User equipment context exploitation

Abstract

Example embodiments of the present disclosure provide a scheme for user equipment context utilization. An apparatus comprising at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to receive, from a first network node of a plurality of network nodes, information indicating a presence of a context associated with the apparatus at the plurality of network nodes, identify a second network node of the plurality of network nodes based on the information and a level of a signal received from the second network node; and send a communication recovery request to the second network node, the request including the information.

Description

Technical Field

[0001] Some example embodiments may generally relate to mobile or wireless telecommunications systems, such as Long Term Evolution (LTE) or 5G radio access technologies or New Radio (NR) access technologies, or other communication systems. For example, some embodiments may relate to systems and / or methods for user equipment (UE) context utilization and sharing. Background Technology

[0002] A communication network can be used as a facility to enable communication between two or more communication devices or to provide communication devices with access to a data network. A mobile or wireless communication network is an example of a communication network. Communication devices may be served by an application server.

[0003] Communication networks can operate according to standards such as those provided by the 3rd Generation Partnership Project (3GPP) or the European Telecommunications Standards Institute (ETSI). Examples of standards provided by 3GPP are the so-called 3GPP standards used for various generations of cellular technologies, such as the 3GPP standards for 4G, 5G, 6G, and so on. Summary of the Invention

[0004] The independent claims provide the subject matter for several aspects. Additional aspects are defined in the dependent claims.

[0005] In a first aspect, a user equipment (UE) is provided. The UE includes at least one processor and at least one memory, the at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, together with the at least one processor, to cause the user equipment to receive from a first network node of a plurality of network nodes information including offsets indicating the presence of a context associated with the device in the plurality of network nodes, to identify a second network node based on the information and the level of a signal received from a second network node of the plurality of network nodes; and to send a communication recovery request to the second network node, the request including the information.

[0006] In a second aspect, a method for a user equipment is provided. The method includes the steps of: receiving from a first network node, among a plurality of network nodes, information including offsets indicating the presence of context associated with the device among the plurality of network nodes; identifying a second network node based on the information and the level of a signal received from a second network node among the plurality of network nodes; and sending a communication recovery request to the second network node, the request including the information.

[0007] In a third aspect, a non-transitory computer-readable medium is provided, including instructions that, when executed by a user equipment, cause the user equipment to perform at least the following operations: receiving from a first network node of a plurality of network nodes information including offsets indicating the presence of a context associated with the device in the plurality of network nodes, identifying a second network node based on the information and the level of a signal received from a second network node of the plurality of network nodes; and sending a communication recovery request to the second network node, the request including the information.

[0008] In a fourth aspect, a user equipment (UE) is provided. The UE includes components for performing the following operations: receiving from a first network node of a plurality of network nodes information including offsets indicating the presence of context associated with the device in the plurality of network nodes, identifying a second network node based on the information and the level of a signal received from a second network node of the plurality of network nodes; and sending a communication recovery request to the second network node, the request including the information.

[0009] In a fifth aspect, a user equipment (UE) is provided. The UE includes at least one processor and at least one memory, the at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, together with the at least one processor, to cause the user equipment to receive information from a first network node of a plurality of network nodes, the information indicating the presence of a context associated with the device in the plurality of network nodes; to identify a second network node based on the information and the level of a signal received from a second network node of the plurality of network nodes; and to send a communication recovery request to the second network node, the request including the information.

[0010] In a sixth aspect, a method for a user equipment is provided. The method includes the steps of: receiving information from a first network node among a plurality of network nodes, the information indicating the presence of a context associated with the device among the plurality of network nodes; identifying a second network node based on the information and the level of a signal received from a second network node among the plurality of network nodes; and sending a communication recovery request to the second network node, the request including the information.

[0011] In a seventh aspect, a non-transitory computer-readable medium is provided, including instructions that, when executed by a user equipment, cause the user equipment to perform at least the following operations: receiving from a first network node of a plurality of network nodes information indicating the presence of a context associated with the device in the plurality of network nodes; identifying a second network node based on the information and the level of a signal received from a second network node of the plurality of network nodes; and sending a communication recovery request to the second network node, the request including the information.

[0012] In an eighth aspect, a user equipment (UE) is provided. The UE includes components for performing the following operations: receiving information from a first network node among a plurality of network nodes indicating the presence of a context associated with the device in the plurality of network nodes; identifying a second network node based on the information and the level of a signal received from a second network node among the plurality of network nodes; and sending a communication recovery request to the second network node, the request including the information. Attached Figure Description

[0013] Some exemplary embodiments will now be described with reference to the accompanying drawings.

[0014] Figure 1 An example of a wireless communication network is shown;

[0015] Figure 2 The signal flow graph is shown;

[0016] Figure 3 The signal flow graph is shown;

[0017] Figure 4 A flowchart is shown;

[0018] Figure 5 An example of the device is shown. Detailed Implementation

[0019] It will be readily understood that components of certain example embodiments, as generally described and illustrated in the accompanying drawings, can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for UE context copying is not intended to limit the scope of any particular embodiment, but rather represents selected example embodiments.

[0020] The following embodiments are exemplary. Although this specification may refer to "a," "an," or "some" embodiments in several places throughout the text, this does not necessarily mean that every reference refers to the same embodiment, or that a particular feature applies only to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments. For the purposes of this disclosure, the phrases "at least one of A or B," "at least one of A and B," and "A and / or B" mean (A), (B), or (A and B). For the purposes of this disclosure, the phrases "A or B" and "A and / or B" mean (A), (B), or (A and B). For the purposes of this disclosure, the phrases "A, B, and / or C" mean (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0021] It should be understood that while the terms "first" and "second," etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0022] The described embodiments can be implemented in radio systems, such as those including at least one of the following radio access technologies (RATs): Global Microwave Access Interoperability (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System based on Basic Wideband Code Division Multiple Access (W-CDMA) (UMTS, 3G), High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), LTE-Advanced, and Enhanced LTE (eLTE). The term 'eLTE' here refers to LTE evolution connected to a 5G core. LTE is also known as Evolved UMTS Terrestrial Radio Access (EUTRA) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN). The term "resource" can refer to radio resources such as physical resource blocks (PRBs), radio frames, subframes, time slots, subbands, frequency regions, subcarriers, beams, etc. The terms "transmit" and / or "receive" can refer to wirelessly transmitting and / or receiving via a radio propagation channel on a radio resource.

[0023] However, the embodiments are not limited to the system / RAT given as an example, but those skilled in the art can apply this technical solution to other communication systems / networks that are provided with the necessary attributes. Some examples of suitable communication networks include 5G networks and / or 6G networks. The 3GPP technical solution to 5G is called New Radio (NR). 6G is envisioned as a further development of 5G. NR has been envisioned to use multiple-input multiple-output (MIMO) multi-antenna transmission technology, more base stations or nodes than the current network deployment of LTE (the so-called small cell concept), including macro sites that cooperate with smaller local access nodes, and may also employ various radio technologies to achieve better coverage and enhanced data rates. 5G will likely include more than one radio access technology / radio access network (RAT / RAN), each optimized for certain use cases and / or spectrum. 5G mobile communications can have a wider range of use cases and associated applications, including video streaming, augmented reality, different data sharing methods, and various forms of machine-type applications, including vehicle safety, different sensors, and real-time control. 5G is expected to have multiple radio interfaces, namely sub-6GHz, cmWave, and mmWave, and can be integrated with existing legacy radio access technologies such as LTE.

[0024] Figure 1 An example of a communication system to which embodiments of the present invention can be applied is shown. The system may include a control node 110 providing one or more cells (such as cell 100) and a control node 112 providing one or more other cells (such as cell 102). For example, each cell may be, for example, a macro cell, micro cell, femtocell, or picocell. Alternatively, a cell may define a coverage area or service area for a corresponding access node. Control nodes 110 and 112 may be evolved Node Bs (eNBs) such as in LTE and LTE-A, ng-eNBs such as in eLTE, gNBs in 5G, or any other means capable of controlling radio communications and managing radio resources within the cell. Control nodes 110 and 112 may be referred to as base stations, network nodes, or access nodes.

[0025] The system can be a cellular communication system consisting of a radio access network of access nodes, each access node controlling one or more cells. Access node 110 can provide radio access to other networks such as the Internet to user equipment (UE) 120 (one or more UEs). Radio access can include downlink (DL) communication from the control node to UE 120 and uplink (UL) communication from UE 120 to the control node.

[0026] Additionally, although not shown, one or more local access nodes may be arranged such that the cell provided by the local access node at least partially overlaps with the cell of access nodes 110 and / or 112. The local access node can provide radio access within a sub-cell. Examples of sub-cells may include microcells, picocells, and / or femtocells. Typically, a sub-cell provides a hotspot within a macrocell. The operation of the local access node can be controlled by the access node providing the sub-cell within its control area. Typically, the control node for a small cell may also be referred to as a base station, network node, or access node.

[0027] The system can have multiple UEs 120 and 122. Each of them can be served by the same or different control nodes 110 and 112. If a D2D communication interface is established between UEs 120 and 122, they can communicate with each other.

[0028] The term "terminal device" or "UE" refers to any terminal device capable of wireless communication. As an example and not a limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). This terminal device may include, but is not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop-mounted devices (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPEs), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms “terminal equipment”, “communication equipment”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0029] According to some embodiments, the UE can be configured to be in an inactive state to save power. As an example, the inactive state may include an Independent Radio Resource Control (RRC) state known as RRC_INACTIVE. The RRC inactive mode or state, first introduced in 3GPP Release 15 for 5G NR, was designed to address the challenges (i.e., signaling overhead and latency) that arise when the UE transitions from idle mode to connected mode, while the UE can still have similar power savings as when it is in RRC_IDLE. In the RRC inactive state, the UE is connected to the Access and Mobility Management Function (AMF), which is called Connection Management (CM). The UE also has a stored Access Stratum (AS) context. The AS context can be referred to as the context associated with the UE because it includes the latest radio bearer configuration for data / signaling transmissions, as well as security keys and algorithms for integrity protection and encryption in the radio interface. Furthermore, in this specification, the AS context may also be simply referred to as the UE context. The AMF has a signaling connection to the gNB. Reference Figure 1 This can be done between gNB 112 and core 116, where the AMF can reside. The last UE connection context information (i.e., during the RRC connection mode / state, which is also represented as RRC_CONNECTED) is maintained in both the UE and the last serving NG-RAN (i.e., gNB).

[0030] In addition to connected states (e.g., RRC_CONNECTED) and idle states (e.g., RRC_IDLE), one purpose of introducing inactive states is to reduce UE power consumption by mitigating the control plane (CP) procedures and associated delays used during RRC state changes. The RRC_INACTIVE mode allows the UE to transition back to RRC_CONNECTED via an RRC recovery procedure with minimal delay and reduced signaling overhead. While in RRC_INACTIVE, the UE performs cell reselection measurements and can move within an area configured by the NG-RAN as the RAN Notification Area (RNA) without notifying the NG-RAN. 3GPP TS38.331 defines the procedures associated with the RRC recovery transition from an inactive state to a connected state, including RNA updates.

[0031] During RRC recovery triggered by data such as mobile-initiated or mobile-terminated data, if the UE is camped and recovering in a gNB different from the last serving gNB, the new gNB needs to perform a UE context retrieval. Similarly, when the UE completes an RNA update (RNAU) upon exiting the RNA, the new gNB also needs to retrieve the UE context from the last serving gNB. This process ensures that the UE context is always in the RNA where the UE is located.

[0032] Cell reselection can also be performed when the UE is in RRC_INACTIVE mode. Cell reselection is a UE-controlled mobility procedure that does not involve any network. This procedure ensures that the UE can re-establish a connection with the optimal cell once a connection request is received from the network via paging, or when the UE itself initiates the required connection. The cell reselection evaluation procedure is described in TS 38.304, Clause 5.2.4, and is based on the UE's measurements of its camped cell, and if the measurement value from the camped cell is lower than a configured value, it is based on the UE's measurements of a list of neighboring cells. For example, cell reselection can occur if the measured received signal from another cell is higher than a configured threshold (which may be referred to as theshX, HighP) relative to the camped cell, and during a configured time period (which may be referred to as Treselection). This timer can define the triggering time criterion for cell reselection. Currently, cell reselection is primarily based on signal quality (e.g., Reference Received Quality, RSRQ) and strength (e.g., Reference Received Power, RSRP). However, offsets can also be used to prioritize one cell over another: either a frequency layer (using a carrier-specific offset broadcast in System Information Block SIB5, called q-OffsetFreq) or a cell (using a cell-specific offset broadcast in SIB4, called q-OffsetCell). The Qoffset parameter, which determines the relationship between the serving cell and neighboring cells, can provide network operators with additional flexibility in managing traffic between cells.

[0033] When a UE is in the RRC_INACTIVE state, the UE context is typically stored in only one gNB and must be relocated / retrieved when necessary, as discussed above. The UE context retrieval process may introduce some latency during RRC recovery. This increased latency may not be optimal for services requiring low-latency connectivity establishment. Additionally, UE context retrieval may fail, for example, because the last serving gNB is already very far from the new gNB that requires the UE context. It can be beneficial to copy the UE context to multiple locations (e.g., multiple gNBs) and know the location of its context. In other words, the UE can benefit from knowing which gNBs retain its UE context or the UE's inactive AS context or the context associated with the UE.

[0034] After the UE's last serving gNB identifies one or more neighboring gNBs as potential cells that the UE can reselect while in RRC_INACTIVE and shares the UE context with these gNBs, it notifies the UE of the cells that have received and / or retained its UE context. This can be determined and performed before the UE is released from its RRC connection and sent to the UE along with an RRC release message with a pause configuration message when the UE is transitioned to RRC_INACTIVE. In one embodiment, during an inactive mode mobility procedure, the UE can utilize knowledge of which gNBs retain its UE context to prioritize cells for cell reselection and connect to gNBs that retain their context. The inactive mode mobility procedure may involve cell reselection. In another embodiment, when the UE wants to switch to RRC_Connected mode, the UE can utilize knowledge of which gNBs retain its UE context. If, when switching to RRC_Connected mode, the UE connects to gNBs that do not retain their UE context, the UE can share knowledge with these gNBs about which gNBs retain their UE context. Thus, a gNB that does not retain its UE context can extract the UE context from the most appropriate gNB that does.

[0035] The knowledge of which gNBs retain the UE context can be expressed as an offset indicating the presence of the UE-associated context (UE context) across multiple gNBs, which can be considered as multiple gNBs or network nodes. More specifically, the offset may include parameters that can indicate the presence of the UE context across multiple network nodes. Additionally or alternatively, the knowledge of which gNBs retain the UE context can be expressed as information indicating the presence of the UE context across multiple network nodes. More specifically, the information indicating the presence of the UE context across multiple network nodes may be in the form of a list indicating these network nodes that retain the UE-associated context (UE context).

[0036] Figure 2 A high-level flowchart of UE context utilization is shown. For the sake of description and as a non-limiting example, it can be considered that... Figure 2 UE 120 and Figure 1 The UE 120 shown is the same. Similarly, Figure 2 The last service gNB 110 can be with Figure 1 The gNB 110 shown is the same. Similarly, Figure 2 gNB 112 can be used with Figure 1The same applies to gNB 112. gNB 110 can be considered to retain information indicating the presence of the context (also called UE context or UEC) associated with UE 120 in multiple other gNBs, which may also be referred to as multiple gNBs or more generally multiple network nodes. This information may include offsets indicating the presence of the UE context in multiple gNBs. In 202, gNB 110 can copy this UE context to multiple gNBs. Copying the UE context may mean that gNB 110 directly sends the UE context to the other(multiple) gNBs(s). UE context copying can be used to create copies of the UE context to another gNB / multiple additional gNBs, making the UE context available when the UE establishes a connection to that cell.

[0037] In step 204, the last serving gNB 110 to which UE 120 is connected shares information about the UE context location with UE 120. gNB 110, considered a network node, shares this information by sending it to UE 120. The UE context location can indicate which gNBs retain the UE context. Furthermore, in step 204, the information sent from gNB 110 and received by UE 120 includes offsets indicating the presence of the UE context in multiple gNBs. In an embodiment, this information, and the corresponding offsets included in it, can indicate the presence or retention of the UE context in multiple gNBs (which may be referred to as multiple gNBs or multiple network nodes) in the form of a value. This value can be referred to as an offset value. In another embodiment, the offsets included in the information can include a parameter indicating the presence or retention of the UE context in multiple gNBs. This parameter can be referred to as q-gNBUEC, and it can have a value of 1db or -1db. A value of 1db can indicate the presence of the UE context in multiple gNBs. A value of -1db can indicate the absence of the UE context in multiple gNBs. In an embodiment, the two values ​​can indicate the presence or absence of the UE context in a single gNB or at least one gNB.

[0038] In step 206, it is assumed that UE 120 has received information from the last serving gNB 110 and can utilize this information to optimize its mobility in inactive mode. In an embodiment, when cell reselection is performed, UE 120 can store this information and utilize it by prioritizing cells with its UE context. Additionally or alternatively, when UE 120 transitions from RRC_INACTIVE to RRC_CONNECTED and another gNB does not have or retains its UE context, UE 120 can utilize it by sharing information with that other gNB. In this case, in step 208, UE 120 shares UE context location information with gNB 112, which can be considered a gNB without a UE context, i.e., neither retaining nor having a UE context. The UE context location information can be the same as the UE context location information received by UE 120 from the last serving gNB 110 in step 204. Upon receiving UE context location information, gNB 112 can utilize this information to optimize the extraction of the UE context from one or more other gNBs that retain the UE context. These one or more other gNBs can be the multiple gNBs mentioned above. In embodiments, these one or more other gNBs can be referred to as multiple gNBs or network nodes.

[0039] Figure 3A signaling diagram for UE context utilization according to some embodiments is shown. In 302, some gNBs (e.g., gNB1 110 and / or gNB 111) broadcast the parameter q-gNBUEC in a System Information Block (SIB) (which may be SIB3). In 304, UE 120 in RRC_Connected mode performs signal measurements on its camped cell and reports these measurements to gNB1 110. As part of the mobility process, UE in RRC_CONNECTED mode performs measurements on its serving cell and a list of neighboring cells or carriers, and periodically and / or whenever a measurement reporting event is met. In 306, gNB 110 may identify one or more candidate network nodes, i.e., gNBs, to which the UE can perform cell reselection when the UE is in RRC_INACTIVE mode. Measurements from UE 120 can be used at the gNB to determine which neighboring cells (candidate nodes) should receive the UE context when transitioning the UE to RRC_INACTIVE mode. These candidate nodes are nodes that the UE can restore its connection once the UE switches to RRC_Connected mode. For example, if gNB3 111 is a candidate node, then in 308, gNB1 can forward the UE context to gNB3. When the UE is switched to RRC_INACTIVE, the network node gNB1 serving UE 120 does not delete the UE context and therefore retains it. In 310, gNB 110 can generate the determined candidate list, and when gNB 110 triggers the transition of the UE to RRC_INACTIVE mode, gNB 110 can send it to UE 120 in 312. The RRC release message 312 can contain information about which gNBs retain the UE context in the form of a list or in the form of information elements (e.g., gNB-UEC). UE 120 receives the determined list of candidates as candidate cells or as candidate gNBs that have already received UE 120's AS context in the RRC release 312 with a pause configuration message. When the UE is released to the RRC_INACTIVE state, an RRC release with a pause configuration message is sent to the UE. In 314, UE 120 is in RRC_INACTIVE mode. In 316, UE 120 may store and process information indicating the presence of a UE context in a gNB. In an embodiment, processing this information means that UE 120 identifies a second network node or gNB that is different from the gNB1 110 that retains the UE context. This second network node may be one of multiple network nodes that retain the UE context. This identification may be based solely on the fact that this network node retains the UE context.Alternatively or additionally, the identifier may use the fact that the network node preserves the UE context and the level of signals received from the network node as a criterion. The level of the signal can be measured as the Reference Signal Received Power (RSRP).

[0040] As mentioned above, the information about the UE context retained by the network node can be indicated by an offset. This offset can indicate the presence of the UE context in one or more network nodes or gNBs. Furthermore, also as mentioned above, this information can be in the form of an offset value containing the parameter q-gNBUEC. This offset value can be in the following form:

[0041] Qoffset = q-OffsetFreq + q-OffsetCell + q-gNBUEC.

[0042] In this formula, q-OffsetFreq is the carrier-specific offset broadcast in System Information Block SIB5, and q-OffsetCell is the cell-specific offset broadcast in SIB4.

[0043] If the identification of the second network node is based on two criteria—the fact that the second network node preserves the UE context and the level of signal strength—then the offset Qoffset will be applied to the measured RSRP. This can be in the following form:

[0044] RSRPneighbor – q-Offset.

[0045] RSRPneighbor can indicate the reference signal received power measured from a neighboring gNB (e.g., gNB3 111 or gNB4 112). Similarly, RSRPserving can indicate the RSRP measured from the gNB or cell that serves UE 120 and that UE 120 is connected to or camped on when UE 120 is in RRC_inactive mode. For example, if in 318, UE 120 detects the presence of data to be transmitted or received, such as, for example, Mobile Initiation (MO) or Mobile Termination (MT) data, the UE will need to send an RRC recovery to the gNB in ​​order to be able to switch to RRC connected mode. If UE 120 is camped on, for example, gNB1 110 and recovers to a gNB different from gNB1, such as gNB4 112, then gNB4 will need to preserve the UE context.

[0046] As described above, the UE can identify the second network node to determine which gNB the UE recovers to. This identification can be based on applying an offset value to the measured RSRP. Furthermore, this identification can be based on the following comparison:

[0047] RSRPneighbor – q-Offset>RSRPserving + q-HysT

[0048] A cell or network node or gNB (which will be a neighboring gNB that satisfies the above comparison) can be given higher priority for UE 120 to connect to in the event of cell reselection.

[0049] For example, if gNB4 does not retain the UE context and UE 120 decides to perform RRC recovery with gNB4, then in 320, UE 120 sends an RRC recovery request including gNB-UEC to gNB4 112. In 322, gNB4 can process gNB-UEC, which provides information about which network node the UE context resides in, to determine where it is best to retrieve the UE context. For example, it can determine that gNB3 can provide the UE context fastest (e.g., due to the existence of a direct Xn link with it). gNB3 111 retains the UE context when it receives the UE context in step 308. In this case, in 324 and 326, gNB4 112 can request the UE context from gNB3 and receive the UE context in the response from gNB3 111.

[0050] Once gNB4 retains the UE context, it can send an RRC recovery to UE 120 in step 328, and the UE can respond with an RRC recovery completion message in step 330. UE 120 then enters RRC connection mode and can serve MO / MT data requests.

[0051] In some of the embodiments described above, UE 120 and various network nodes (e.g., gNB, last serving gNB (anchor gNB), and Access and Mobility Management Function (AMF)) can participate in recovery-related operations triggered by the UE with UE context retrieval. The UE can be in the RRC_INACTIVE state and the CM_CONNECTED state.

[0052] A UE in the RRC_INACTIVE state can be configured by the last serving node using a UE-specific RAN-based notification area (RNA) (e.g., using a RAN-NotificationAreaInfo message). This RAN-based notification area (RNA) can cover one or more cells belonging to one or more gNBs. Within this area, the UE can move without notifying the network of its location (e.g., cell (re)selection within the RNA can be transparent to the network). The network can page the UE using RAN-level paging from cells within the RNA.

[0053] Figure 4 A flowchart of method 400 according to an embodiment is shown. Method 400 includes steps performed by a UE (which may be, for example, UE120). In 410, the UE receives information indicating the presence of UE context information in a plurality of network nodes. The network nodes may be gNBs. The information may be received from one of the plurality of network nodes (which may be a first network node). The information may be received by one of the plurality of network nodes. The plurality of network nodes may be referred to as several network nodes. In an embodiment, the information may be an offset indicating whether a network node retains the UE context. The offset may indicate the presence of the UE context in the form of a parameter (which may be, for example, referred to as q-gNBUEC). In an embodiment, the parameter, such as q-gNBUEC, may be broadcast by the network node in a system information block. In another embodiment, the information may be a list containing network nodes that retain the UE context. Additionally or alternatively, the list may contain network nodes that do not retain the UE context. The list may be compiled by one of the plurality of network nodes. Alternatively, it may be extracted from different network entities (e.g., AMFs). In an embodiment, the information indicating the presence of UE context information in multiple network nodes may include both a list of network nodes that retain or do not retain the UE context and an offset indicating the presence of the UE context.

[0054] In 420, the UE identifies a network node different from the first network node, which could be a second network node. This identification is based on information about whether the UE context exists (or is retained) in the network node / gNB, and also on the signal level received from a certain gNB. In an embodiment, the UE can identify the second network node so that cell reselection can be performed when the UE is, for example, in an inactive mode. In another embodiment, the UE can identify the second network node when it wants to return to RRC connection mode, for example, if it needs to transmit data. In either or both cases, the UE can prioritize gNBs that retain the UE context. The signal level received from that gNB can also determine whether the UE prioritizes or selects that particular gNB. In an embodiment, the UE can decide to select a gNB that does not retain the UE context (e.g., gNB4 112).

[0055] In step 430, the UE sends a communication restoration request to the gNB4 112 to which it wants to connect or camp. This information includes information indicating the existence of a UE context. This information may be referred to as gNB-UEC and can always be sent from the UE to the gNB it wants to connect to or camp. Alternatively, this information can only be sent to the gNB if the UE identifies itself as having a gNB that does not retain a UE context. When gNB4 112 receives the communication restoration request from UE 120, it can check whether it itself has a UE context. If gNB4 has not yet retained a UE context, it can analyze the information in the restoration request and determine which gNB or cell to use to extract the UE context. For example, in Figure 3 In section 324, gNB4 requests the UE context from gNB3.

[0056] Figure 5 An example of a device 50 according to an embodiment is shown. Device 50 may be an element in or associated with a communication network. It may take the form of a user equipment (UE), mobile device (ME), mobile station, mobile device, fixed device, IoT device, or other types of device. As described herein, the device may alternatively be referred to as, for example, user equipment, mobile station, mobile gear, mobile unit, mobile device, user equipment, subscriber station, wireless terminal, tablet computer, smartphone, IoT device, sensor or NB-IoT device, watch or other wearable device, head-mounted display (HMD), vehicle, drone, medical device and its applications (e.g., remote surgery), industrial device and its applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. As an example, device 50 may be implemented in, for example, a wireless handheld device, a wireless plug-in accessory, etc.

[0057] In some example embodiments, device 50 may include one or more processors, one or more computer-readable storage media (e.g., memory, storage device, etc.), one or more radio access components (e.g., radio interface, modem, transceiver, etc.) and / or user interface. In some embodiments, device 50 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and / or any other radio access technology. It should be noted that those skilled in the art will understand that device 50 may include... Figure 5 Components or features not shown in the diagram.

[0058] like Figure 5As shown in the example, device 50 may include or be coupled to processor 12 for processing information and executing instructions or operations. Processor 12 may be any type of general-purpose or special-purpose processor. In practice, as an example, processor 12 may include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), field-programmable gate array (FPGA), application-specific integrated circuit (ASIC), and processor based on a multi-core processor architecture. Although in Figure 5 A single processor 12 is shown, but multiple processors may be utilized according to other embodiments. For example, in some embodiments, apparatus 50 may include two or more processors that can form a multiprocessor system capable of supporting multiprocessing (e.g., in this case, processor 12 may represent multiple processors). In some embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0059] The processor 12 can perform functions associated with the operation of the device 50, including, for example, precoding of antenna gain / phase parameters, encoding and decoding of individual bits forming communication messages, formatting of information, and overall control of the device 50, including processes related to the management of communication resources.

[0060] Device 50 may also include or be coupled to memory 14 (internal or external), which may be coupled to processor 12 for storing information and instructions executable by processor 12. Memory 14 may be one or more memories and may be of any type suitable for the local application environment, and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and / or removable memory. For example, memory 14 may include random access memory (RAM), read-only memory (ROM), static storage devices such as disks or optical discs, hard disk drives (HDDs), or any other type of non-transitory machine or computer-readable medium, and any combination thereof. Instructions stored in memory 14 may include program instructions 15 or computer program code that, when executed by processor 12, enable device 50 to perform the tasks described herein.

[0061] In embodiments, device 50 may also include or be coupled to an (internal or external) drive or port configured to accept and read external computer-readable storage media, such as an optical disc, USB drive, flash drive, or any other storage media. For example, the external computer-readable storage media may store computer programs or software executed by processor 12 and / or device 50.

[0062] In some embodiments, device 50 may further include or be coupled to one or more antennas for receiving downlink signals from device 50 and transmitting them via an uplink. Device 50 may also include a transceiver or radio interface 16 configured to transmit and receive information. Radio interface 16 may include a modem coupled to antenna 25. The radio interface may comply with a variety of radio access technologies, including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, etc. The radio interface may include other components such as filters, converters (e.g., digital-to-analog converters), signal processing components, and inverse fast Fourier transform (IFFT) modules to process symbols carried by the downlink or uplink, such as orthogonal frequency division multiple access (OFDMA) symbols.

[0063] For example, radio interface 16 may be configured to modulate information onto a carrier waveform for transmission by antenna(s) and demodulate information received via the antennas for further processing by other elements of device 50. In other embodiments, radio interface 16 may be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some embodiments, device 50 may include input and / or output devices (I / O devices). In some embodiments, device 50 may also include user interface 18, such as a graphical user interface or a touchscreen.

[0064] In an embodiment, memory 14 stores software modules that provide functionality when executed by processor 12. These modules may include, for example, an operating system that provides operating system functionality to device 50. The memory may also store one or more functional modules, such as applications or programs, to provide additional functionality to device 50. Components of device 50 may be implemented in hardware or as any suitable combination of hardware and software. According to an example embodiment, device 50 may optionally be configured to communicate with other devices via wireless or wired communication links according to any radio access technology, such as NR.

[0065] According to some embodiments, the processor 12 and memory 14 may be included in or form part of the processing or control circuitry. Furthermore, in some embodiments, the radio interface 16 may be included in or form part of the transceiver circuitry.

[0066] As discussed above, according to some embodiments, device 50 may be, for example, a UE, mobile device, mobile station, ME, IoT device, and / or NB-IoT device. According to some embodiments, device 50 may be controlled by memory 14 and processor 12 to perform functions associated with the example embodiments described herein. For example, in some embodiments, device 50 may be configured to perform one or more processes depicted in any flowchart or signaling diagram described herein, such as Figures 1 to 4 Those shown. For example, in one embodiment, device 50 may be controlled by memory 14 and processor 12 to perform. Figure 4 The method.

[0067] In some embodiments, the user equipment may include methods or any variations thereof for performing the above discussions (e.g., references...). Figure 4 The components of the described method. Examples of such components may include one or more processors, memory, and / or computer program code for performing the operation.

[0068] The above embodiments can provide the benefit that the UE can know which gNBs or other network nodes retain its UE context, thus optimizing its behavior in cases such as RRC_INACTIVE mode mobility or RRC_CONNECTED recovery operations. It can be considered that implementations of certain example embodiments result in improved functionality of the communication network and its nodes, and therefore constitute at least an improvement in the technical field of UE mobility and connectivity.

[0069] In some example embodiments, the functionality of any methods, processes, signaling diagrams, algorithms, or flowcharts described herein may be implemented by software and / or computer program code or code portions stored in memory or other computer-readable or tangible media and executed by a processor.

[0070] In some example embodiments, the apparatus or user equipment may be included in or associated with at least one software application, module, unit, or entity, wherein the at least one software application, module, unit, or entity is configured to perform arithmetic operations or is configured to be a program or a portion thereof (including added or updated software routines) executed by at least one operating processor. A program, also referred to as a program product or computer program, includes software routines, applets, and macros, and may be stored in any device-readable data storage medium and may include program instructions for performing specific tasks.

[0071] A computer program product may include one or more computer-executable components that, when the program runs, are configured to perform some example embodiments. The one or more computer-executable components may be at least one piece of software code or code. Modifications and configurations for implementing the functionality of the example embodiments may be executed as routines(s), which(s) may be implemented as added or updated software routines(s). In one example, the software routines(s) may be downloaded to the device.

[0072] As an example, software or computer program code or code portions may be in the form of source code, object code, or some intermediate form, and may be stored in some type of carrier, distribution medium, or computer-readable medium, which may be any entity or device capable of carrying the program. Such a carrier may include, for example, recording media, computer memory, read-only memory, optoelectronic and / or electrical carrier signals, telecommunication signals, and / or software distribution packages. Depending on the required processing power, the computer program may execute in a single electronic digital computer, or it may be distributed across multiple computers. The computer-readable medium or computer-readable storage medium may be a non-transitory medium.

[0073] In other example embodiments, the function may be performed by hardware or circuitry included in the device (e.g., device 50), for example by using an application-specific integrated circuit (ASIC), a programmable gate array (PGA), a field-programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the function may be implemented as a signal, such as an intangible form carried by an electromagnetic signal that can be downloaded from the Internet or other networks.

[0074] According to example embodiments, an apparatus such as a UE, network node, device, or corresponding component may be configured as a circuit, computer, or microprocessor (such as a single-chip computer element) or chipset, which may include at least a memory for providing storage capacity for arithmetic operations(s) and / or an arithmetic processor for performing arithmetic operations(s).

[0075] The exemplary embodiments described herein are equally applicable to both singular and plural implementations, regardless of whether singular or plural language is used in the description of certain embodiments. For example, embodiments describing the operation of a single network node are equally applicable to embodiments involving multiple instances of network nodes, and vice versa.

[0076] It will be readily understood by those skilled in the art that the exemplary embodiments discussed above can be implemented using hardware elements with different operating sequences and / or configurations different from those disclosed. Therefore, while some embodiments have been described, it will be apparent to those skilled in the art that certain modifications, variations, and alternative constructions will be readily apparent while remaining within the spirit and scope of the exemplary embodiments.

[0078] List of abbreviations

[0079] AMF Access and Mobility Management Functions

[0080] AS Access Layer

[0081] DRB Data Radio Bearer

[0082] MO Mobile Initiation

[0083] MT movement terminated

[0084] NR New Radio

[0085] RAN (Radio Access Network)

[0086] RNA RAN Notification Region

[0087] RNAU RAN notification region update

[0088] RRC Radio Resource Control

[0089] RSRP reference signal received power

[0090] RSRQ reference signal reception quality

[0091] SRB signal radio bearer

[0092] UE User Equipment

[0093] UEC UE context

[0094] UPF User Plane Functions

[0095] Example 1. An apparatus comprising at least one processor and at least one memory, the at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, together with the at least one processor, to cause the apparatus to: receive information from a first network node among a plurality of network nodes, the information indicating the presence of a context associated with the apparatus in the plurality of network nodes; identify a second network node based on the information and the level of a signal received from a second network node among the plurality of network nodes; and send a communication recovery request to the second network node, the request including the information. Example 2. The apparatus according to Example 1, wherein the information indicating the presence of the context associated with the apparatus in a plurality of network nodes includes a list indicating the plurality of network nodes that retain the context associated with the apparatus. Example 3. The apparatus according to Example 1 is further configured to: switch to a radio resource control inactive mode before identifying the second network node based on information and the level of signals received from the second network node.

[0096] Example 4. The apparatus according to Example 3, wherein the apparatus is switched to a radio resource control inactive mode based on the apparatus receiving a radio resource control release message from the first network node. Example 5. The apparatus according to Example 1 or 3 is further configured to: when the apparatus is in a radio resource control inactive mode, perform cell reselection on the second network node based on information and the level of signals received from the second network node among a plurality of network nodes. Example 6. The apparatus according to Example 1, wherein the second network node belongs to a list indicating multiple network nodes that retain the context associated with the apparatus. Example 7. The apparatus according to Example 1, wherein the first network node belongs to a list indicating multiple network nodes that retain the context associated with the apparatus. Example 8. A method for a user equipment, comprising: receiving information from a first network node among a plurality of network nodes, the information indicating the presence of a context associated with the device among the plurality of network nodes; identifying a second network node based on the information and the level of a signal received from a second network node among the plurality of network nodes; and sending a communication recovery request to the second network node, the request including the information. Example 9. The method according to Example 8, wherein the information indicating the presence of the context associated with the device in a plurality of network nodes includes a list indicating the plurality of network nodes that retain the context associated with the device. Example 10. The method according to Example 8 further includes: switching to a radio resource control inactive mode before identifying the second network node based on information and the level of signals received from the second network node. Example 11. The method according to Example 10 further includes: when the device is in a radio resource control inactive mode, performing cell reselection on the second network node based on information and the level of signals received from the second network node among a plurality of network nodes.

[0097] Example 12. The method according to Example 8, wherein the second network node belongs to a list indicating multiple network nodes that retain the context associated with the device.

[0098] Example 13. The method according to Example 8, wherein the first network node belongs to a list indicating multiple network nodes that retain the context associated with the device. Example 14. A computer-readable medium including instructions that, when executed by a user equipment, cause the user equipment to perform at least the following operations: receive information from a first network node among a plurality of network nodes, the information indicating the presence of a context associated with the device among the plurality of network nodes; identify a second network node based on the information and the level of a signal received from a second network node among the plurality of network nodes; and send a communication recovery request to the second network node, the request including the information.

Claims

1. An apparatus comprising at least one processor and at least one memory, the at least one memory including computer program code, wherein the at least one memory and the computer program code are configured together with the at least one processor to cause the apparatus to: Information is received from a first network node among a plurality of network nodes, the information indicating the presence of a context associated with the device among the plurality of network nodes; The second network node is identified based on the information and the level of the signal received from the second network node among the plurality of network nodes; as well as A communication recovery request is sent to the second network node, the request including the aforementioned information.

2. The apparatus of claim 1, wherein the information indicating the presence of the context associated with the apparatus in the plurality of network nodes includes a list indicating the plurality of network nodes that retain the context associated with the apparatus.

3. The apparatus according to claim 1, further comprising: Before identifying the second network node based on the information and the level of the signal received from the second network node, the system switches to a radio resource control inactive mode, and The device is switched to a radio resource control inactive mode based on the device receiving a radio resource control release message from the first network node.

4. The apparatus according to claim 1 or 3 is further configured such that: When the device is in the Radio Resource Control Inactive Mode, cell reselection is performed on the second network node based on the information and the level of the signal received from the second network node among the plurality of network nodes.

5. The apparatus of claim 1, wherein the second network node belongs to the list, the list indicating the plurality of network nodes that retain the context associated with the apparatus, and The first network node belongs to the list, which indicates the plurality of network nodes that retain the context associated with the device.

6. A method for a user equipment, comprising: Information is received from a first network node among a plurality of network nodes, the information indicating the presence of a context associated with the device among the plurality of network nodes; The second network node is identified based on the information and the level of the signal received from the second network node among the plurality of network nodes; as well as A communication recovery request is sent to the second network node, the request including the aforementioned information.

7. The method of claim 6, wherein the information indicating the presence of the context associated with the device in the plurality of network nodes includes a list indicating the plurality of network nodes that retain the context associated with the device.

8. The method of claim 6, further comprising: Before identifying the second network node based on the information and the level of the signal received from the second network node, the system switches to a radio resource control inactive mode, and When the device is in the Radio Resource Control Inactive Mode, cell reselection is performed on the second network node based on the information and the level of the signal received from the second network node among the plurality of network nodes.

9. The method of claim 6, wherein the second network node belongs to the list, the list indicating the plurality of network nodes that retain the context associated with the device, and The first network node belongs to the list, which indicates the plurality of network nodes that retain the context associated with the device.

10. A computer-readable medium comprising instructions that, when executed by a user equipment, cause the user equipment to perform at least the following operations: Information is received from a first network node among a plurality of network nodes, the information indicating the presence of a context associated with the device among the plurality of network nodes; The second network node is identified based on the information and the level of the signal received from the second network node among the plurality of network nodes; as well as A communication recovery request is sent to the second network node, the request including the aforementioned information.

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