System and method for managing sequence number during transmission of a message in a network

Abstract

The present disclosure provides a system (208), a device (204), and a method (400) for managing a Non-Access Stratum (NAS) sequence number during a transmission of a NAS message in a network. The method (400) includes generating (402) the NAS message including a NAS sequence number and transmitting (404) the NAS message and the NAS 5 sequence number to the network. Further, the method (400) includes determining (406) that a transmission of the NAS message has failed and utilizing (408) the same NAS sequence number to retransmit the NAS message to the network based on the determination. Therefore, the method (400) overcomes the issue of the NAS sequence number jumping caused by lower layer failures during NAS message retransmission. By detecting failures of the NAS message 0 and notifying the NAS layer, the device (204) avoids incrementing the NAS sequence number, ensuring integrity check success at the network.

Description

SYSTEM AND METHOD FOR MANAGING SEQUENCE NUMBER DURING TRANSMISSION OF A MESSAGE IN A NETWORKRESERVATION OF RIGHTS

[0001] A portion of the disclosure of this patent document contains material, which is subject to intellectual property rights such as but are not limited to, copyright, design, trademark, integrated circuit (IC) layout design, and / or trade dress protection, belonging to Jio Platforms Limited (JPL) or its affiliates (hereinafter referred as owner). The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all rights whatsoever. All rights to such intellectual property are fully reserved by the owner.FIELD OF PRESENT DISCLOSURE

[0002] The embodiments of the present disclosure generally relate to a field of wireless communication, and specifically to a system and a method for retransmitting a Non- Access Stratum (NAS) message utilizing the same NAS sequence number in the event of a failure of an initial NAS message transmission, thereby maintaining a consistency in the NAS sequence number to ensure that the same NAS sequence number is utilized for both the initial NAS message transmission and any subsequent retransmissions of the NAS message.BACKGROUND OF PRESENT DISCLOSURE

[0003] The following description of the related art is intended to provide background information pertaining to the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section is used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of the prior art.

[0004] In existing methods, when a registered Narrow Band Internet of Things (NB IoT) / Long-Term Evolution (LTE) or 5th Generation (5G) User Equipment (UE) is in Radio Resource Control (RRC) idle state and its application layer or Session Initiation Protocol (SIP) client wants to initiate a Mobile Originated (MO) data session, a Non-Access Stratum (NAS) layer initiates a security-protected Control Plane Service Request (CPSR) / Service Request (SR) using the applicable integrity / ciphering algorithm. Alongside the NAS message, a NAS layer of a UE also sends a sequence number and the calculated MessageAuthentication Code (MAC). Subsequently, a RRC layer initiates an RRC connection setup and sends an RRC connection request to the Enode B / gNodeB.

[0005] However, despite the RRC connection being established, the RRC connection complete carrying the actual piggybacked CPSR / SR message is not sent due to issues at the Physical (PHY) layer, Medium Access Control (MAC) layer, or RLC layer. Since the NAS layer of the UE does not receive any response from a network for the CPSR / SR, it retransmits the security-protected SR / CPSR message. This retransmission includes an incremented sequence number and the respective MAC, which may again fail at the lower layers. The NAS layer of the UE persists in incrementing the NAS sequence number in the retransmitted NAS message. After a few retries, the security-protected NAS message may finally reach the Mobility Management Entity (MME), but with a jumped sequence number and the corresponding calculated MAC. When the SR / CPSR reaches the MME / Access and Mobility Management Function (AMF) with a jumped sequence number and MAC, the MME / AMF fails to decode the message due to MAC integrity mismatch. Consequently, the MME / AMF responds with a service reject message to the UE.

[0006] There is, therefore, a need in the art to provide an improved method for managing sequence number during a transmission of a message to the network by overcoming the deficiencies of the prior art(s).OBJECTS OF THE PRESENT DISCLOSURE

[0007] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are listed herein below.

[0008] It is an object of the present disclosure to provide a system and a method for detecting a transmission failure of a Non-Access Stratum (NAS) message at a lower layer and transmitting a failure notification message to an upper layer, thereby enhancing network reliability and efficiency.

[0009] Another object of the present disclosure is to provide a system and a method for utilizing the same NAS sequence number while retransmitting a NAS message due to a transmission failure of the previous NAS message, thereby preventing mismatches of Message Authentication Code (MAC) identities and maintaining data integrity across a network.SUMMARY

[0010] This section is provided to introduce certain objects and aspects of the present disclosure in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.

[0011] In an aspect, the present disclosure relates to a system for managing a Non- Access Stratum (NAS) sequence number during a transmission of a NAS message in a network. The system includes one or more processors and a memory operatively coupled to the one or more processors, wherein the memory comprises processor-executable instructions, which on execution, cause the one or more processors to receive the NAS message including a NAS sequence number from a device and determine that the reception of the NAS message has failed. Further, the one or more processors are to transmit a failure notification message to the device based on the determination and receive the NAS message along with the same NAS sequence number retransmitted by the device in response to the failure notification message.

[0012] In an embodiment, the one or more processors may establish Radio Resource Control (RRC) connection setup between the device and the system based on a Service Request (SR) message generated by the device corresponding to an initiation of data transmission.

[0013] In an embodiment, the one or more processors may receive the NAS message encrypted with a Message Authentication Code Identity (MAC-ID) from the device.

[0014] In an embodiment, the one or more processors may determine that the NAS sequence number is not modified when the NAS message is received from the device.

[0015] In an embodiment, a header of the NAS message comprises the NAS sequence number.

[0016] In another aspect, the present disclosure relates to a method for managing a NAS sequence number during a transmission of a NAS message in a network. The method includes generating, by one or more processors associated with a device, the NAS message including the NAS sequence number and transmitting, by the one or more processors, the NAS message and the NAS sequence number to the network. Further, the method includes determining, by the one or more processors, that a transmission of the NAS message has failed and utilizing, by the one or more processors, the NAS sequence number to retransmit the NAS message to the network based on the determination.

[0017] In an embodiment, for determining, by the one or more processors, that the transmission of the NAS message has failed, the method may include receiving, by the one or more processors, a failure notification message from a lower layer associated with the device and detecting, by the one or more processors, that the transmission of the NAS message has failed at the lower layer based on the received failure notification message.

[0018] In an embodiment, for generating, by one or more processors, the NAS message including the NAS sequence number, the method may include generating, by the one or more processors, a Service Request (SR) message corresponding to an initiation of data transmission and facilitating, by the one or more processors, via a Radio Resource Control (RRC) layer associated with the device and the lower layer, RRC connection setup of the device with the network based on the SR message

[0019] In an embodiment, for transmitting, by one or more processors, the NAS message and the NAS sequence number to the network, the method may include determining, by the one or more processors, a Message Authentication Code Identity (MAC-ID) using the NAS sequence number and encrypting, by the one or more processors, the NAS message with the MAC-ID prior to the transmission of the NAS message to the network.

[0020] Yet another aspect, the present disclosure relates to a device for managing a Non-Access Stratum (NAS) sequence number during a transmission of a NAS message in a network. The device includes one or more processors and a memory operatively coupled to the one or more processors, where the memory includes processor-executable instructions, which on execution, cause the one or more processors to generate the NAS message including the NAS sequence number and transmit the NAS message and the NAS sequence number to the network. Further, the one or more processors determine that a transmission of the NAS message has failed and utilize the NAS sequence number to retransmit the NAS message to the network based on the determination.

[0021] In an embodiment, the one or more processors may receive a failure notification message from a lower layer associated with the device and detect that the transmission of the NAS message has failed at the lower layer based on the received failure notification message.

[0022] In an embodiment, the one or more processors may generate a Service Request (SR) message corresponding to an initiation of data transmission and facilitate, via a Radio Resource Control (RRC) layer associated with the device and the lower layer, RRC connection setup of the device with the network based on the SR message.

[0023] In an embodiment, the one or more processors may determine a Message Authentication Code Identity (MAC-ID) using the NAS sequence number and encrypt the NAS message with the MAC-ID prior to the transmission of the NAS message to the network.

[0024] In an embodiment, the NAS sequence number may not be modified prior to the retransmission of the NAS message to the network.

[0025] In another aspect, the present disclosure relates to a non-transitory computer- readable medium comprising processor-executable instructions that cause a processor to generate a Non-Access Stratum (NAS) message including a NAS sequence number, transmit the NAS message and the NAS sequence number to a network, determine that a transmission of the NAS message has failed, and utilize the NAS sequence number to retransmit the NAS message to the network based on the determination.BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which are incorporated herein, and constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and systems which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that disclosure of such drawings includes the disclosure of electrical components, electronic components, or circuitry commonly used to implement such components.

[0027] FIG. 1 illustrates a sequence diagram (100) for handling a transmission failure of a Non-Access Stratum (NAS) message, in accordance with prior arts.

[0028] FIG. 2A illustrates an example network architecture (200A) of communication between a User Equipment (UE) (204) and a system (208), in accordance with an embodiment of the present disclosure.

[0029] FIG. 2B illustrates an example block diagram (200B) of the UE (204) for managing a NAS sequence number during a transmission of the NAS message in a network, in accordance with an embodiment of the present disclosure.

[0032] FIG. 3 illustrates a sequence diagram for implementing an example method (300) for managing the NAS sequence number during the transmission of the NAS message in the network, in accordance with embodiments of the present disclosure.

[0033] FIG. 4 illustrates a flow diagram of an example method (400) for managing the NAS sequence number during the transmission of the NAS message in the network, in accordance with embodiments of the present disclosure.

[0034] FIG. 5 illustrates an example computer system (500) in which or with which embodiments of the present disclosure may be utilized in accordance with embodiments of the present disclosure.

[0035] The foregoing shall be more apparent from the following more detailed description of the disclosure.DETAILED DESCRIPTION

[0036] In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein.

[0037] The ensuing description provides exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth.

[0038] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail to avoid obscuring the embodiments.

[0039] Also, it is noted that individual embodiments may be described as a process that is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process,many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed but could have additional steps not included in a figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling function or the main function.

[0040] The word “exemplary” and / or “demonstrative” is used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as “exemplary” and / or “demonstrative” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising” as an open transition word without precluding any additional or other elements.

[0041] Reference throughout this specification to “one embodiment” or “an embodiment” or “an instance” or “one instance” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0043] FIG. 1 illustrates an example sequential diagram (100) for handling a transmission failure of a Non-Access Stratum (NAS) message, in accordance with prior arts.

[0044] Referring to FIG. 1, at (118A), when a registered Narrowband Internet of Things (NB IoT) / Long-Term Evolution (LTE) or 5th Generation (5G) User Equipment (UE) is in a Radio Resource Control (RRC) idle state, an application layer (102) of the UE or a Session Initiation Protocol (SIP) client / event (104) needs to initiate a Mobile Originated (MO) data session. Based on the indication from the application layer (102) / SIP client (104), a NAS layer (106) (e.g., an upper layer) sends a Control Plane Service Request (CPSR) / Service Request (SR) message to an RRC layer (108) as represented in (118B). The SIP event (104) interacts with the application layer (102) to get any additional information required to process a service request.

[0045] At (120A), the RRC connection request message is forwarded to an L2 (110) (e.g., a data link layer). Further, at (120B), the RRC connection request message is again forwarded to an LI (112) (e.g., a physical (Phy) layer or a lower layer or Medium Access Control (MAC) layer or Radio Link Control (RLC) layer). Further, at (120C), the RRC connection request message is transmitted to a Radio Access Network (RAN) (114) (e.g., EnodeB / GNodeB). At (122), the RAN (114) transmits a RRC connection setup message to the RRC layer (108) in response to the RRC connection request message.

[0046] At (214A), the RRC layer (108) transmits an RRC connection setup completion message that carries a dedicated NAS message to the LI (112). At (124B), while the LI (112) transmits the RRC connection setup completion message along with the dedicated NAS message to the RAN (114), the transmission of the RRC connection setup completion message along with the dedicated NAS message fails. Once failure occurs, the NAS layer (106) waits for an acknowledgment from the RAN (114) for a certain time period. If the NAS layer (106) does not receive any acknowledgment from the RAN (114), the NAS layer (106) determines that the SR is not received by the RAN (114) as represented in (126).

[0047] At (128), the NAS layer (106) again retransmits the SR with incremented NAS sequence number to the RAN (114). If the retransmission of the NAS message again fails, the NAS layer (106) determines that the SR is not received by the RAN (114) as represented in (130). The step (128) repeats as represented in (132). At (134), if the retransmission of the NAS message is successfully in reaching a core network (116), the core network (116) determines that an integrity check failure has occurred due to a mismatch of a Message Authentication Code identity (MAC-ID) as represented in (136). These retransmitted messages eventually reach the MME / AMF with the NAS sequence number inconsistency. Asa consequence of this discrepancy in the estimated NAS sequence number, the MAC-ID calculated by the MME mismatches, leading to integrity check failures. At (138), the core network transmits a service reject message to the NAE layer (106).

[0048] In these existing methods, an issue arises when the Mobility Management Entity (MME) or Access and Mobility Management Function (AMF) fails to decode the received message due to a MAC identity (MAC-ID) and integrity mismatch. This failure occurs when the calculated MAC-ID of the received message does not match the expected MAC-ID calculated by a Mobility Management Entity (MME)ZAccess and Mobility Management Function (AMF) (e.g., the core network (116)). Consequently, the MME / AMF cannot verify the authenticity and integrity of the received message, leading to a loss of trust in the message content. As a result, the MME / AMF initiates a response mechanism by reverting with a service reject message to the UE. This rejection indicates to the UE that the received message cannot be processed further due to integrity concerns, prompting the UE to take corrective actions or retry the communication process.

[0049] Unlike the existing methods, the present disclosure provides a method for retransmitting a NAS message utilizing the same NAS sequence number in the event of a failure of an initial NAS message transmission, thereby maintaining consistency in the NAS sequence number to ensure that the same NAS sequence number is utilized for both the initial NAS message transmission and any subsequent retransmissions of the NAS message. The method may include transmitting a NAS message along with a NAS sequence number to a network and determining that a transmission of the NAS message has failed. Further, the method may utilize same NAS sequence number for retransmitting the NAS message to the network based on the determination.

[0050] The present disclosure may address a challenge where the UE may eliminate the need to increment the NAS sequence number during the retransmission of a security protected NAS message, restricting from failures at the lower layers. Additionally, the present disclosure may provide a process where the lower layer identifies delivery failures of packets associated with the security protected NAS message and indicates a NAS layer (e.g., an upper layer) about the failure. Upon receiving this indication, the NAS layer may make a decision to refrain from incrementing the NAS sequence number, thereby maintaining consistency and preventing integrity check failures.

[0051] Various embodiments of the present disclosure will be explained in detail with reference to FIGs. 2A-5.

[0052] FIG. 2A illustrates an example network architecture (200A) of communication between a device (204) and a system (208), in accordance with an embodiment of the present disclosure.

[0053] As illustrated in FIG. 2A, by way of example and not by not limitation, the exemplary network architecture (200A) may include a plurality of UEs (204-1, 204-2...204- N), which may be individually referred as the UE (204) and collectively referred as the UEs (204). The UE (204) may be associated with a plurality of users (202-1, 202-2...202-N). The plurality of users (202-1, 202-2...202-N) may be individually referred as the user (202) and collectively referred as the users (202). It may be appreciated that the UE (204) may be interchangeably referred as a device such as an Internet of Things (loT) device or a computing device.

[0054] In an embodiment, the UE (204) may include smart devices operating in a smart environment, for example, an loT system. The UE (204) may be, for example, but are not limited to, a set-up box, a smart television (TV), a streaming media player, a media centre personal computer (PC), and so on. In an embodiment, the UE (204) may include but is not limited to, smartphones, smart watches, smart sensors (e.g., mechanical, thermal, electrical, magnetic, etc.), networked appliances, networked peripheral devices, networked lighting systems, communication devices, networked vehicle accessories, networked vehicular devices, smart accessories, tablets, smart television (TV), computers, smart security system, smart home system, other devices for monitoring or interacting with or for the users and / or entities, or any combination thereof.

[0055] A person of ordinary skill in the art will appreciate that the UE (204) may include, but is not limited to, intelligent, multi-sensing, network-connected devices, that can integrate seamlessly with each other and / or with a central server or a cloud-computing system or any other device that is network-connected.

[0056] In an embodiment, the UE (204) may include, but is not limited to, a handheld wireless communication device (e.g., a mobile phone, a smartphone, a phablet device, and so on), a wearable computer device (e.g., a head-mounted display computer device, a headmounted camera device, a wristwatch computer device, and so on), a Global Positioning System (GPS) device, a laptop computer, a tablet computer, or any type of portable computer, a media playing device, a portable gaming system, and / or any other type of computer device with wireless communication capabilities, and the like. In an embodiment, that the UE (204) may include, but is not limited to, any electrical, electronic, electromechanical, or equipment, or a combination of one or more of the above devices such as Virtual Reality (VR) devices,Augmented Reality (AR) devices, a laptop, a general-purpose computer, a desktop, a personal digital assistant, a tablet computer, a mainframe computer, or any other computing device, where the UE (204) may include one or more in-built or externally coupled accessories including, but not limited to, a visual aid device such as a camera, an audio aid, a microphone, a keyboard, and input devices for receiving input from the user (202) or the entity such as a touchpad, a touch-enabled screen, an electronic pen, and the like.

[0057] A person of ordinary skill in the art will appreciate that the UE (204) may not be restricted to the mentioned devices and various other devices may be used.

[0058] In an exemplary embodiment, the UE (204) may communicate with a system (208) through a network (206). The network (206) may be a core network. It may be appreciated that the system (208) may be interchangeably referred to as an MME / AMF throughout the disclosure. The network (206) may include, by way of example but not limitation, at least a portion of one or more networks having one or more nodes that transmit, receive, forward, generate, buffer, store, route, switch, process, or a combination thereof, etc. one or more messages, packets, signals, waves, voltage or current levels, some combination thereof, or so forth. The network (206) may include, by way of example but not limitation, one or more of a wireless network, a wired network, an internet, an intranet, a public network, a private network, a packet-switched network, a circuit-switched network, an ad hoc network, an infrastructure network, a Public-Switched Telephone Network (PSTN), a cable network, a cellular network, a satellite network, a fiber optic network, some combination thereof. It may be appreciated that the network (206) may be interchangeably referred to as a bandwidth constraint cellular network.

[0059] In an embodiment, the system (208) may receive the NAS message including a NAS sequence number from a device and determine that the reception of the NAS message has failed. Further, the system (208) may transmit a failure notification message to the device based on the determination and receive the same NAS message along with the NAS sequence number retransmitted by the device in response to the failure notification message.

[0060] In an exemplary embodiment, the UE (204) may transmit the NAS message along with the NAS sequence number and detect that a transmission of the NAS message has failed at a lower layer associated with the UE (204), where the lower layer may transmit the failure notification message to an upper layer associated with the UE (204). Further, the UE (204) may utilize the same NAS sequence number for retransmitting the NAS message to the network (206).

[0061] Although FIG. 2A shows exemplary components of the network architecture (200), in other embodiments, the network architecture (200A) may include fewer components, different components, differently arranged components, or additional functional components than depicted in FIG. 2A. Additionally, or alternatively, one or more components of the network architecture (200A) may perform functions described as being performed by one or more other components of the network architecture (200A).

[0062] FIG. 2B illustrates an example block diagram (200B) of a UE (204) for managing a NAS sequence number during a transmission of a NAS message, in accordance with an embodiment of the present disclosure.

[0063] In an embodiment, and as shown in FIG. 2B, the UE (204) (e.g., a device) may be, but not limited to an electronic device, a mobile phone, a laptop, a desktop, and other portable devices. In an embodiment, the UE (204) may include one or more processors (210) that may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and / or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more processors (210) may be configured to fetch and execute computer-readable instructions stored in a memory (212) of the UE (204). The memory (212) may store one or more computer-readable instructions or routines, which may be fetched and executed to create or share the data units over a network service. The memory (212) may include any non- transitory storage device including, for example, volatile memory such as Random-Access Memory (RAM), or non-volatile memory such as an Erasable Programmable Read-Only Memory (EPROM), a flash memory, and the like.

[0064] In an embodiment, the UE (204) may also include an interface (214). The interface (214) may include a variety of interfaces, for example, a variety of interfaces, for example, interfaces for data input and output devices, referred to as I / O devices, storage devices, and the like. The interface (214) may facilitate communication of the UE (204) with various devices coupled to it. The interface (214) may also provide a communication pathway for one or more components of the UE (204). Examples of such components include, but are not limited to, processing engine (216) and a database (218).

[0065] In an embodiment, the processing engine (216) may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing engine (216). In examples, described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing engine (216) may beprocessor-executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the one or more processors (210) may comprise a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the processing engine (216). In such examples, the UE (204) may comprise the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the UE (204) and the processing resource. In other examples, the processing engine (216) may be implemented by an electronic circuitry. In an embodiment, the database (218) may comprise data that may be either stored or generated as a result of functionalities implemented by any of the components of the processors (210) or the processing engine (216) or the UE (204). In an exemplary embodiment, the processing engine (216) may include a sequence number determination module (220), a NAS message failure detection module (222), and other module(s) (224). The other module(s) (224) may implement functionalities that supplement applications / functions performed by the processing engine 216.

[0066] In an embodiment, the UE (204) is configured with a plurality of layers, but not limited to, a data-link layer, a NAS layer, a RRC layer, a physical layer, a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, and the like. In an embodiment, when the UE (204) intends to send data to a network, initially, the one or more processors (210) may generate a SR message and corresponding to an initiation of data transmission and facilitate a RRC connection setup of the device with the network based on the SR message. In an embodiment, a header of the NAS message may include the NAS sequence number. Further, the RRC layer may transmit the RRC connection setup completion message that may carry the dedicated NAS message to the network. In an embodiment, the NAS message may be encrypted by MAC-ID before transmitting the NAS message to the network.

[0067] In an embodiment, while transmitting the NAS message to the network, the NAS message failure detection module (222) may detect that a transmission of the NAS message has failed due to various factors, such as a handover failure, interference occurrence, network congestion, or any other errors or issues. In exemplary embodiments, the NAS message failure detection module (222) may be configured at the lower layer. Once the failure of the transmission of the NAS message is detected at the lower layer, the lower layer may generate a failure notification message and transmit the failure notification message tothe upper layer. In an embodiment, once the upper layer receives the failure notification message, the upper layer may determine that the transmission of the NAS message has been failed. Due to the failure of the transmission of the NAS message, the sequence number determination module (220) may utilize the same NAS sequence number which is previously used to calculate the MAC-ID and retransmitting the NAS message along with the same NAS sequence number to the network. In exemplary embodiments, the sequence number determination module (220) may be configured with the upper layer.

[0068] In this process, the sequence number determination module (220) may not increment or decrement the NAS sequence number while retransmitting the NAS message to the network. For example, if the UE (204) initially utilizes the NAS sequence number 1 to calculate the MAC-ID and transmit the NAS message to the network, and subsequently encounters the failure at the lower layer during the initial transmission of the NAS message, the UE (204) may opt to use the same NAS sequence number 1 when retransmitting the NAS message to the network. Therefore, this approach may prevent the occurrence of the NAS sequence number jumping (e.g., incrementing or decrementing), thereby ensuring that the estimated NAS sequence number at an MME / AMF matches the one sent by the UE (204). Consequently, this may prevent integrity check failures of the NAS message at the MME / AMF and mitigate further failures.

[0069] Although FIG. 2B shows exemplary components of the UE (204), in other embodiments, the UE (204) may include fewer components, different components, differently arranged components or additional functional components than depicted in FIG. 2B. Additionally, or alternatively, one or more components of the UE (204) may perform functions described as being performed by one or more other components of the UE (204).

[0070] In an embodiment, the system (e.g., 208) may include one or more processors and a memory similar to the one or more processors (210) and the memory (212) associated with the UE (204). In an embodiment, the system (208) may be configured to receive the NAS message including the NAS sequence number from the UE (204) and determine that the reception of the NAS message has failed. Further, the system (208) may generate the failure notification message and transmit the failure notification message to the device based on the determination. Once the system (208) transfers the failure notification message to the device, the system (208) may receive the NAS message along with the same NAS sequence number retransmitted by the UE (204) in response to the failure notification message.

[0071] In an embodiment, the system (208) may establish the RRC connection setup between the UE (204) and the system (208) based on the SR message generated by the UE(204) corresponding to the initiation of the data transmission. In an embodiment, the system (208) may receive the NAS message encrypted with the MAC-ID from the UE (204). In an embodiment, the system (208) may determine that the NAS sequence number is not modified when the NAS message is received from the UE (204).

[0072] FIG. 3 illustrates a sequence diagram for implementing an example method (300) for managing the NAS sequence number during the transmission of the NAS message, in accordance with embodiments of the present disclosure.

[0073] Referring to FIG. 3, at (316A), when a registered NB loT / LTE or 5G UE is in an RRC idle state, an application layer (e.g., an embedded application (302)) of the UE (e.g., 204) indicates to initiate a MO data session. Based on the indication from the application layer (302) / SIP client, a NAS layer (304) (e.g., an upper layer) may transmit a security protected CPSR / SR message to an RRC layer (306) using an application integrity or ciphering algorithm as represented in (316B).

[0074] At (318A), the RRC connection request message may be forwarded to an L2 (308) (e.g., a data link layer). Further, at (318B), the RRC connection request message may again be forwarded to an LI (310) (e.g., a Phy layer or a lower layer or MAC layer or RLC layer). Further, at (318C), the RRC connection request message may be transmitted to a RAN (312) (e.g., EnodeB / GNodeB). At (320), the RAN (114) may transmit a RRC connection setup message to the RRC layer (108) in response to the RRC connection request message.

[0075] At (322A), the RRC layer (306) may transmit an RRC connection setup completion message that carries a dedicated NAS message along with a NAS sequence number and calculated MAC-ID to the LI (310) through the L2 (308). At (322B), while the LI (310) transmits the RRC connection setup completion message to the RAN (312), the transmission of the RRC connection setup completion message carrying an actual piggybacked CPSR / SR message is not sent due to issues at the LI (310). Once failure occurs, the NAS layer (304) waits for an acknowledgment from the RAN (312) for a certain time period and the NAS layer (304) may determine that the SR is not received by the RAN (312) as represented in (324). At (326), meanwhile, the LI (310) may transmit a failure notification message (e.g., an indication of failure) to the NAS layer (304). In exemplary embodiments, the failure notification message may represent the failure of delivering the security protected NAS message. Based on the reception of the failure notification message from the LI (310), the NAS layer (304) may retransmit the NAS message (e.g., retry SR) without incrementing the NAS sequence number (e.g., utilizing the same NAS sequence number) to the RAN (312) as represented in (328).

[0076] In an embodiment, if the retransmission of the NAS message again fails, the NAS layer (106) may determine that the NAS message is not received by the RAN (312) as represented in (330) and the LI (310) may transmit the failure notification message to the NAS layer (304) as represented in (332). Based on the reception of another failure notification message from the LI (310), the NAS layer (304) may retransmit the NAS message without incrementing the NAS sequence number to the RAN (312) as represented in (334). After multiple retransmissions and failure indication from the LI (310), the security protected NAS message may be delivered to an MME / AMF (314) (e.g., a core network or a system (206)). If the retransmission of the NAS message is successfully reached the MME / AMF (314), the MME / AMF (314) may calculate an integrity check of the NAS message by inputting the NAS sequence number sent by the UE (204) as represented in (336). As the estimated NAS sequence number and the UE (204) sent NAS sequence number matches, the MAC-ID calculated by MME / AMF matches with the MAC-ID sent by the UE (204). At (338), the MME / AMF may transmit a service accept message to the NAE layer (304).

[0077] In this operation, the lower layers (e.g., the LI (310)), including the MAC layer, the RLC layer, and the Phy layer, may be configured to detect failures in delivering packets mapped to a specific NAS message. Upon detecting such failures, the lower layers (e.g., the LI (310)) may send the failure notification message to the NAS layer (304) about the encountered issue. Subsequently, based on the indication received from the lower layers (e.g., the LI (310)), the NAS layer (304) may make a decision regarding whether to increment the NAS sequence number. This decision-making process may ensure that the NAS layer (304) may adapt its behaviour in response to the detected failures, thereby maintaining the integrity and reliability of the communication process.

[0078] FIG. 4 illustrates a flow diagram of an example method (400) for managing a NAS sequence number during a transmission of a NAS message in a network, in accordance with embodiments of the present disclosure.

[0079] Referring to FIG. 4, at (402), the method (400) may include generating the NAS message including a NAS sequence number. In an embodiment, the method (400) may include generating a SR message corresponding to an initiation of data transmission and facilitating, by the one or more processors (210), via a RRC layer associated with the device (204) and the lower layer, a RRC connection setup of the device with the network based on the SR message.

[0080] At (404), the method (400) may include transmitting the NAS message along with the NAS sequence number to the network. In an embodiment, the method (400) may include determining a MAC-ID using the NAS sequence number and encrypting the NAS message with the MAC-ID prior to the transmission of the NAS message to the network. At (406), the method (400) may include determining that a transmission of the NAS message has failed. In an embodiment, the method (400) may include receiving a failure notification message from a lower layer associated with the device and detecting that the transmission of the NAS message has failed at the lower layer based on the received failure notification message. At (408), the method (400) may include utilizing same NAS sequence number for retransmitting the NAS message to the network based on the determination. In an embodiment, the NAS sequence number may not be incremented or decremented before retransmitting the NAS message to the network. In an embodiment, a header of the NAS message may include the NAS sequence number.

[0081] FIG. 5 illustrates an exemplary computer system (500) in which or with which embodiments of the present disclosure may be utilized in accordance with embodiments of the present disclosure.

[0082] As shown in FIG. 5, the computer system (500) may include an external storage device (510), a bus (520), a main memory (530), a read-only memory (540), a mass storage device (550), a communication port(s) (560), and a processor (570). A person skilled in the art will appreciate that the computer system (500) may include more than one processor (570) and communication ports (560). The processor (570) may include various modules associated with embodiments of the present disclosure. The communication port(s) (560) may be any of an RS-232 port for use with a modem-based dialup connection, a 10 / 100 Ethernet port, a Gigabit or 10 Gigabit port using copper or fiber, a serial port, a parallel port, or other existing or future ports. The communication ports(s) (560) may be chosen depending on a network, such as a Local Area Network (LAN), Wide Area Network (WAN), or any network to which the computer system (500) connects.

[0083] In an embodiment, the main memory (530) may be a Random Access Memory (RAM), or any other dynamic storage device commonly known in the art. The read-only memory (540) may be any static storage device(s) e.g., but not limited to, a Programmable Read Only Memory (PROM) chip for storing static information e.g., start-up or basic input / output system (BIOS) instructions for the processor (570). The mass storage device (550) may be any current or future mass storage solution, which can be used to store information and / or instructions. Exemplary mass storage solutions include, but are notlimited to, Parallel Advanced Technology Attachment (PATA) or Serial Advanced Technology Attachment (SATA) hard disk drives or solid-state drives (internal or external, e.g., having Universal Serial Bus (USB) and / or Firewire interfaces).

[0084] In an embodiment, the bus (520) may communicatively couple the processor(s) (570) with the other memory, storage, and communication blocks. The bus (520) may be, e.g., a Peripheral Component Interconnect PCI) / PCI Extended (PCI-X) bus, Small Computer System Interface (SCSI), USB, or the like, for connecting expansion cards, drives, and other subsystems as well as other buses, such a front side bus (FSB), which connects the processor (570) to the computer system (500).

[0085] In another embodiment, operator and administrative interfaces, e.g., a display, keyboard, and cursor control device may also be coupled to the bus (520) to support direct operator interaction with the computer system (500). Other operator and administrative interfaces can be provided through network connections connected through the communication port(s) (560). Components described above are meant only to exemplify various possibilities. In no way should the aforementioned exemplary computer system (500) limit the scope of the present disclosure.

[0086] While considerable emphasis has been placed herein on the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be implemented merely as illustrative of the disclosure and not as a limitation.ADVANTAGES OF THE PRESENT DISCLOSURE

[0087] The present disclosure utilizes the same Non-Access Stratum (NAS) sequence number for retransmitting the NAS message to maintain consistency in the communication process.

[0088] The present disclosure detects the NAS message failures at a lower layer and initiates retransmissions with the same NAS sequence number, thereby avoiding discrepancies between the expected and received NAS sequence numbers on the network side.

[0089] The present disclosure reduces the occurrence of transmission errors and integrity check failures, thereby providing a more reliable and consistent communication process.

[0090] The present disclosure avoids unnecessary retransmissions and integrity check failures that translate into cost savings for network operators and service providers.

Claims

We Claim:

1. A system (208) for managing a Non-Access Stratum (NAS) sequence number during a transmission of a NAS message, comprising: one or more processors; and a memory operatively coupled to the one or more processors, wherein the memory comprises processor-executable instructions, which on execution, cause the one or more processors to: receive the NAS message including a NAS sequence number from a device; determine that the reception of the NAS message has failed; transmit a failure notification message to the device based on the determination; and receive the NAS message along with the same NAS sequence number retransmitted by the device in response to the failure notification message.

2. The system (208) as claimed in claim 1, wherein the one or more processors are to establish Radio Resource Control (RRC) connection setup between the device and the system (208) based on a Service Request (SR) message generated by the device corresponding to an initiation of data transmission.

3. The system (208) as claimed in claim 1, wherein the one or more processors are to receive the NAS message encrypted with a Message Authentication Code Identity (MAC- ID) from the device.

4. The system (208) as claimed in claim 1, wherein the one or more processors are to determine that the NAS sequence number is not modified when the NAS message is received from the device.

5. The system (208) as claimed in claim 1, wherein a header of the NAS message comprises the NAS sequence number.

6. A method (400) for managing a Non-Access Stratum (NAS) sequence number during a transmission of a NAS message in a network, comprising: generating (402), by one or more processors (210) associated with a device (204), the NAS message including a NAS sequence number; transmitting (404), by the one or more processors (210), the NAS message and the NAS sequence number to the network;determining (406), by the one or more processors (210), that a transmission of the NAS message has failed; and utilizing (408), by the one or more processors (210), the same NAS sequence number to retransmit the NAS message to the network based on the determination.

7. The method (400) as claimed in claim 6, wherein determining (406), by the one or more processors (210), that the transmission of the NAS message has failed comprises: receiving, by the one or more processors (210), a failure notification message from a lower layer associated with the device (204); and detecting, by the one or more processors (210), that the transmission of the NAS message has failed at the lower layer based on the received failure notification message.

8. The method (400) as claimed in claim 7, wherein generating (402), by one or more processors (210), the NAS message including the NAS sequence number comprises: generating, by the one or more processors (210), a Service Request (SR) message corresponding to an initiation of data transmission; and facilitating, by the one or more processors (210), via a Radio Resource Control (RRC) layer associated with the device (204) and the lower layer, RRC connection setup of the device (204) with the network based on the SR message.

9. The method (400) as claimed in claim 8, wherein transmitting (404), by one or more processors (210), the NAS message and the NAS sequence number to the network comprises: determining, by the one or more processors (210), a Message Authentication Code Identity (MAC-ID) using the NAS sequence number; and encrypting, by the one or more processors (210), the NAS message with the MAC-ID prior to the transmission of the NAS message to the network.

10. A device (204) for managing a Non-Access Stratum (NAS) sequence number during a transmission of a NAS message in a network, comprising: one or more processors (210); and a memory (212) operatively coupled to the one or more processors (210), wherein the memory (212) comprises processor-executable instructions, which on execution, cause the one or more processors (210) to: generate the NAS message including a NAS sequence number; transmit the NAS message and the NAS sequence number to the network;determine that a transmission of the NAS message has failed; and utilize the same NAS sequence number to retransmit the NAS message to the network based on the determination.

11. The device (204) as claimed in claim 10, wherein the one or more processors (210) are to: receive a failure notification message from a lower layer associated with the device (204); and detect that the transmission of the NAS message has failed at the lower layer based on the received failure notification message.

12. The device (204) as claimed in claim 11, wherein the one or more processors (210) are to: generate a Service Request (SR) message corresponding to an initiation of data transmission; and facilitate, via a Radio Resource Control (RRC) layer associated with the device (204) and the lower layer, RRC connection setup of the device (204) with the network based on the SR message.

13. The device (204) as claimed in claim 12, wherein the one or more processors (210) are to: determine a Message Authentication Code Identity (MAC-ID) using the NAS sequence number; and encrypt the NAS message with the MAC-ID prior to the transmission of the NAS message to the network.

14. The device (204) as claimed in claim 10, wherein the NAS sequence number is not modified prior to the retransmission of the NAS message to the network.

15. The device (204) as claimed in claim 14, wherein a header of the NAS message comprises the NAS sequence number.

16. A non-transitory computer-readable medium comprising processor-executable instructions that cause a processor to: generate a Non-Access Stratum (NAS) message including a NAS sequence number; transmit the NAS message and the NAS sequence number to a network; determine that a transmission of the NAS message has failed; and utilize the NAS sequence number to retransmit the NAS message to the network based on the determination.

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