WO2020218858A1

WO2020218858A1 - Method and system for performing 4g-5g core interworking function

Info

Publication number: WO2020218858A1
Application number: PCT/KR2020/005396
Authority: WO
Inventors: Naveen Kumar Srinivasa Naidu; Chethan MAHADEV; Sridharan NATARAJAN; Chandan Swarup PATRA
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2019-04-24
Filing date: 2020-04-23
Publication date: 2020-10-29

Abstract

Disclosed herein is a method and Interworking Function (IWF) for connecting Service Based Architecture (SBA) based 5G network nodes to legacy 4G nodes like PCRF and HSS without doing any modification on the legacy network entities. For this purpose, the IWF is configured to provide connectivity between the 5G and the 4G and it acts as protocol bridge to connect two different technologies. On one side, the IWF works with legacy network nodes over the existing protocols like Diameter or GTP. On the other side IWF provides HTTP 2.0 interface to the 5G networks. That is, the IWF acts like 4G network nodes to the legacy nodes and provides SBA based interfaces for the 5G entities, thereby enabling 5G network to seamlessly interwork with 4G and reduce dependency on the legacy vendors and enables faster adaptation of 5G for the incumbent operators.

Description

METHOD AND SYSTEM FOR PERFORMING 4G-5G CORE INTERWORKING FUNCTION

The present subject matter is, in general, related to fifth-generation (5G) cellular networks. Particularly, but not exclusively, the present disclosure relates to a method and interworking function for establishing an interworking between the 5G cellular networks and fourth-generation (4G) cellular networks.

To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.

The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.

In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.

In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier(FBMC), non-orthogonal multiple access(NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

Presently, 5G cellular networks are being deployed alongside the 4G cellular networks and both the networks will coexist for some more time. During the parallel deployment of the 5G cellular networks and related architecture, the devices with dual capabilities, i.e., 4G/5G switch capabilities, may be used in the field. Further, since the 5G cellular network may not have complete coverage in the initial times, a 4G/5G handover will be common. However, during handover and registration of the devices with 4G and 5G, the 4G network nodes need to be interworking with the 5G core. This interworking method is crucial for obtaining subscriber information, downloading dynamic policies for treating the sessions etc., which will be used for establishing a seamless connection to the devices.

Further, the 5G cellular networks use a Service Based Architecture (SBA) and the 5G core understands only Hyper Text Transfer Protocol 2.0 (HTTP 2.0) requests. As a result, all reference-based protocols like Diameter, General Packet Radio Service (GPRS) and Tunneling Protocol (GTP) are eliminated in the 5G core.

However, the legacy 4G core network understands and works on the reference-based architecture mentioned above and uses protocols like Diameter, GTP and GTP` and the like, for communication. This poses a challenge for smooth handover between the 4G and 5G cellular networks.

Additionally, in order to connect to the 5G cellular networks, the 4G cellular network nodes need to implement HTTP 2.0 functionality and implement the 5G specification, so that a smoother interworking is achieved. This puts dependency on the legacy equipment vendors to upgrade the system for interworking, failing to which, the operator needs to replace the entire node with another vendor. Consequently, above tasks will delay the deployment of 5G if there is delay in resolution of the dependencies. Therefore, a method to achieve an interworking model, which aims to reduce the dependency and enable faster deployment of the 5G cellular networks may be desirable.

Disclosed herein is a method for establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network. The method comprises receiving, by an Interworking Function (IWF) unit, a first service request for accessing Unified Data Management (UDM) service, from a User Equipment (UE) operating in the 5G cellular network. Further, the method comprises validating the first service request based on predefined service policies corresponding to the UE. The predefined service policies are retrieved from a policy manager associated with the 5G cellular network. Upon validating the first service request, the method comprises converting the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Home Subscriber Server (HSS) associated with the 4G cellular network.

Further, disclosed herein is a method for establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network. The method comprises receiving, by an Interworking Function (IWF) unit, a first service request for accessing a Policy Control Function (PCF) service, from a User Equipment (UE) operating in the 5G cellular network. Further, the method comprises validating the first service request based on predefined service policies corresponding to the UE. The predefined service policies are retrieved from a policy manager associated with the 5G cellular network. Upon validating the first service request, the method comprises converting the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Policy and Charging Rules Function (PCRF) node associated with the 4G cellular network.

Furthermore, the present disclosure relates to an Interworking Function (IWF) unit for establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network. The IWF unit comprises a processor and a memory. The memory is communicatively coupled to the processor and stores processor-executable instructions, which on execution, cause the processor to receive a first service request for accessing Unified Data Management (UDM) service, from a User Equipment (UE) operating in the 5G cellular network. Further, the instructions cause the processor to, validate the first service request based on predefined service policies corresponding to the UE. The predefined service policies are retrieved from a policy manager associated with the 5G cellular network. Subsequent to validating, the instructions cause the processor to convert the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Home Subscriber Server (HSS) associated with the 4G cellular network.

Furthermore, the present disclosure relates to an Interworking Function (IWF) unit for establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network. The IWF unit comprises a processor and a memory. The memory is communicatively coupled to the processor and stores processor-executable instructions, which on execution, cause the processor to receive a first service request for accessing a Policy Control Function (PCF) service, from a User Equipment (UE) operating in the 5G cellular network. Thereafter, the instructions cause the processor to validate the first service request based on predefined service policies corresponding to the UE. The predefined service policies are retrieved from a policy manager associated with the 5G cellular network. Further, the instructions cause the processor to convert the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Policy and Charging Rules Function (PCRF) node associated with the 4G cellular network.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

According to the present disclosure, network interworking can be performed without modification of a legacy network entity. Therefore, by applying the network interworking method according to the present disclosure, a 5G network can smoothly interact with 4G and reduce dependency on legacy vendors. In addition, 5G can be quickly applied to existing operators.

The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and regarding the accompanying figures, in which:

FIG. 1 and FIG. 2 show exemplary environment of establishing an interworking between a 5G cellular network and a 4G cellular network in accordance with some embodiments of the present disclosure.

FIG. 3 shows a detailed block diagram of an Interworking Function (IWF) in accordance with some embodiments of the present disclosure.

FIGS. 4 - 6 show flowcharts illustrating methods of retrieving and updating user profile and policy information in accordance with some embodiments of the present disclosure.

FIG. 7A and 7B illustrate various implementations of the Interworking Function (IWF) unit in accordance with some embodiments of the present disclosure.

FIG. 8 shows a flowchart illustrating method of establishing an interworking between a 5G cellular network and a 4G cellular network in accordance with some embodiments of the present disclosure.

FIG. 9 shows an exemplary computing unit in accordance with some embodiments of the present disclosure.

It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and executed by a computer or processor, whether such computer or processor is explicitly shown.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the specific forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

The terms “comprises”, “comprising”, “includes”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device, or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

The present disclosure relates to a method and Interworking Function (IWF) for connecting Service Based Architecture (SBA) based 5G network nodes to legacy 4G nodes like Policy and Charging Rules Function (PCRF) and Home Subscriber Server (HSS) without performing any modification on the legacy network entities. For this purpose, the IWF is configured to provide connectivity between the 5G and the 4G and it acts as protocol bridge to connect two different technologies. On one side, the IWF works with legacy network nodes over the existing protocols like Diameter or GPRS Tunneling Protocol (GTP). On the other side IWF provides HTTP 2.0 interface to the 5G networks. That is, the IWF acts like 4G network nodes to the legacy nodes and provides SBA based interfaces for the 5G entities, thereby enabling 5G network to seamlessly interwork with 4G and reduce dependency on the legacy vendors and enables faster adaptation of 5G for the incumbent operators.

In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

In an embodiment, as shown in FIG. 1, the environment 100 may include a User Equipment (UE) 101 and an Interworking Function (IWF) unit 105 that functions as a bridge between the 5G cellular network architecture and the 4G cellular network architecture. In an embodiment, the UE 101 may include, without limiting to, a mobile phone or a laptop of the service consumer. Further, the IWF unit 105 may be an intermediate network interface that connects both the 5G cellular network and the 4G cellular network.

On the 5G cellular network architecture, there may be a Unified Data Management (UDM) node, which is configured to manage network user data as a single, centralized element. Similarly, on the 4G cellular network architecture, there may be a Home Subscriber Server, which ensures smooth functioning of the 4G and/or Long Term Evolution (LTE) networks and functions as a master user database stored in a single node. In an embodiment, the UDM node 103 in the 5G architecture may be considered equivalent to the HSS 107 in the 4G architecture.

In an embodiment, when the UE 101 is operating on the 5G cellular network supported by the 5G cellular network architecture, the UE 101 may access the UDM service 110 through the UDM node 103, without intervention of the IWF unit 105. However, suppose, when the UE 101 moves to a 4G cellular network, and still tries to access the UDM service 110, there may be lapse in the connectivity as the 4G cellular network architecture does not support/provide the UDM service 110. In such a scenario, the IWF unit 105 functions as a bridge between the 5G cellular network and the 4G cellular network and operates in the following manner.

That is, when the UE 101 and/or the service consumer in the 5G cellular network sends an UDM service request 102 to the UDM node 103, a Network Repository Node (NRF) node associated with the UDM node 103 (not shown in FIG. 1), may assign an IWF instance to the UE 101 for providing the requested service to the UE. Thereafter, the UE 101 in the 5G cellular network may send a HTTP 2.0 request 104, corresponding to the UDM service request 102, to the IWF unit 105, assuming that the IWF unit 105 may provide the required UDM service 110. In an embodiment, upon receiving the HTTP 2.0 request 104 for the UDM service 110, the IWF unit 105 may convert the HTTP 2.0 request 104 to a corresponding Diameter request 106 and forward it to the HSS 107 in the 4G cellular network. The HSS 107 may process the Diameter request 106 and generate a suitable service response 108 for the Diameter request 106. Upon receiving the service response 108 from the HSS 107, the IWF unit 105 may map the service response 108 to the corresponding HTTP 2.0 response and forward it to the UDM node 103. Finally, the UE 101 may access the UDM service 110 from the UDM node 103, as if the service is being provided by the UDM node 103. Thus, the IWF unit 105 ensures a seamless switching between the 5G cellular network and the 4G cellular network, irrespective of what service is being requested by the service consumer and/or the UE.

FIG. 2 illustrates interworking between the 5G cellular network and the 4G cellular network with respect to Policy Control Function (PCF) services. In an embodiment, implementation of the IWF unit 105 for handling the PCT services may be similar to that of the UDM service 110 illustrated in FIG. 1, except that the IWF unit 105 interacts with a PCF node 203 on the 5G cellular network and a Policy and Charging Rules Function (PCRF) node 207 on the 4G cellular network. In an embodiment, the PCF mode on the 5G cellular network may be configured to provide policy rules for control plane functions like network slicing, roaming and mobility management. The PCRF node 207 on the 4G cellular network may be equivalent to the PCF node 203 on the 5G cellular network and may be responsible for service management and control of the 4G/LTE network services.

In an embodiment, when the UE 101 and/or the service consumer in the 5G cellular network sends a PCF service request 202 to the PCF node 203, a NRF node (not shown in FIG. 2) associated with the PCF node 203, may assign an IWF instance to the UE 101 for providing the requested service to the UE. Thereafter, the UE 101 in the 5G cellular network may send a HTTP 2.0 request 109, corresponding to the PCF service request 202, to the IWF unit 105, assuming that the IWF unit 105 may provide the required PCF service. In an embodiment, upon receiving the HTTP 2.0 request 109 for the PCF service, the IWF unit 105 may convert the HTTP 2.0 request 109 to a corresponding Diameter request 206 and forward it to the PCRF node 207 in the 4G cellular network. The PCRF node 207 may process the Diameter request 206 and generate a suitable PCF service response 208 for the Diameter request 206. Upon receiving the PCF service response 208 from the PCRF node 207, the IWF unit 105 may map the PCF service response 208 to the corresponding HTTP 2.0 response and forward it to the PCF node 203. Finally, the UE 101 may access the PCF service from the PCF node 203, as if the service is being provided by the PCF node 203. Thus, even in the case of PCF requests, the IWF unit 105 ensures a seamless switching between the 5G cellular network and the 4G cellular network.

FIG. 3 shows a detailed block diagram of an Interworking Function (IWF) unit 105 in accordance with some embodiments of the present disclosure.

In an embodiment, the Interworking Function (IWF) unit 105 may include an I/O interface 301, a processor 303, a memory 305, a parser 307, a translator 309, an internal Domain Name System (DNS) 311, an interfaces function 313 and a lookup database 315.

In an embodiment, the I/O interface 301 may include one or more input/output components and interfaces of the IWF unit 105 that enable the IWF unit 105 to communicate with various components on the 4G and 5G cellular network architectures. For example, the I/O interface 301 helps the IWF unit 105 establish connection with the UDM node 103 and the PCF node 203 on the 5G cellular network architecture and the HSS 107 and PCRF node 207 on the 4G cellular network architecture. The processor 303 may be configured to perform each function of the IWF unit 105 in accordance with various methods and embodiments of the present disclosure. The memory 305 may be communicatively coupled to the processor 303 and may store data and modules required for normal operations of the processor 303.

In an embodiment, the parser 307 may be configured for extracting various network attributes. As an example, the parser 307 may be responsible for analysing the requests received from the UE, extracting and storing parameters such as Mobile Country Codes (MCC), Mobile Network Code (MNC) and Globally Unique Temporary ID (GUTI) from the requests, initiating DNS query database with the values of MCC and MNC parameters and receiving DNS reply Internet Protocol (IP) addresses. Further, the parse may be responsible for sending IP and Message (profile or policy) to a translator 309, re-packing the reply from the translator 309 and forwarding it to the requested Access and Mobility Management Function (AMF) 405 or Session Management Function (SMF) 601.

In an embodiment, the translator 309 may be configured for translating HTTP 2.0 requests into corresponding Diameter requests and vice-versa. That is, the translator 309 may be configured for building a Diameter message and sending the query to the IP received from the parser 307. Further, the translator 309 may receive the Diameter reply from the HSS 107 or the PCRF node 207 and then build a HTTP 2.0 message and forward the HTTP 2.0 response to the parser 307.

In an embodiment, the internal DNS 311 may be configured for receive the values of the parameters MCC and MNC as input to the query DB. Further, the internal DNS 311 may resolve the MCC and MNC value by looking into the DNS entries. Finally, the internal DNS 311 may even reply the corresponding IP to the parser 307.

In an embodiment, the interfaces function 313 may be configured for establishing an association between the internal and the external communication within the IWF unit 105.

In an embodiment, the lookup database 315 or the routing table may be configured for maintaining a table of entries between the MCC, MNC to the corresponding HSS 107, PCRF and the IP. The HSS 107 and PCRF IP address may be determined based on known information from the network planning of the operators. Table 1 shows an exemplary table entry in the lookup database 315.

MCC, MNC	HSS, PCRF table	IP
amf_MCCMNC1	hss1.mccmnc.orgpcrf1.mcc.mnc.org	10.21.x.110.21.x.2
smf_MCCMNC1	pcrf1.mccmnc.org	10.21.x.1
amf_MCCMNC2	hss2.mccmnc.orgpcrf2.mcc.mnc.org	10.22.x.110.22.x.2
smf_MCCMNC2	pcrf2.mccmnc.org	10.22.x.2

FIG. 4 shows a sequence diagram illustrating various actions performed while retrieving a user profile through an AMF/IWF unit 405. As shown in the figure, at time 410, the UE 101 may be initially attached to the 4G cellular network. Further, at time 411 the UE 101 may move into to the 5G cellular network and send a registration request with 5G GUTI request to an authentication node 403 associated with the AMF 405. Further, at time 413, the 5G GUTI request may be sent to the AMF 405, which then derives a SUPI through “Identity Request”. Subsequently, at time 415, the AMF 405 may forward the request to the UDM for the UE 101 profile retrieval. In an embodiment, the AMF 405 may forward the request to either an Unstructured Data Storage Function (UDSF) or a User Defined Routing (UDR), depending on the architecture of the network. Further at time 417, the AMF 405 may get a reply as “Deregistration Notify” as no association is found between the UE 101 and the UDM or UDSF/UDR. This is because, the UDM node 103 would not recognize the service request originating from the UE 101 in the 4G cellular network.

Therefore, at time 419, the AMF 405 invokes the IWF and internally make a request to the IWF by passing the 5G-GUTI to the IWF to fetch the UE 101 profile from an appropriate HSS 107. Subsequently, at

time

421 and 423, the IWF queries towards the HSS 107 and requests subscription information from the HSS 107. In response, at time 425, the HSS 107 may reply the appropriate UE 101 profile data to the IWF. Thereafter, at time 427, the IWF may forward the response and the UE 101 profile to the AMF 405. Subsequently, at time 429, the AMF 405 may update the UE 101 profile information into the UDM node 103 (or UDSF/UDR) and create an association in the UDM node 103. This completes the profile retrieval process using the IWF.

FIG. 5 shows a sequence diagram illustrating various actions performed while performing an Access and Mobility (AM) policy association through an AMF/IWF unit 405. At time 511, the UE 101 may be attached to the 4G cellular network and eventually may move to the 5G cellular network and complete the registration process. Further, at time 513, the UE 101 profile information may be derived from the UDM or the UDSF/UDR. Subsequently, at time 515, the AMF 405 may request PCF for the UE 101 policy association. However, as indicated in time 517, the AMF 405 may get a failure reply from the PCF as there is no policy association about the UE 101 in the PCF.

Therefore, at time 519, the AMF 405 internally makes a request to the IWF unit 105 to fetch the UE 101 policy from the PCF based on the 5G-GUTI. As indicated in

time

521 and 523, the IWF may query the request towards the PCRF node 207 and may request the subscription information from the PCRF node 207. In response, at time 525, the PCRF node 207 may reply the UE 101 policy information to the IWF unit 105. Finally, at time 527, the IWF unit 105 may forward the UE 101 policy information to the AMF 405 and the AMF 405 may apply the AM policy to the user at time 527. Thereafter, at time 529, the PCF may be updated with the policy information to be used in future processing.

FIG. 6 shows a sequence diagram illustrating various actions performed during Session Management (SM) policy association through an AMF/IWF unit 405. At time 603, the UE 101 may be initially attached to the 4G cellular network and may move to the 5G cellular network. Subsequently, at

time

605 and 607, the UE 101 AM policy association procedure may be completed as shown in FIG. 5. Thereafter, at time 609, the Session Management Function (SMF) 601 may request the PCF for performing the UE 101 policy association. However, at time 611, the SMF 601 may get a failure reply from the PCF since the PCF has no policy association about the UE.

Therefore, at time 613, the SMF 601 may internally make a request to the IWF to fetch the UE 101 policy with 5G-GUTI. Further, at

time

615 and 617, the IWF may query the request towards the PCRF node 207 for sending the subscription information. Thereafter, at time 619, PCRF node 207 may forward the UE 101 policy information to the IWF and the IWF may forward the reply to the SMF 601 at time 621. Subsequently, at time 623, the SMF 601 may apply the SM policy to the user and update the PCF for future processing. Finally, the SM policy association and the registration may be completed at

times

627 and 629 by accepting the registration request of the UE.

FIG. 7A and 7B illustrate various implementations of the Interworking Function (IWF) unit 105 in accordance with some embodiments of the present disclosure.

In an embodiment, as shown in FIG. 7A, the UE 101 may be deployed as a standalone interface between the 4G cellular network architecture i.e., the Serving GPRS Support Node (SGSN) 701, the HSS 107 and the PCRF node 207, and the 5G cellular network architecture defined by the Service Based Architecture (SBA), i.e. the AMF 405 and the SMF 601. Here, the IWF unit 105 may be deployed external to each entity of the 4G and the 5G cellular network architectures, thereby making the IWF unit 105 robust and easily accessible for upgrade and related activities.

In an alternative embodiment, as shown in FIG. 7B, the IWF unit 105 may be deployed within the AMF 405 and/or the SMF 601, as an internal configuration of the AMF 405 and SMF 601 interfaces. Additionally, the IWF unit 105 may be configured to be accessible by the HSS 107 and the PCRF node 207 to attend the any service requests made by the UE 101 or the service consumer.

As illustrated in FIG. 8, the method 800 may include one or more blocks illustrating a method for establishing an interworking between 5G cellular network and a 4G cellular network . The order in which the method 800 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

At block 801, the method 800 includes receiving, by the IWF unit 105, a first service request for accessing at least one of a Unified Data Management (UDM) service or a Policy Control Function (PCF) service, from a User Equipment (UE) 101 operating in the 5G cellular network. In an embodiment, the first service request may be a HyperText Transfer Protocol 2.0 (HTTP 2.0) based request for the UDM service 110 or the PCF service. Further, the first service request for the UDM/PCF may be received through a UDM node 103 associated with the 5G cellular network.

At block 803, the method 800 includes validating, by the IWF unit 105, the first service request based on predefined service policies corresponding to the UE. In an embodiment, the predefined service policies may be retrieved from a policy manager associated with the 5G cellular network. Further, the predefined service policies may be validated by comparing the service policies, retrieved from the policy manager, with the service policies subscribed by the user of the UE. As an example, the predefined service policies may comprise at least one of a Quality of Service (QoS) agreement and network subscription details of the UE.

At block 805, the method 800 includes converting, by the IWF unit 105, the first service request to a second service request corresponding to the 4G cellular network. In an embodiment, the second service request may be a Diameter protocol request corresponding to at least one of the Home Subscriber Server (HSS) 107 or a Policy and Charging Rules Function (PCRF) node 207 associated with the 4G cellular network. Upon converting the first service request into the second service request, the second service request may be transmitted to the HSS 107 or the PCRF node 207 associated with the 4G cellular network.

In an embodiment, after generating the second service request, the IWF unit 105 may obtain a service response from the HSS 107 and/or the PCRF node 207 and map the service response to the UDM service 110 and/or the PCF service corresponding to the first service request. Thereafter, the IWF unit 105 may provide the UDM service 110 and/or the PCF service to the UE 101 operating in the 5G cellular network for establishing the interworking between the 5G cellular network and the 4G cellular network. In an embodiment, the interworking may further comprise dynamically registering and deregistering the HSS 107 and/or the PCRF node 207 to the interworking function unit during the interworking for ensuring smooth transitions between the 5G cellular network and the 4G cellular network.

In an embodiment, establishing the interworking may comprise retrieving a network service profile of the UE 101 from the HSS 107 and/or the PCRF node 207 corresponding to the 4G network and then updating the network service profile of the UE 101 on the corresponding UDM node 103 and/or the PCF node 203 associated with the 5G network. This ensures that the UE 101 can continue to access the same service subscribed earlier by the user.

Computer System

FIG. 9 illustrates a block diagram of an exemplary computing unit 900 for implementing embodiments consistent with the present disclosure. In an embodiment, the computer system 900 may be the Interworking Function (IWF) unit 105 illustrated in FIG. 1, which may be used for establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network. The computer system 900 may include a central processing unit (“CPU” or “processor”) 902. The processor 902 may comprise at least one data processor for executing program components for executing user- or system-generated business processes. A user may include a person, a user of the User Equipment (UE) 101, a network operator or any system/sub-system being operated parallelly to the computing unit 900 (also referred as computer system 900). The processor 902 may include specialized processing units such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc.

The processor 902 may be disposed in communication with one or more input/output (I/O) devices (911 and 912) via I/O interface 901. The I/O interface 901 may employ communication protocols/methods such as, without limitation, audio, analog, digital, stereo, IEEE®-1394, serial bus, Universal Serial Bus (USB), infrared, PS/2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), high-definition multimedia interface (HDMI), Radio Frequency (RF) antennas, S-Video, Video Graphics Array (VGA), IEEE® 802.n /b/g/n/x, Bluetooth, cellular (e.g., Code-Division Multiple Access (CDMA), High-Speed Packet Access (HSPA+), Global System For Mobile Communications (GSM), Long-Term Evolution (LTE) or the like), etc. Using the I/O interface 901, the computer system 900 may communicate with one or more I/

O devices

911 and 912.

In some embodiments, the processor 902 may be disposed in communication with a communication network 909 via a network interface 903. The network interface 903 may communicate with the communication network 909. The network interface 903 may employ connection protocols including, without limitation, direct connect, Ethernet (e.g., twisted pair 10/100/1000 Base T), Transmission Control Protocol/Internet Protocol (TCP/IP), token ring, IEEE® 802.11a/b/g/n/x, etc. Using the network interface 903 and the communication network 909, the computer system 900 may communicate with the 4G cellular network architecture and the 5G cellular network architecture for receiving one or more requests for establishing an interworking between the two networks.

In an implementation, the communication network 909 may be implemented as one of the several types of networks, such as intranet or Local Area Network (LAN) and such within the organization. The communication network 909 may either be a dedicated network or a shared network, which represents an association of several types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), Transmission Control Protocol/Internet Protocol (TCP/IP), Wireless Application Protocol (WAP), etc., to communicate with each other. Further, the communication network 909 may include a variety of network devices, including routers, bridges, servers, computing devices, storage devices, etc.

In some embodiments, the processor 902 may be disposed in communication with a memory 905 (e.g., RAM 913, ROM 914, etc. as shown in FIG. 9) via a storage interface 904. The storage interface 904 may connect to memory 905 including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as Serial Advanced Technology Attachment (SATA), Integrated Drive Electronics (IDE), IEEE-1394, Universal Serial Bus (USB), fiber channel, Small Computer Systems Interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, Redundant Array of Independent Discs (RAID), solid-state memory devices, solid-state drives, etc.

The memory 905 may store a collection of program or database components, including, without limitation, user/application interface 906, an operating system 907, a web browser 908, and the like. In some embodiments, computer system 900 may store user/application data 906, such as the data, variables, records, etc. as described in this invention. Such databases may be implemented as fault-tolerant, relational, scalable, secure databases such as Oracle^® or Sybase^®.

The operating system 907 may facilitate resource management and operation of the computer system 900. Examples of operating systems include, without limitation, APPLE^® MACINTOSH^® OS X^®, UNIX^®, UNIX-like system distributions (E.G., BERKELEY SOFTWARE DISTRIBUTION^® (BSD), FREEBSD^®, NETBSD^®, OPENBSD, etc.), LINUX^® DISTRIBUTIONS (E.G., RED HAT^®, UBUNTU^®, KUBUNTU^®, etc.), IBM^® OS/2^®, MICROSOFT^® WINDOWS^® (XP^®, VISTA^®/7/8, 10 etc.), APPLE^® IOS^®, GOOGLE TM ANDROID TM, BLACKBERRY^® OS , or the like.

The user interface 906 may facilitate display, execution, interaction, manipulation, or operation of program components through textual or graphical facilities. For example, the user interface 906 may provide computer interaction interface elements on a display system operatively connected to the computer system 900, such as cursors, icons, check boxes, menus, scrollers, windows, widgets, and the like. Further, Graphical User Interfaces (GUIs) may be employed, including, without limitation, APPLE^® MACINTOSH® operating systems’ Aqua^®, IBM® OS/2^®, MICROSOFT^® WINDOWS^® (e.g., Aero, Metro, etc.), web interface libraries (e.g., ActiveX^®, JAVA^®, JAVASCRIPT^®, AJAX, HTML, ADOBE^® FLASH^®, etc.), or the like.

The web browser 908 may be a hypertext viewing application. Secure web browsing may be provided using Secure Hypertext Transport Protocol (HTTPS), Secure Sockets Layer (SSL), Transport Layer Security (TLS), and the like. The web browsers 908 may utilize facilities such as AJAX, DHTML, ADOBE^® FLASH^®, JAVASCRIPT^®, JAVA^®, Application Programming Interfaces (APIs), and the like. Further, the computer system 900 may implement a mail server stored program component. The mail server may utilize facilities such as ASP, ACTIVEX^®, ANSI^® C++/C#, MICROSOFT^®, .NET, CGI SCRIPTS, JAVA^®, JAVASCRIPT^®, PERL^®, PHP, PYTHON^®, WEBOBJECTS^®, etc. The mail server may utilize communication protocols such as Internet Message Access Protocol (IMAP), Messaging Application Programming Interface (MAPI), MICROSOFT^® exchange, Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), or the like. In some embodiments, the computer system 900 may implement a mail client stored program component. The mail client may be a mail viewing application, such as APPLE^® MAIL, MICROSOFT^® ENTOURAGE^®, MICROSOFT^® OUTLOOK^®, MOZILLA^® THUNDERBIRD^®, and the like.

Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present invention. A computer-readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term “computer-readable medium” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., non-transitory. Examples include Random Access Memory (RAM), Read-Only Memory (ROM), volatile memory, nonvolatile memory, hard drives, Compact Disc (CD) ROMs, Digital Video Disc (DVDs), flash drives, disks, and any other known physical storage media.

Advantages of the embodiments of the present disclosure are illustrated herein.

In an embodiment, the method of present disclosure may be used for establishing an interworking between the 5G cellular network and the 4G cellular network.

In an embodiment, the method of present disclosure enable a UE, operating in the 5G cellular network, to seamlessly connect to a 4G cellular network when the 5G cellular network is unavailable.

In an embodiment, the method of present disclosure reduces dependency on the legacy vendors providing 4G cellular network service and also enables faster adaptation of the 5G cellular network for the incumbent operators.

Evidently, the present disclosure has a practical application and provides a technically advanced solution to the technical problems associated with existing techniques for switching between the 4G and 5G cellular networks. The aforesaid technical advancements and practical applications of the disclosed method may be attributed to the development and deployment of the IWF unit, which translates HTTP 2.0 requests to Diameter/GTP and vice versa and registers as a service consumer on behalf of legacy nodes and provides service to the 5G core nodes. These aspects have been claimed the amended method claims 1 and 8.

In light of the technical advancements provided by the disclosed method and system, the claimed steps, as discussed above, are not routine, conventional, or well-known aspects in the art, as the claimed steps provide the aforesaid solutions to the technical problems existing in the conventional technologies. Further, the claimed steps clearly bring an improvement in the functioning of the network itself, as the claimed steps provide a technical solution to a technical problem.

The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

The terms "including", "comprising", “having” and variations thereof mean "including but not limited to", unless expressly specified otherwise. The enumerated listing of items does not imply that any or all the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

When a single device or article is described herein, it will be clear that more than one device/article (whether they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether they cooperate), it will be clear that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

The present disclosure can be used when a 4G network and a 5G network coexist.

Claims

A method of establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network, the method comprising:

receiving, by an interworking function unit, a first service request for accessing Unified Data Management (UDM) service, from a User Equipment (UE) operating in the 5G cellular network;

validating, by the interworking function unit, the first service request based on predefined service policies corresponding to the UE, wherein the predefined service policies are retrieved from a policy manager associated with the 5G cellular network; and

converting, by the interworking function unit, the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Home Subscriber Server (HSS) associated with the 4G cellular network.
The method as claimed in claim 1, wherein the first service request is a HyperText Transfer Protocol 2.0 (HTTP 2.0) based request for the UDM service.
The method as claimed in claim 1, wherein the first service request from the UE is received through a UDM node associated with the 5G cellular network.
The method as claimed in claim 1, wherein the second service request is a Diameter protocol request corresponding to the HSS.
The method as claimed in claim 1, wherein the predefined service policies comprise at least one of a Quality of Service (QoS) agreement and network subscription details of the UE.
The method as claimed in claim 1 further comprises dynamically registering and deregistering the HSS to the interworking function unit during the interworking.
The method as claimed in claim 1 further comprises:

obtaining, by the interworking function unit, a service response from the HSS and mapping the service response to the UDM service corresponding to the first service request; and

providing, by the interworking function unit, the UDM service to the UE operating in the 5G cellular network, for establishing the interworking between the 5G cellular network and the 4G cellular network.
The method as claimed in claim 7, wherein establishing the interworking further comprises:

retrieving a network service profile of the UE from the HSS; and

updating the network service profile of the UE on UDM node associated with the 5G network.
A method of establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network, the method comprising:

receiving, by an interworking function unit, a first service request for accessing a Policy Control Function (PCF) service, from a User Equipment (UE) operating in the 5G cellular network;

validating, by the interworking function unit, the first service request based on predefined service policies corresponding to the UE, wherein the predefined service policies are retrieved from a policy manager associated with the 5G cellular network; and

converting, by the interworking function unit, the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Policy and Charging Rules Function (PCRF) node associated with the 4G cellular network.
The method as claimed in claim 9, wherein the first service request is a HyperText Transfer Protocol 2.0 (HTTP 2.0) based request for the PCF service and the first service request is received from a PCF node associated with the 5G cellular network.
The method as claimed in claim 9, wherein the second service request is a Diameter protocol request corresponding to the PCRF node.
The method as claimed in claim 9 further comprises dynamically registering and deregistering the PCRF node with the interworking function unit during the interworking.
The method as claimed in claim 9 further comprises:

obtaining, by the interworking function unit, a service response from the PCRF node and mapping the service response to the PCF service corresponding to the first service request; and

providing, by the interworking function unit, the PCF service to the UE operating in the 5G cellular network, thereby establishing the interworking between the 5G cellular network and the 4G cellular network.
The method as claimed in claim 13, wherein establishing the interworking further comprises:

retrieving a network service profile of the UE from the PCRF node; and

updating the network service profile of the UE on a PCF node associated with the 5G network.
An Interworking Function (IWF) unit for establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network, the IWF unit comprising:

a processor; and

a memory, communicatively coupled to the processor, wherein the memory stores processor-executable instructions, which on execution, cause the processor to:

receive a first service request for accessing Unified Data Management (UDM) service, from a User Equipment (UE) operating in the 5G cellular network;

validate the first service request based on predefined service policies corresponding to the UE, wherein the predefined service policies are retrieved from a policy manager associated with the 5G cellular network; and

convert the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Home Subscriber Server (HSS) associated with the 4G cellular network.
The IWF unit as claimed in claim 15, wherein the first service request is a HyperText Transfer Protocol 2.0 (HTTP 2.0) based request for the UDM service.
The IWF unit as claimed in claim 15, wherein the first service request from the UE is received through a UDM node associated with the 5G cellular network.
The IWF unit as claimed in claim 15, wherein the second service request is a Diameter protocol request corresponding to the HSS.
The IWF unit as claimed in claim 15, wherein the predefined service policies comprise at least one of a Quality of Service (QoS) agreement and network subscription details of the UE.
The IWF unit as claimed in claim 15, wherein the processor is further configured to dynamically register and deregister the HSS to the IWF unit during the interworking.
The IWF unit as claimed in claim 15, wherein the processor is further configured to:

obtain a service response from the HSS and mapping the service response to the UDM service corresponding to the first service request; and

provide the UDM service to the UE operating in the 5G cellular network, thereby establishing the interworking between the 5G cellular network and the 4G cellular network.
The IWF unit as claimed in claim 21, wherein the processor establishes the interworking by:

retrieving a network service profile of the UE from the HSS; and

updating the network service profile of the UE on UDM node associated with the 5G network.
An Interworking Function (IWF) unit for establishing an interworking between a fifth-generation (5G) cellular network and a fourth-generation (4G) cellular network, the IWF unit comprising:

a processor; and

a memory, communicatively coupled to the processor, wherein the memory stores processor-executable instructions, which on execution, cause the processor to:

receive a first service request for accessing a Policy Control Function (PCF) service, from a User Equipment (UE) operating in the 5G cellular network;

validate the first service request based on predefined service policies corresponding to the UE, wherein the predefined service policies are retrieved from a policy manager associated with the 5G cellular network; and

convert the first service request to a second service request corresponding to the 4G cellular network and transmitting the second service request to a Policy and Charging Rules Function (PCRF) node associated with the 4G cellular network.
The IWF unit as claimed in claim 23, wherein the first service request is a HyperText Transfer Protocol 2.0 (HTTP 2.0) based request for the PCF service and the first service request is received from a PCF node associated with the 5G cellular network.
The IWF unit as claimed in claim 23, wherein the second service request is a Diameter protocol request corresponding to the HSS.
The IWF unit as claimed in claim 23, wherein the processor is further configured to dynamically register and deregister the PCRF node with the IWF unit during the interworking.
The IWF unit as claimed in claim 23, wherein the processor is further configured to:

obtain a service response from the PCRF node and mapping the service response to the PCF service corresponding to the first service request; and

provide the PCF service to the UE operating in the 5G cellular network, thereby establishing the interworking between the 5G cellular network and the 4G cellular network.
The IWF unit as claimed in claim 27, wherein the processor establishes the interworking by:

retrieving a network service profile of the UE from the PCRF node; and

updating the network service profile of the UE on a PCF node associated with the 5G network.