Latency-based over-zone handover

Abstract

A method is disclosed, comprising: determining, by an apparatus, whether an over-zone handover of a target user node of a plurality of user nodes may cause a latency of one or more links between the target user node and one or more other user nodes of the plurality of user nodes to be greater than a tolerable latency; selecting, by the apparatus, a subset of the plurality of user nodes for over-zone handover based at least in part on the determination, where the subset includes at least the target user node; selecting, by the apparatus, a target access point from the plurality of access points for the over-zone handover; and transmitting, by the device to a subset of the plurality of user nodes, an indication to perform a cross-zone handover from the device to the target access point.

Description

Technical Field

[0001] The following exemplary embodiments relate to wireless communication. Background Art

[0002] Some wireless communication applications may require low communication latency. Therefore, solutions for reducing communication latency are desired. Summary of the Invention

[0003] The scope of protection sought for each exemplary embodiment is set forth by the independent claims. The exemplary embodiments and features (if any) described in this specification that do not fall within the scope of the independent claims should be construed as examples useful for understanding the various embodiments.

[0004] According to one aspect, there is provided an apparatus including at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine whether a handover of a target user node among a plurality of user nodes will result in a latency of one or more links between the target user node and one or more other user nodes among the plurality of user nodes being greater than a tolerable latency; select, at least in part based on the determination, a subset of the plurality of user nodes for the handover, where the subset includes at least the target user node; select a target access point from a plurality of access points for the handover; and transmit an indication for performing a handover from the apparatus to the target access point to the subset of the plurality of user nodes.

[0005] According to another aspect, there is provided a device including: means for determining whether a handover of a target user node among a plurality of user nodes will result in a latency of one or more links between the target user node and one or more other user nodes among the plurality of user nodes being greater than a tolerable latency; means for selecting, at least in part based on the determination, a subset of the plurality of user nodes for the handover, where the subset includes at least the target user node; means for selecting a target access point from a plurality of access points for the handover; and means for transmitting an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

[0006] According to another aspect, a method is provided, including: determining, by a device, whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; selecting, by the device, at least partially based on the determination, a subset of the plurality of user nodes for the handover, where the subset at least includes the target user node; selecting, by the device, a target access point from a plurality of access points for the handover; and transmitting, by the device, an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

[0007] According to another aspect, a computer program including instructions is provided, which when executed by a device causes the device to at least perform the following: determining whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; selecting, at least partially based on the determination, a subset of the plurality of user nodes for the handover, where the subset at least includes the target user node; selecting a target access point from a plurality of access points for the handover; and transmitting an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

[0008] According to another aspect, a computer-readable medium including program instructions is provided, which when executed by a device causes the device to at least perform the following: determining whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; selecting, at least partially based on the determination, a subset of the plurality of user nodes for the handover, where the subset at least includes the target user node; selecting a target access point from a plurality of access points for the handover; and transmitting an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

[0009] According to another aspect, there is provided a non-transitory computer-readable medium including program instructions that, when executed by a device, cause the device to at least perform the following: determine whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; select, at least in part based on the determination, a subset of the plurality of user nodes for the handover, where the subset includes at least the target user node; select a target access point from a plurality of access points for the handover; and transmit an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

[0010] According to another aspect, there is provided a system including at least a target user node and an access point of a wireless communication network. The access point is configured to: determine whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; select, at least in part based on the determination, a subset of the plurality of user nodes for the handover, where the subset includes at least the target user node; select a target access point from a plurality of access points for the handover; and transmit an indication for performing a handover from the access point to the target access point to the subset of the plurality of user nodes. The target user node is configured to: receive the indication from the access point; and perform a handover from the access point to the target access point based on the indication.

[0011] According to another aspect, there is provided a system including a target user node and an access point of a wireless communication network. The access point includes means for: determining whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; selecting, at least in part based on the determination, a subset of the plurality of user nodes for the handover, where the subset includes at least the target user node; selecting a target access point from a plurality of access points for the handover; and transmitting an indication for performing a handover from the access point to the target access point to the subset of the plurality of user nodes. The target user node includes means for: receiving the indication from the access point; and performing a handover from the access point to the target access point based on the indication. Description of the Drawings

[0012] Hereinafter, various exemplary embodiments will be described in more detail with reference to the drawings, where

[0013] Figure 1 Illustrates an example of a cellular communication network;

[0014] Figure 2A Illustrates an example of a modular sub - network in a robot / in production;

[0015] Figure 2B Illustrates an example of a vehicular sub - network;

[0016] Figure 2C Illustrates an example of an in - body sub - network;

[0017] Figure 2D Illustrates an example of a sub - network inside a house;

[0018] Figure 3A Illustrates an example of the increased end - to - end delay caused by handover of a user equipment;

[0019] Figure 3B Illustrates an example of the increased end - to - end delay caused by handover of a user equipment;

[0020] Figure 4 Illustrates a signaling diagram;

[0021] Figure 5 Illustrates a flowchart;

[0022] Figure 6 Illustrates a flowchart;

[0023] Figure 7 Illustrates a flowchart;

[0024] Figure 8 Illustrates an example of a list of access point channel qualities;

[0025] Figure 9 Illustrates an example of a list of user groups; and

[0026] Figure 10 Illustrates an example of a device. Detailed implementation manners

[0027] The following embodiments are exemplary. Although the specification may refer to "one", "a" or "some" embodiments at multiple places in the text, this does not necessarily mean that each reference is to the same embodiment, or that a particular feature is only suitable for a single embodiment. Individual features of different embodiments can also be combined to provide other embodiments.

[0028] Next, a wireless access architecture based on Long-Term Evolution Advanced (LTE-A), New Radio (NR, 5G), Ultra 5G, or Sixth Generation (6G) will be used as an example of an access architecture to which these example embodiments can be applied to describe different example embodiments. However, the example embodiments are not limited to such an architecture. It will be apparent to those skilled in the art that, by appropriately adjusting parameters and procedures, the example embodiments can also be applied to other types of communication networks with suitable devices. Some examples of other options for suitable systems can be Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Long-Term Evolution (LTE, essentially the same as E-UTRA), Wireless Local Area Network (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Personal Communication Service (PCS), Wideband Code Division Multiple Access (WCDMA), systems using Ultra-Wideband (UWB) technology, sensor networks, Mobile Ad Hoc Networks (MANET), and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof.

[0029] Figure 1 An example of a simplified system architecture is described, in which some elements and functional entities are shown. They are all logical units, and their implementations can be different from those shown. Figure 1 The connections shown are logical connections; the actual physical connections can be different. It will be apparent to those skilled in the art that the system can also include other functions and structures in addition to Figure 1 those shown.

[0030] However, the example embodiments are not limited to the system given as an example, but those skilled in the art can apply the solution to other communication systems with the necessary attributes.

[0031] Figure 1 The example of... illustrates a part of an exemplary radio access network.

[0032] Figure 1User equipments 100 and 102 are shown, which are configured to wirelessly connect with an access point (AP) 104 providing a radio cell (such as an evolved NodeB (abbreviated as eNB or eNodeB) or a next-generation NodeB (abbreviated as gNB or gNodeB)) on one or more communication channels in the radio cell. The physical link from the user equipment to the access point can be referred to as the uplink (UL) or reverse link, and the physical link from the access point to the user equipment can be referred to as the downlink (DL) or forward link. The user equipment can also communicate directly with another user equipment via sidelink (SL) communication. It should be understood that the access point or its functions can be implemented by any entity such as a node, host, server, or access point suitable for this purpose.

[0033] The communication system can include multiple access points. In this case, these access points can also be configured to communicate with each other via wired or wireless links designed for this purpose. These links can be used for signaling purposes and also for routing data from one access point to another. The access point can be a computing device configured to control the radio resources of the communication system to which it is coupled. The access point can also be referred to as a base station, base transceiver station (BTS), access node, or any other type of interface device (including a relay station capable of operating in a wireless environment). The access point can include or be coupled to a transceiver. A connection to an antenna unit can be provided from the transceiver of the access point, and the antenna unit establishes a two-way radio link to the user equipment. The antenna unit can include multiple antennas or antenna elements. The access point can also be connected to a core network 110 (CN or next-generation core NGC). Depending on the technology deployed, the corresponding parties that the access point can be connected to on the CN side can be a serving gateway (S-GW, routing and forwarding user data packets), a packet data network gateway (P-GW) for providing a connection between the user equipment and an external packet data network, a user plane function (UPF), a mobility management entity (MME), or an access and mobility management function (AMF), etc.

[0034] The user equipment illustrates a type of device that can allocate and specify resources on the air interface, and thus any feature described herein regarding the user equipment can be implemented with a corresponding device (such as a relay node).

[0035] An example of such a relay node can be a layer 3 relay (self-backhaul relay) towards an access point. The self-backhaul relay node can also be referred to as an integrated access and backhaul (IAB) node. The IAB node can include two logical parts: a mobile terminal (MT) part, responsible for the (multiple) backhaul links (i.e., the link between the IAB node and the donor node (also called the parent node)); and a distributed unit (DU) part, responsible for the (multiple) access links, i.e., the sub-links between the IAB node and the user equipment and / or between the IAB node and other IAB nodes (multi-hop scenario).

[0036] Another example of such a relay node can be a layer 1 relay called a repeater. The repeater can amplify the signal received from the access point and forward it to the user equipment, and / or amplify the signal received from the user equipment and forward it to the access point.

[0037] The user equipment can also be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, user node, terminal device, or user equipment (UE), to name but a few. The user equipment can refer to a portable computing device including a wireless mobile communication device operating with or without a subscriber identity module (SIM), including but not limited to the following types of devices: mobile stations (mobile phones), smartphones, personal digital assistants (PDAs), cellular phones, devices using a wireless modem (such as alarm or measurement devices, etc.), laptop computers and / or touchscreen computers, tablets, gaming consoles, notebooks, multimedia devices, reduced-capability (RedCap) devices, wireless sensor devices, or any device integrated in a vehicle.

[0038] It should be understood that the user equipment can also be an almost exclusive uplink-only device, an example of which can be a camera or video camera that loads images or video clips onto the network. The user equipment can also be a device capable of operating in an Internet of Things (IoT) network, which is a scenario where objects can have the ability to transmit data over a network without human-to-human or human-to-computer interaction. The user equipment can also utilize the cloud. In some applications, the user equipment may include small portable or wearable devices with radio components (such as watches, headphones, or glasses), and the computing can be performed in the cloud or in another user equipment. The user equipment (or in some example embodiments, the layer 3 relay node) can be configured to perform one or more user equipment functions.

[0039] The various techniques described herein can also be applied to cyber - physical systems (CPSs) (systems of collaborative computing elements that control physical entities). CPSs can implement and utilize a large number of interconnected ICT devices (sensors, actuators, processor microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber - physical systems are a sub - category of cyber - physical systems, where the physical systems under discussion can have inherent mobility. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals.

[0040] In addition, although these devices are described as a single entity, different units, processors, and / or storage units can be implemented ( Figure 1 not all of which are shown in

[0041] 5G can use multiple - input multiple - output (MIMO) antennas, more base stations or nodes than LTE (the so - called small cell concept), including macro - sites that cooperate with small sites, and employ various radio technologies depending on service requirements, use cases, and / or available spectrum. 5G mobile communications can support a wide range of use cases and related applications, including video streaming, augmented reality, different ways of data sharing, and various forms of machine - type applications (such as (massive) machine - type communication (mMTC), including vehicle safety, different sensors, and real - time control. 5G may have multiple radio interfaces, namely sub - 6 GHz, centimeter - wave, and millimeter - wave, and be able to integrate with existing traditional radio access technologies (such as LTE). The integration with LTE can be implemented as, for example, a system where LTE can provide macro - coverage, while 5G radio interface access can be achieved through small cells aggregated to LTE. In other words, 5G can support cross - RAT operability (such as LTE - 5G) and cross - RI operability (cross - radio interface operability, such as sub - 6 GHz - centimeter - wave - millimeter - wave). One of the concepts considered in 5G networks can be network slicing, where multiple independent and dedicated virtual sub - networks (network instances) can be created within substantially the same infrastructure to run services with different requirements for latency, reliability, throughput, and mobility.

[0042] The current architecture in LTE networks can be fully distributed in the radio and fully centralized in the core network. Low-latency applications and services in 5G may require content to be closer to the radio, leading to local breakout and multi-access edge computing (MEC). 5G can enable analysis and knowledge generation to occur at the data source. This approach may require leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC can provide a distributed computing environment for hosting applications and services. It also has the ability to store and process content very close to cellular users for faster response times. Edge computing can cover a wide range of technologies, such as wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer ad hoc networking and processing, and can also be classified as local cloud / fog computing and grid / mesh computing, dew computing, mobile edge computing, cloudlets, distributed data storage and retrieval, self-healing autonomous networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and / or latency-critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

[0043] The communication system can also communicate with one or more other networks 113 (such as the public switched telephone network or the Internet) or utilize the services they provide. The communication network can also support the use of cloud services, for example, at least a portion of the core network operations can be performed as cloud services (which is described by the "cloud" 114 in Figure 1 this). The communication system can also include a central control entity, etc., to provide facilities for networks of different operators to cooperate, for example, in spectrum sharing.

[0044] The access point can also be divided into: a radio unit (RU) including a radio transceiver (TRX), i.e., a transmitter (Tx) and a receiver (Rx); one or more distributed units (DU) 105, which can be used for so-called layer 1 (L1) processing and real-time layer 2 (L2) processing; and a central unit (CU) 108 (also referred to as a centralized unit), which can be used for non-real-time L2 and layer 3 (L3) processing. The CU 108 can be connected to one or more DUs 105 via, for example, the F1 interface. This split can centralize the CU relative to the cell site and the DU, while the DU can be more distributed and can even remain at the cell site. The CU and the DU can also be collectively referred to as the baseband or baseband unit (BBU). The CU and the DU can also be included in the radio access point (RAP).

[0045] CU 108 can be defined as a logical node that bears higher layer protocols for the access point, such as Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and / or Packet Data Convergence Protocol (PDCP). DU 105 can be defined as a logical node that bears the Radio Link Control (RLC), Media Access Control (MAC), and / or Physical (PHY) layers of the access point. The operation of the DU is at least partially controlled by the CU. The CU may include a Control Plane (CU-CP), which can be defined as a logical node that bears the RRC protocol and the control plane part of the PDCP for the CU of the access point. The CU may also include a User Plane (CU-UP), which can be defined as a logical node that bears the user plane part of the PDCP protocol and the SDAP protocol for the CU of the access point.

[0046] The cloud computing platform can also be used to run CU 108 and / or DU 105. The CU can run in the cloud computing platform and can be referred to as a virtualized CU (vCU). In addition to the vCU, a virtualized DU (vDU) may also run in the cloud computing platform. Furthermore, there may also be a combination where the DU can use a so-called bare metal solution, such as an Application Specific Integrated Circuit (ASIC) or a Customer-Specific Standard Product (CSSP) System-on-Chip (SoC) solution. It should also be understood that the functional distribution between the above-mentioned access point units, or between different core network operations and access point operations, can be different.

[0047] Network Function Virtualization (NFV) and Software Defined Network (SDN) can be utilized to introduce edge cloud into the Radio Access Network (RAN). Using the edge cloud can mean that the access point operation is at least partially executed in a server, host, or node that is operably coupled to a Remote Radio Head (RRH) or Radio Unit (RU) or an access point including radio components. The node operation can also be distributed among multiple servers, nodes, or hosts. The application of the cloudRAN architecture can enable the RAN real-time functions to be executed on the RAN side (e.g., in DU 105), and the non-real-time functions can be executed in a centralized manner (e.g., in CU 108).

[0048] It should also be understood that the functional distribution between the core network operation and the access point operation can be different from that of LTE or even non-existent. Some other technological advancements that can be used include big data and all-IP, which can change the way the network is built and managed. The 5G (or New Radio, NR) network can be designed to support multiple multi-level architectures, where the MEC server can be placed between the core and the access point. It is worth mentioning that MEC can also be applied to the 4G network.

[0049] 5G can also enhance or supplement the coverage of 5G services by leveraging non-terrestrial communications (e.g., satellite communications), such as by providing backhaul. Possible use cases can provide service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or in-vehicle passengers, or ensure service availability for critical communications and future railway / maritime / aviation communications. Satellite communications can utilize geostationary orbit (GEO) satellite systems or low Earth orbit (LEO) satellite systems, especially megaconstellations (systems with hundreds of (nano)satellites deployed). A given satellite 106 in a megaconstellation can cover several satellite-enabled network entities that create terrestrial cells. Terrestrial cells can be created by terrestrial relay nodes or access points 104 located on the ground or on satellites.

[0050] It will be obvious to those skilled in the art that the described system is merely an example of a part of a radio access system and that in practice, the system may include multiple access points, user equipment may have access to multiple radio cells, and the system may also include other devices such as physical layer relay nodes or other network elements, etc. At least one of the access points may be a home eNodeB or a home gNodeB.

[0051] In addition, in the geographical area of a radio communication system, multiple different types of radio cells and multiple radio cells may be provided. Radio cells can be macrocells (or umbrella cells), which can be large cells with diameters up to several tens of kilometers, or smaller cells such as microcells, femtocells, or picocells. Figure 1 The access points can provide any of these types of cells. A cellular radio system can be implemented as a multi-layer network including several radio cells. In a multi-layer network, one access point can provide one or more radio cells, and thus multiple access points may be required to provide such a network structure.

[0052] To meet the requirements for improving the deployment and performance of communication systems, the concept of "plug-and-play" access points can be introduced. Networks capable of using "plug-and-play" access points may also include a home node B gateway or HNB-GW ( Figure 1 (not shown in the figure). The HNB-GW, which can be installed within the operator's network, aggregates traffic from a large number of home eNodeBs or home gNodeBs back to the core network.

[0053] 6G networks are expected to adopt flexible decentralized and / or distributed computing systems and architectures and ubiquitous computing, with local spectrum licensing, spectrum sharing, infrastructure sharing and intelligent automation management based on mobile edge computing, artificial intelligence, short packet communications and blockchain technology. Key features of 6G may include intelligent connection management and controller functions, programmability, integrated sensing and communication, reduced energy footprint, trusted infrastructure, scalability and affordability. In addition to this, 6G also targets new use cases, covering the integration of positioning and perception capabilities into system definitions to unify user experience in the physical and digital worlds.

[0054] Some example embodiments relate to the scenario of a sub-network integrated into an X network with a multi-AP architecture. The sub-network integrated into the X network is envisioned as a new network architecture paradigm for certain 6G short-range scenarios with high reliability and low latency requirements. Figure 2A , Figure 2B , Figure 2C and Figure 2D Some examples of sub-networks integrated into the X network are shown.

[0055] Figure 2A An example of an in-robotics / in-production module sub-network 210 is illustrated.

[0056] Figure 2B An example of an onboard sub-network 220 is illustrated.

[0057] Figure 2C An example of an in vivo sub-network 230 is illustrated.

[0058] Figure 2D An example of an in-premises sub-network 240 is illustrated.

[0059] The sub-networks may have the following attributes and technical characteristics: 1) support extreme performance requirements in terms of latency, reliability and / or throughput; 2) low transmit power, which means limited coverage (e.g., on the order of a few meters); 3) star or tree topology, with one AP integrated into the X network and one or more UEs integrated into the X network controlled by the AP; 4) overall mobility of the AP and associated UEs, but lack of / limited mobility on different sub-networks; 5) cover part of a wide area network (WAN), but need to continue to work outside the network coverage.

[0060] However, it should be noted that some example embodiments are not limited to sub-networks integrated into the X-network, and they may be applicable to any wireless network in cellular technology with a multi-AP architecture where low latency communications are beneficial as part of the service.

[0061] In a multi-AP subnetwork, user nodes can ideally connect to the AP with the best direct link. It can also be assumed that groups of user nodes performing the same task or connected to the same controller are located near each other and are thus more likely to connect to the same AP.

[0062] In this document, the term "user node" refers to a user of wireless communication. For example, a user node can include a user equipment (also known as UE) or an edge function, such as a controller function (CF).

[0063] Figure 3A and Figure 3B Illustrates some examples of end-to-end (E2E) traffic flows in the subnetwork.

[0064] Figure 3A Illustrates an example of increased E2E latency due to user equipment handover. In Figure 3A , a first user equipment 301 is communicating with a second user equipment 302 in the same subnetwork (these user equipments can be, for example, sensors, controllers, or actuators). The E2E traffic link between the two user equipments 301, 302 is mediated by at least one primary AP 303 and can have one or more other secondary APs 304 involved.

[0065] Refer to Figure 3A , in box 300, an initial setup is performed to connect the two user equipments 301, 302 to the same AP 303, and the E2E packet transmission between the user equipments 301, 302 passes through one AP 303.

[0066] In box 310, the first user equipment 301 is handed over to another AP 304. Therefore, compared to box 300, the link between the two user equipments 301, 302 experiences a longer E2E latency because the packets need to be exchanged between the two APs 303, 304 when passing between the user equipments 301, 302.

[0067] Figure 3B Illustrates another example of increased E2E latency caused by user equipment handover. In Figure 3B , a first user equipment 321 is communicating with a CF 322 acting as an edge function at the primary AP 323. The edge function is a software-defined function, such as a software-defined direct current (DC) motor controller, which is located in the edge cloud, in this case, the edge cloud at the primary AP 323.

[0068] Refer to Figure 3B , in box 320, an initial setup is performed where the controller function 322 for the first user equipment 321 is located at the serving AP 323 of the first user equipment 321.

[0069] In block 330, the first user equipment 321 hands over from AP 323 to another AP 324. Thus, compared to block 320, the link between the first user equipment 321 and its controller function 322 experiences a longer E2E latency.

[0070] User nodes connected to the same AP can take advantage of the low E2E latency because the traffic between these user nodes can be processed by the edge processing unit in the connected AP. As the link quality naturally varies, it is a possible scenario for one or more user nodes to hand over from one AP to another AP, for example, in a dynamic environment with moving obstacles, such as in an industrial motion control sub-network, to maintain communication reliability.

[0071] By switching (handing over) one user node to a different AP, an additional communication hop and its imposed latency are added to the E2E latency experienced by the traffic. For example, in Figure 3B the case where, since the CF 322 remains in the same AP 323, after the user equipment 321 hands over to a different AP 324, the E2E link between the user equipment 321 and CF322 spans at least two channel hops. Thus, for example, in a low-latency use case, when a user node needs to hand over between APs and needs to maintain a low E2E latency, tracking such handovers is beneficial.

[0072] Some example embodiments can solve this problem and provide a solution based on the "group handover" concept to reduce the operation latency of sub-network devices integrated in the X network, for example. However, it should be noted that some example embodiments are not limited to sub-networks and they can be applied to any wireless communication network with mobile user nodes.

[0073] Some example embodiments can be used to monitor the group handover requirements of user nodes (e.g., user equipment and / or edge functions) based on the channel quality and quality of service (QoS) requirements of the user nodes; minimize the amount of group handover requests by optimizing the subset of user nodes used for handover and the selection of corresponding target APs for that subset; and force handovers for user nodes that generally do not require handovers (e.g., based on the good channel quality of the currently serving AP) to provide system-level E2E low-latency services.

[0074] Some example embodiments may be beneficial for sub-network user nodes having, for example, strict latency requirements. The presence of multiple sub-network APs allows for better coverage and improved reliability (e.g., through multi-AP transmission / reception). By performing group handover simultaneously, the additional latency imposed on the link during the handover operation by all user nodes within the same group can be reduced. Group handover may be required for at least some of the user nodes within the same group having the strictest latency requirements.

[0075] Figure 4 A signaling diagram is illustrated according to an example embodiment of group handover operation for a multi-AP wireless sub-network.

[0076] Referring Figure 4 , in block 401, multiple user nodes in the sub-network transmit measurement information to the serving AP. The serving AP may also share the measurement information with one or more other APs. The measurement information may indicate the channel quality between a given user node and one or more APs (e.g., the serving AP and / or one or more other APs), and / or the channel quality between multiple user nodes.

[0077] As used herein, the term "user node" refers to a user of wireless communication. For example, a user node may include a user equipment (also referred to as UE) or an edge function, such as a CF.

[0078] In block 402, the serving AP measures the channel quality to user nodes in the sub-network. For example, when a user node transmits a pilot signal (reference signal), the serving AP evaluates the channel quality between the serving AP and the given user node by measuring the received signal power of the pilot signal.

[0079] As used herein, the term "channel" refers to the wireless medium between two wireless devices (e.g., a user node and an AP).

[0080] In block 403, one or more other APs in the sub-network measure their channel quality to user nodes in the sub-network.

[0081] In block 404, one or more other APs report to the serving AP information indicating the channel quality between the one or more other access points and user nodes in the sub-network. In other words, the serving AP may act as a central coordinator to collect channel quality measurement values from APs in the sub-network.

[0082] Step 405: The serving AP generates an AP channel quality list and a user group list. The AP channel quality list may also be referred to as the first list herein, and the user group list may also be referred to as the second list herein.

[0083] The AP link quality list can be centrally generated at the serving AP based on the channel quality measurements of the APs in the subnet. Alternatively, the AP channel quality list can also be collected or generated separately at each AP. For example, each AP can measure the link quality to different user nodes and then generate a summary AP channel quality list by sharing this information among the APs in the subnet. For example, this information exchange can be performed periodically.

[0084] The AP channel quality list indicates the APs available in the subnet and the corresponding channel quality between these APs and the user nodes in the subnet. The channel quality can be a time-varying quantity, which can be re-measured and updated according to the change rate. The AP channel quality list can be updated periodically or on demand for one user node or a group of user nodes, for example, when it is determined to initiate a handover (HO) of one or more user nodes (i.e., when it is considered necessary to perform a handover for one or more user nodes). In Figure 8 An example of the AP channel quality list is illustrated.

[0085] The user group list indicates the user nodes in one or more user groups and the multiple links between the multiple user nodes in a given user group. The user group list can also indicate, for each of the multiple links between the multiple user nodes, a first value (denoted as R) representing the tolerable delay of the link and a second value (denoted as L) representing the delay of the link. An example of the user group list is as Figure 9 shown.

[0086] For example, the user group list can be generated through the interface between the enterprise controller and the serving AP, where the enterprise controller knows which user nodes belong to the same group and which links are established between them. In addition, in some cellular networks, when a service link is established, for example, at the Transmission Control Protocol (TCP) / Internet Protocol (IP) level between two user nodes, the core network may be able to track it and share this information with the radio network node (e.g., the serving AP). For the subnet, most services can be processed "locally", which means that an underlying protocol similar to TCP / IP can be used to establish links between user nodes. The interface between this protocol and the scheduler of the serving AP can be used to collect the user group list information.

[0087] In this article, the term "link" refers to the end-to-end service link between two user nodes (e.g., between two user devices or between a user device and an edge function block). In this article, the term "service" can refer to data service.

[0088] A given user group may include one or more user devices and / or one or more edge functions that communicate with each other. For example, a motion control user group may include a CF, where the CF is connected to one or more actuator / sensor user devices and controls these devices. The CF and the user devices connected to it may form a user group. Note that a wireless network (including sub-networks) may serve one or more user groups.

[0089] Each link in the user group (e.g., the link between an actuator user device and the CF, or the link between two user devices) can be assigned a value pair (R, L), where R is the tolerable delay, e.g., the number of communication hops tolerable under the E2E requirements for a given traffic link, and L is the actual delay in the link, e.g., the number of hops the packet actually travels when communicating between the two ends of the link (e.g., for a 1 ms delay requirement, R = 2 hops can be tolerated, and for a 0.5 ms delay, R = 1 hop can be tolerated). The goal is to have L ≤ R for all links.

[0090] The user group list can be updated based on the traffic links added (initiated) or deleted (terminated) in the sub-network, or based on the user nodes added to or removed from the sub-network.

[0091] In block 406, the target user node transmits a channel quality update to the serving AP. Here, the term "target user node" refers to the user node that is to handover from the serving AP to another AP. Considering the time-varying characteristics of the channel, the channel quality report transmitted by the user node can be updated periodically or on demand. If the channel quality update indicates a degradation in channel quality, a handover may be required.

[0092] In block 407, based on the channel quality update, the serving AP detects the need for the target user node to handover to another AP. For example, when the channel from the target user node to the serving AP is estimated or measured as a poor channel, the serving AP can detect the need for a handover.

[0093] In block 408, the serving AP determines whether the handover of the target user node will cause the delay of one or more links between the target user node and one or more other user nodes in the same user group to be greater than the tolerable delay.

[0094] In block 409, based on the determination in block 408, the serving AP selects or identifies a subset of user nodes from the user group for simultaneous group handover. The subset of user nodes includes at least the target user node and may also include one or more other user nodes from the same user group. The subset of user nodes can be selected at least in part based on the user group list (the second list).

[0095] A subset of user nodes can be referred to as the “target HO list” in this document, and it can be selected to minimize the number of handovers while ensuring that for all links L ≤ R and the AP channel quality of all user nodes in the subnetwork is higher than the desired threshold.

[0096] For example, if a handover of a target user node will cause one or more links to satisfy L > R (i.e., the latency generated after the handover is greater than the tolerable latency), then a subset of user nodes in the user group can be identified accordingly, and the subnetwork initiates a simultaneous group handover for these user nodes. In other words, based on the determination that the handover of the target user node will cause the latency of one or more links between the target user node and one or more other user nodes to be greater than the tolerable latency, a subset of user nodes can be selected to include the target user node and one or more other user nodes. The serving AP can force the handover for one or more other user nodes even if they may not need a handover, i.e., the channel quality between the serving AP and the one or more other user nodes can be higher than the channel quality threshold.

[0097] Alternatively, a subset of user nodes can be selected to include only the target user node based on the determination that the handover of the target user node will not cause the latency of one or more links between the target user device and one or more other user nodes to be greater than the tolerable latency.

[0098] In block 410, the serving AP selects or identifies a target AP for group handover based on the AP channel quality list (the first list). If as a result of the handover, all links (for the same user group to which the target user node belongs) satisfy L ≤ R, then the best AP for the handover of the target user node can be identified based on the AP channel quality list of the target user node. In other words, the target access point can be selected by comparing the channel quality between the target user node and multiple access points in the AP channel quality list and selecting the access point with the highest channel quality among the multiple access points. The target AP refers to the AP to which the subset of user nodes handovers from the serving AP.

[0099] In block 411, the serving AP transmits a handover request to the target AP to request the handover of the subset of user nodes from the serving AP to the target AP. In the case where an edge function (such as CF) is in the target HO list for group handover, the serving AP can also (e.g., via a wireless connection between APs) provide the function attributes and required stored data for the edge function to the target AP.

[0100] In block 412, the target AP transmits a response message to the serving AP to indicate that the handover is accepted.

[0101] In block 413, the serving AP transmits an indication (e.g., a handover command and an RRC reconfiguration) to a subset of user nodes (e.g., the target user node and one or more other user nodes) for performing a handover of the subset of user nodes from the serving AP to the target AP.

[0102] In block 414, based on the indication, the target user node performs a handover from the serving AP to the target AP.

[0103] In block 415, based on the indication, one or more other user nodes perform a handover from the serving AP to the target AP (if they are so indicated).

[0104] In block 416, the subset of user nodes transmits a reconfiguration complete message to the target AP to indicate that the handover has been successfully completed.

[0105] Figure 5 The flowchart illustrates an algorithm for selecting a subset of user nodes and a target AP for handover according to an example embodiment. For example, the algorithm can be executed at a Figure 4 serving access point for identifying a subset of user nodes in block 408 and for identifying a target AP in block 409.

[0106] When a user node (referred to herein as the target user node) in a subnetwork needs to handover from one AP to another AP, the subnetwork should ensure that the E2E link meets the E2E delay requirement after the handover is completed. Therefore, the subnetwork can predict the change in the E2E delay of the link before the actual handover is executed. Thus, the R and L values of each link can be calculated in order to find the best handover arrangement. If, as a result of the handover, one or more links satisfy L > R (i.e., the resulting delay is greater than the tolerable delay), the subnetwork may need to take further measures.

[0107] To this end, a subset of user nodes (target HO list) in the user group of the target user node can be identified, and the subnetwork can initiate a simultaneous group handover of these user nodes. The subset can include the target user node, or the target user node and one or more other user nodes within the user group, or all user nodes within the user group. The subset can be selected to minimize the number of handovers while ensuring that for all links L ≤ R and the AP channel quality of all user nodes is higher than the required threshold.

[0108] It should be noted that Figure 5 only one example embodiment for implementing such a constraint is illustrated, and an algorithm different from the Figure 5 algorithm shown in can also be used to implement such a constraint.

[0109] Refer to Figure 5, in block 501, a "target HO list" is generated, where the target HO list initially includes the target user node. During the iterative process, other user nodes in the user group of the target user node can be added to the target HO list. The goal is to keep the list as small as possible to reduce the handover load. At the end of the algorithm, all user nodes in the target HO list will complete the handover together. The goal of this algorithm is to find an AP that satisfies at least the following conditions: the channel quality of all user nodes in the target HO list is higher than the expected threshold; and all user nodes in the user group satisfy the updated L ≤ R. If no such AP is found, all nodes in the target group can perform the handover together.

[0110] In block 502, the algorithm searches the user group list for links to and from the target user node with R - L < 1.

[0111] If none of the links to / from the target user node have R - L < 1 (block 502: no), then the target HO list will only include the target user node, and the algorithm continues to block 503, then to block 504, that is, perform the handover to the best AP for the target user node, and the L values of these links can be updated according to the handover arrangement. Otherwise, if one or more links to / from the target user node have R - L < 1 (block 502: yes), then the algorithm continues to block 505.

[0112] In block 503, based on the AP channel quality list, a suitable target AP for handover is selected such that the handover of the target user node satisfies L ≤ R.

[0113] In block 504, initiate the handover of the user nodes in the target HO list to the selected target AP.

[0114] In block 505, the algorithm adds one or more other user nodes to the "target HO list" based on determining that the handover of the target user node will result in a delay greater than the tolerable delay (R - L < 1) for one or more links between the target user node and one or more other user nodes. The algorithm identifies one or more candidate access points from the multiple access points in the channel quality list, whose channel quality to the user nodes in the "target HO list" is higher than the expected threshold. When the target user node hands over to each of the one or more APs, the algorithm calculates the updated L values for these links for the user nodes in the "target HO list".

[0115] Figure 3A and Figure 3BSome examples for updating the L value are provided. The L value can correspond to the actual number of communication hops that the link between two user nodes 301, 302, 321, 322 needs to go through. Therefore, as handover occurs, the association between the user node and the AP also changes, which means that the L value of a given service link can also change. The update here means taking into account this change after handover. For example, in Figure 3A in the box 300, there is one communication hop via AP 303 in the link between two user nodes 301, 302. Therefore, the L value of the link between two user nodes 301, 302 can be 1. In Figure 3A in the box 310, after the user node 301 hands over to another AP 304, there are two communication hops via two APs 303, 304 in the link between two user nodes 301, 302. Therefore, the updated L value of the link between two user nodes 301, 302 can be 2.

[0116] In box 506, the algorithm determines whether there is any AP among the identified one or more APs such that the updated L values of all the links of the user nodes in the user group satisfy L ≤ R after the target user node hands over.

[0117] If such an AP is found (box 506: yes), the algorithm proceeds to box 503 and then to box 504, that is, initiates the handover of the user nodes in the target HO list to the selected AP. Otherwise, if no such AP is found (box 506: no), the algorithm proceeds to box 507.

[0118] In box 507, for each of the identified one or more candidate APs, the algorithm calculates the updated L values of these links of the user group when all the user nodes in the "target HO list" hand over to the same AP.

[0119] In box 508, the algorithm determines whether there is any AP among the identified one or more candidate APs such that the updated L values (from box 507) of all the links of the user nodes in the user group satisfy L ≤ R after the user nodes in the 'target HO list' hand over.

[0120] If such an AP is found (box 508: yes), the algorithm proceeds to box 511 and then to box 512, that is, initiates the handover of all the user nodes in the "target HO list" to the selected AP. Otherwise, if no such AP is found (box 508: no), the algorithm proceeds to box 509.

[0121] In block 509, the algorithm includes all user nodes in the user group in the "target HO list" and proceeds in parallel to block 510, followed by blocks 511 and 512. In this case, an inter-cell handover of all user nodes within the user group to an AP that meets the channel quality requirements of all user nodes in the user group is initiated.

[0122] In block 510, the algorithm identifies one or more candidate access points from among multiple access points in the AP channel quality list whose channel quality to the user nodes in the target HO list (i.e., the entire user group) is higher than a threshold, and calculates the updated L value for the user group after the inter-cell handover.

[0123] In block 511, a target AP that satisfies L ≤ R for all user nodes in the user group is selected from among the one or more APs identified in block 508 or block 510. In other words, the target access point can be selected from among one or more candidate access points based on determining that the inter-cell handover of the users in the target HO list to the target access point will result in a delay of all links between the user nodes in the user group being less than or equal to the tolerable delay.

[0124] In block 512, an inter-cell handover of the user nodes in the target HO list to the selected target AP is initiated.

[0125] It should be noted that the above algorithm assumes that the APs in the network are deployed to provide an AP selection that meets the QoS constraints, taking into account the dynamics of the environment. If such an AP cannot be selected, the problem may be considered infeasible and the operation may stop.

[0126] Figure 6 The flowchart illustrates an example embodiment of a method performed by a device. For example, the device may be, or include, or be included in a network element of a wireless communication network. The network element may correspond to Figure 1 access point 104 of Figure 3A AP 303 of Figure 3B AP 323 of Figure 4 the serving AP.

[0127] Referring to Figure 6 in block 601, the device determines whether an inter-cell handover of a target user node among multiple user nodes will result in a delay of one or more links between the target user node and one or more other user nodes among the multiple user nodes being greater than the tolerable delay.

[0128] For example, the multiple user nodes may include at least one of the following: multiple user devices, or one or more edge functions and one or more user devices. The device, the multiple access points, and the multiple user nodes may be located in the same subnetwork.

[0129] In block 602, the apparatus selects a subset of a plurality of user nodes for handover based at least in part on the determination, wherein the subset includes at least the target user node.

[0130] For example, the subset of the plurality of user nodes can be selected to include the target user node based on determining that the handover of the target user node will not cause the latency of one or more links to be greater than a tolerable latency.

[0131] As another example, the subset of the plurality of user nodes can be selected to include the target user node and one or more other user nodes based on determining that the handover of the target user node will cause the latency of one or more links to be greater than a tolerable latency.

[0132] In block 603, the apparatus selects a target access point for handover from among a plurality of access points.

[0133] In block 604, the apparatus transmits an indication for performing a handover from the apparatus to the target access point to the subset of the plurality of user nodes.

[0134] Figure 7 A flowchart illustrating an example embodiment of a method performed by an apparatus is shown. For example, the apparatus can be, or include, or be included in a network element of a wireless communication network. The network element can correspond to Figure 1 access point 104 of Figure 3A AP 303 of Figure 3B AP 323 of Figure 4 the serving AP of

[0135] Referring to Figure 7 , in block 701, the apparatus determines whether the handover of a target user node among a plurality of user nodes will cause the latency of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable latency.

[0136] For example, the plurality of user nodes can include at least one of the following: a plurality of user equipments, or one or more edge functions and one or more user equipments. The apparatus, the plurality of access points, and the plurality of user nodes can be in the same subnetwork.

[0137] In block 702, the apparatus selects a subset of a plurality of user nodes for handover based at least in part on the determination, wherein the subset includes at least the target user node.

[0138] For example, the subset of the plurality of user nodes can be selected to include the target user node based on determining that the handover of the target user node will not cause the latency of one or more links to be greater than a tolerable latency.

[0139] As another example, a subset of a plurality of user nodes can be selected to include a target user node and one or more other user nodes based on determining that handover of the target user node will result in a delay of one or more links being greater than a tolerable delay.

[0140] In block 703, the apparatus selects a target access point from among a plurality of access points for handover.

[0141] In block 704, the apparatus transmits an indication for performing a handover from the apparatus to the target access point to a subset of the plurality of user nodes.

[0142] In block 705, the apparatus determines whether the subset of the plurality of user nodes includes at least one edge function.

[0143] In block 706, based on determining that the subset includes at least one edge function (block 705: Yes), the apparatus transmits information including attributes associated with the at least one edge function and stored data to the target access point.

[0144] As used above Figures 4 to 7 The blocks, associated functions, and information exchanges (messages) described do not follow an absolute chronological order, and some of them can be executed simultaneously or in an order different from the described order. Other functions can also be performed between or within them, and other information can be sent and / or other rules can be applied. Some of the blocks or parts of the blocks or one or more of the messages can also be omitted or replaced by corresponding blocks or parts of the blocks or one or more of the messages.

[0145] As used herein, "at least one of the following: <list of two or more elements>" and "at least one of <list of two or more elements>" and similar phrasings, where the list of two or more elements is joined by "and" or "or", means at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0146] Figure 8 An example of an AP channel quality list 800 is illustrated. In Figure 8 N user nodes and M APs are listed, and the channel quality between user node n and AP m is indicated by an entry represented by Q m,n The type of channel quality can vary according to embodiments. For example, the entry Q m,n can indicate reference signal received power (RSRP), signal-to-interference-plus-noise ratio (SINR), and / or large-scale fading (average RSRP in time and frequency).

[0147] Figure 9 An example of a user group list 900 is illustrated. In Figure 9In it, CF#y(AP#x) represents the controller function number y, which is at the AP number x.

[0148] In the sub-network, data flows between user nodes can be initiated for specific functions. For example, as described above, an E2E link can be established between a controller device and an actuator device, and a link between a sensor and the same controller device, for the purpose of a motion control operation. In such a case, groups of user nodes in the sub-network can be formed in the communication world based on underlying functions shared in the physical world. Here it is assumed that these user groups are disjoint. For the case of groups having shared user nodes, some example embodiments can be applied by merging these groups or by iterating operations on these groups to ensure that the E2E latency remains below the required level.

[0149] Figure 10 An example of a device 1000 including an apparatus for performing one or more of the above example embodiments is illustrated. For example, the apparatus 1000 can be a device such as a network element of a wireless communication network, or include a network element of a wireless communication network, or be a device contained in a network element of a wireless communication network. For example, the wireless communication network can refer to a radio access network. The network element can correspond to Figure 1 the access point 104, or Figure 3A the AP 303, or Figure 3B the AP323, or Figure 4 the serving AP. The network element can also be referred to as, for example, a network node, a radio access network (RAN) node, a next-generation radio access network (NG-RAN) node, a NodeB, an eNB, a gNB, a base transceiver station (BTS), a base station, an NR base station, a 5G base station, an access node, an access point (AP), a relay node, a repeater, an integrated access and backhaul (IAB) node, an IAB donor node, a distributed unit (DU), a central unit (CU), a baseband unit (BBU), a radio unit (RU), a radio head, a remote radio head (RRH), or a transmit and receive point (TRP).

[0150] The apparatus 1000 may include, for example, circuitry or a chipset suitable for implementing one or more of the above-described example embodiments. The apparatus 1000 may be an electronic device including one or more electronic circuits. The apparatus 1000 may include a communication control circuit 1010 (such as at least one processor) and at least one memory 1020 storing instructions 1022 which, when executed by the at least one processor, cause the apparatus 1000 to perform one or more of the above-described example embodiments. Such instructions 1022 may include, for example, computer program code (software), where the at least one memory and the computer program code (software) are configured to, together with the at least one processor, cause the apparatus 1000 to perform one or more of the above-described example embodiments. The at least one processor and the at least one memory storing the instructions may provide means for providing or causing the execution of any of the above methods and / or blocks.

[0151] The processor is coupled to the memory 1020. The processor is configured to read data from and write data to the memory 1020. The memory 1020 may include one or more storage units. The storage units may be volatile or non-volatile. It should be noted that there may be one or more non-volatile memory units and one or more volatile memory units, alternatively, one or more units in the non-volatile memory, alternatively, one or more units in the volatile memory. The volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). The non-volatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), flash memory, optical memory, or magnetic memory. Generally, the memory may be referred to as a non-transitory computer-readable medium. The term "non-transitory" as used herein is a limitation of the medium itself (i.e., tangible, rather than a signal), rather than a limitation of data storage persistence (e.g., RAM vs. data). Read-only memory). The memory 1020 stores computer-readable instructions executed by the processor. For example, the non-volatile memory stores the computer-readable instructions, and the processor uses the volatile memory to temporarily store data and / or instructions for executing the instructions.

[0152] The computer-readable instructions may have been pre-stored in the memory 1020, alternatively or additionally, they may be received by the apparatus via an electromagnetic carrier signal and / or may be copied from a physical entity such as a computer program product. Execution of the computer-readable instructions causes the apparatus 1000 to perform one or more of the above functions.

[0153] Memory 1020 can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. The memory may include a configuration database for storing configuration data. For example, the configuration database may store a current list of neighboring cells, and in some example embodiments, may also store the structure of the frames used in the detected neighboring cells.

[0154] Apparatus 1000 may also include a communication interface 1030, which includes hardware and / or software for implementing a communication connection according to one or more communication protocols. The communication interface 1030 includes at least one transmitter (Tx) and at least one receiver (Rx), which may be integrated into the apparatus 1000 or may be connected to the apparatus 1000. The communication interface 1030 may provide means for performing some of the blocks of the one or more example embodiments described above. The communication interface 1030 may include one or more components controlled by a corresponding control unit, such as: power amplifiers, digital front ends (DFEs), analog-to-digital converters (ADCs), digital-to-analog converters (DACs), frequency converters, (de)modulators, and / or encoder-decoder circuits.

[0155] The communication interface 1030 provides the apparatus with radio communication capabilities for communicating in a cellular communication system. For example, the communication interface may provide a radio interface to one or more user nodes. Apparatus 1000 may also include another interface towards a core network (such as a network coordinator device or an AMF) and / or an access point of the cellular communication system.

[0156] Apparatus 1000 may also include a scheduler 1040 configured to allocate radio resources. The scheduler 1040 may be configured together with the communication control circuit 1010, or may be configured separately.

[0157] It is noted that apparatus 1000 may also include Figure 10 various components not shown in the figure. The various components may be hardware components and / or software components.

[0158] The term "circuitry" as used in this application may refer to one or more or all of the following: (a) only a hardware implementation of circuitry (such as an implementation only in analog and / or digital circuitry); and (b) a combination of hardware circuitry and software, such as, for example (where applicable): (i) a combination of analog and / or digital hardware circuitry and software / firmware; and (ii) a hardware processor and any part of the software (including a digital signal processor), the software, and the memory, which work together to enable a device such as a mobile phone to perform various functions; and (c) hardware circuitry and / or a processor that requires software (such as firmware) to operate, such as a microprocessor or a part of a microprocessor, but the software may not be present when not required to operate.

[0159] This definition of circuitry applies to all uses of the term in this application (including in any claims). As a further example, as used in this application, the term "circuitry" also encompasses an implementation of only hardware circuitry or a processor (or processors) or a part of hardware circuitry or a processor and its (or their) accompanying software and / or firmware. For example and where applicable to a particular claim element, the term circuitry also encompasses a baseband integrated circuit or a processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

[0160] The techniques and methods described herein can be implemented in various ways. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. For a hardware implementation, the apparatus of the example embodiments can be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. For firmware or software, the implementation can be through modules (such as procedures, functions, etc.) of at least one chipset that perform the functions described herein. The software code can be stored in a storage unit and executed by a processor. The storage unit can be implemented inside or outside the processor. In the latter case, it can be communicatively coupled to the processor via various means, as is well known in the art. Additionally, the components of the systems described herein can be rearranged and / or supplemented by additional components so as to facilitate the achievement of the various aspects described regarding them, and they are not limited to the exact configurations shown in a given figure, as will be understood by those skilled in the art.

[0161] It will be apparent to those skilled in the art that, with the progress of technology, the concept of the present invention can be implemented in various ways. The embodiments are not limited to the above exemplary embodiments, but may vary within the scope of the claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate rather than limit the exemplary embodiments.

Claims

1. A device includes at least one processor and at least one memory storing instructions which, when executed by the at least one processor, cause the device to at least: Determine whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; Select, at least in part based on the determination, a subset of the plurality of user nodes for handover, wherein the subset at least includes the target user node; Select a target access point from a plurality of access points for handover; And Transmit an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

2. The device according to claim 1, wherein The target access point is selected by comparing a channel quality between the target user node and the plurality of access points and selecting an access point having the highest channel quality among the plurality of access points.

3. The device according to any one of the preceding claims, wherein, Based on determining that the handover of the target user node will not cause the delay of the one or more links to be greater than the tolerable delay, select the subset of the plurality of user nodes to include the target user node.

4. The device according to any one of claims 1-2, wherein, Based on determining that the handover of the target user node will cause the delay of the one or more links to be greater than the tolerable delay, select the subset of the plurality of user nodes to include the target user node and the one or more other user nodes.

5. The device according to claim 4, further configured to: Identify one or more candidate access points from the plurality of access points, the channel quality of which to the subset of the plurality of user nodes is higher than a threshold, Among them, Based on determining that a handover of the subset of the plurality of user nodes to the target access point will cause a delay of all links between the plurality of user nodes to be less than or equal to the tolerable delay, select the target access point from the one or more candidate access points.

6. The apparatus according to claim 5, wherein, The channel quality between the device and the one or more other user nodes is higher than the threshold.

7. The device according to any one of the preceding claims, further configured to: Receive information indicating a channel quality between the plurality of access points and the plurality of user nodes from the plurality of access points; and Generate a first list indicating the channel quality between the plurality of access points and the plurality of user nodes based on the information, wherein, Select the target access point at least in part based on the first list.

8. The device according to claim 7, further configured to: Periodically update the first list, or update the first list when determining to initiate a handover of the target user node.

9. The device according to any one of the preceding claims, further configured to: Generate a second list that indicates, for each of the multiple links between the multiple user nodes, a first value indicating the tolerable delay of the link and a second value indicating the delay of the link, wherein, The subset of the plurality of user nodes is selected at least in part based on the second list.

10. The device according to claim 9, further configured to: Update the second list based on a link added to or deleted from the plurality of links, or based on a user node added to or deleted from the plurality of user nodes.

11. The device according to any one of the preceding claims, further configured to: Determine whether the subset of the plurality of user nodes includes at least one edge function; and Transmit information including attributes and stored data associated with the at least one edge function to the target access point based on determining that the subset includes the at least one edge function.

12. The apparatus according to any one of the preceding claims, wherein, The plurality of user nodes includes at least one of the following: a plurality of user devices, or one or more edge functions and one or more user devices.

13. The device according to claim 1, wherein, The device, the plurality of access points, and the plurality of user nodes are in the same subnetwork.

14. An apparatus, comprising: means for determining whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; means for selecting a subset of the plurality of user nodes for the handover at least in part based on the determination, wherein the subset includes at least the target user node; means for selecting a target access point from a plurality of access points for the handover; and means for transmitting an indication to perform a handover from the apparatus to the target access point to the subset of the plurality of user nodes.

15. A method, comprising: determining, by a device, whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; selecting, by the device, at least in part based on the determination, a subset of the plurality of user nodes for the handover, wherein the subset includes at least the target user node; selecting, by the device, a target access point from a plurality of access points for the handover; and transmitting, by the device, an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

16. A non-transitory computer-readable medium including program instructions that, when executed by a device, cause the device to at least perform the following: determine whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; select at least in part based on the determination, a subset of the plurality of user nodes for the handover, wherein the subset includes at least the target user node; select a target access point from a plurality of access points for the handover; and transmit an indication for performing a handover from the device to the target access point to the subset of the plurality of user nodes.

17. A system, at least including a target user node and an access point of a wireless communication network; Among them, The access point is configured to: determine whether a handover of a target user node among a plurality of user nodes will cause a delay of one or more links between the target user node and one or more other user nodes among the plurality of user nodes to be greater than a tolerable delay; Select a subset of the plurality of user nodes for the handover based at least in part on the determination, wherein the subset includes at least the target user node; Select a target access point from the plurality of access points for the handover; and Transmit an indication for performing the handover from the access point to the target access point to the subset of the plurality of user nodes; Wherein the target user node is configured to: Receive the indication from the access point; and Based on the indication, perform the handover from the access point to the target access point.

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