WO2024103852A1

WO2024103852A1 - Nes specific cho mechanism

Info

Publication number: WO2024103852A1
Application number: PCT/CN2023/111083
Authority: WO
Inventors: Le Yan; Congchi ZHANG; Mingzeng Dai; Lianhai WU
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-08-03
Filing date: 2023-08-03
Publication date: 2024-05-23

Abstract

Example embodiments of the present disclosure relate to a first network node, a second network node, a UE, methods, processors, and computer storage medium for NES specific CHO mechanism. In the solution, a first network node may transmit NES related information to a second network node, where the NES related information includes time related information about when NES mode of a first cell is to be changed and/or a cause value or an indication which indicates a change of NES mode of the first cell. Accordingly, the second network node may be aware of the NES related information associated with the first cell. In addition, one or more further operations may be further performed, therefore a CHO may be well implemented considering the NES related information.

Description

NES SPECIFIC CHO MECHANISM

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to devices, methods, apparatuses, and computer readable medium for network energy saving (NES) specific conditional handover (CHO) mechanism.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

CHO is defined as a handover that is executed by the UE when one or more handover execution conditions are met. When NES technology is considered, some more details need to be further studied.

SUMMARY

The present disclosure relates to devices, methods, apparatuses, and computer readable medium for NES specific CHO mechanism or CHO mechanism when NES technology is applied.

In a first aspect, there is provided a first network node. The first network node comprises at least one memory; and at least one processor coupled with the at least one memory and configured to cause the first network node to: determine network energy saving (NES) related information comprising at least one of: time related information about when an NES mode of a first cell provided by the first network node is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and transmit, to a second network node, the NES related information.

In a second aspect, there is provided a second network node. The second network node comprises at least one memory; and at least one processor coupled with the at least one memory and configured to cause the second network node to: receive, from a first network node, NES related information comprising at least one of: time related information about when an NES mode of a first cell is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and perform at least one operation based on the NES related information.

In a third aspect, there is provided a UE. The UE comprises at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: receive, from a source radio access network (RAN) node, a message comprising one of: common time related information, specific time related information associated with the UE, or the common time related information and a value associated with the UE; and determine a start time for triggering a CHO execution or a start time for evaluating at least one of: one or more CHO execution conditions, and one or more NES specific CHO execution conditions.

In a fourth aspect, there is provided a method performed by the first network node. The method comprises: determining NES related information comprising at least one of: time related information about when an NES mode of a first cell provided by the first network node is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and transmitting, to a second network node, the NES related information.

In a fifth aspect, there is provided a method performed by the second network node. The method comprises: receiving, from a first network node, NES related information comprising at least one of: time related information about when an NES mode of a first cell is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and performing at least one operation based on the NES related information.

In a sixth aspect, there is provided a method performed by the UE. The method comprises: receiving, from a source RAN node, a message comprising one of: common time related information, specific time related information associated with the UE, or the common time related information and a value associated with the UE; and determining a start time for triggering a CHO execution or a start time for evaluating at least one of: one or more CHO execution conditions, and one or more NES specific CHO execution conditions.

In a seventh aspect, there is provided a processor for wireless communication. The processor comprises at least one controller coupled with at least one memory and configured to cause the processor to: determine NES related information comprising at least one of: time related information about when an NES mode of a first cell provided by the first network node is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and transmit, to a second network node, the NES related information.

In an eighth aspect, there is provided a processor for wireless communication. The processor comprises at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a first network node, NES related information comprising at least one of: time related information about when an NES mode of a first cell is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and perform at least one operation based on the NES related information.

In a ninth aspect, there is provided a processor for wireless communication. The processor comprises at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a RAN node, a message comprising one of: common time related information, specific time related information associated with the UE, or the common time related information and a value associated with the UE; and determine a start time for triggering a CHO execution or a start time for evaluating at least one of: one or more CHO execution conditions, and one or more NES specific CHO execution conditions.

In some implementations of the method and the first network node described herein, the first network node is a DU of a base station and the second network node is a CU of the base station, and further comprising: receiving, from the second network node, a request for the NES related information, wherein the information is transmitted in response to the request.

In some implementations of the method and the first network node described herein, the first network node is a source RAN node, and further comprising: transmitting, to a UE, a message comprising one of: common time related information, specific time related information associated with the UE, or the common time related information and a value associated with the UE.

In some implementations of the method and the first network node described herein, the first network node is a source RAN node, and further comprising: transmitting, to a UE, a first configuration indicating one or more conditional handover (CHO) execution conditions; and transmitting, to the UE, a second configuration indicating one or more NES specific CHO execution conditions.

In some implementations of the method and the first network node described herein, further comprising: in accordance with a determination that the one or more CHO execution conditions are not fulfilled, transmitting the second configuration to the UE.

In some implementations of the method and the first network node described herein, further comprising: receiving, from the UE, a message or an indication indicating that the one or more CHO execution conditions are not fulfilled.

In some implementations of the method and the second network node described herein, further comprising: allocating random access channel (RACH) resources, performing a modification or replace or update of a configuration or resources reserved for a conditional handover (CHO) procedure, or performing a cancellation of the configuration or resources reserved for the CHO procedure.

In some implementations of the method and the second network node described herein, further comprising: performing a modification or replace or update of a configuration or resources reserved for a CHO procedure.

In some implementations of the method and the second network node described herein, the first network node is a DU of a base station and the second network node is a CU of the base station, and further comprising: transmitting, to the first network node receive, a request for the NES related information, wherein the NES related information is transmitted in response to the request.

In some implementations of the method and the UE described herein, further comprising: receiving, from the source RAN node, a first configuration indicating the one or more CHO execution conditions; and receiving, from the source RAN node, a second configuration indicating the one or more NES specific CHO execution conditions.

In some implementations of the method and the UE described herein, further comprising: transmitting, to the source RAN node, a message or an indication indicating that the one or more CHO execution conditions are not fulfilled, and wherein the second configuration is transmitted by the source RAN node based on the message or the indication.

In some implementations of the method and the UE described herein, further comprising: in accordance with a determination that the one or more CHO execution conditions are not fulfilled, evaluating the one or more NES specific CHO execution conditions by one of: using one or more measurement results previously derived for evaluating the one or more CHO execution conditions, or releasing the one or more measurement results previously derived for evaluating the one or more CHO execution conditions, and deriving one or more new measurement results for evaluating the one or more NES specific CHO execution conditions.

In some implementations of the method and the UE described herein, further comprising: in accordance with a determination that a first candidate target cell fulfills its related CHO execution condition and a second candidate target cell fulfills its related NES specific CHO execution conditions, determining to trigger the CHO execution to the first candidate target cell.

In some implementations of the methods, the first network node, and the second network node described herein, the first network node is a source radio access network (RAN) node, the second network node is a candidate target RAN node, the first cell is a serving cell of a user equipment (UE) , and wherein the NES related information is comprised in a handover (HO) request message or a handover cancel message.

In some implementations of the methods, the first network node, and the second network node described herein, the first network node is a candidate target RAN node, the second network node is a source RAN node, the first cell is a candidate target cell of a UE, and wherein the NES related information is comprised in a conditional handover cancel message.

In some implementations of the methods, the first network node, and the second network node described herein, the first network node is a central unit (CU) of a base station and the second network node is a distributing unit (DU) of the base station.

In some implementations of the methods, the first network node, and the second network node described herein, the time related information comprises: a time length associated with a time for transmitting the request by the second network node, or a time length associated with a time for receiving the request by the first network node.

In some implementations of the methods, the first network node, and the second network node described herein, the first network node is a DU of a base station and the second network node is a CU of the base station, and wherein the NES related information is comprised in one of: a UE context release request message, or a UE context modification required message.

In some implementations of the methods, the first network node, and the second network node described herein, the base station is a source RAN node, and the first cell is a serving cell of a UE.

In some implementations of the methods, the first network node, and the second network node described herein, the base station is a candidate target RAN node, and the first cell is a candidate target cell of a UE.

In some implementations of the methods, the first network node, and the second network node described herein, the time related information comprises: an absolute time indicating a start time or an end time of changing the NES mode of the first cell, or a time length indicating a time duration from a first time to the absolute time, wherein the first time is a time for transmitting the NES related information by the first network node or a time for receiving the NES related information by the second network node.

In some implementations of the methods, the first network node, and the second network node described herein, the cause value or the indication indicates one of: the first cell is in the NES mode, the first cell is to be in the NES mode, the first cell is out of the NES mode, or the first cell is to be out of NES mode.

In some implementations of the methods, the first network node, and the UE described herein, the first configuration and the second configuration are comprised in a same message or two separate messages.

In some implementations of the methods, the first network node, and the UE described herein, the one or more NES specific CHO execution conditions are easier to be fulfilled than the one or more CHO execution conditions.

In some implementations of the methods, the first network node, and the UE described herein, the second configuration comprises one or more offsets compared to the one or more CHO execution conditions, and the one or more NES specific CHO execution conditions are determined based on the one or more CHO execution conditions and the one or more offsets.

In some implementations of the methods, the first network node, and the UE described herein, each of the one or more CHO execution conditions is associated with a conditional event A3 and/or a conditional event A5, and each of the one or more NES specific CHO execution conditions is associated with at least one conditional event A4.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system in which some embodiments of the present disclosure can be implemented;

FIG. 2 illustrates a schematic diagram of an example communication network in which some embodiments of the present disclosure can be implemented;

FIG. 3 illustrates a schematic diagram of an example architecture of an RAN node in which some embodiments of the present disclosure can be implemented;

FIG. 4 illustrates a signalling chart illustrating a communication process in accordance with some example embodiments of the present disclosure;

FIG. 5 illustrates a signalling chart illustrating another communication process in accordance with some example embodiments of the present disclosure;

FIG. 6 illustrates a signalling chart illustrating another communication process in accordance with some example embodiments of the present disclosure;

FIG. 7 illustrates an example of a device that is suitable for implementing embodiments of the present disclosure;

FIG. 8 illustrates an example of a processor that is suitable for implementing some embodiments of the present disclosure;

FIG. 9 illustrates a flowchart of an example method implemented at a first network node in accordance with aspects of the present disclosure;

FIG. 10 illustrates a flowchart of an example method implemented at a second network node in accordance with aspects of the present disclosure; and

FIG. 11 illustrates a flowchart of an example method implemented at a UE in accordance with some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below. In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

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

It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms. In some examples, values, procedures, or apparatuses are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. As used herein, the singular forms “a, ” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises, ” “comprising, ” “has, ” “having, ” “includes” and/or “including, ” when used herein, specify the presence of stated features, elements, components and/or the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. For example, the term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The use of an expression such as “A and/or B” can mean either “only A” or “only B” or “both A and B. ” Other definitions, explicit and implicit, may be included below.

FIG. 1 illustrates an example of a wireless communications system 100 in which some embodiments of the present disclosure can be implemented. The wireless communications system 100 may include one or more network entities 102 (also referred to as network equipment (NE) ) , one or more UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as a long term evolution (LTE) network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as a new radio (NR) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a radio access network (RAN) , a base transceiver station, an access point, a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, message, broadcast, etc. ) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, message, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.

The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in FIG. 1. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment) , as shown in FIG. 1. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.

A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink (SL) . For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an S1, N2, N3, or another network interface) . The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface) . In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102) . In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106) . In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 102 may include one or more of a central unit (CU) , a distributed unit (DU) , a radio unit (RU) , a RAN Intelligent Controller (RIC) (e.g., a Near-Real Time RIC (Near-RT RIC) , a Non-Real Time RIC (Non-RT RIC) ) , a Service Management and Orchestration (SMO) system, or any combination thereof.

An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations) . In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3) , a layer 2 (L2) ) functionality and signaling (e.g., Radio Resource Control (RRC) , service data adaption protocol (SDAP) , Packet Data Convergence Protocol (PDCP) ) . The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (L1) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU.

Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs) . In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU) .

A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1-C, F1-U) , and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface) . In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links.

The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.

The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an S1, N2, N3, or another network interface) . The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 118 using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106) .

In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

A CHO procedure is defined as a handover that is executed by the UE when one or more handover execution conditions are met. The UE starts evaluating the execution condition (s) upon receiving the CHO configuration, and stops evaluating the execution condition (s) once a handover is executed. The following principles may apply to CHO: The CHO configuration contains the configuration of CHO candidate target cell (s) generated by the candidate target gNB (s) and execution condition (s) generated by the source gNB. An execution condition may consist of one or two trigger condition (s) (e.g., CHO events A3/A5) . An execution condition can be called as a CHO execution condition. For one candidate target cell, one CHO execution condition can be configured. Only single RS type is supported and at most two different trigger quantities (e.g. RSRP and RSRQ, RSRP and SINR, etc. ) can be configured simultaneously for the evaluation of CHO execution condition of a candidate target cell. When one or more CHO execution conditions are fulfilled, the UE can select a candidate target cell whose CHO execution condition is fulfilled as a target cell, and perform CHO execution to the target cell, e.g. synchronization with the target cell, or access to the target cell. While executing CHO, i.e. from the time when the UE starts synchronization with target cell, UE does not monitor source cell.

NES is of great importance for environmental sustainability, to reduce environmental impact (greenhouse gas emissions) , and for operational cost savings. NES mode or NES technology could be one of the followings: Example 1: gNB is expected to turn off all transmission and reception for data traffic and reference signal during Cell DTX/DRX non-active periods. Example 2: gNB is expected to turn off its transmission/reception only for data traffic during Cell DTX/DRX non-active periods (i.e., gNB will still transmit/receive reference signals) . Example 3: gNB is expected to turn off its dynamic data transmission/reception during Cell DTX/DRX non-active periods (i.e., gNB is expected to still perform transmission/reception in periodic resources, including SPS, CG-PUSCH, SR, RACH, and SRS) . Example 4: gNB is expected to only transmit reference signals (e.g., CSI-RS for measurement) .

It is proposed to enhance the CHO framework by considering NES mode of a cell. however, some details should be further defined.

Embodiments of the present disclosure provide a solution for NES specific CHO mechanism. In the solution, a first network node may transmit NES related information to a second network node, where the NES related information includes time related information about when NES mode of a first cell is to be changed and/or a cause value or an indication which indicates a change of NES mode of the first cell. Accordingly, the second network node may be aware of the NES related information associated with the first cell. In addition, one or more further operations may be further performed, therefore CHO mechanism may be well implemented, e.g. the resources may be utilized in a more efficient way and a resource waste may be avoided. Principles and implementations of the present disclosure will be described in detail below with reference to the figures.

In the present disclosure, “A cell is in NES mode” may include the case where the cell is using an NES technique (e.g. applying “Cell DTX/DRX” or others NES technology) , or the cell is turning/switching off or the cell is in cell-off state.

In the present disclosure, the NES mode of a cell may change, for example, the cell in NES mode may be changed to the cell in non-NES mode, the cell turning off may be changed to the cell turning on; for example, the cell in non-NES mode may be changed to the cell in NES mode, the cell turning on may be changed to the cell turning off.

In some examples, a cell may be in NES mode, or a cell may enter NES mode, or the NES mode of the cell is activated, or an SSB is not available for the cell. In some examples, a cell may be turned off, or a cell may enter a cell-off state. In some examples, a cell may be out of NES mode, or the NES mode of the cell is deactivated, or an SSB is available for the cell. In some examples, a cell may be turned on, or a cell may enter a cell-on state.

In some examples, currently a cell is in non-NES mode, at a later time point or after a period of time, the NES mode of the cell may change, for example, the cell may to be in NES mode, or the cell may enter NES mode, or the NES mode of the cell may to be activated, or an SSB may to be not available for the cell, or the cell may to be turned off, or the cell may enter a cell-off state. In some examples, currently a cell is in NES mode, at a later time point or after a period of time, the NES mode of the cell may change, for example, the cell may to be out of NES mode, or the NES mode of the cell may to be deactivated, or an SSB may to be available for the cell, or the cell may to be turned on, or the cell may enter a cell-on state.

In the present disclosure, a change of NES mode may also be referred to as a switching or toggling of NES mode.

In some examples, when Cell DTX/DRX is applied as an NES technique, Cell DTX/DRX may be turned on and off dynamically, which can cause the NES mode of a cell change. NES mode may change slower and once turned on/off remains so for seconds or longer (minutes/hours) . It is assumed that NES Mode toggling is much stable/slower (in seconds or minutes) but does not preclude more frequent NES mode changes.

FIG. 2 illustrates a schematic diagram of an example communication network 200 in which some embodiments of the present disclosure can be implemented. As shown in FIG. 2, the communication network 200 may include a RAN node 210, a RAN node 220, and a UE 230.

In a scenario that a CHO procedure may be trigger or performed, the RAN node 210 may be referred to as a source RAN node 210 and the RAN node 220 may be referred to as a candidate target RAN node 220.

In some implementations, the source RAN node 210 may provide one or more cells. For example, the UE 230 may be located in a serving cell (or a source cell) which is provided by the source RAN node 210.

In some implementations, the candidate target RAN node 220 may provide one or more cells. For example, at least one candidate target cell may be provided by the candidate target RAN node 220. When one candidate target cell is selected as target cell by the UE, the candidate target RAN which provides the candidate target cell is exactly a target RAN node.

In some implementations, the source RAN node 210 and the candidate target RAN node 220 may communicate with each via an Xn interface or via X2 interface. In some implementations, the UE 230 and the source RAN node 210, the UE 230 and the candidate target RAN node 220 may communicate with each via a Uu interface.

It is to be understood that the numbers of devices and their connection relationships and types shown in FIG. 2 are only for the purpose of illustration without suggesting any limitation. The environment may include any suitable numbers of devices adapted for implementing embodiments of the present disclosure. For example, one or more other candidate target RAN nodes may further be included.

FIG. 3 illustrates a schematic diagram of an example communication network 300 in which some embodiments of the present disclosure can be implemented. As shown in FIG. 3, the communication network 300 may include a CU 310, and DUs 320-1 through 320-3. For ease of description, the DUs 320-1 through 320-3 may be separately or collectively referred to as a DU 320.

The communication network 300 illustrates a CU-DU split architecture. In some implementations, the CU 310 and the DU 320 may communicate with each via an F1 interface.

It is to be understood that the number of devices in FIG. 3 is given for the purpose of illustration without suggesting any limitations to the present disclosure. For example, the number of DUs may be more or less.

Reference is further made to FIG. 4, which illustrates a signalling chart illustrating communication process 400 in accordance with some example embodiments of the present disclosure. The process 400 may involve a first network node 401 and a second network node 402.

In the process 400, the first network node 401 determines, at 410, NES related information, where the NES related information may include: time related information about when an NES mode of a first cell provided by the first network node 401 is to be changed, and/or a cause value or an indication indicating a change of the NES mode of the first cell.

In some implementations, the first network node 410 may determines that an NES mode of a first cell is to be changed. In some example embodiments, the first network node 401 may determine that the first cell will change from the non-NES mode to the NES mode, of the first cell will turn off. In some example embodiments, the first network node 401 may determine that the first cell will change from the NES mode to the non-NES mode, or the first cell will turn on.

In some example embodiments, the first network node 401 may generate NES related information, e.g. based on the determination that the NES mode of a first cell is to be changed. In some examples, the NES related information is associated with the first cell. In some examples, the NES related information may also be called as NES associated information, NES specific information, or information for short.

In the process 400, the first network node 401 transmits, at 420, the NES related information to the second network node 402.

In some example embodiments, the NES related information may include time related information about when the NES mode of the first cell is to be changed. In some examples, the time related information may indicate when the NES mode of the first cell will be changed explicitly or implicitly.

In some examples, the time related information may include an absolute time which indicates a start time or an end time of changing the NES mode of the first cell. For example, the absolute time may be a universal time coordinated (UTC) time indicating a start time when the first cell to be in NES mode, or applying NES technology or switching off. For example, the absolute time may be a UTC time indicating a start time when the first cell to be out of NES mode, or stopping applying NES technology or switching on.

In some examples, the time related information may include a relative time which indicates a time length (or time duration or a period of time or a timer) from a reference time to the absolute time. For example, the reference time may be a time when the first network node 401 transmitting the NES related information. For example, the reference time may be a time when the second network node 402 receiving the NES related information. For example, the reference time may be a time when the second network node 402 transmitting a request for the NES related information. For example, the reference time may be a time when the first network node 401 receiving the request for the NES related information.

It is to be noted that the examples of the reference time are listed only for illustration without any limitation, for example, the reference time may be associated with a time when at least one CHO execution condition is met.

In some example embodiments, the NES related information may include a cause value or an indication which indicates a change of the NES mode of the first cell. In some examples, the cause value or the indication may indicate that the first cell is in NES mode or cell-off state or SSB of the first cell is not available. In some examples, the cause value or the indication may indicate that the first cell is out of the NES mode or cell-on state or SSB of the first cell is not available. In some examples, the cause value or the indication may indicate that the first cell is going to be in NES mode or is going to be turned off. In some examples, the cause value or the indication may indicate that the first cell is going to be out of NES mode or is going to be turned on.

In some example embodiments, the NES related information may include both the time related information and the cause value or the indication discussed above.

In the process 400, the second network node 402 performs, at 430, at least one operation based on the NES related information. Some details of the at least one operation will be discussed below with various scenarios.

In some implementations, the first network node 401 is the source RAN node 210 as shown in FIG. 2, and the second network node 402 is the candidate target RAN node 220 as shown in FIG. 2. In some examples, the first cell may be a serving cell (or a source cell) of the UE 230, which is provided by the source RAN node 210.

In some example embodiments, the NES related information may be included in a HO request message.

In some examples, the source RAN node 210 may transmit the NES related information to the candidate target RAN node 220 in a handover request message. For example, the handover request message may be transmitted in CHO preparation phase.

In some examples, the source RAN node 210 may transmit time related information to the candidate target RAN node 220. For example, the time related information may include an absolute time (such as a UTC time or an SFN timing) to indicate a start time when the source cell entering NES mode/applying NES technology/switching off. For example, the time related information may include a relative time, e.g., a time duration indicating the amount of time the candidate target RAN node 220 to wait before the source cell entering NES mode/cell-off state after CHO is prepared or HO request message is received.

In some examples, the candidate target RAN node 220 may allocate RACH resources based on the NES related information. For example, the candidate target RAN node 220 may allocate proper RACH resources for one or more candidate target cells. For example, the RACH resources may be allocated by the candidate target RAN node 220 upon or after the serving cell (or a source cell) enters NES mode/cell-off state. Therefore, the candidate target RAN node 220 may prepare proper RACH resources, in such a way, a resource waste may be avoided.

In some example embodiments, the NES related information may be included in a handover cancel message.

In some examples, when NES mode of the serving cell (or a source cell) changes, the source RAN node 210 may update the CHO configuration. For example, the CHO configuration may include a list of candidate target cells (e.g., CHO candidate target PCell list) , which may be updated accordingly. In other words, the list of candidate target cells may be different when the serving cell (or the source cell) enters NES mode (or turns off) or be out of the NES mode (or turns on) , correspondingly, configurations for the candidate target cells may be different when the serving cell (or the source cell) enters NES mode (or turns off) or be out of the NES mode (or turns on) . In some examples, the source RAN node 210 may perform a CHO configuration update procedure.

In some examples, the source RAN node 210 may transmit a handover request message to the candidate target RAN node 220, where the handover request message may include the NES related information. For example, the NES related information may include a cause value or an indication to provide a reason for the CHO replace/configuration update. For example, the cause value may indicate a new cause of the CHO configuration update, e.g., NES mode of the serving cell (or source cell) to be changed, or NES mode of the serving cell (or source cell) changes, or SSB of the serving cell (or source cell) is not available. For example, the indication may be a one-bit flag, which indicates that the NES mode of the serving cell (or source cell) to be changed, or NES mode of the serving cell (or source cell) changes, or SSB of the serving cell (or source cell) is not available. After receiving the handover request message, the candidate target RAN node 220 provides updated CHO configuration.

In some examples, the updated CHO configuration may be also provided to the UE 230.

In some examples, a configuration or resources reserved for a CHO procedure at the candidate target RAN node 220 may be changed (such as modified, replaced, updated, or cancelled) based on the NES related information.

In some example embodiments, the source RAN node 210 may determine to cancel configured CHO procedure, e.g., due to a change of the NES mode of the serving cell (or source cell) . In some examples, the source RAN node 210 may transmit a handover cancel message to the candidate target RAN node 220, where the handover cancel message includes the NES related information. For example, the NES related information may include a cause value or an indication to provide a reason for the CHO cancellation. For example, the cause value may indicate a new cause of cancelling the CHO configuration, e.g., NES mode of the serving cell (or source cell) to be changed, or NES mode of the serving cell (or source cell) changes, or SSB of the serving cell (or source cell) is not available. For example, the indication may indicate that the NES mode of the serving cell (or source cell) to be changed, or NES mode of the serving cell (or source cell) changes, or SSB of the serving cell (or source cell) is not available.

In some examples, a configuration or resources reserved for a CHO procedure at the candidate target RAN node 220 may be cancelled based on the handover cancel message which includes the NES related information.

In some implementations, the first network node 401 is the candidate target RAN node 220 as shown in FIG. 2, and the second network node 402 is the source RAN node 210 as shown in FIG. 2. In some examples, the first cell may be a candidate target cell of the UE 230.

In some example embodiments, when NES mode of a candidate target cell changes, a CHO configuration update procedure may be performed. In some examples, the candidate target RAN node 220 may transmit a conditional handover cancel message to the source RAN node 210, where the conditional handover cancel message include the NES related information. For example, the NES related information may include a cause value or an indication to provide a reason for the CHO cancellation. For example, the cause value may indicate a new cause, e.g., NES mode of the candidate target cell to be changed, or NES mode of the candidate target cell changes, or SSB of the candidate target cell is not available. For example, the indication may indicate that the NES mode of the candidate target cell to be changed, or NES mode of the candidate target cell changes, or SSB of the candidate target cell is not available.

In some examples, a configuration or resources reserved for a CHO procedure at the candidate target RAN node 220 may be changed (such as modified, replaced, or updated) . For example, after receiving the conditional handover cancel message, the source RAN node 210 may trigger a new CHO preparation procedure to modify/replace/update the CHO configuration, e.g., to trigger candidate target RAN node determine/generate a new CHO configuration. For example, the source RAN node 210 may transmit a handover request message to one or more candidate target nodes based on the new CHO configuration.

In some implementations, the first network node 401 is the CU 310 as shown in FIG. 3, and the second network node 402 is the DU 320 as shown in FIG. 3. In some examples, the source RAN node 210 may include the CU 310 and the DU 320, and the first cell may be a serving cell (or a source cell) of the UE 230 which is provided by the source RAN node 210. In some other examples, the candidate target RAN node 220 may include the CU 310 and the DU 320, and the first cell may be a candidate target cell of the UE 230 which is provided by the candidate target RAN node 220.

In some examples, the CU 310 may determine when the first cell will enter NES mode or cell-off state. In some examples, the CU 310 may determine time related information of the first cell, e.g. based on one or more of: a cell load, a number of UEs, one or more measurement results from one or more UEs.

In some examples, the CU 310 may inform the time related information to the DU 320. For example, the time related information may include an absolute time (such as a UTC time or an SFN timing) to indicate a start time when the first cell applying NES technology or entering NES mode/cell-off state. For example, the time related information may include a relative time, e.g., a time duration indicating the amount of time to wait before the first cell applying NES technology or entering NES mode/cell-off state after receiving the time related information from the CU 310. The DU 320 may apply the time related information received from the CU 310, or reject the time related information received from the CU 310.

In some examples, the CU 310 may transmit the cause value or the indication to the DU 320. For example, the cause value may indicate a new cause, e.g., NES mode of the first cell to be changed, or NES mode of the first cell changes, or SSB of the first cell is not available. For example, the indication may indicate that the NES mode of the first cell to be changed, or NES mode of the first cell changes, or SSB of the first cell is not available.

In some examples, the NES related information from the CU 310 to the DU 320 may be included in a UE context release command message or in a UE context modification request message.

In some implementations, the first network node 401 is the DU 320 as shown in FIG. 3, and the second network node 402 is the CU 310 as shown in FIG. 3. In some examples, the source RAN node 210 may include the CU 310 and the DU 320, and the first cell may be a serving cell (or a source cell) of the UE 230 which is provided by the source RAN node 210. In some other examples, the candidate target RAN node 220 may include the CU 310 and the DU 320, and the first cell may be a candidate target cell of the UE 230 which is provided by the candidate target RAN node 220.

In some example embodiments, the CU 310 may transmit a request for the NES related information to the DU 320. In some example embodiments, the DU 320 may determine the NES related information of the first cell. For example, the DU 320 may determine when the first cell will apply NES technology or enter NES mode or be in cell-off state. In some example embodiments, the DU 320 may transmit the NES related information to the CU 310, in response to the request from the CU 310.

In some examples, the DU 320 may inform the time related information to the CU 310. For example, the time related information may include an absolute time (such as a UTC time or an SFN timing) to indicate a start time when the first cell applying NES technology or entering NES mode/cell-off state. For example, the time related information may include a relative time, e.g., a time duration indicating the amount of time to wait before the first cell applying NES technology or entering NES mode/cell-off state after receiving the time related information from the DU 320 or after the CU 310 transmitting the request.

In some examples, the DU 320 may transmit the cause value or the indication to the CU 310. For example, the cause value may indicate a new cause, e.g., NES mode of the first cell to be changed, or NES mode of the first cell changes, or SSB of the first cell is not available. For example, the indication may indicate that the NES mode of the first cell to be changed, or NES mode of the first cell changes, or SSB of the first cell is not available.

In some examples, the NES related information from the DU 320 to the CU 310 may be included in a UE context release request message or in a UE context modification required message.

It is to be understood that some example embodiments are describe with reference to FIG. 4, which are only for illustration without any limitation of the scope of the present disclosure. In some other implementations, the first network node 401 may provide the time related information and the cause value, or the time related information and the indication, to the second network node 402. In some other implementations, in case there may be one or more candidate target RAN nodes, the source RAN node 210 may transmit the NES related information of a source cell to each of the one or more candidate target RAN nodes, and/or any of the one or more candidate target RAN nodes may transmit the NES related information of a candidate target cell to the source RAN node 210. For ease of brevity, some more implementations will not be listed herein.

According to some example embodiments discussed with reference to FIG. 4, a first network node may transmit NES related information to a second network node, where the NES related information includes time related information about when NES mode of a first cell is to be changed and/or a cause value or an indication which indicates a change of NES mode of the first cell. As such, the second network node may be aware of the NES related information of the first cell. In addition, one or more further operations may be further performed, therefore a CHO procedure may be well implemented.

In some deployments, there may be only one cell can be configured as the neighbour cell/candidate target cell that may be selected as the target cell by a UE, when CHO is used for the scenario that the source cell enters NES mode/cell-off state, many UEs in the source cell may trigger CHO execution to the same target cell at same time, and signalling/RACH storm would happen.

Embodiments of the present disclosure provide a solution for NES specific CHO, different UEs in the source cell may trigger CHO execution at different times to a same (candidate) target cell. Therefore, the signalling/RACH storm may be avoided.

FIG. 5 illustrates a signalling chart illustrating communication process 500 in accordance with some example embodiments of the present disclosure. The process 500 may involve the source RAN node 210 and the UE 230 as shown in FIG. 2. It would be appreciated that the process 500 may be applied to other communication scenarios, which will not be described in detail.

In the process 500, the source RAN node 210 transmits, at 510, a message to the UE 230. The UE 230 further, at 520, determines to trigger a CHO execution or evaluate traditional/legacy CHO execution condition (s) and/or NES specific CHO execution condition (s) , e.g., based on the message from the source RAN node 210.

In some examples, a CHO execution is triggered may mean that a handover to a target cell which satisfies one CHO execution condition configured for the target cell or one NES specific CHO execution condition configured for the target cell is performed, e.g. synchronize to the target cell, access to the target cell via RACH procedure.

In some implementations, a time-based CHO mechanism may be applied considering NES, a combination of measurement-based event (e.g. CondEventA3/A4/A5 execution condition) can be configured together with time information (e.g. a timer or a period of time or a UTC time or an SFN timing) . For example, UE starts the timer when UE receives the CHO configuration, e.g., including CondEventA3/A4/A5 execution condition, the timer information, and RRCReconfiguration for each (candidate) target PCell. Once the timer expires, UE starts to evaluate the measurement-based event (e.g. CondEventA3/A4/A5 execution condition) .

In some example embodiments, the source RAN node 210 may configure different time related information to different UEs in the source cell, in this way, different UEs may trigger CHO execution at different times.

In some examples, the message may include common time related information and a value associated with the UE 230. In some other examples, the message may include specific time related information associated with the UE 230.

In some examples, the common time related information may be baseline time related information. The common time related information may include an absolute time or a relative time. For example, the absolute time (such as a UTC time or an SFN timing) may indicate a time when the source cell will apply NES technology or enter NES mode or turn off. For example, the relative time may indicate a time length (or time duration or a period of time or a timer) from a time when receiving the common time related information (or when transmitting the common time related information by the source RAN node 210 or when selecting the target cell) to the absolute time. In other words, the relative time may indicate the absolute time implicitly.

In some examples, the source RAN node 210 may determine multiple values for multiple UEs in the source cells respectively. For example, the source RAN node 210 may generate a random value from a range 0～1 (between 0 to 1) for each of the multiple UEs.

In some embodiments, the source RAN node 210 may configure the common time related information and associated random value to the UE 230. It is to be understood that the associated random value to the UE 230 may be different from another random value to another UE.

For example, the UE 230 may determine (e.g., calculate) a start time based on the message which includes the common time related information and a value associated with the UE 230 (i.e., the associated random value) . In some examples, the start time may be based on: the associated random value *the common time related information. In some examples, the UE 230 may trigger CHO execution after the associated random value *the common time related information since receiving the message (e.g., an RRC reconfiguration message including the common time related information and a value associated with the UE 230) or after receiving a CHO configuration from the source RAN node 210 or after selecting the target cell. In some examples, the UE 230 may evaluate one or more CHO execution conditions, and/or one or more NES specific CHO execution conditions after the associated random value *the common time related information since receiving the message (e.g., an RRC reconfiguration message including the common time related information and a value associated with the UE 230) or after receiving a CHO configuration from the source RAN node 210 or after selecting the target cell.

In some other embodiments, the source RAN node 210 may determine different time values for different UEs. In some examples, the source RAN node 210 may determine the specific time related information associated with the UE 230 as (arandom value associated with the UE 230 *the common time related information) , that is, the specific time related information associated with the UE 230 = a random value associated with the UE 230 *the common time related information. In some examples, the source RAN node 210 may configure the specific time related information associated with the UE 230 to the UE 230. It is to be understood that different time related information may be configured to different UEs. It is to be understood that the specific time related information associated with the UE 230 may be different from another configured specific time related information associated with another UE.

For ease of description, the specific time related information associated with the UE 230 may be represented as T_UE.

For example, if the specific time related information associated with the UE 230 is an absolute time, the UE 230 may trigger CHO execution or evaluate one or more CHO execution conditions and/or one or more NES specific CHO execution conditions when the absolute time T_UE arrives.

For example, if the specific time related information associated with the UE 230 is a relative time, the UE 230 may trigger CHO execution after T_UE since receiving the specific time related information or after receiving a CHO configuration from the source RAN node 210 or after selecting the target cell. For another example, if the specific time related information associated with the UE 230 is a relative time, the UE 230 may evaluate one or more CHO execution conditions and/or one or more NES specific CHO execution conditions after T_UE since receiving the specific time related information or after receiving a CHO configuration from the source RAN node 210.

In some example embodiments, the message may include common time related information. In some examples, the common time related information may be baseline time related information. The common time related information may include an absolute time or a relative time. For example, the absolute time (e.g. such as a UTC time or an SFN timing) may indicate a time when the source cell will apply NES technology or enter NES mode or turn off. For example, the relative time may indicate a time length (or time duration or a period of time or a timer) from a time when receiving the common time related information (or when transmitting the common time related information by the source RAN node 210 or when selecting the target cell) to the absolute time. In other words, the relative time may indicate the absolute time implicitly.

In some examples, upon receiving the common time related information or upon selecting the target cell for CHO execution, the UE 230 may determine a value, e.g., generates a random value in the range of 0～1. For example, the UE 230 may determine the value by default, or the source RAN node 210 indicates the UE 230 to generate the random value.

In some examples, the UE 230 may trigger CHO execution after (generated random value*the common time related information) since receiving the common time related information or after receiving a CHO configuration from the source RAN node 210 or after selecting the target cell. In some examples, the UE 230 may evaluate one or more CHO execution conditions and/or one or more NES specific CHO execution conditions after (generated random value*the common time related information) since receiving the common time related information or after receiving a CHO configuration from the source RAN node 210. In some examples, the UE 230 performs CHO execution to the target cell upon selecting the target cell (e.g., may transmit a RACH preamble towards the target cell) .

In some implementations, a signalling-based CHO mechanism may be applied considering NES, the signalling may be an indication concerning that the serving cell may enter NES mode, or serving cell may switch off. In some examples, the indication may be an L1/L2 signalling, for example, L1 signalling (e.g. group common DCI) is used as the indication to indicate the change of NES mode of the source cell, or L2 signalling (like MAC CE) is used, or other.

In some examples, the source RAN node 210 may send the CHO configuration (e.g. including CondEventA3/A4/A5 execution condition (s) and RRCReconfiguration for each candidate target cell) to the UE 230. In some examples, if the source cell decides to apply NES technology or enter NES mode/cell-off state, the source RAN node 210 may send the signalling for triggering handover to the UE 230 (e.g. the signalling may be an indication concerning that the source cell entering NES mode/cell-off state, the indication may be a L1 signalling (e.g. group common DCI) or L2 signalling (like MAC CE) or other) .

In some example embodiments, upon receiving the indication concerning the source cell entering NES mode/cell-off state from source RAN node 210, the UE 230 may determine a value. In some examples, the UE 230 may generate a random value in the range of 0～1. In some examples, the UE 230 may determine a start time for triggering the CHO execution, where the start time may be a time point that is after (generated random value*slot/symbol/frame) since receiving the indication concerning the source cell entering NES mode/cell-off state or since selecting the target cell. In some examples, the UE 230 performs CHO execution to the target cell upon selecting the target cell (e.g., may transmit a RACH preamble towards the target cell) .

In some other example embodiments, upon a CHO execution condition is fulfilled or upon the UE 230 selects the target cell for CHO execution, the UE 230 may determine a value. In some examples, the UE 230 may generate a random value in the range of 0～1. In some examples, the UE 230 performs CHO execution to the target cell (e.g., may transmit a RACH preamble towards the target cell) , after (generated random value*slot/symbol/frame) since selecting the target cell.

According to some example embodiments with reference to FIG. 5, the UE 230 may trigger the CHO execution, or evaluate one or more traditional/legacy CHO execution conditions and/or one or more NES specific CHO execution conditions if configured to the UE 230, based on a message from the source RAN node 210. In some examples, different time information may be configured for different UEs, in this way, different UEs in the source cell may trigger CHO execution at different times towards a same candidate target cell. Therefore, the signalling/RACH storm may be avoided.

Reference is further made to FIG. 6, which illustrates a signalling chart illustrating communication process 600 in accordance with some example embodiments of the present disclosure. The process 600 may involve the source RAN node 210 and the UE 230 as shown in FIG. 2. It would be appreciated that the process 600 may be applied to other communication scenarios, which will not be described in detail.

In the process 600, the source RAN node 210 transmits, at 610, a first configuration to the UE 230, wherein the first configuration may indicate one or more traditional/legacy CHO execution conditions. The source RAN node 210 transmits, at 620, a second configuration to the UE 230, wherein the second configuration may indicate one or more NES specific CHO execution conditions. At 630, the UE 230 determines to trigger a CHO execution, or the UE 230 determines to evaluate the one or more traditional/legacy CHO execution conditions and/or the one or more NES specific CHO execution conditions if configured to the UE, e.g., based on the first configuration and the second configuration respectively.

In some examples, the source RAN node 210 may configure one or more candidate target cells to the UE 230. For each of the one or more candidate target cells, a traditional/legacy CHO execution condition may be configured, which means that one candidate target cell has its related traditional/legacy CHO execution condition. The traditional/legacy CHO execution condition may be associated with or may consist of one or more trigger conditions. For example, each of the one or more traditional/legacy CHO execution conditions may be associated with or may consist of a CHO event A3/A4/A5, or may be associated with or may consist of a CHO event A3/A5.

In some examples, the source RAN node 210 may configure one or more candidate target cells to the UE 230. For each of one or more candidate target cells, an NES specific CHO execution condition may be configured, which means that one candidate target cell has its related NES specific CHO execution condition. The NES specific CHO execution condition may be associated with or may consist of one or more trigger conditions. For example, each of the one or more NES specific CHO execution conditions may be associated with or may consist of a CHO event A3/A4/A5, or may be associated with or may consist of a CHO event A4.

In some implementations, the NES specific CHO execution condition is easier to be fulfilled than the traditional/legacy CHO execution conditions.

In some implementations, for a candidate target cell configured to the UE 230, one traditional/legacy CHO execution condition may be configured by the source RAN node 210. In some implementations, for a candidate target cell configured to the UE 230, one NES specific CHO execution condition may be configured by the source RAN node 210. In some implementations, for a candidate target cell configured to the UE 230, both one traditional/legacy CHO execution condition and one NES specific CHO execution condition may be configured by the source RAN node 210.

In some implementations, the first configuration and the second configuration may be included in a same message. In some examples, the source RAN node 210 may, e.g., in an initial HO preparation phase, determine both the one or more CHO execution conditions (e.g., traditional/legacy CHO execution conditions) and the one or more NES specific CHO execution conditions. In some examples, the source RAN node 210 may configure both the one or more CHO execution conditions (e.g., traditional/legacy CHO execution conditions) and the one or more NES specific CHO execution conditions to the UE 230 in a same message, such as an RRC reconfiguration message. In some examples, the UE 230 may receive the one or more CHO execution conditions (e.g., traditional/legacy CHO execution conditions) and the one or more NES specific CHO execution conditions at same time.

In some other implementations, the first configuration and the second configuration may be included in different messages.

In some examples, the source RAN node 210 may configure the one or more traditional/legacy CHO execution conditions first, e.g., before the source cell decides to enter NES mode or cell off state. In some examples, if the one or more CHO execution conditions are not fulfilled, i.e. there is no target cell can be handover to, the source RAN node 210 may configure the one or more NES specific CHO execution conditions. In some examples, the one or more traditional/legacy CHO execution conditions may be associated with or may consist of one or more legacy conditional events (CondEvents) A3/A4/A5. In some examples, the one or more NES specific CHO execution conditions may be associated with or may consist of one or more NES specific conditional events, e.g. CondEvents A3/A4/A5.

In some embodiments, the first configuration may further include information of a timer (e.g. such as period of a new timer Txxx) . In some examples, the UE 230 may start the timer upon receiving the one or more traditional/legacy CHO execution conditions or upon evaluating the one or more traditional/legacy CHO execution conditions. In some examples, the UE 230 may determine that none of the one or more traditional/legacy CHO execution conditions is fulfilled, or there is no target cell can be handover to, when the timer expires. For example, none of at least one candidate target cell fulfills the one or more traditional/legacy CHO execution conditions.

In some examples, the UE 230 may transmit a message or an indication to the source RAN node 210, where the message or the indication may indicate that the one or more traditional/legacy CHO execution conditions are not fulfilled, or indicate there is no target cell can be handover to. For example, if the UE 230 determines that there is no good candidate target cell (e.g. such as CHO candidate target PCell) can fulfill the one or more traditional/legacy CHO execution conditions, then the UE 230 may transmit the message or the indication. For example, the message may be a measurement report.

In some examples, if the source RAN node 210 determines that the one or more CHO execution conditions are not fulfilled, e.g., based on the message or the indication received from the UE 230, the source RAN node 210 may configure the one or more NES specific CHO execution conditions.

For example, the second configuration may include the one or more NES specific CHO execution conditions, e.g., one or more NES specific CondEvents A3/A4/A5.

For example, the second configuration may include one or more offsets compared to the one or more traditional/legacy CHO execution conditions. For example, the one or more NES specific CondEvents A3/A4/A5 may be determined based on the one or more traditional/legacy CHO execution conditions and the one or more offsets.

For example, for anyone traditional/legacy CHO execution condition within one or some or all of the one or more traditional/legacy CHO execution conditions, the source RAN node 210 may configure an offset corresponding to the anyone traditional/legacy CHO execution condition separately. The offsets configured to the anyone traditional/legacy CHO execution condition may be same or different. For example, the source RAN node 210 may configure a first offset corresponding to the anyone traditional/legacy CHO execution condition, and configure a second offset corresponding to another anyone traditional/legacy CHO execution condition.

For example, the one or more NES specific CHO execution conditions may be easier to be fulfilled than the one or more traditional/legacy CHO execution conditions. As a specific example, for a candidate target cell, a traditional/legacy CHO execution condition may be associated with a threshold (represented as Thres1) , and an offset is configured correspondingly, then an NES specific CHO execution condition may be associated with another threshold, which can be represented as (Thres1+offset) .

In some examples, the source RAN node 210 may configure the one or more traditional/legacy CHO execution conditions first, e.g., before the source cell decides to enter NES mode or cell off state. Then, the source RAN node 210 may configure the one or more NES specific CHO execution conditions. In some examples, if the one or more traditional/legacy CHO execution conditions are not fulfilled i.e. there is no target cell can be handover to, the source RAN node 210 may configure the one or more NES specific CHO execution conditions. In some examples, the one or more traditional/legacy CHO execution conditions may be associated with or may consist of one or more conditional events (CondEvents) A3/A5. In some examples, the one or more NES specific CHO execution conditions may be associated with or may consist of one or more CondEvents A4. In some examples, after receiving the one or more NES specific CHO execution conditions, the UE stops evaluation of the one or more traditional/legacy CHO execution conditions, and starts evaluation of the one or more NES specific CHO execution conditions.

In some examples, if the source RAN node 210 determines that the one or more traditional/legacy CHO execution conditions are not fulfilled, e.g., based on the message or the indication received from the UE 230, the source RAN node 210 may configure the one or more NES specific CHO execution conditions. For example, the second configuration may include the one or more NES specific CHO execution conditions, e.g., which may be associated with or may consist of one or more CondEvents A4.

In some implementations, the UE 230 starts the evaluate the one or more traditional/legacy CHO execution conditions after receiving the first configuration, for example, the UE 230 performs RRM measurement, and selects a target cell whose execution condition is fulfilled to handover to, e.g. based on measurement results or the configured one or more traditional/legacy CHO execution conditions. In some examples, if the one or more CHO execution conditions are not fulfilled, e.g. in a time-based CHO mechanism, or in a signalling-based CHO mechanism when an indication (which indicates that the source cell will enter NES mode or cell-off state) is received from the source RAN node 210, then the UE 230 may start to evaluate the one or more NES specific CHO execution conditions. For example, the UE behavior of the UE 230 may be preconfigure, predefined, or indicated by the source RAN node 210, the present disclosure does not limit this aspect. In some examples, the UE 230 may evaluate the one or more NES specific CHO execution conditions using one or more measurement results that is derived while evaluating the one or more traditional/legacy CHO execution conditions, that is the previous one or more measurement results may be continued used to determine whether the one or more NES specific CHO execution conditions are fulfilled. In some other examples, the UE 230 may release the one or more measurement results that is derived while evaluating the one or more traditional/legacy CHO execution conditions, determine one or more new measurement results by RRM measurement, and evaluate the one or more NES specific CHO execution conditions using the one or more new measurement results.

In some implementations, in case the first configuration and the second configuration are included in a same message, the UE 230 may evaluate both the one or more traditional/legacy CHO execution conditions and the one or more NES specific CHO execution conditions upon receiving the same message which includes the first configuration and the second configuration.

In some example embodiments, if neither the one or more traditional/legacy CHO execution conditions nor the one or more NES specific CHO execution conditions is fulfilled, e.g. in a time-based CHO mechanism, or in a signalling-based CHO mechanism when the UE 230 receives an indication (which indicates that the source cell will enter NES mode or cell-off state) from the source RAN node 210, the UE 230 may perform a CHO recovery procedure as legacy that is specified in Rel-16.

In some example embodiments, if a candidate target cell fulfills its related traditional/legacy CHO execution condition but the one or more NES specific CHO execution conditions are not fulfilled, e.g. in a time-based CHO mechanism, or in a signalling-based CHO mechanism when the UE 230 receives an indication (which indicates that the source cell will enter NES mode or cell-off state) from the source RAN node 210, the UE 230 may perform a CHO execution to the candidate target cell. For example, the candidate target cell is a CHO candidate PCell which fulfills its related traditional/legacy CHO execution condition among the one or more traditional/legacy CHO execution conditions but does not fulfill its related NES specific CHO execution condition among the one or more NES specific CHO execution conditions.

As mentioned above, for a candidate target cell, the source RAN node 210 may correspondingly configure a traditional/legacy CHO execution condition, which may be considered as its related traditional/legacy CHO execution condition. As mentioned above, for a candidate target cell, the source RAN node 210 may correspondingly configure an NES specific CHO execution condition, which may be considered as its related NES specific CHO execution condition.

In some example embodiments, if a candidate target cell fulfills its related NES specific CHO execution condition but the one or more CHO execution conditions are not fulfilled, e.g. in a time-based CHO mechanism, or in a signalling-based CHO mechanism when the UE 230 receives an indication (which indicates that the source cell will enter NES mode or cell-off state) from the source RAN node 210, the UE 230 may perform a CHO execution to the candidate target cell. For example, the candidate target cell is a CHO candidate PCell which fulfills its related NES specific CHO execution condition but does not fulfill its related traditional/legacy CHO execution condition.

In some example embodiments, if a first candidate target cell fulfills its related NES specific CHO execution condition and a second candidate target cell fulfills its related traditional/legacy CHO execution condition, e.g. in a time-based CHO mechanism, or in a signalling-based CHO mechanism, the UE 230 may perform a CHO execution to the first candidate target cell. In case the CHO execution to the first candidate target cell is failed, the UE 230 may perform a CHO execution to the second candidate target cell. For example, the UE 230 may prioritize to handover to the first candidate target cell (e.g., a CHO candidate PCell) which fulfills one of the one or more NES specific CHO execution conditions.

It is to be understood that the process 500 and the process 600 can be combined, for example, the UE 230 may determine a start time when to evaluate the one or more traditional/legacy CHO execution conditions or the one or more NES specific CHO execution conditions at 520 based on time related information from the source RAN node 210, wherein the one or more traditional/legacy CHO execution conditions and the one or more NES specific CHO execution conditions may be configured at 610 and 620 respectively. It is to be understood that some other examples may be further derived from a combination of the process 500 and the process 600, which will not be listed herein for brevity.

According to some example embodiments with reference to FIG. 6, the configuration of the one or more traditional/legacy CHO execution conditions and/or the one or more NES specific CHO execution conditions may be provided to the UE 230, and a behavior of the UE 230 is defined. Therefore, the efficiency of the CHO may be guaranteed.

FIG. 7 illustrates an example of a device 700 that is suitable for implementing embodiments of the present disclosure. The device 700 may be an example of a first network node, a second network node, a source RAN node, or a UE as described herein. The device 700 may support wireless communication with the source RAN node 210, the candidate target RAN node 220, the UE 230, the CU 310, or the DU 320, or any combination thereof. The device 700 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 702, a memory 704, a transceiver 706, and, optionally, an I/O controller 708. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 702, the memory 704, the transceiver 706, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 702, the memory 704, the transceiver 706, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 702, the memory 704, the transceiver 706, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 702 and the memory 704 coupled with the processor 702 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 702, instructions stored in the memory 704) .

For example, the processor 702 may support wireless communication at the device 700 in accordance with examples as disclosed herein. The processor 702 may be configured to operable to support a means for determining NES related information comprising at least one of: time related information about when an NES mode of a first cell provided by the first network node is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and means for transmitting, to a second network node, the NES related information. The processor 702 may be configured to operable to support a means for receiving, from a first network node, NES related information comprising at least one of: time related information about when an NES mode of a first cell is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell; and means for performing at least one operation based on the NES related information. The processor 702 may be configured to operable to support a means for receiving, from a source RAN node, a message comprising one of: common time related information, specific time related information associated with the UE, or the common time related information and a value associated with the UE; and means for determining a start time for triggering a CHO execution or a start time for evaluating at least one of: one or more CHO execution conditions, and one or more NES specific CHO execution conditions.

The processor 702 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 702 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 702. The processor 702 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 704) to cause the device 700 to perform various functions of the present disclosure.

The memory 704 may include random access memory (RAM) and read-only memory (ROM) . The memory 704 may store computer-readable, computer-executable code including instructions that, when executed by the processor 702 cause the device 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 702 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 704 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 708 may manage input and output signals for the device 700. The I/O controller 708 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 708 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 708 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 708 may be implemented as part of a processor, such as the processor 706. In some implementations, a user may interact with the device 700 via the I/O controller 708 or via hardware components controlled by the I/O controller 708.

In some implementations, the device 700 may include a single antenna 710. However, in some other implementations, the device 700 may have more than one antenna 710 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 706 may communicate bi-directionally, via the one or more antennas 710, wired, or wireless links as described herein. For example, the transceiver 706 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 706 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 710 for transmission, and to demodulate packets received from the one or more antennas 710. The transceiver 706 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 710 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 710 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

FIG. 8 illustrates an example of a processor 800 that is suitable for implementing some embodiments of the present disclosure. The processor 800 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 800 may include a controller 802 configured to perform various operations in accordance with examples as described herein. The processor 800 may optionally include at least one memory 804, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 800 may optionally include one or more arithmetic-logic units (ALUs) 800. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 800 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 800) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 802 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 800 to cause the processor 800 to support various operations in accordance with examples as described herein. For example, the controller 802 may operate as a control unit of the processor 800, generating control signals that manage the operation of various components of the processor 800. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 802 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 804 and determine subsequent instruction (s) to be executed to cause the processor 800 to support various operations in accordance with examples as described herein. The controller 802 may be configured to track memory address of instructions associated with the memory 804. The controller 802 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 802 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 800 to cause the processor 800 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 802 may be configured to manage flow of data within the processor 800. The controller 802 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 800.

The memory 804 may include one or more caches (e.g., memory local to or included in the processor 800 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 804 may reside within or on a processor chipset (e.g., local to the processor 800) . In some other implementations, the memory 804 may reside external to the processor chipset (e.g., remote to the processor 800) .

The memory 804 may store computer-readable, computer-executable code including instructions that, when executed by the processor 800, cause the processor 800 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 802 and/or the processor 800 may be configured to execute computer-readable instructions stored in the memory 804 to cause the processor 800 to perform various functions. For example, the processor 800 and/or the controller 802 may be coupled with or to the memory 804, the processor 800, the controller 802, and the memory 804 may be configured to perform various functions described herein. In some examples, the processor 800 may include multiple processors and the memory 804 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 800 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 800 may reside within or on a processor chipset (e.g., the processor 800) . In some other implementations, the one or more ALUs 800 may reside external to the processor chipset (e.g., the processor 800) . One or more ALUs 800 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 800 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 800 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 800 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 800 to handle conditional operations, comparisons, and bitwise operations.

The processor 800 may support wireless communication in accordance with examples as disclosed herein. The processor 800 may be configured to or operable to support a means for operations described in some embodiments of the present disclosure.

FIG. 9 illustrates a flowchart of a method 900 performed by a first network node in accordance with aspects of the present disclosure. The operations of the method 900 may be implemented by a device or its components as described herein. For example, the operations of the method 900 may be performed by a first network node 401 as mentioned in FIG. 4. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 910, the method may include determining NES related information comprising at least one of: time related information about when an NES mode of a first cell provided by the first network node is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell. The operations of 910 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 910 may be performed by the first network node 401, which may be the source RAN node 210 or the candidate target RAN node 220 as described with reference to FIG. 2, or the CU 310 or the DU 320 as described with reference to FIG. 3.

At 920, the method may include transmitting, to a second network node, the NES related information. The operations of 920 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 920 may be performed by the first network node 401, which may be the source RAN node 210 or the candidate target RAN node 220 as described with reference to FIG. 2, or the CU 310 or the DU 320 as described with reference to FIG. 3.

FIG. 10 illustrates a flowchart of a method 1000 performed by a second network node in accordance with aspects of the present disclosure. The operations of the method 1000 may be implemented by a device or its components as described herein. For example, the operations of the method 1000 may be performed by the second network node 402 as mentioned in FIG. 4. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1010, the method may include receiving, from a first network node, NES related information comprising at least one of: time related information about when an NES mode of a first cell is to be changed, or a cause value or an indication indicating a change of the NES mode of the first cell. The operations of 1010 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1010 may be performed by the second network node 402, which may be the source RAN node 210 or the candidate target RAN node 220 as described with reference to FIG. 2, or the CU 310 or the DU 320 as described with reference to FIG. 3.

At 1020, the method may include performing at least one operation based on the NES related information. The operations of 1020 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1020 may be performed by the second network node 402, which may be the source RAN node 210 or the candidate target RAN node 220 as described with reference to FIG. 2, or the CU 310 or the DU 320 as described with reference to FIG. 3.

FIG. 11 illustrates a flowchart of a method 1100 performed by a UE in accordance with aspects of the present disclosure. The operations of the method 1100 may be implemented by a device or its components as described herein. For example, the operations of the method 1100 may be performed by the UE 230 in FIG. 2. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1110, the method may include receiving, from a source RAN node, a message comprising one of: common time related information, specific time related information associated with the UE, or the common time related information and a value associated with the UE. The operations of 1110 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1110 may be performed by the UE 230 as described with reference to FIG. 2.

At 1120, the method may include determining a start time for triggering a CHO execution or a start time for evaluating at least one of: one or more traditional/legacy CHO execution conditions, and one or more NES specific CHO execution conditions. The operations of 1120 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1120 may be performed by the UE 230 as described with reference to FIG. 2.

It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

As used herein, including in the claims, an article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A first network node comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the first network node to:

determine network energy saving (NES) related information comprising at least one of:

time related information about when an NES mode of a first cell provided by the first network node is to be changed, or

a cause value or an indication indicating a change of the NES mode of the first cell; and

transmit, to a second network node, the NES related information.
The first network node of claim 1, wherein the first network node is a source radio access network (RAN) node, the second network node is a candidate target RAN node, the first cell is a serving cell of a user equipment (UE) , and wherein the NES related information is comprised in a handover (HO) request message or a handover cancel message.
The first network node of claim 1, wherein the first network node is a candidate target RAN node, the second network node is a source RAN node, the first cell is a candidate target cell of a UE, and wherein the NES related information is comprised in a conditional handover cancel message.
The first network node of claim 1, wherein the first network node is a central unit (CU) of a base station and the second network node is a distributing unit (DU) of the base station.
The first network node of claim 1, wherein the first network node is a DU of a base station and the second network node is a CU of the base station, and wherein the at least one processor is further configured to cause the first network node to:

receive, from the second network node, a request for the NES related information, wherein the information is transmitted in response to the request.
The first network node of claim 1, wherein the time related information comprises:

an absolute time indicating a start time or an end time of changing the NES mode of the first cell, or

a time length indicating a time duration from a first time to the absolute time, wherein the first time is a time for transmitting the NES related information by the first network node or a time for receiving the NES related information by the second network node.
The first network node of claim 1, wherein the cause value or the indication indicates one of:

the first cell is in the NES mode,

the first cell is to be in the NES mode,

the first cell is out of the NES mode, or

the first cell is to be out of NES mode.
The first network node of claim 1, wherein the first network node is a source RAN node, and wherein the at least one processor is further configured to cause the first network node to:

transmit, to a UE, a first configuration indicating one or more conditional handover (CHO) execution conditions; and

transmit, to the UE, a second configuration indicating one or more NES specific CHO execution conditions.
The first network node of claim 8, wherein the second configuration comprises one or more offsets compared to the one or more CHO execution conditions, and the one or more NES specific CHO execution conditions are determined based on the one or more CHO execution conditions and the one or more offsets.
The first network node of claim 8, wherein each of the one or more CHO execution conditions is associated with a conditional event A3 and/or a conditional event A5, and each of the one or more NES specific CHO execution conditions is associated with at least one conditional event A4.
A second network node comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the second network node to:

receive, from a first network node, network energy saving (NES) specific information comprising at least one of:

time related information about when an NES mode of a first cell is to be changed, or

a cause value or an indication indicating a change of the NES mode of the first cell; and

perform at least one operation based on the NES related information.
The second network node of claim 11, wherein the first network node is a source radio access network (RAN) node, the second network node is a candidate target RAN node, the first cell is a serving cell of a user equipment (UE) , and wherein the NES related information is comprised in a handover (HO) request message or a handover cancel message.
The second network node of claim 12, wherein the at least one processor is configured to cause the second network node to:

allocate random access channel (RACH) resources,

perform a modification or replace or update of a configuration or resources reserved for a conditional handover (CHO) procedure, or

perform a cancellation of the configuration or resources reserved for the CHO procedure.
A user equipment (UE) comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

receive, from a source radio access network (RAN) node, a message comprising one of:

common time related information,

specific time related information associated with the UE, or

the common time related information and a value associated with the UE; and

determine a start time for triggering a conditional handover (CHO) execution or a start time for evaluating at least one of: one or more CHO execution conditions, and one or more NES specific CHO execution conditions.
The UE of claim 14, wherein the at least one processor is configured to cause the UE to:

receive, from the source RAN node, a first configuration indicating the one or more CHO execution conditions; and

receive, from the source RAN node, a second configuration indicating the one or more NES specific CHO execution conditions.
The UE of claim 15, wherein the second configuration comprises one or more offsets compared to the one or more CHO execution conditions, and the one or more NES specific CHO execution conditions are determined based on the one or more CHO execution conditions and the one or more offsets.
The UE of claim 15, wherein each of the one or more CHO execution conditions is associated with a conditional event A3 and/or a conditional event A5, and each of the one or more NES specific CHO execution conditions is associated with at least one conditional event A4.
The UE of claim 15, wherein the at least one processor is configured to cause the UE to:

in accordance with a determination that the one or more CHO execution conditions are not fulfilled, evaluate the one or more NES specific CHO execution conditions by one of:

using one or more measurement results previously derived for evaluating the one or more CHO execution conditions, or

releasing the one or more measurement results previously derived for evaluating the one or more CHO execution conditions, and deriving one or more new measurement results for evaluating the one or more NES specific CHO execution conditions.
The UE of claim 15, wherein the at least one processor is configured to cause the UE to:

in accordance with a determination that a first candidate target cell fulfills its related CHO execution condition and a second candidate target cell fulfills its related NES specific CHO execution conditions, determine to trigger the CHO execution to the first candidate target cell.
A method performed by a first network node, comprising:

determining network energy saving (NES) related information comprising at least one of:

time related information about when an NES mode of a first cell provided by the first network node is to be changed, or

a cause value or an indication indicating a change of the NES mode of the first cell; and

transmitting, to a second network node, the NES related information.