Congestion detection of network slice

Abstract

Example embodiments of the present disclosure relate to apparatuses, methods and computer readable storage medium for congestion detection of a network slice. In a method, congestion of a first network slice is detected based on at least one parameter. The at least one parameter may include at least one of an amount of data utilized in the first network slice, or a delay in the first network slice. In response to detecting that the first network slice is congested, the apparatus initiates replacement of one or more terminal devices from the first network slice to a second network slice.

Description

CONGESTION DETECTION OF NETWORK SLICEFIELDS

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to apparatuses, methods and computer readable storage medium for congestion detection of a network slice.BACKGROUND

[0002] Congestion occurs when network resources are overwhelmed by the demand for data transmission, which may lead to a significant degradation in network performance and quality of service. By detecting congestion early and accurately, network operators can take proactive measures to alleviate the issue, ensuring smooth and efficient network operations. Congestion may be detected based on implemented Packet Data Convergence Protocol (PDCP) counters or PDCP timers. The PDCP counters or PDCP timers may help detect congestion by monitoring certain metrics related to the transmission and reception of data packets, such as packet loss rate, retransmission rate, transmission queue length, etc. Moreover, congestion may be detected at transport level based on configured transmission admission control thresholds.SUMMARY

[0003] In a first aspect of the present disclosure, there is provided an apparatus. The apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: detect congestion of a first network slice based on at least one parameter, the at least one parameter comprising at least one of an amount of data utilized in the first network slice, or a delay in the first network slice; and in response to detecting that the first network slice is congested, initiate replacement of the one or more terminal devices from the first network slice to a second network slice.

[0004] In a second aspect of the present disclosure, there is provided a method. The method comprises: detecting congestion of a first network slice based on at least one parameter, the at least one parameter comprising at least one of an amount of data utilized in the first network slice, or a delay in the first network slice; and in response to detecting that the first network slice is congested, initiating replacement of the one or more terminaldevices from the first network slice to a second network slice.

[0005] In a third aspect of the present disclosure, there is provided an apparatus. The apparatus comprises means for detecting congestion of a first network slice based on at least one parameter, the at least one parameter comprising at least one of an amount of data utilized in the first network slice, or a delay in the first network slice; and means for in response to detecting that the first network slice is congested, initiating replacement of the one or more terminal devices from the first network slice to a second network slice.

[0006] In a fourth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the second aspect.

[0007] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0009] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0010] FIG. 2 illustrates a flowchart of an example method in accordance with some example embodiments of the present disclosure;

[0011] FIG. 3 illustrates a flowchart of an example process of slice congestion detection and slice replacement based on utilized data in accordance with some example embodiments of the present disclosure;

[0012] FIG. 4 illustrates an example diagram of slice replacement for user equipment (UE) based on congestion at a slice level in accordance with some example embodiments of the present disclosure;

[0013] FIG. 5 illustrates a flowchart of an example process of slice congestion detection and slice replacement based on delay in accordance with to some example embodiments of the present disclosure;

[0014] FIG. 6 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0015] FIG. 7 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0016] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0017] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0018] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0019] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0020] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, theterm “and / or” includes any and all combinations of one or more of the listed terms.

[0021] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0022] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0024] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed foroperation.

[0025] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0026] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0027] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the appliedterminology and technology. In some example embodiments, a radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0028] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0029] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resourcefor describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0030] As mentioned above, congestion may be detected based on implemented PDCP counters or PDCP timers or at TRS level. However, there is no implementation available that may detect congestion at a slice level and take appropriate actions like triggering congestion detection via Operation Administration and Maintenance (0AM) and further to 5G core network (CN) for slice replacement.

[0031] The network slice replacement feature is used to replace a Single (S) Network Slice Selection Assistance Information (NSSAI) with an alternative S-NSSAI when an S- NSSAI becomes available or congested. The network slice replacement may be triggered in the following cases. The 0AM sends a notification to Access and Mobility Function (AMF) when a S-NSSAI becomes unavailable or congested (and also when this S-NSSAI becomes available again) and provides the alternative S-NSSAI to AMF. At present, there is no implementation that identifies slice level congestion at a RAN.

[0032] Example embodiments of the present disclosure propose a congestion detection solution for a network slice. In this solution, congestion of a first network slice is detected based on at least one parameter . The at least one parameter includes at least one of an amount of data utilized in the first network slice, or a delay in the first network slice. After detecting that the first network slice is congested, the apparatus initiates replacement of one or more terminal devices from the first network slice to a second network slice.

[0033] This solution may address the issues related to how 0AM detects a congested S- NSSAI and informs the 5G CN (e.g. AMF) to trigger network slice replacement. This solution enables slice-level congestion detection and replacement, thereby avoiding possible call drops due to congestion on a slice level.

[0034] FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented.

[0035] As shown in FIG. 1, the communication environment 100 includes an access network device 130 (e.g., gNB) which may be deployed in a RAN such as a 5G RAN. The access network device 130 may serve a first network slice 120-1, a second network slice 120-2, ..., a N-th network slice 120-N. N represents a positive integer. For the purpose of discussions, the plurality of network slices 120-1, ..., 120-N will be individually orcollectively referred to as network slice(s) 120. The communication environment 100 further includes a terminal device 110 (e.g., a UE) which may communicate with other terminal devices using any network slice of network slices 120.

[0036] The communication environment 100 further includes an 0AM 140. In some embodiments, the 0AM 140 may be a component within the access network device 130 and the 0AM 140 may operate, maintain, or manage the access network device 130 via 01 interface. In an example, the 0AM 140 may be deployed in the access network device 130. Alternatively, the 0AM 140 may be deployed separately and communicate with the access network device 130.

[0037] The communication environment 100 may further include a CN device 150 (such as an AMF), which may be a 5G CN device. In some example embodiments, the 0AM 140 may communicate with the CN device 150 to trigger a slice replacement for the terminal device 110.

[0038] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0039] It is to be understood that the numbers of devices are illustrated in FIG. 1 only for the purpose of illustration without suggesting any limitations. The communication environment 100 may include any suitable numbers of terminal devices and network devices for implementing embodiments of the present disclosure.

[0040] In various example embodiments, a congestion mechanism is proposed at a slicelevel. In the communication environment 100, congestion of a network slice (e.g., the first network slice 120-1) which is used by the terminal device 110 may be detected. After detecting that the network slice is congested, replacement of the slice may be initialized to move the terminal device 110 from the network slice to another network slice (e.g., the second network slice 120-2). In an example, congestion detection and replacement of the congested slice may be implemented by the 0AM 140.

[0041] In some example embodiments, the congestion detection may be based on measurement information and may trigger an 0AM based congestion notification to the 5G CN. Some example implementations will be described below with reference to FIGS. 2 to 7.

[0042] FIG. 2 illustrates a flowchart of an example method 200 in accordance with some example embodiments of the present disclosure. In some example embodiments, the method 200 may be implemented at the 0AM 140 in FIG. 1. In some other example embodiments, for example, in the case that the 0AM 140 is physically integrated into or implemented as a part of the access network device 130, the method 200 may be implemented by the access network device 130. For the purpose of discussion, the method 200 will be described from the perspective of the 0 AM 140 with reference to FIG. 1.

[0043] At block 210, the 0AM 140 detects congestion of a network slice (referred to as first network slice 120-1) based on at least one parameter. The at least one parameter may include at least one of an amount of data utilized in the first network slice 120-1, or a delay in the first network slice 120-1.

[0044] In some example embodiments, the congestion of the first network slicel20-l may be detected using a table storing information related to the first network slice 120-1. The information may indicate at least one of a number of terminal devices attached to the first network slice 120-1, an amount of data utilized by these terminal devices in the first network slice 120-1, or an average processing delay observed in the first network slice 120-1. In an example, the table may be an Inter Working Function (IWF) table or other forms of tables that may store the details such as the number of UEs attached to a particular slice and / or the data utilized.

[0045] In some example embodiments, the table may be updated in response to one or more terminal devices 110 registering with or starting use of the first network slice 120- 1. In an example, this table may be updated when a UE starts using a particular slice.

[0046] Alternatively, or in addition, the table may be updated in response to one or more terminal devices 110 deregistering with or stopping use of the first network slice 120-1. In an example, the entry will be removed when the UE deregisters or stops using the slice.

[0047] In some example embodiments, the 0AM 140 may determine that the first network slice 120-1 is congested, based on a value of a parameter of the at least one parameter associated with the first network slice 120-1 being equal to or greater than a value of a first threshold.

[0048] In some example embodiments, the parameter may comprise the amount of data utilized in the first network slice. In some example embodiments, the value of the first threshold may be set based on an amount of data allowed in the first network slice 120-1. In an example, the amount of data utilized in the first network slice 120-1 may be the total data utilized by UEs in that slice and the parameter may be named as calculatedtotalUEdatautilizationperSlice. The value of the first threshold may be set based on the maximum data utilization a slice may withstand without any discard. Such a value of the first threshold may be named as upperthresh dataUtilization perslice. The maximum data utilization may be named as maxDataUtilizationPerSlice which may be assumed to equal to 1000 megabytes (MB), for example.

[0049] In some example embodiments, the parameter may comprise the delay in the first network slice. In some example embodiments, the value of the first threshold may be set based on a sum of an average delay and a buffer delay (referred to as a first buffer delay) in the first network slice 120-1. In an example, the delay in the first network slice may include a downlink (DL) delay, an uplink (UL) delay, or a combined DL and UL delay. The average delay may be an average PDCP delay a slice can withstand without packet discard and may be named as Average delay per Slice. In an example, the first buffer delay in the first network slice 120-1 may be determined as an additionally buffer delay, beyond which the packets may get discarded per slice after a hysteresis timer is expired.

[0050] In some example embodiments, a value of the first buffer delay is set as an upper limit of a buffer delay in the first network slice 120-1. In an example, the first buffer delay may be named as upperBuffer delay per Slice.

[0051] At block 220, in response to detecting that the first network slice 120-1 is congested, the 0AM 140 initiates replacement of one or more terminal devices 110 fromthe first network slice 120-1 to a second network slice 120-2.

[0052] In some example embodiments, if it is detected that the first network slice is congested, the 0 AM 140 may increment a count (referred to as a first count) of congestion of the first network slice 120-1. In an example, if the amount of data utilized in the first network slice 120-1 (e.g., calculatedtotalUEdatautilizationperSlice) exceeds the value of the first threshold (e.g., upperthresh dataUtilization perslice), the first network slice 120- 1 may be detected as congested. The RAN may introduce a counter, named as Congestion threshold per Slice, to determine the first count of congestion to detect congestion. A value of Congestion threshold per Slice may be incremented after detecting that the first network slice is congested.

[0053] In another example, if the calculated delay in the first network slice 120-1 exceeds the sum of the average delay (e.g., Average delay per Slice) and the first buffer delay (e.g., upperBuffer delay per Slice) in the first network slice 120-1 (where the sum is an example of the value of the first threshold), the first network slice 120-1 may be detected as congested. In this example, another counter for the first count of congestion may be introduced to determine the maximum delay after which the counter can be incremented. This counter may be named as DL Congestion Delay per Slice.

[0054] It is to be understood that the names and definitions of the parameters and counter described herein are only examples but not limited. Any names and definitions may be used or defined for the parameters and counters depending on the 3 GPP standardization.

[0055] In some example embodiments, the 0AM 140 may determine the one or more terminal devices 110 registered with the first network slice 120-1, to be moved from the first network slice 120-1 to the second network slice 120-2. In an example, the 0AM 140 may detect a list of a subset of terminal devices registered with the first network slice 120-1 eligible for replacement.

[0056] In some example embodiments, the 0AM 140 may send a notification to a core network (e.g., the CN device 150 such as an AMF) to move the one or more terminal devices 110 from the first network slice 120-1 to the second network slice 120-2. In an example, the 0AM 140 may list all terminal devices (e.g., UEs) using the IWF table. Then, slice replacement may be initiated to all listed UEs.

[0057] As described above, performance management (PM) counter(s) may be introduced for each supported network slice. The PM counter(s) measure the slice congestion and the number of terminal devices to which the slice replacement is required to be triggered based on the data utilization threshold, or the packet delay to indicate the slice level congestion at the RAN. Then, the 0AM 140 that monitors these counters based on the configured threshold values may detect slice congestion and accordingly inform the 5G CN (e.g. AMF) for slice replacement.

[0058] In some example embodiments, the notification may include one or more identifiers of the one or more terminal devices 110 to be moved. Since the 0AM 140 is aware of the individual UE data consumption and / or delay from, for example, the IWF table, the 0AM 140 may also indicate to the 5G CN the UE identifiers that could be moved to a different network slice. In an example, the CN may move the one or more terminal devices 110 from the first network slice 120-1 to the second network slice 120-2 based on their identifiers.

[0059] In some example embodiments, after at least one terminal device of the one or more terminal devices 110 has been moved from the first network slice 120-1 to the second network slice 120-2, the 0AM 140 may increment a count (referred to as a second count) of a number of terminal devices 110 moved from the first network slice 120-1. In an example, a counter, named as Slice replacement initiated UEs, may be used to determine the second count of the number of terminal devices moved from the first network slice. The second count may be either in percentage or the actual number calculated.

[0060] In some example embodiments, at block 230, once the first network slice is free for utilization, the 0AM 140 may initiate replacement again from the second network slice to the first network slice based on thresholds and counters.

[0061] For example, the 0AM 140 may determine that the first network slice 120-1 is no longer congested, if a value of a parameter of the at least one parameter associated with the first network slice is equal to or less than a value of a second threshold. Based on the first network slice 120-1 being no longer congested, the 0AM 140 may send a notification to a core network to move at least one terminal device of the one or more terminal devices 110 back to the first network slice 120-1. In an example, if the first network slice 120-1 is longer congested, the 0AM 140 may send a notification to replace terminal devices back to the original network slice and then the terminal devices may be replaced back toits original network slice.

[0062] In some example embodiments, the parameter may comprise the amount of data utilized in the first network slice 120-1, and the value of the second threshold may be set based on an amount of data allowed in the first network slice 120-1. In an example, the value of the second threshold for moving terminal devices back to an original network slice may be less than the value of the first threshold for moving terminal devices to another network slice.

[0063] In some example embodiments, the parameter may comprise the delay in the first network slice 120-1 and the value of the second threshold may be set based on a sum of an average delay and a second buffer delay in the first network slice 120-1. In some example embodiments, the value of the second buffer delay may be set as a lower limit of a buffer delay in the first network slice 120-1 which may be less than the upper limit of the buffer delay.

[0064] In some example embodiments, if it is determined that the first network slice 120-1 is no longer congested, the 0AM 140 may decrement the first count of congestion of the first network slice 120-1. In some example embodiments, if it is determined that a terminal device of the at least one terminal device having been moved back to the first network slice 120-1, the 0AM 140 may decrement the second count of the number of terminal devices 110 moved from the first network slice 120-1. In some example embodiments, after the one or more terminal devices 110 moved from the first network slice 120-1 are moved back to the first network device 120-1, the 0AM 140 may reset at least one of the first count of congestion of the first network slice 120-1, or the second count of the number of terminal devices moved from the first network slice 120-1.

[0065] Some example processes of slice congestion detection and slice replacement will be described below with reference to FIGS. 3 to 4. Reference is first made to FIG. 3, in a process 300 in FIG. 3, slice congestion detection and slice replacement may be based on utilized data. The process 300 may be implemented at the 0AM 140 in FIG. 1. For the purpose of discussion, the process 300 will be described from the perspective of the 0AM 140.

[0066] As illustrated, at block 310, the 0AM 140 may determine the maximum data utilization (e.g., maxDataUtilizationPerSlice) a slice may withstand without any discard (as an example of the amount of data allowed in the slice). maxDataUtilizationPerSlicemay be assumed to be equal to X (e.g., 1000MB). The 0AM 140 may also determine the first threshold (e.g., the upper threshold) above which RAN can initiate slice replacement. Alternatively, or in addition, the 0AM 140 may determine the second threshold (e.g., the lower threshold) below which slice can be considered not congested after a hysteresis timer is expired. In an example, the upper threshold, e.g., named as upperthresh dataUtilization perslice, may be assumed to be equal to Y (e.g., 900MB). The lower threshold, e.g., named as lowerthresh dataUtilization perslice, may be assumed to be equal to Z (e.g., 700MB). A time length of the hysteresis timer may be assumed to be equal to t sec (e.g., 10s).

[0067] In some example embodiments, prior to block 310, the 0AM 140 may prepare an IWF table or a similar table that stores the details such the number of terminal devices (e.g., UEs) attached to a particular slice and the data utilized. This table may be updated when a UE starts using a particular slice and the entry will be removed when the UE deregisters or stops using the slice.

[0068] At block 320, the 0AM 140 may calculate and monitor the data utilized per slice (e.g., calculatedtotalUEdatautilizationperSlice) every t s. Based on this information, the 0AM 140 may determine whether slice congestion occurs.

[0069] In some example embodiments, RAN may introduce two counters for slice congestion detection, for example, including Congestion threshold per Slice and Slice replacement initiated UEs. If the value of calculatedtotalUEdatautilizationperSlice exceeds upperthresh dataUtilization perslice at block 330, the process 300 may proceed to block 350 where the 0AM 140 may list all such UEs using the IWF table, increment the value of Congestion threshold per Slice, increment the value of Slice replacement initiated UEs with the calculated number of UEs and initiate slice replacement to all listed UEs.

[0070] If the value of calculatedtotalUEdatautilizationperSlice is less than upperthresh dataUtilization perslice at block 340, the process 300 may proceed to block 360 where for the listed UEs, the 0AM 140 may send a notification to replace UEs back to original slice (i.e., the first network slice 120-1) so that UEs are replaced back to its original slice. In addition, the 0 AM 140 may decrement the Slice replacement initiated UEs counter by the number of UEs replaced back and also decrement the Congestion threshold per Slice counter. In a case where all UEs arereplaced back and calculatedtotalUEdatautilizationperSlice is below the configured lowerthresh dataUtilization perslice, then the two counters calculatedtotalUEdatautilizationperSlice and Slice replacement initiated UEs may be reset.

[0071] FIG. 4 illustrates an example process 400 of slice replacement for UEs based on congestion detection at a slice level in accordance with some example embodiments of the present disclosure. The process 400 may be implemented by the 0AM 140 in FIG. 1. For the purpose of discussion, the process 400 will be described from the perspective of the 0AM 140.

[0072] As illustrated, in slice 1 410, once UE 1 412, UE 2 414 and UE n 416 exceeds the threshold 900MB (as an example of the first threshold), the 0AM 140 may send a notification to the 5G CN and slice replacement may be initiated. These UEs may be moved from slice 1 410 to slice 2 420 which has the threshold below 700MB (as an example of the second threshold). Once the data utilization is below 700 MB, 0AM sends notification to 5G CN and these UEs are moved back to slice 1 as before.

[0073] FIG. 5 illustrates a flowchart of another example process 500 of slice congestion detection and slice replacement based on delay in accordance with to some example embodiments of the present disclosure. The process 500 may be implemented at the 0AM 140 in FIG. 1. For the purpose of discussion, the process 500 will be described from the perspective of the 0AM 140.

[0074] As illustrated, at block 510, the 0AM 140 may determine the average PDCP delay (e.g., Average delay per Slice) a slice can withstand without packet discard. Average delay per Slice may be assumed to be equal to M (e.g., 0.9 microseconds). It is to be noted that the delay for PDCP service data unit (SDU) may be calculated as time difference between the reception of the PDCP SDU from Next Generation-User Plane Protocol (NG-U) and the transmission of DL PDCP protocol data unit (PDU) towards a radio link control (RLC) layer.

[0075] The 0AM 140 may also determine the additional buffer delay beyond which the packets may get discarded per slice after a hysteresis timer is expired. The buffer delay may have an upper limit (e.g., upperBuffer delay per Slice) and a lower limit (e.g., lowerBuffer delay per Slice). The upper limit may be assumed to be equal to N (e.g., 0.5 microseconds), and the lower limit may be assumed to be equal to L (e.g., 0.3microseconds). In an example, the time length of the hysteresis timer may be assumed to be equal to t s (e.g., 10s).

[0076] In some example embodiments, prior to block 510, the 0AM 140 may prepare a similar or same IWF table as described in the process 300. The following counters per slice may also be used, which include DL PDCP SDU delay per slice per Public Land Mobile Network (PLMN) (measurement in microseconds) and UL PDCP SDU delay per slice per PLMN (measurement in microseconds). Using the above counters, the counter DL Congestion Delay per Slice and / or UL Congestion Delay per Slice may be introduced to determine the maximum delay after which the counter can be incremented.

[0077] At block 520, the 0AM 140 may calculate and monitor DL congestion delay and / or UL congestion delay per slice every t s. At block 530, if a value of DL congestion delay or UL congestion delay exceeds the sum of Average delay per Slice and upperBuffer delay per Slice, the process 500 may proceed to block 550 where the 0AM 140 may list all such UEs using the IWF table, update the DL Congestion Delay per Slice counter or the UL Congestion Delay per Slice counter, increment the Slice replacement initiated UEs counter with the calculated number of UEs and initiate slice replacement to all listed UEs.

[0078] If DL congestion delay or UL congestion delay is less than the sum of Average delay per Slice and lowerBuffer delay per Slice at block 540, the process 500 may proceed to block 560 where for the listed UEs, the 0AM 140 may send a notification to replace UEs back to original slice so that UEs are replaced back to its original slice. In addition, the 0AM 140 may decrement the Slice replacement initiated UEs counter by the number of UEs replaced back and also decrement the DL Congestion Delay per Slice counter or the UL Congestion Delay per Slice counter. In a case where all UEs are replaced back and the calculated delay falls below the sum of Average delay per Slice and lowerBuffer delay per Slice, the counters Slice replacement initiated UEs, DL Congestion Delay per Slice and UL Congestion Delay per Slice may be reset.

[0079] In some example embodiments, an apparatus capable of performing any of the method 200 (for example, the 0AM 140 in FIG. 1) may comprise means for performing the respective operations of the method 200. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or softwaremodule. The apparatus may be implemented as or included in the OAM 140 in FIG. 1.

[0080] In some example embodiments, the apparatus comprises means for detecting congestion of a first network slice based on at least one parameter, the at least one parameter comprising at least one of an amount of data utilized in the first network slice, or a delay in the first network slice; and means for in response to detecting that the first network slice is congested, initiating replacement of the one or more terminal devices from the first network slice to a second network slice.

[0081] In some example embodiments, the congestion of the first network slice is detected using a table storing information related to the first network slice, the information indicating at least one of a number of terminal devices attached to the first network slice, an amount of data utilized by these terminal devices in the first network slice, or an average processing delay observed in the first network slice.

[0082] In some example embodiments, the table is updated in response to at least one of one or more terminal devices registering with or starting use of the first network slice, or one or more terminal devices deregistering with or stopping use of the first network slice.

[0083] In some example embodiments, the apparatus further comprises: means for determining that the first network slice is congested, based on a value of a parameter of the at least one parameter associated with the first network slice being equal to or greater than a value of a first threshold.

[0084] In some example embodiments, the parameter comprises the amount of data utilized in the first network slice, and the value of the first threshold is set based on an amount of data allowed in the first network slice.

[0085] In some example embodiments, the parameter comprises the delay in the first network slice, and the value of the first threshold is set based on a sum of an average delay and a first buffer delay in the first network slice.

[0086] In some example embodiments, a value of the first buffer delay is set as an upper limit of a buffer delay in the first network slice.

[0087] In some example embodiments, the apparatus further comprises: means for in response to detecting that the first network slice is congested, incrementing a first count of congestion of the first network slice.

[0088] In some example embodiments, the apparatus further comprises: means for determining the one or more terminal devices registered with first network slice, to be moved from the first network slice to the second network slice.

[0089] In some example embodiments, cause the apparatus to initiate the replacement by: sending a notification to a core network to move the one or more terminal devices from the first network slice to the second network slice.

[0090] In some example embodiments, the notification includes one or more identifiers of the one or more terminal devices to be moved.

[0091] In some example embodiments, the apparatus further comprises: means for in response to at least one terminal device of the one or more terminal devices having been moved from the first network slice to the second network slice, incrementing a second count of a number of terminal devices moved from the first network slice.

[0092] In some example embodiments, the apparatus further comprises: means for determining that the first network slice is no longer congested, based on a value of a parameter of the at least one parameter associated with the first network slice being equal to or less than a value of a second threshold; and means for sending a notification to a core network to move at least one terminal device of the one or more terminal devices back to the first network slice, based on the first network slice being no longer congested.

[0093] In some example embodiments, the parameter comprises the amount of data utilized in the first network slice, and the value of the second threshold is set based on an amount of data allowed in the first network slice.

[0094] In some example embodiments, the parameter comprises the delay in the first network slice, and the value of the second threshold is set based on a sum of an average delay and a second buffer delay in the first network slice.

[0095] In some example embodiments, a value of the second buffer delay is set as a lower limit of a buffer delay in the first network slice.

[0096] In some example embodiments, the apparatus further comprises: means for in response to determining that the first network slice is no longer congested, decrementing a first count of congestion of the first network slice.

[0097] In some example embodiments, the apparatus further comprises: means for inresponse to determining that a terminal device of the at least one terminal device having been moved back to the first network slice, decrementing a second count of a number of terminal devices moved from the first network slice.

[0098] In some example embodiments, the apparatus further comprises: means for in response to the one or more terminal devices moved from the first network slice being moved back to the first network device, resetting at least one of a first count of congestion of the first network slice, or a second count of a number of terminal devices moved from the first network slice.

[0099] In some example embodiments, the apparatus comprises an operation administration and maintenance device.

[0100] In some example embodiments, the apparatus further comprises means for performing other operations in some example embodiments of the method 200 or the 0AM 140. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the apparatus.

[0101] FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing example embodiments of the present disclosure. The device 600 may be provided to implement a communication device, for example, the 0AM 140 as shown in FIG. 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[0102] The communication module 640 is for bidirectional communications. The communication module 640 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 640 may include at least one antenna.

[0103] The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may havemultiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0104] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 624, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

[0105] A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The instructions of the program 630 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 630 may be stored in the memory, e.g., the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

[0106] The example embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 5. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0107] In some example embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0108] FIG. 7 shows an example of the computer readable medium 700 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 700has the program 630 stored thereon.

[0109] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0110] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non- transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0111] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0112] In the context of the present disclosure, the computer program code or relateddata may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0113] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0114] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

[0115] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:

1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: detect congestion of a first network slice based on at least one parameter, the at least one parameter comprising at least one of an amount of data utilized in the first network slice, or a delay in the first network slice; and in response to detecting that the first network slice is congested, initiate replacement of one or more terminal devices from the first network slice to a second network slice.

2. The apparatus of claim 1, wherein the congestion of the first network slice is detected using a table storing information related to the first network slice, the information indicating at least one of: a number of terminal devices attached to the first network slice, an amount of data utilized by these terminal devices in the first network slice, or an average processing delay observed in the first network slice.

3. The apparatus of claim 2, wherein the table is updated in response to at least one of: one or more terminal devices registering with or starting use of the first network slice, or one or more terminal devices deregistering with or stopping use of the first network slice.

4. The apparatus of any of claims 1 to 3, wherein the at least one memory and the at least one processor cause the apparatus to: determine that the first network slice is congested, based on a value of a parameter of the at least one parameter associated with the first network slice being equal to orgreater than a value of a first threshold.

5. The apparatus of claim 4, wherein the parameter comprises the amount of data utilized in the first network slice, and the value of the first threshold is set based on an amount of data allowed in the first network slice.

6. The apparatus of claim 4, wherein the parameter comprises the delay in the first network slice, and the value of the first threshold is set based on a sum of an average delay and a first buffer delay in the first network slice.

7. The apparatus of claim 6, wherein a value of the first buffer delay is set as an upper limit of a buffer delay in the first network slice.

8. The apparatus of any of claims 1 to 7, wherein the at least one memory and the at least one processor further cause the apparatus to: in response to detecting that the first network slice is congested, increment a first count of congestion of the first network slice.

9. The apparatus of any of claims 1 to 8, wherein the at least one memory and the at least one processor further cause the apparatus to: determine the one or more terminal devices registered with first network slice, to be moved from the first network slice to the second network slice.

10. The apparatus of any of claims 1 to 9, wherein the at least one memory and the at least one processor cause the apparatus to initiate the replacement by: sending a notification to a core network to move the one or more terminal devices from the first network slice to the second network slice.

11. The apparatus of claim 10, wherein the notification includes one or moreidentifiers of the one or more terminal devices to be moved.

12. The apparatus of any of claims 1 to 11, wherein the at least one memory and the at least one processor further cause the apparatus to: in response to at least one terminal device of the one or more terminal devices having been moved from the first network slice to the second network slice, increment a second count of a number of terminal devices moved from the first network slice.

13. The apparatus of any of claims 1 to 12, wherein the at least one memory and the at least one processor further cause the apparatus to: determine that the first network slice is no longer congested, based on a value of a parameter of the at least one parameter associated with the first network slice being equal to or less than a value of a second threshold; and send a notification to a core network to move at least one terminal device of the one or more terminal devices back to the first network slice, based on the first network slice being no longer congested.

14. The apparatus of claim 13, wherein the parameter comprises the amount of data utilized in the first network slice, and the value of the second threshold is set based on an amount of data allowed in the first network slice.

15. The apparatus of claim 13, wherein the parameter comprises the delay in the first network slice, and the value of the second threshold is set based on a sum of an average delay and a second buffer delay in the first network slice.

16. The apparatus of claim 15, wherein a value of the second buffer delay is set as a lower limit of a buffer delay in the first network slice.

17. The apparatus of any of claims 13 to 15, wherein the at least one memory andthe at least one processor further cause the apparatus to: in response to determining that the first network slice is no longer congested, decrement a first count of congestion of the first network slice.

18. The apparatus of any of claims 13 to 17, wherein the at least one memory and the at least one processor further cause the apparatus to: in response to determining that a terminal device of the at least one terminal device having been moved back to the first network slice, decrement a second count of a number of terminal devices moved from the first network slice.

19. The apparatus of any of claims 13 to 18, wherein the at least one memory and the at least one processor further cause the apparatus to: in response to the one or more terminal devices moved from the first network slice being moved back to the first network device, reset at least one of a first count of congestion of the first network slice, or a second count of a number of terminal devices moved from the first network slice.

20. The apparatus of any of claims 1 to 19, wherein the apparatus comprises an operation administration and maintenance device.

21. A method comprising: detecting congestion of a first network slice based on at least one parameter, the at least one parameter comprising at least one of an amount of data utilized in the first network slice, or a delay in the first network slice; and in response to detecting that the first network slice is congested, initiating replacement of the one or more terminal devices from the first network slice to a second network slice.

22. An apparatus comprising:means for detecting congestion of a first network slice based on at least one parameter, the at least one parameter comprising at least one of an amount of data utilized in the first network slice, or a delay in the first network slice; and means for in response to detecting that the first network slice is congested, initiating replacement of the one or more terminal devices from the first network slice to a second network slice.

23. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 21.

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