, UE 111 may communicate information to PCF 121 via one or more other network nodes (e.g., AMF 122 in fig. 1). In addition, in another embodiment, UE 111 may transmit the above information with the SUPI, e.g., during initial registration. Alternatively or in addition, UE 111 may transmit the above information to PCF 121 when a local problem occurs that results in loss of the originally configured policy. This information enables PCF 121 to better decide which policy needs to be distributed to UE 111, avoiding unnecessary signaling overhead.

In block 620, UE 111 receives at least one policy rule from PCF 121 for a subscriber associated therewith. In some embodiments, if UE 111 transmits PEI to PEF 121 in block 610 and PEI is the same as PEI retrieved by PCF 121 from UDR 123, UE 111 may receive only updated UE policies (if any) from PCF 121. On the other hand, if the PEI transmitted by UE 111 in block 610 is different from the PEI retrieved by PCF 121 from UDR 123, then UE 111 may receive all UE policies from PCF 121 in block 620. Alternatively or additionally, if UE 111 transmits a policy synchronization request to PCF 121 in block 610, it may receive all UE policies from PCF 121 in block 620.

In some embodiments of the present disclosure, an apparatus for policy distribution is provided. The apparatus may be embodied in/as a network device, such as PCF 121 in fig. 1 or PCF 202 in fig. 2. The device comprises: means for receiving at least one of a request for policy synchronization and a device identifier from a terminal device; means for determining whether to distribute policy rules to the terminal device based on the received at least one of the policy synchronization request and the device identifier; and means for controlling policy distribution to the terminal device based on the determination.

In some embodiments of the present disclosure, a further apparatus for policy distribution is provided. The further apparatus may be embodied in/as a terminal device, such as UE 111 in fig. 1 or UE 201 in fig. 2. The device comprises: means for transmitting at least one of a request for policy synchronization and a device identifier to a network device for determining policy distribution; and means for receiving at least one policy rule from the network device for a subscriber associated with the terminal device.

Fig. 7 illustrates a simplified block diagram of an apparatus 700, which apparatus 700 may be embodied in/as a terminal device, such as the UE 111 shown in fig. 1, or in/as a network device, such as the PCF 121 shown in fig. 1.

As shown by way of example in fig. 7, the apparatus 700 includes a processor 710 that controls the operation and function of the apparatus 700. For example, in some embodiments, the processor 710 may implement various operations by way of instructions 730 stored in a memory 720 coupled thereto. Memory 720 may be of any suitable type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory terminal devices, magnetic memory terminal devices and systems, optical memory terminal devices and systems, fixed memory, and removable memory, as non-limiting examples. Although only one memory cell is shown in fig. 7, there may be multiple physically distinct memory cells in apparatus 700.

Processor 710 may be of any suitable type suitable to the local technical environment and may include, by way of non-limiting example, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor DSP, and a processor based on a multi-core processor architecture. The apparatus 700 may also include a plurality of processors 710.

Processor 710 may also be coupled with a transceiver 740, which transceiver 740 enables receiving and transmitting information. For example, processor 710 and memory 720 may cooperate to implement methods 300 or 600 described with reference to fig. 2-6. It should be appreciated that all of the features described above with reference to fig. 2-6 are also applicable to the apparatus 700 and will not be described in detail herein.

Various embodiments of the present disclosure may be implemented by one or more computer programs or computer program products executable by a processor (e.g., processor 710 in fig. 7), software, firmware, hardware, or a combination thereof.

Although some of the above description is made in the context of the communication network shown in fig. 1, it should not be construed as limiting the spirit and scope of the present disclosure. The principles and concepts of the present disclosure may be more generally applied to other scenarios.

In addition, the present disclosure may also provide a carrier containing the above-mentioned computer program (e.g., computer instructions/program 730 in fig. 7). The carrier includes a computer-readable storage medium and a transmission medium. The computer readable storage medium may include, for example, an optical disk or an electronic memory device such as a RAM (random access memory), ROM (read only memory), flash memory, magnetic tape, CD-ROM, DVD, blu-ray disk, etc. A transmission medium may include, for example, electrical, optical, radio, acoustical or other form of propagated signals, such as carrier waves, infrared signals, etc.

The techniques described herein may be implemented by various means such that an apparatus implementing one or more functions of a corresponding apparatus described with an embodiment includes not only prior art means but also means for implementing one or more functions of a corresponding apparatus, and it may include separate means for each separate function or means that may be configured to perform two or more functions. For example, the techniques may be implemented in hardware (e.g., circuitry or a processor), firmware, software, or a combination thereof. For firmware or software, implementation can be through modules (e.g., procedures, functions, and so on) that perform the functions described herein.

Some example embodiments herein have been described above with reference to block diagrams and flowchart illustrations of methods and apparatus. It will be understood that each block of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, respectively, can be implemented by various means including computer program instructions. These computer program instructions may be loaded onto a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create means for implementing the functions specified in the flowchart block or blocks.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any implementations or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular implementations. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination and the claimed combination may be directed to a subcombination or variation of a subcombination.

It is obvious to a person skilled in the art that as technology advances, the inventive concept can be implemented in various ways. The above-described embodiments are given for illustration and not limitation of the present disclosure, and it is to be understood that modifications and variations may be made without departing from the spirit and scope of the disclosure, as will be readily appreciated by those skilled in the art. Such modifications and variations are considered to be within the scope of the disclosure and the appended claims. The scope of the present disclosure is defined by the appended claims.

Claims

1. A method for policy distribution in a communication system, comprising:

receiving at least one of a request for policy synchronization and a device identifier from a terminal device;

determining whether policy rules are to be distributed to the terminal device based on the received at least one of the request for policy synchronization and the device identifier; and

policy distribution to the terminal device is controlled based on the determination.

2. The method of claim 1, wherein the determining comprises:

in response to receiving the device identifier, obtaining, from the further network device: information about policy rules for subscribers associated with the terminal device, and a stored device identifier for the terminal device; and

In response to receiving the device identifier that is different from the stored device identifier, determining to transmit to the terminal device all available policy rules for the subscriber.

3. The method of claim 2, wherein the determining further comprises:

determining a delivery status for a policy rule from the information about the policy rule in response to the received device identifier being the same as the stored device identifier; and

determining whether an updated policy rule is to be distributed to the terminal device based on the delivery status of policy rules.

4. The method of claim 3, wherein determining whether an updated policy rule is to be distributed to the terminal device based on the delivery status of policy rules comprises:

determining the policy rule as the updated policy rule to be distributed to the terminal device in response to the delivery status indicating that the latest version of the policy rule has not been delivered to the terminal device; or alternatively

And in response to the delivery status indicating that the latest version of all policy rules has been delivered to the terminal device, determining that no policy rules are to be distributed to the terminal device.

5. The method of claim 2, wherein the information about policy rules further comprises a rule identifier or a policy segment identifier.

6. The method of claim 1, wherein the determining comprises:

in response to receiving the request for policy synchronization, it is determined to transmit all available policy rules associated with the subscriber to the terminal device.

7. The method according to claim 1, wherein the device identifier comprises a permanent device identifier PEI of the terminal device.

8. The method of claim 1, wherein controlling policy distribution to the terminal device comprises:

in response to determining that at least one policy rule is to be distributed to the terminal device, transmitting the at least one policy rule to the terminal device.

9. The method of claim 8, wherein transmitting the at least one policy rule to the terminal device comprises:

responsive to the determined size of the at least one policy rule exceeding a predetermined threshold, segmenting the determined at least one policy rule into a plurality of pieces of information having a size equal to or less than the predetermined threshold, and transmitting the plurality of pieces of information to the terminal device; or alternatively, the process may be performed,

Transmitting the determined at least one policy rule to the terminal device without segmentation in response to the determined size of the at least one policy rule being equal to or less than a predetermined threshold.

10. The method of any one of claims 1 to 9, further comprising:

maintaining policy rules, the device identifier and a delivery status of the policy rules for subscribers associated with the terminal device; and

transmitting the policy rule, the device identifier and the delivery status for the policy rule to a further network device in response to a policy association for the terminal device being terminated.

11. The method of claim 10, wherein maintaining the delivery state for the policy rule comprises:

in response to receiving a notification from the further network device about updating a policy rule, the delivery status for the policy rule is set to indicate that the latest version of the policy rule has not been delivered to the terminal device.

12. The method of claim 10, wherein maintaining the delivery status for the policy rule for the terminal device comprises:

In response to receiving a message from the terminal device regarding successful delivery of a policy rule, the delivery status for the policy rule is set to indicate that the latest version of the policy rule has been delivered to the terminal device.

13. A method of policy distribution in a communication system, comprising:

transmitting, by the terminal device, at least one of a request for policy synchronization and a device identifier to the network device for determining policy distribution; and

policy rules are received from the network device for subscribers associated with the terminal device.

14. The method of claim 13, wherein the transmitting comprises:

during initial registration, the at least one of the request for policy synchronization and the device identifier is transmitted to the network device.

15. A network device, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device at least to:

16. The network device of claim 15, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to determine the at least one policy rule by:

in response to receiving the device identifier, obtaining, from the further network device: information about policy rules for subscribers associated with the terminal device, and a stored device identifier of the terminal device; and

in response to the received device identifier being different from the stored device identifier, determining to transmit to the terminal device all available policy rules for the subscriber associated with the terminal device.

17. The network device of claim 16, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to further determine the at least one policy rule by:

Determining a delivery status for a policy rule from the information about the policy rule in response to the received device identifier being the same as the stored device identifier;

determining whether an updated policy rule is to be transmitted to the terminal device based on the delivery status of policy rules.

18. The network device of claim 17, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to:

19. The network device of claim 17, wherein the information about policy rules further comprises a rule identifier or a policy segment identifier.

20. The network device of claim 15, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to determine by:

In response to receiving the request for policy synchronization, it is determined to transmit to the terminal device all available policy rules for subscribers associated with the terminal device.

21. The network device of claim 15, wherein the device identifier comprises a permanent device identifier PEI of the terminal device.

22. The network device of claim 15, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to control policy distribution to the terminal device by:

23. The network device of claim 15, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to transmit the determined at least one policy rule to the terminal device by:

24. The network device of any of claims 15 to 23, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the network device to:

25. The network device of claim 24, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to maintain the delivery status for the policy rule by:

26. The network device of claim 24, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network device to maintain the delivery status for the policy rule by:

27. A terminal device, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code are configured to, with the at least one processor, cause the terminal device at least to:

transmitting at least one of a request for policy synchronization and a device identifier to a network device for determining policy distribution; and

at least one policy rule is received from the network device for a subscriber associated with the terminal device.

28. The terminal device of claim 27, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the terminal device to transmit the at least one of the request for policy synchronization and the device identifier to the network device during initial registration.

29. A network device, comprising:

means for receiving at least one of a request for policy synchronization and a device identifier from a terminal device;

means for determining whether policy rules are to be distributed to the terminal device based on the received at least one of the request for policy synchronization and the device identifier; and

means for controlling policy distribution to the terminal device based on the determination.

30. A terminal device, comprising:

means for transmitting at least one of a request for policy synchronization and a device identifier to a network device for determining policy distribution; and

means for receiving at least one policy rule from the network device for a subscriber associated with the terminal device.

31. A computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method of any of claims 1 to 12.

32. A computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to any of claims 13 to 14.