Method, apparatus and system for modifying candidate cells for L1 / L2-based inter-cell mobility

Abstract

The present disclosure describes methods, systems, and devices for modifying candidate cells for inter-cell mobility based on Layer 1 or Layer 2 (L1 / L2) signaling. A method comprises: a first network node modifying at least one candidate cell (CC) for inter-cell mobility based on a measurement report by: the first network node receiving a measurement report from a user equipment (UE); and the first network node sending a CC modification message to the second network node, the CC modification message comprising a modified CC list based on the measurement report. Another method includes supporting modification of at least one CC for inter-cell mobility based on measurement reports by receiving a CC modification message from a first network node, the CC modification message including a list of modified CCs based on measurement reports received from a UE by the first network node.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications. In particular, the present disclosure relates to methods, devices, and systems for modifying candidate cells for inter-cell mobility based on layer 1 or layer 2 (L1 / L2) signaling. Background Art

[0002] Wireless communication technology is driving the world towards an increasingly interconnected and networked society. High-speed and low-latency wireless communications rely on efficient network resource management and allocation between user devices and radio access network nodes (including but not limited to base stations). The next-generation network is expected to provide high-speed, low-latency and ultra-reliable communication capabilities and meet the needs of different industries and users.

[0003] Mobility is one of the important aspects of the rapid development of cellular mobile communication systems. When a user equipment (UE) moves from one cell border to another, it will encounter many problems / difficulties related to cell change. These problems / difficulties may include extended latency, higher signaling overhead and / or long interruption time.

[0004] The present disclosure describes various embodiments for modifying candidate cells for inter-cell mobility based on layer 1 or layer 2 (L1 / L2) signaling, solving at least one of the problems / difficulties discussed above. Various embodiments in the present disclosure can achieve low latency, low overhead, and short interruption time, thereby improving the efficiency and / or performance of wireless communications. Summary of the invention

[0005] This document relates to methods, systems and devices for wireless communications, and more specifically, to methods, systems and devices for modifying candidate cells for inter-cell mobility based on layer 1 or layer 2 (L1 / L2) signaling. Various embodiments of the present disclosure can improve resource utilization efficiency, improve latency performance of wireless communications, and / or save energy consumption of user equipment.

[0006] In one embodiment, the present disclosure describes a method for wireless communication. The method includes: a first network node modifies at least one candidate cell (CandidateCell, CC) for inter-cell mobility based on a measurement report in the following manner: the first network node receives a measurement report from a UE; and the first network node sends a CC modification message to a second network node, the CC modification message including a modified CC list based on the measurement report.

[0007] In one embodiment, the present disclosure describes a method for wireless communication. The method includes: a second network node supports modifying at least one CC for inter-cell mobility based on a measurement report by: the second network node receives a CC modification message from a first network node, the CC modification message including a modified CC list based on a measurement report received by the first network node from a UE.

[0008] In some other embodiments, a device for wireless communication may include: a memory storing instructions; and a processing circuit communicating with the memory. When the processing circuit executes the instructions, the processing circuit is configured to perform the above method.

[0009] In some other embodiments, a device for wireless communication may include: a memory storing instructions; and a processing circuit communicating with the memory. When the processing circuit executes the instructions, the processing circuit is configured to perform the above method.

[0010] In some other embodiments, a computer-readable medium includes instructions that, when executed by a computer, cause the computer to perform the above method.

[0011] The above and other aspects and embodiments thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A A schematic diagram of a wireless communication system is shown.

[0013] Figure 1B A schematic diagram of a base station is shown.

[0014] Figure 2 An example of a network node is shown.

[0015] Figure 3 An example of a user device is shown.

[0016] Figure 4A A flow chart of a wireless communication method is shown.

[0017] Figure 4B A flow chart of another wireless communication method is shown.

[0018] Figure 5A A flow chart of an exemplary embodiment of wireless communications is shown.

[0019] Figure 5B A flow chart of another exemplary embodiment of wireless communication is shown.

[0020] Fig. 6A A flow chart of an exemplary embodiment of wireless communications is shown.

[0021] Figure 6B A flow chart of another exemplary embodiment of wireless communication is shown.

[0022] Fig. 7A A flow chart of an exemplary embodiment of wireless communications is shown.

[0023] Figure 7B A flow chart of another exemplary embodiment of wireless communication is shown.

[0024] Figure 7C A flow chart of an exemplary embodiment of wireless communications is shown.

[0025] Fig.7D A flow chart of another exemplary embodiment of wireless communication is shown.

[0026] Figure 8 A flow chart of an exemplary embodiment of wireless communications is shown.

[0027] Fig. 9 A flow chart of an exemplary embodiment of wireless communications is shown. DETAILED DESCRIPTION

[0028] The present disclosure will now be described in detail below with reference to the accompanying drawings, which are a part of the present disclosure and show specific examples of embodiments by way of illustration. However, it should be noted that the present disclosure can be implemented in various different forms, and therefore, the subject matter covered or claimed is intended to be interpreted as not being limited to any embodiment set forth below.

[0029] Throughout the specification and claims, terms may have nuanced meanings that are suggested or implied by the context, not just the explicitly stated meanings. Likewise, the phrases "in one embodiment" or "in some embodiments" as used herein do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" as used herein do not necessarily refer to different embodiments. The phrases "in one embodiment" or "in some embodiments" as used herein do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" as used herein do not necessarily refer to different embodiments. For example, the subject matter intended to be claimed includes exemplary embodiments or combinations of all or part of embodiments.

[0030] Typically, terms can be understood at least in part based on their use in context. For example, terms such as "and", "or" or "and / or" used herein can include multiple meanings, which can depend at least in part on the context in which the terms are used. Typically, "or" if used in an association list, such as A, B or C, means A, B and C, which are used here for inclusion, and A, B or C, which are used here for exclusion. In addition, the terms "one or more" or "at least one" used herein, at least in part depending on the context, can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. Similarly, terms such as "one", "a kind of" or "the" can be understood to express singular or plural usage, at least in part depending on the context. In addition, the term "based on" or "determined by..." can be understood to not necessarily be intended to express a set of exclusive factors, but can allow the presence of additional factors that are not necessarily explicitly described, which also depends at least in part on the context.

[0031] The present disclosure describes various embodiments for modifying candidate cells for inter-cell mobility based on layer 1 or layer 2 (L1 / L2) signaling.

[0032] Wireless communication technology is driving the world towards an increasingly interconnected and networked society. High-speed and low-latency wireless communications rely on efficient network resource management and allocation between user equipment and radio access network nodes (including but not limited to base stations). The next-generation network is expected to provide high-speed, low-latency and ultra-reliable communication capabilities and meet the needs of different industries and users. Mobility is one of the important aspects of the rapid development of cellular mobile communication systems. When a UE moves from one cell boundary to another, it will encounter many problems / difficulties related to cell changes. These problems / difficulties may include extended latency, higher signaling overhead and / or long interruption time.

[0033] For example, in some embodiments, the serving cell change may be triggered by Layer 3 (L3) measurements and may be accomplished by a reconfiguration triggered by Radio Resource Control (RRC) signaling, with synchronous changes to the Primary cell (PCell) and the Primary Secondary cell (PSCell), and synchronous release and addition of the Secondary cell (SCell) when applicable. These embodiments may include a full L2 (and / or L1) reset, resulting in longer latency, greater signaling overhead, and / or longer interruption time compared to beam switching mobility. In some embodiments, during the L1 / L2 mobility candidate cell configuration phase between the Central Unit (CU) and the Distributed Unit (DU), the DU may not be able to dynamically adjust the candidate cell list based on the L1 measurement report.

[0034] Various embodiments of the present disclosure include processes and signaling for the DU to dynamically adjust candidate cell configurations based on L1 measurement reports during the candidate cell configuration phase. Various embodiments of the present disclosure can achieve low latency, low overhead, and short interruption time, thereby improving the efficiency and / or performance of wireless communications.

[0035] Figure 1A An exemplary cellular wireless communication network 100 (also referred to as a wireless communication system) is shown, which includes a core network 110 , a radio access network (RAN) 120 , and one or more UEs 130 .

[0036] RAN 120 also includes a plurality of base stations 122 and 124. Base station 122 and one or more UE 130 communicate with each other via Over the Air (OTA) wireless communication resources 140. Wireless communication network 100 may be implemented as, for example, a 2G, 3G, 4G / LTE, 5G or 6G cellular communication network. Correspondingly, base stations 122 and 124 may be implemented as 2G base stations, 3G nodeBs, LTE eNBs or 5G New Radio (NR) gNBs. UE 130 may be implemented as a mobile or fixed communication device for accessing wireless communication network 100. One or more UE 130 may include, but are not limited to, mobile phones, Internet of Things (IoT) devices, machine-type communications (MTC) devices, laptops, tablets, personal digital assistants, wearable devices, distributed remote sensor devices, roadside assistant equipment and desktop computers. As an alternative to a cellular wireless network environment, RAN 120 and the principles described below may be implemented as other types of wireless access networks, such as Wi-Fi, Bluetooth, ZigBee and WiMax networks.

[0037] exist Figure 1A In the exemplary wireless communication system 100 of FIG. 1 , one or more UEs 130 may connect to a base station 122 via an OTA interface 140 and establish a communication session. The communication session between the UE 130 and the base station 122 may utilize downlink (DL) transmission resources and / or uplink (UL) transmission resources. The DL transmission resources carry data from the base station 122 to the UE 130, and the UL transmission resources carry data from the UE 130 to the base station 122. In some cases, such as when the base station 122 is unavailable or when the UE 130 moves into the coverage of the base station 124, one or more UEs 130 may connect to the base station 124 and establish a communication session.

[0038] refer to Figure 1B , the base station (e.g., gNB) 122 may have a control-distributed separation structure, which may include a control unit (CU) 160 and one or more distributed units (DU) 171 and / or 172. The 5G Core Network (5GC) may communicate with the gNB via the NG interface between the 5GC and the gNB. The gNB and another gNB may communicate via the Xn-C interface. The gNB-CU may communicate with one or more gNB-DUs via the F1 interface.

[0039] In some embodiments, in a CU / DU separated architecture, a gNB-CU is defined as a logical node that hosts the RRC, SDAP, and PDCP protocols of a gNB or the RRC and PDCP protocols of an en-gNB, and controls the operation of one or more gNB-DUs. A gNB-DU is defined as a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and the operation of the logical node is partially controlled by the gNB-CU. One gNB-DU supports one or more cells. One cell is supported by only one gNB-DU.

[0040] In some embodiments, in order to reduce the handover interruption time and improve mobility reliability (i.e., mobility robustness), conditional handover (CHO) may be proposed. CHO is defined as a handover performed by the UE when an execution condition is met. The UE starts evaluating the execution condition upon receiving the CHO configuration, and stops evaluating the execution condition once the handover is triggered. The CHO configuration includes a candidate PCell configuration generated by a candidate target node and the corresponding execution condition of the candidate cell.

[0041] In some embodiments, in order to improve mobility reliability (i.e., mobility robustness) in the case of a Secondary Node (SN) change or addition of an SN, a Conditional PSCell Addition / Change (CPAC) may be proposed. Similar to CHO, CPAC is defined as having configured CPAC execution conditions that determine when / whether to execute the corresponding PSCell add / change command. Once the CPAC configuration is received, the UE starts evaluating the conditions and executes the CPAC command only when the conditions are met.

[0042] In some implementations, in order to reduce mobility interruption, a handover process based on a dual active protocol stack (DAPS) may be proposed. In a handover process based on DAPS, the UE remains connected to both the source cell and the target cell until the source cell is released after successfully randomly accessing the target cell.

[0043] Figure 2An example of an electronic device 200 implementing a network base station is shown. The exemplary electronic device 200 may include a wireless transmission / reception (Transmitting / Receiving, Tx / Rx) circuit 208 for sending / receiving communications with UE and / or other base stations. The electronic device 200 may also include a network interface circuit 209 for enabling the base station to communicate with other base stations and / or a core network via, for example, optical or wired interconnection, Ethernet and / or other data transmission media / protocols. The electronic device 200 may optionally include an input / output (Input / Output, I / O) interface 206 for communicating with an operator or the like.

[0044] The electronic device 200 may further include a system circuit 204. The system circuit 204 may include a processor 221 and / or a memory 222. The memory 222 may include an operating system 224, instructions 226, and parameters 228. The instructions 226 may be configured for one or more processors in the processor 221 to perform the functions of a network node. The parameters 228 may include parameters that support the execution of the instructions 226. For example, the parameters may include network protocol settings, bandwidth parameters, radio frequency mapping allocations, and / or other parameters.

[0045] Figure 3An example of an electronic device implementing a terminal device 300 (e.g., UE) is shown. UE 300 may be a mobile device, such as a smart phone or a mobile communication module provided in a vehicle. UE 300 may include a communication interface 302, a system circuit 304, an I / O interface 306, a display circuit 308, and a storage device 309. The display circuit may include a user interface 310. System circuit 304 may include any combination of hardware, software, firmware, or other logic / circuits. System circuit 304 may be implemented, for example, with one or more systems on a chip (Systems on a Chip, SoC), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), discrete analog and digital circuits, and other circuits. System circuit 304 may be part of an implementation of any desired function in UE 300. In this regard, the system circuit 304 may include logic that facilitates, for example, decoding and playing music and video (e.g., MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playing); running applications; accepting user input; saving and retrieving application data; establishing, maintaining, and terminating cellular phone calls or data connections, such as Internet connections; establishing, maintaining, and terminating wireless network connections, Bluetooth connections, or other connections; and displaying relevant information on the user interface 310. The user interface 310 and the I / O interface 306 may include a graphical user interface, a touch-sensitive display, tactile feedback or other tactile output, voice or facial recognition input, buttons, switches, speakers, and other user interface elements. Other examples of the I / O interface 306 may include microphones, video and still image cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headphone and microphone input / output jacks, Universal Serial Bus (USB) connectors, memory card slots, radiation sensors (e.g., IR sensors), and other types of inputs.

[0046] refer to Figure 3, the communication interface 302 may include radio frequency (RF) transmission (Tx) and reception (Rx) circuits 316 that handle the transmission and reception of signals through one or more antennas 314. The communication interface 302 may include one or more transceivers. The transceiver may be a wireless transceiver that includes modulation / demodulation circuits, digital to analog converters (DAC), shaping tables, analog to digital converters (ADC), filters, waveform shapers, filters, preamplifiers, power amplifiers, and / or other logic for transmitting and receiving through one or more antennas or (for some devices) through a physical (e.g., wired) medium. The signals transmitted and received may follow any of a variety of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM), frequency channels, bit rates, and encodings. As a specific example, the communication interface 302 may include a transceiver that supports transmission and reception under 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High Speed ​​Packet Access (HSPA) +, 4G / Long Term Evolution (LTE), 5G standards and / or 6G standards. However, the techniques described below are applicable to other wireless communication technologies, whether from the 3rd Generation Partnership Project (3GPP), GSM Association, 3GPP2, IEEE or other partners or standards bodies.

[0047] refer to Figure 3 , the system circuit 304 may include one or more processors 321 and a memory 322. The memory 322 stores, for example, an operating system 324, instructions 326, and parameters 328. The processor 321 is configured to execute the instructions 326 to implement the desired functions of the UE 300. The parameters 328 may provide and specify configuration and operating options for the instructions 326. The memory 322 may also store any BT, WiFi, 3G, 4G, 5G, 6G, or other data that the UE 300 will send or has received through the communication interface 302. In various embodiments, the system power of the UE 300 may be provided by a power storage device such as a battery or a transformer.

[0048] The present disclosure describes various embodiments for modifying candidate cells for inter-cell mobility based on layer 1 or layer 2 (L1 / L2) signaling, which may be implemented in part or in whole in Figures 2 to 3 The method is implemented on a network base station and / or user equipment described in the embodiment.

[0049] In various embodiments, L1 / L2 based inter-cell mobility may belong to intra-DU inter-cell mobility, where the UE moves from a first cell to a second cell, and the first cell and the second cell are within the same gNB-DU.

[0050] In various embodiments, L1 / L2-based inter-cell mobility may belong to inter-DU inter-cell mobility, where the UE moves from one or more first cells in a first gNB-DU to one or more second cells in a second gNB-DU, and the first gNB-DU and the second gNB-DU are within the same gNB-CU.

[0051] refer to Figure 4A , the present disclosure describes various embodiments of a method 400 for wireless communication, the method comprising: a first network node modifies at least one CC for inter-cell mobility based on a measurement report. The method 400 may include some or all of the following steps: step 410, the first network node receives a measurement report from a UE; and / or step 420, the first network node sends a CC modification message to a second network node, the CC modification message including a modified CC list based on the measurement report.

[0052] refer to Figure 4B , the present disclosure describes various embodiments of a method 450 for wireless communication, the method comprising: a second network node supporting modification of at least one CC for inter-cell mobility based on a measurement report. The method 450 may include step 460, the second network node receiving a CC modification message from the first network node, the CC modification message including a modified CC list based on a measurement report received by the first network node from a UE.

[0053] In various embodiments and / or implementations of the present disclosure, a network node may be referred to as a network element.

[0054] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, in response to the inter-cell mobility belonging to intra-distributed unit (intra-DU) inter-cell mobility, the first network node includes a distributed unit (gNB-DU) of the base station; in response to the inter-cell mobility belonging to inter-distributed unit (inter-DU) inter-cell mobility, the first network node includes a source gNB-DU; and / or the second network node includes a control unit (gNB-CU) of the base station.

[0055] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, inter-cell mobility includes mobility based on layer 1 or layer 2 signaling (L1 / L2 mobility); and / or the measurement report includes an L1 measurement report.

[0056] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the CC modification message includes a modified CC configuration corresponding to a modified CC list; and / or the first network node sends a second message to the second network node, the second message including the modified CC configuration corresponding to the modified CC list.

[0057] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the CC modification message belongs to the F1 interface message; and / or the modified CC list includes at least one of the following: a CC list to be cancelled, a CC list to be added, and a DU recommended CC list.

[0058] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the F1 interface message includes at least one of the following: a UE context release request message, a UE context modification request message, or a UE context modification response message.

[0059] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, inter-cell mobility belongs to intra-DU inter-cell mobility; in response to receiving a CC modification message from the first network node, the second network node sends a modified RRCReconfiguration message to the first network node, and the modified RRCReconfiguration message includes a modified CC configuration based on the modified CC list; the first network node forwards the modified RRCReconfiguration message to the UE; and / or the first network receives a modified RRCReconfigurationComplete message from the UE and forwards the modified RRCReconfigurationComplete message to the second network node.

[0060] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, before the first network node receives a measurement report from the UE: the first network node receives a CU recommended CC list from the second network node; and / or the first network node sends an accepted CC list and an accepted CC configuration corresponding to the accepted CC list to the second network node.

[0061] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, before the first network node receives a measurement report from the UE: in response to receiving an acceptance CC configuration from the first network node, the second network node sends an acceptance RRCReconfiguration message to the first network node, the acceptance RRCReconfiguration message including the acceptance CC configuration; the first network node forwards the acceptance RRCReconfiguration message to the UE; and / or the first network receives an acceptance RRCReconfigurationComplete message from the UE and forwards the acceptance RRCReconfigurationComplete message to the second network node.

[0062] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the first network node receives an initial measurement report from the UE; in response to receiving the CU recommended CC list from the second network node, the first network node sends an accepted CC list, a DU recommended CC list and their corresponding CC configurations to the second network node, wherein the accepted CC list and the DU recommended CC list are based on the CU recommended CC list and the initial measurement report; the second network node sends an accept RRCReconfiguration message to the first network node, and the accept RRCReconfiguration message includes an accept CC configuration; the first network node forwards the accept RRCReconfiguration message to the UE; and / or the first network receives an accept RRCReconfigurationComplete message from the UE and forwards the accept RRCReconfigurationComplete message to the second network node.

[0063] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the modified CC list includes a CC list to be cancelled; the CC modification message includes a UE context release request message; and / or the first network node sends a modified CC configuration corresponding to the modified CC list to the second network node.

[0064] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the modified CC list includes a CC list to be added; and / or the first network node sends a modified CC configuration corresponding to the modified CC list to the second network node;

[0065] In some implementations, in addition to part or all of other implementations or embodiments described in the present disclosure, when the CC modification message includes a UE context modification required message, the first network node receives a confirmation message from the second network node.

[0066] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, when the CC modification message includes an access success message, the second network node does not need to send a response message to the first network node, so the first network node does not receive a confirmation message from the second network node.

[0067] In some implementations, in addition to part or all of other implementations or embodiments described in the present disclosure, the CC modification message includes modifying the CC configuration; and / or the first network node sends a second message to the second network node, the second message including modifying the CC configuration.

[0068] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, inter-cell mobility belongs to intra-CU and inter-DU inter-cell mobility between a first network node and a third network node; in response to receiving a CC modification message from the first network node, the second network node sends a modified RRCReconfiguration message to the first network node, the modified RRCReconfiguration message including a modified CC configuration based on a modified CC list; the first network node forwards the modified RRCReconfiguration message to the UE; and / or the first network receives a modified RRCReconfigurationComplete message from the UE and forwards the modified RRCReconfigurationComplete message to the second network node.

[0069] In some embodiments, in addition to some or all of the other embodiments or examples described in the present disclosure, the third network node includes a candidate gNB-DU.

[0070] In various embodiments / implementations of the present disclosure, the candidate gNB-DU (or referred to as candidate DU) may be referred to as a target gNB-DU (or referred to as target DU).

[0071] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, before the first network node receives a measurement report from the UE: the third network node receives a CU recommended CC list from the second network node; and / or the third network node sends an accepted CC list and an accepted CC configuration corresponding to the accepted CC list to the second network node.

[0072] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, before the first network node receives a measurement report from the UE: the second network node sends a second F1 interface message to the first network node, the second F1 interface message including a configured CC list; and / or in response to receiving the second F1 interface message, the first network node sends a response message to the second network node.

[0073] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, before the first network node receives a measurement report from the UE: the second network node sends an accept RRCReconfiguration message to the first network node, the accept RRCReconfiguration message including accepting the CC configuration; the first network node forwards the accept RRCReconfiguration message to the UE; and / or the first network receives an accept RRCReconfigurationComplete message from the UE and forwards the accept RRCReconfigurationComplete message to the second network node.

[0074] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the first network node receives an initial measurement report from the UE; in response to receiving the CU recommended CC list from the second network node, the first network node sends at least one of the following to the second network node: an accepted CC list, a DU recommended CC list and its corresponding CC configuration, wherein the accepted CC list and the DU recommended CC list are based on the CU recommended CC list and the initial measurement report; the second network node sends an accept RRCReconfiguration message to the first network node, and the accept RRCReconfiguration message includes an accept CC configuration; the first network node forwards the accept RRCReconfiguration message to the UE; and / or the first network receives an accept RRCReconfigurationComplete message from the UE and forwards the accept RRCReconfigurationComplete message to the second network node.

[0075] In some implementations, in addition to part or all of other implementations or embodiments described in the present disclosure, the modified CC list includes a CC list to be cancelled; and / or the CC modification message includes a UE context release request message.

[0076] In some embodiments, in addition to part or all of other embodiments or examples described in the present disclosure, the modified CC list includes a CC list to be added; the CC modification message includes a UE context modification request message; the first network node sends a modified CC configuration corresponding to the modified CC list to the second network node; and / or the first network node receives a confirmation message from the second network node.

[0077] In some implementations, in addition to part or all of other implementations or embodiments described in the present disclosure, the CC modification message includes modifying the CC configuration; and / or the first network node sends a second message to the second network node, the second message including modifying the CC configuration.

[0078] In some embodiments, in addition to some or all of the other embodiments or examples described in the present disclosure, at least one of the accepted RRCReconfiguration message or the modified RRCReconfiguration message is transmitted from the second network node to the first network node via a DL RRC message transmission message; and / or at least one of the accepted RRCReconfigurationComplete message or the modified RRCReconfigurationComplete message is transmitted from the first network node to the second network node via an UL RRC message transmission message.

[0079] The present disclosure describes various embodiments of non-limiting examples of supporting inter-cell mobility based on layer 1 or layer 2 (L1 / L2) signaling. For non-limiting examples, a DU (e.g., a source DU) may determine candidate cells to be modified (including but not limited to cancellation / removal / addition / new suggestion) based on an L1 measurement report from a UE. The DU may send a list of candidate cells to be cancelled / added / suggested and a generated candidate cell configuration (e.g., CellGroupConfig) to a CU via an F1 interface message (e.g., a UE context release request message for release, a UE context modification request message for addition, a UE context modification response message for suggestion, or other messages).

[0080] Figure 5A An exemplary embodiment of modifying candidate cells for L1 / L2 based intra-DU inter-cell mobility is shown, where a UE 591 may move from a first cell operated by a gNB-DU 592 to a second cell operated by the same gNB-DU 592. In some embodiments, the gNB-DU may communicate with a gNB-CU 594, which may be referred to as intra-CU intra-DU inter-cell mobility. The exemplary embodiment may include some or all of the following steps. The following steps are labeled with step numbers, which are used to label the steps and do not impose any restrictions on the order / sequence of the steps.

[0081] Referring to step 501, the gNB-CU (or referred to as "CU") determines a candidate cell list (or referred to as a recommended candidate cell list), for example, based on RRM measurements. The CU sends the recommended candidate cell list to the gNB-DU (or referred to as "DU") via an F1 interface message (e.g., a UE context modification request message or other message) to request the DU to establish a candidate cell. The message may also include an indication indicating that the process is for L1 / L2 mobility, and / or an indication indicating which type of L1 / L2 mobility the process is for.

[0082] Referring to step 502, the DU determines whether to establish a candidate cell as recommended, and sends the generated candidate cell configuration (e.g., CellGroupConfig) to the CU via, for example, a UE context modification response message. When the DU fails to establish some candidate cells, the DU may also include an accepted cell list (e.g., a list of cells that have been successfully established) or a failed / rejected cell list (e.g., a list of cells that failed to be established) in the message. The DU may also include a generated trigger event / execution condition (e.g., a mobility triggered for the UE or CU) in the message.

[0083] Referring to step 503, the CU sends the generated RRCReconfiguration message to the DU, for example, via a DL RRC messaging message. The RRC message includes the candidate cell configuration and may also include a triggering event / condition associated with the candidate cell (eg, mobility triggered for the UE).

[0084] Referring to step 504, the DU forwards the received RRCReconfiguration message to the UE.

[0085] Referring to steps 505 and 506, the UE responds to the DU with an RRCReconfigurationComplete message, and the DU forwards the message to the CU, for example, via a UL RRC messaging message.

[0086] Referring to step 507, the UE sends an L1 measurement report to the DU.

[0087] Referring to step 508, the DU determines the candidate cells to be cancelled. The DU sends the candidate cell list to be cancelled and the generated candidate cell configuration (eg, CellGroupConfig) to the CU via an F1 interface message (eg, UE context release request message or other message).

[0088] In some embodiments, the F1 interface message may include a UE context release request message. The UE context release request message may belong to a category 2 message, which does not require the message receiver to send a response message to the message sender. When the CU receives the UE context release request message from the DU, the CU does not need to send a DU response message in response to the UE context release request message.

[0089] Steps 509 , 510 , 511 , and 512 may be performed similarly to steps 503 , 504 , 505 , and 506 , respectively.

[0090] Steps 507 and 508 (referred to as 599) describe an embodiment in which the DU determines a candidate cell list to be cancelled based on the L1 measurement report received from the UE, and the DU sends the candidate cell list to be cancelled to the CU via an F1 interface message.

[0091] In some other embodiments, reference Figure 5B , steps 507 and 508 (referred to as 598) may be performed between steps 502 and 503, wherein the DU receives an L1 measurement report from the UE after step 502 and determines candidate cells to be cancelled, and the DU sends a list of candidate cells to be cancelled to the CU via an F1 interface message.

[0092] Fig. 6A Another exemplary embodiment for modifying candidate cells for L1 / L2 based inter-DU inter-cell mobility is shown, where a UE 691 may move from a cell operated by a source gNB-DU 692 to another cell operated by a candidate gNB-DU 693. In some embodiments, the source gNB-DU and the candidate gNB-DU may communicate with the same gNB-CU 694, which may be referred to as intra-CU inter-DU inter-cell mobility. The exemplary embodiment may include some or all of the following steps. The following steps are labeled with step numbers, which are used to label the steps and do not impose any restrictions on the order / sequence of the steps.

[0093] Referring to step 601, the gNB-CU (or referred to as "CU") determines candidate cells, for example, based on RRM measurements. The CU sends a list of recommended candidate cells to the candidate gNB-DU (or referred to as "candidate DU") via an F1 interface message (e.g., a UE context setup request message or other message) to request the candidate DU to establish the candidate cells. The message may also include an indication indicating that the process is for L1 / L2 mobility, and / or an indication indicating which type of L1 / L2 mobility the process is for.

[0094] In the present disclosure, in various embodiments / implementations, a candidate gNB-DU may be referred to as a candidate gNB-DU.

[0095] Referring to step 602, the candidate gNB-DU may determine whether to establish the candidate cell as suggested, and send the generated candidate cell configuration (e.g., CellGroupConfig) to the CU via, for example, a UE context setup response message. When the DU fails to establish some candidate cells, the candidate DU may also include an accepted cell list (e.g., including a list of cells that have been successfully established) and / or a failed / rejected cell list (e.g., including a list of cells that failed to be established) in the message.

[0096] Referring to step 603, the CU sends the configured candidate cell list to the source gNB-DU (or referred to as the source DU) via an F1 interface message (e.g., a UE context modification request message). The message may also include a trigger event / execution condition generated by the CU (e.g., mobility triggered for the DU).

[0097] Referring to step 604, the source DU responds with a UE context modification response message. The message may also include a triggering event / execution condition generated by the DU (eg, for UE-triggered mobility or CU-triggered mobility).

[0098] Steps 605, 606, 607, 608, 609, 610, 611, 612, 613 and 614 may be performed similarly to steps 503, 504, 505, 506, 507, 508, 509, 510, 511 and 512, respectively.

[0099] Steps 609 and 610 (referred to as 699) describe an embodiment in which the source DU determines a candidate cell list to be cancelled based on the L1 measurement report received from the UE, and the source DU sends the candidate cell list to be cancelled to the CU via an F1 interface message.

[0100] In some other embodiments, reference Figure 6B , steps 609 and 610 (referred to as 698) may be performed between steps 604 and 605, wherein the source DU receives an L1 measurement report from the UE after step 604 and determines candidate cells to be cancelled, and the source DU sends a list of candidate cells to be cancelled to the CU via an F1 interface message.

[0101] Fig. 7AAn exemplary embodiment of modifying candidate cells for L1 / L2 based intra-DU inter-cell mobility is shown, where a UE 791 may move from a first cell operated by a gNB-DU 792 to a second cell operated by the same gNB-DU 792. In some embodiments, the gNB-DU may communicate with a gNB-CU 794, which may be referred to as intra-CU intra-DU inter-cell mobility. The exemplary embodiment may include some or all of the following steps. The following steps are labeled with step numbers, which are used to label the steps and do not impose any restrictions on the order / sequence of the steps.

[0102] Steps 701 , 702 , 703 , 704 , 705 , 706 , and 707 may be performed similarly to steps 501 , 502 , 503 , 504 , 505 , 506 , and 507 , respectively.

[0103] Referring to step 708, the gNB-DU (or "DU") determines the candidate cells to be added. The DU sends the candidate cell list to be added and the generated candidate cell configuration (e.g., CellGroupConfig) to the gNB-CU (or "CU") via an F1 interface message (e.g., UE Context Modification Request message or other message).

[0104] In some embodiments, the F1 interface message may include a UE context modification required message. The UE context modification required message may belong to a category 1 message, which requires the message receiver to send a response message to the message sender. When the CU receives the UE context modification required message from the DU, the CU needs to send a response message to the DU in response to the UE context modification required message.

[0105] (See step 709).

[0106] Referring to step 709, the CU responds to the DU with a confirmation message (eg, UE Context Modification Confirm message).

[0107] Steps 710 , 711 , 712 , and 713 may be performed similarly to steps 509 , 510 , 511 , and 512 , respectively, and steps 509 , 510 , 511 , and 512 may be performed similarly to steps 503 , 504 , 505 , and 506 , respectively.

[0108] Steps 707, 708 and 709 (referred to as 799) describe an implementation method in which the DU determines a list of candidate cells to be added based on the L1 measurement report received from the UE, the DU sends the list of candidate cells to be added to the CU via an F1 interface message, and when the F1 interface message is a category 1 message, the CU responds to the DU with a confirmation message.

[0109] In some other embodiments, reference Figure 7B , steps 707, 708 and 709 (referred to as 798) can be performed between steps 702 and 703, wherein the DU receives an L1 measurement report from the UE after step 702 and determines candidate cells to be added, the DU sends a list of candidate cells to be added to the CU via an F1 interface message, and when the F1 interface message is a category 1 message, the CU responds to the DU with a confirmation message.

[0110] In some other implementations, any combination of the following may occur simultaneously: a candidate cell list to be cancelled corresponding to a candidate cell release, a candidate cell list to be added corresponding to a candidate cell addition, a suggested candidate cell list, etc. In the following, the combination of a candidate cell list to be added and a candidate cell list to be cancelled is taken as a non-limiting example.

[0111] refer to Figure 7C In 797, a single F1 interface message may include a candidate cell list to be added and a candidate cell list to be cancelled. The DU determines the candidate cell list to be added and the candidate cell list to be cancelled based on the L1 measurement report received from the UE, and the DU sends the candidate cell list to be added and the candidate cell list to be cancelled to the CU via the F1 interface message, and when the F1 interface message is a category 1 message, the CU responds to the DU with a confirmation message. In various embodiments, 797 may be replaced by Fig. 7A 799 or Figure 7B 798 of them.

[0112] refer to Fig.7D In step 796, two F1 interface messages may be used: one F1 interface message includes a list of candidate cells to be added; and the other F1 interface message includes a list of candidate cells to be cancelled. The DU determines the list of candidate cells to be added and the list of candidate cells to be cancelled based on the L1 measurement report received from the UE, and the DU sends the list of candidate cells to be added and the list of candidate cells to be cancelled to the CU via two F1 interface messages. For each F1 interface message, depending on whether the message is a category 1 message or a category 2 message, the CU responds to the DU with a confirmation message or does not respond to the DU. For a non-limiting example, in step 731, the DU sends a UE context release request message including a list of candidate cells to be cancelled and / or a generated candidate cell configuration (e.g., CellGroupConfig); and because the UE context release request message is a category 2 message, the CU does not need to respond to it. In some embodiments, the order of steps 731 and 708 may be different, for example, step 708 may be performed before step 731. In various embodiments, 796 may replace Fig. 7A 799 or Figure 7B 798 of them.

[0113] In various embodiments of inter-DU inter-cell mobility based on L1 / L2, the source DU may send a candidate cell list to be added and a candidate cell list to be cancelled to the CU simultaneously or continuously. As a non-limiting example, 796 (or 797) may replace one of the following: Fig. 6A 699 of them Figure 6B 698 and / or Fig. 9 999 in it.

[0114] Figure 8 An exemplary embodiment of modifying candidate cells for L1 / L2 based intra-DU inter-cell mobility is shown, where a UE 891 may move from a first cell operated by a gNB-DU 892 to a second cell operated by the same gNB-DU 892. In some embodiments, the gNB-DU may communicate with a gNB-CU 894, which may be referred to as intra-CU intra-DU inter-cell mobility. The exemplary embodiment may include some or all of the following steps. The following steps are labeled with step numbers, which are used to label the steps and do not impose any restrictions on the order / sequence of the steps.

[0115] Referring to step 801, the UE sends an L1 measurement report to the DU. The L1 measurement report may be referred to as an initial or first measurement report, and in step 808 the UE sends another L1 measurement report to the DU.

[0116] Referring to step 802, the CU determines the candidate cells, for example, based on RRM measurements. The CU sends a list of recommended candidate cells to the DU via an F1 interface message (e.g., a UE context modification request message or other message) to request the DU to establish the candidate cells. The message may also include an indication indicating that the process is for L1 / L2 mobility, and / or an indication indicating which type of L1 / L2 mobility the process is for.

[0117] Referring to step 803, the DU determines whether to set the candidate cell as the CU recommended candidate cell, and determines its recommended candidate cell based on the L1 measurement report, and sends the generated candidate cell configuration (e.g., CellGroupConfig) to the CU via, for example, a UE context modification response message. When the DU fails to establish some candidate cells, the DU may also include an accepted cell list (e.g., including a list of cells that have been successfully established) or a failed / rejected cell list (e.g., including a list of cells that failed to be established) in the message. The DU may also include a list of recommended cells based on the L1 measurement report. The DU may also include a generated trigger event / execution condition (e.g., mobility triggered for the UE or CU) in the message.

[0118] Steps 804, 805, 806, 807, 808, 809, 810, 811, 812, 813 and 814 may be performed similarly to steps 703, 704, 705, 706, 707, 708, 709, 711, 712 and 713, respectively.

[0119] In 899 , in some other implementations, any combination of the following may occur simultaneously: a candidate cell list to be cancelled corresponding to a candidate cell release, a candidate cell list to be added corresponding to a candidate cell addition, a recommended candidate cell list, etc. 797 and 796 may be used as non-limiting examples of 899 .

[0120] Fig. 9 Another exemplary embodiment for modifying candidate cells for L1 / L2 based inter-DU inter-cell mobility is shown, where a UE 991 may move from a cell operated by a source gNB-DU 992 to another cell operated by a candidate gNB-DU 993. In some embodiments, the source gNB-DU and the candidate gNB-DU may communicate with the same gNB-CU 994, which may be referred to as intra-CU inter-DU inter-cell mobility. The exemplary embodiment may include some or all of the following steps. The following steps are labeled with step numbers, which are used to label the steps and do not impose any restrictions on the order / sequence of the steps.

[0121] Steps 901 and 902 may be performed similarly to steps 601 and 602 , respectively.

[0122] Referring to step 903, the UE sends an L1 measurement report to the source DU. The L1 measurement report may be referred to as an initial or first measurement report, and in step 910 the UE sends another L1 measurement report to the DU.

[0123] Step 904 may be performed similarly to step 603 .

[0124] Referring to step 905, the source DU determines its recommended candidate cell based on the L1 measurement report, and sends the generated candidate cell configuration (e.g., CellGroupConfig) to the CU via, for example, a UE context modification response message. The message may also include a trigger event / execution condition generated by the DU (e.g., for UE-triggered mobility or CU-triggered mobility).

[0125] Steps 906, 907, 908, 909, 910, 911, 912, 913, 914, 915 and 916 may be performed similarly to 703, 704, 705, 706, 707, 708, 709, 710, 711, 712 and 713, respectively.

[0126] In 999 , in some other implementations, any combination of the following may occur simultaneously: a candidate cell list to be cancelled corresponding to a candidate cell release, a candidate cell list to be added corresponding to a candidate cell addition, a recommended candidate cell list, etc. 797 and 796 may be used as non-limiting examples of 999 .

[0127] The present disclosure describes methods, apparatus, and computer-readable media for wireless communications. The present disclosure addresses the problem of modifying candidate cells for L1 / L2-based inter-cell mobility. The methods, devices, and computer-readable media described in the present disclosure can facilitate the performance of wireless communications by modifying candidate cells for L1 / L2-based inter-cell mobility, thereby improving efficiency and overall performance. The methods, devices, and computer-readable media described in the present disclosure can improve the overall efficiency of a wireless communication system.

[0128] Throughout the specification, references to features, advantages, or similar language do not mean that all features and advantages that can be achieved with the solution are or should be included in any single implementation thereof. Instead, language referring to features and advantages should be understood to mean that a particular feature, advantage, or characteristic described in conjunction with an embodiment is included in at least one embodiment of the solution. Therefore, throughout the specification, discussions of features and advantages and similar language may, but do not necessarily, refer to the same embodiment.

[0129] Furthermore, in one or more embodiments, the described features, advantages, and characteristics of the present solution may be combined in any suitable manner. Based on the description herein, one of ordinary skill in the relevant art will recognize that the present solution may be practiced without one or more specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be found in certain embodiments that may not be present in all embodiments of the present solution.

Claims

1. A method for wireless communication, comprising: The first network node modifies at least one candidate cell CC for inter-cell mobility based on the measurement report by: The first network node receives the measurement report from a user equipment UE; as well as The first network node sends a CC modification message to the second network node, where the CC modification message includes a modified CC list based on the measurement report.

2. A method for wireless communication, comprising: The second network node supports modifying at least one candidate cell CC for inter-cell mobility based on the measurement report by: The second network node receives a CC modification message from the first network node, the CC modification message comprising a modified CC list based on the measurement report received by the first network node from a user equipment UE.

3. The method according to any one of claims 1 to 2, wherein: In response to the inter-cell mobility belonging to intra-cell mobility within a distributed unit DU, the first network node includes a distributed unit gNB-DU of a base station; In response to the inter-cell mobility belonging to inter-distributed unit DU inter-cell mobility, the first network node includes a source gNB-DU; and The second network node includes a control unit gNB-CU of the base station.

4. The method according to any one of claims 1 to 2, wherein: The inter-cell mobility includes mobility based on layer 1 or layer 2 signaling; and The measurement report includes an L1 measurement report.

5. The method according to any one of claims 1 to 2, wherein: The CC modification message includes a modified CC configuration corresponding to the modified CC list; or The first network node sends a second message to the second network node, the second message including the modified CC configuration corresponding to the modified CC list.

6. The method according to any one of claims 1 to 2, wherein: The CC modification message belongs to the F1 interface message; and The modified CC list includes at least one of the following: a CC list to be cancelled, a CC list to be added, and a DU recommended CC list.

7. The method according to claim 6, wherein: The F1 interface message includes at least one of the following: a UE context release request message, a UE context modification request message, or a UE context modification response message.

8. The method according to any one of claims 1 to 2, wherein: The inter-cell mobility belongs to the inter-cell mobility within the DU; In response to receiving the CC modification message from the first network node, the second network node sends a modified RRCReconfiguration message to the first network node, the modified RRCReconfiguration message including a modified CC configuration based on the modified CC list; The first network node forwards the modified RRCReconfiguration message to the UE; and The first network node receives a modified RRCReconfigurationComplete message from the UE and forwards the modified RRCReconfigurationComplete message to the second network node.

9. The method according to claim 8, wherein: Before the first network node receives the measurement report from the UE: The first network node receives a CU suggestion CC list from the second network node; and The first network node sends an accepted CC list and an accepted CC configuration corresponding to the accepted CC list to the second network node.

10. The method according to any one of claims 8 to 9, wherein: Before the first network node receives the measurement report from the UE: In response to receiving the accept CC configuration from the first network node, the second network node sending an accept RRCReconfiguration message to the first network node, the accept RRCReconfiguration message including the accept CC configuration; The first network node forwards the RRCReconfiguration acceptance message to the UE; as well as The first network receives an accept RRCReconfigurationComplete message from the UE, and forwards the accept RRCReconfigurationComplete message to the second network node.

11. The method according to any one of claims 8 to 9, wherein: The first network node receives an initial measurement report from the UE; In response to receiving the CU recommended CC list from the second network node, the first network node sends an accepted CC list, a DU recommended CC list and their corresponding CC configurations to the second network node, wherein the accepted CC list and the DU recommended CC list are based on the CU recommended CC list and the initial measurement report; The second network node sends an accept RRCReconfiguration message to the first network node, where the accept RRCReconfiguration message includes accepting CC configuration; The first network node forwards the accept RRCReconfiguration message to the UE; and The first network receives an accept RRCReconfigurationComplete message from the UE, and forwards the accept RRCReconfigurationComplete message to the second network node.

12. The method according to any one of claims 8 to 10, wherein: The modified CC list includes a CC list to be cancelled; The CC modification message includes a UE context release request message; and The first network node sends a modified CC configuration corresponding to the modified CC list to the second network node.

13. A method according to any one of claims 8 to 12, wherein: The modified CC list includes a CC list to be added; The first network node sends a modified CC configuration corresponding to the modified CC list to the second network node; and The first network node receives an acknowledgement message from the second network node.

14. The method according to claim 13, wherein: The CC modification message includes the modified CC configuration; or The first network node sends a second message to the second network node, the second message including the modified CC configuration.

15. The method according to any one of claims 1 to 2, wherein: The inter-cell mobility belongs to intra-CU inter-DU inter-cell mobility between the first network node and the third network node; In response to receiving the CC modification message from the first network node, the second network node sends a modified RRCReconfiguration message to the first network node, the modified RRCReconfiguration message including a modified CC configuration based on the modified CC list; The first network node forwards the modified RRCReconfiguration message to the UE; and The first network receives a modified RRCReconfigurationComplete message from the UE and forwards the modified RRCReconfigurationComplete message to the second network node.

16. The method of claim 15, wherein: The third network node includes a candidate gNB-DU.

17. The method according to claim 15, wherein: Before the first network node receives the measurement report from the UE: The third network node receives a CU recommendation CC list from the second network node; and The third network node sends an accepted CC list and an accepted CC configuration corresponding to the accepted CC list to the second network node.

18. The method according to any one of claims 15 to 17, wherein: Before the first network node receives the measurement report from the UE: The second network node sends a second F1 interface message to the first network node, where the second F1 interface message includes a configured CC list; and In response to receiving the second F1 interface message, the first network node sends a response message to the second network node.

19. The method according to any one of claims 15 to 18, wherein: Before the first network node receives the measurement report from the UE: The second network node sends an accept RRCReconfiguration message to the first network node, where the accept RRCReconfiguration message includes the accept CC configuration; The first network node forwards the accept RRCReconfiguration message to the UE; and The first network receives an accept RRCReconfigurationComplete message from the UE, and forwards the accept RRCReconfigurationComplete message to the second network node.

20. The method according to any one of claims 15 to 19, wherein: The first network node receives an initial measurement report from the UE; In response to receiving the CU recommended CC list from the second network node, the first network node sends at least one of the following to the second network node: an accepted CC list, a DU recommended CC list and their corresponding CC configurations, wherein the accepted CC list and the DU recommended CC list are based on the CU recommended CC list and the initial measurement report; The second network node sends an accept RRCReconfiguration message to the first network node, where the accept RRCReconfiguration message includes accepting CC configuration; The first network node forwards the accept RRCReconfiguration message to the UE; and The first network receives an accept RRCReconfigurationComplete message from the UE, and forwards the accept RRCReconfigurationComplete message to the second network node.

21. A method according to any one of claims 15 to 20, wherein: The modified CC list includes a CC list to be cancelled; and The CC modification message includes a UE context release request message.

22. A method according to any one of claims 15 to 21, wherein: The modified CC list includes a CC list to be added; The CC modification message includes a UE context modification request message; The first network node sends a modified CC configuration corresponding to the modified CC list to the second network node; and The first network node receives an acknowledgement message from the second network node.

23. The method of claim 22, wherein: The CC modification message includes the modified CC configuration; or The first network node sends a second message to the second network node, the second message including the modified CC configuration.

24. A method according to any one of claims 8 to 23, wherein: at least one of the accept RRCReconfiguration message or the modified RRCReconfiguration message is transmitted from the second network node to the first network node via a DL RRC messaging message; or At least one of the accept RRCReconfigurationComplete message or the modified RRCReconfigurationComplete message is transmitted from the first network node to the second network node via a UL RRC messaging message.

25. A wireless communication device, comprising a processor and a memory, wherein: The processor is configured to read code from the memory and execute the method according to any one of claims 1 to 24.

26. A computer program product comprising computer readable program medium code stored therein, which, when executed by a processor, causes the processor to perform the method according to any one of claims 1 to 24.

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