CN110999389A

CN110999389A - First network node, client device and method thereof

Info

Publication number: CN110999389A
Application number: CN201780093621.0A
Authority: CN
Inventors: 亨里克·奥鲁佛松; 亨里克·伦奎思; 卡里·朱汉尼·莱佩
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-08-02
Filing date: 2017-08-02
Publication date: 2020-04-10
Anticipated expiration: 2037-08-02
Also published as: WO2019024993A1; CN110999389B

Abstract

The invention relates to a first network node (100) for controlling at least one first cell (402) operating in at least one of an uplink mobility mode and a downlink mobility mode. In the uplink mobility mode, the mobility decision uses uplink measurements, and in the downlink mobility mode, the mobility decision uses downlink measurements. The first network node (100) is further configured to generate a first mobility mode information message (MMIM1) including a current mobility mode of the first cell (402). The current mobility pattern of the first cell (402) is at least one of an uplink mobility pattern and a downlink mobility pattern. The first network node (100) is further configured to send a first mobility pattern information message (MMIM1) to the at least one second network node (200) for controlling the at least one second cell (404). Furthermore, the application relates to a client device (300) as well as a corresponding method and computer program.

Description

First network node, client device and method thereof

Technical Field

The present application relates to a first network node and a client device. Furthermore, the application also relates to a corresponding method and computer program.

Background

In cellular wireless communication systems, such as GSM, UMTS, and LTE, a large number of cells are used to provide large area coverage. In order to manage the mobility of client devices, such as User Equipment (UE), must be able to move between cells of a wireless communication system. In current wireless communication systems, mobility is based primarily on the client device measuring the downlink channel and reporting to the network by the client. The client device detects nearby cells and measures the downlink channels of the detected cells. The measurement results are reported to the network node currently serving the client device. For example, the measurement result is an index indicating the measured downlink channel quality. The mobility decision is made by the serving network node and communicated to the client device. Based on the system architecture, the serving network node may be, for example, a radio access node or a radio access node controller.

In one possible solution for future wireless communication systems, mobility is not always based on measurements of the downlink channel. Instead, mobility may be based on measurements on the uplink channel. Downlink-based mobility requires each cell to frequently broadcast reference signals to client devices that are capable of making measurements. This is not the case for uplink-based mobility, as measurements on the uplink channel are made by the roommate network node. Therefore, by mobility based on uplink, the frequency of cell broadcast reference signals may be reduced, thereby reducing the amount of radio resources required for cell reference signals. Thus, it is preferable to configure each cell to use either downlink-based mobility or uplink-based mobility, so that cells using uplink-based mobility can save radio resources for transmitting reference signals.

Disclosure of Invention

It is an object of embodiments of the present invention to provide a solution that alleviates or solves the disadvantages and problems of the conventional solutions.

It is a further object of embodiments of the present invention to provide a solution with lower signalling overhead and more flexible mobility handling compared to conventional techniques.

The above and other objects are solved by the subject matter of the independent claims. Further advantageous embodiments of the invention are indicated in the dependent claims.

An observed problem on which embodiments of the present invention are based is that when different types of mobility are used in neighboring cells, the previously defined mobility methods cannot be reused directly when switching from downlink based mobility to uplink based mobility. Therefore, there is a need to solve the problem of how to support the use of different types of mobility in neighboring cells.

According to a first aspect of the present invention, the above and other objects are achieved by a first network node in a wireless communication system, for use in a first network node for communicating with a first network node

Controlling at least one first cell operating in at least one of an uplink mobility mode in which a mobility decision uses uplink measurements and a downlink mobility mode in which a mobility decision uses downlink measurements;

generating a first mobility pattern information message including a current mobility pattern of the first cell, wherein the current mobility pattern of the first cell is at least one of the uplink mobility pattern and the downlink mobility pattern; and

sending the first mobility pattern information message to at least one second network node for controlling at least one second cell.

The first network node of the present disclosure may be, for example, a radio access node, or a radio access node controller, or any other suitable network node. In particular, the first network node, as well as the network nodes in general in this disclosure, may be a base station, or a combination of a Base Station (BS) and a Base Station Controller (BSC).

It should also be appreciated that the first network node may interwork with a plurality of second network nodes.

In the present disclosure, uplink measurement and downlink measurement may be understood as measurement of an uplink channel and measurement of a downlink channel, respectively.

In the present disclosure, the current mobility mode of the first cell being at least one of an uplink mobility mode and a downlink mobility mode means that the current mobility mode of the first cell is the uplink mobility mode and/or the downlink mobility mode. Thus, a cell may operate in an uplink mobility mode or a downlink mobility mode, and may also operate concurrently/simultaneously in the uplink mobility mode and the downlink mobility mode.

The first network node according to the first aspect provides a number of advantages compared to conventional solutions. One of the advantages of the first network node is that by informing the second network node about the mobility pattern of the first cell, the second network node is enabled to configure the mobility measurements and reference signal transmission in the cell appropriately. This enables the second network node to handle mobility procedures, such as handover to the first cell. By informing neighboring network nodes about the mobility patterns of their own cells, handovers between cells using different mobility patterns can be handled in a more efficient way. Other mobility procedures, such as cell or network reselection based on client device tracking, may also be configured according to a particular mobility pattern of a cell. This means that different mobility patterns can coexist in the same network and allows a cell to support a single mobility pattern. Thus, the necessary cell reference signal transmission can be reduced in cells using the uplink mobility mode.

In an embodiment of the first network node provided in the first aspect, the first network node is further configured to

Sending the first mobility mode information message as a response to changing the current mobility mode of the first cell.

One of the advantages of this embodiment is that only mobility information messages need to be exchanged when changing the mobility configuration, thereby reducing the signaling overhead between network nodes.

Generating a first mobility mode change request message, wherein the first mobility mode change request message includes a request to change the current mobility mode of the second cell; and

sending the first mobility mode change request message to the second network node.

One of the advantages of this embodiment is that the first network node may request the neighbouring cell to change mobility pattern to support mobility of the client device connected to the cell of the first network node. This enables the first network node to support client devices that are not capable of using a particular mobility pattern.

Receiving a second mobility mode change request message from the second network node, wherein the second mobility mode change request message comprises a request to change the current mobility mode of the first cell; and

determining the current mobility mode of the first cell according to the received second mobility mode change request message.

One of the advantages of this embodiment is that the first network node takes into account the available resources, so that it can determine whether the requested mobility mode change is feasible. For example, downlink mobility requires sending downlink reference signals without causing high interference to neighboring cells, and therefore the first network node needs to determine whether there are sufficient available resources in the cell to configure downlink mobility. Since the second network node may not be aware of all neighbouring cells belonging to the cell of the first network node, it is more appropriate that the first network node determines the mobility pattern and reverts the configured mobility pattern to the second mobility pattern.

In one embodiment of the first network node provided in the first aspect, the transmission periodicity of reference signals associated with at least one of the uplink measurements and the downlink measurements indicates the request to change the current mobility pattern of the first cell or the second cell.

One of the advantages of this embodiment is that a flexible signaling scheme can be achieved, wherein reference signal periodicity can be used to indirectly support client devices with different mobility requirements in a particular mobility mode. For example, in areas where client device movement speeds tend to be low, the reference signal periodicity may be longer. It is also possible to use fewer reference signal transmissions to support downlink mobility measurements for client devices in the energy saving mode, so that the signalling transmission periodically allows the first network node to request indirect change of mobility mode for a particular client device mode. By requesting unlimited periodicity, a single mobility pattern may also be requested within a cell.

Receiving a second mobility pattern information message from the second network node, wherein the second mobility pattern information message comprises a current mobility pattern of the second cell controlled by the second network node.

One of the advantages of this embodiment is that the first network node is informed about the second cell mobility pattern and may configure mobility measurements for client devices connected to the first network node accordingly.

Generating a first mobility pattern information request, wherein the first mobility pattern information request comprises a request for mobility pattern information of the second cell;

sending the first mobility pattern information request to the second network node; and

receiving the second mobility pattern information message from the second network node as a response to transmitting the first mobility pattern information request.

One of the advantages of this embodiment is that the first network node may request information on the neighboring cell configuration at a specific occasion when it needs to configure its own mobility pattern. The mobility pattern information request may be sent, for example, when the first network node reboots or is deployed as part of a mobile network.

In an embodiment of the first network node provided in the first aspect, the second mobility mode information message further comprises a current mobility mode change offer for the second cell, the first network node being further configured to

Sending a denial message to the second network node in response to the current mobility mode change proposal for the second cell if the current mobility mode change proposal for the second cell would cause the client device connected to the first network node to experience a degradation in service level; otherwise

Sending an acknowledgement message to the second network node as a response to the current mobility mode change proposal for the second cell.

Thus, the first network node may be operable to determine whether a client device connected to the first network is affected by a service level degradation according to a current mobility mode change proposal for the second cell. In the present context, a service level degradation may relate to a failure to meet a service level quality, e.g., too high a probability of radio link failure, too long a service interruption time at handover, too low a throughput, too high a data packet transmission delay, too high a packet loss rate, increased energy consumption, etc. Such a degradation in service level may occur if the client device needs to rely on a mobility procedure that is less capable or needs to avoid using cells configured for a certain mobility mode.

One of the advantages of this embodiment is that the first network node may determine whether the proposed mobility mode change to the second cell is acceptable to the client device connected thereto. The first network node may prevent the second node from changing its mobility mode if the mobility mode change is not acceptable, so that the first network node may also maintain a level of service to client devices connected to the first network node if these client devices are to be handed over to the second cell.

Receiving a second mobility pattern information request from the second network node, wherein the second mobility pattern information request comprises a request for mobility pattern information of the first cell; and

sending the first mobility mode information message as a response to receiving the second mobility mode information request.

One of the advantages of this embodiment is that the mobility pattern of the first cell may be informed to the second network node when the second network node needs the information, e.g. when the second network node restarts or joins the network.

In an embodiment of the first network node provided in the first aspect, the first mobility mode information message further comprises a current mobility mode change offer for the first cell, the first network node being further configured to

Receiving a non-acknowledgement message from the second network node in response to transmitting a current mobility mode change offer for the first cell, wherein the non-acknowledgement message indicates that the current mobility mode change offer for the first cell causes a client device connected to the second network node to experience a degradation in service level; otherwise

Receiving an acknowledgement message from the second network node in response to transmitting the current mobility mode change offer for the first cell.

One of the advantages of this embodiment is that the first network node and the second network node may together find a mobility pattern configuration that is valid for both network nodes. This mechanism may be part of a negotiation procedure to calibrate a large number of cell mobility pattern configurations. For example, through coordination among multiple network nodes, all cells of a certain carrier frequency in a larger area may be configured to the same mobility pattern.

In an embodiment of the first network node provided in the first aspect, at least one of the first mobility pattern information messages further comprises an identification of a transmission and reception point associated with the first cell, and the second mobility pattern information message further comprises an identification of a transmission and reception point associated with the second cell.

Thus, the following choices are possible: the first mobility pattern information message comprises an identification of a sending and receiving point associated with the first cell, or the second mobility pattern information message further comprises an identification of a sending and receiving point associated with the second cell, or the first mobility pattern information message further comprises an identification of a sending and receiving point associated with the first cell and the second mobility pattern information message further comprises an identification of a sending and receiving point associated with the second cell.

One of the advantages of this embodiment is that the granularity of the mobility mode configuration can be finer than at the cell level. For example, transmission and reception points located at the edge of a cell may be configured to transmit downlink reference signals, thereby enabling client devices to measure reference signals upon entering the coverage area of the cell. This may make the transition between the areas of uplink and downlink mobility simpler.

Generating a mobility mode configuration message for a client device served by a first network node in a first cell, wherein the mobility mode configuration message comprises an instruction for dual mobility mode operation, as in both the uplink mobility mode and the downlink mobility mode, a valid time period value of the dual mobility mode indicating the instruction; and

sending the mobility mode configuration message to the client device.

One of the advantages of this embodiment is that the mobility of the client device can be handled based on uplink measurements or downlink measurements or a combination of both during the transition when reconfiguring the mobility pattern of one or more cells in the vicinity of the client device.

And generating the mobility mode configuration message for the client device according to the second mobility mode information message.

One of the advantages of this embodiment is that the network node configures the client device according to the mobility pattern configuration of the neighboring cells. In particular, if the neighboring cell is configured for uplink mobility, the mobility mode of the client device may be reconfigured to transmit uplink reference signals; or if the neighboring cell is configured for downlink mobility, the client device may be configured to measure and report the reference signal of the neighboring cell, and so on.

According to a second aspect of the present invention, the above and other objects are fulfilled by a client device in a wireless communication system for

Operating in at least one of an uplink mobility mode and a downlink mobility mode, wherein the client device is configured to send uplink reference signals for a first cell mobility decision in the uplink mobility mode, and the client device is configured to send downlink reference signals for the first cell mobility decision in the downlink mobility mode;

receiving a mobility mode configuration message from a network node, wherein the mobility mode configuration message includes an instruction to operate in a dual mobility mode, a valid time period value of the dual mobility mode indicating the instruction, the operation in the dual mobility mode being to operate in the uplink mobility mode and the downlink mobility mode at the same time; and

operating in the dual mobility mode in response to receiving the mobility mode configuration message.

The client device according to the second aspect provides a number of advantages over conventional solutions. One of the advantages of the present client device is that during the time interval the mobility of the device can be handled by a combination of uplink and downlink measurements, thus not requiring that all cells within the area support the same mobility pattern. Therefore, the requirement of changing the cell mobility mode on configuration change synchronization is lower, and disconnection of client equipment cannot be caused.

According to a third aspect of the present invention, the above and other objects are achieved by a method for a first network node, the method comprising

In an embodiment of the method provided in the third aspect, the method further comprises

In one embodiment of the method provided in the third aspect, the transmission periodicity of the reference signal associated with at least one of the uplink measurement and the downlink measurement indicates the request to change the current mobility pattern of the first cell or the second cell.

In one embodiment of the method provided in the third aspect, the second mobility mode information message further includes a current mobility mode change offer for the second cell, and the method further includes

Sending a denial message to the second network node in response to the current mobility mode change proposal for the second cell if the current mobility mode change proposal for the second cell would cause a client device connected to the first network node to experience a degradation in service level; otherwise

In one embodiment of the method provided in the third aspect, the first mobility mode information message further includes a current mobility mode change offer for the first cell, the method further comprising

In one embodiment of the method provided in the third aspect, at least one of the first mobility pattern information messages further comprises an identification of a transmitting and receiving point associated with the first cell, and the second mobility pattern information message further comprises an identification of a transmitting and receiving point associated with the second cell.

sending the mobility mode configuration message to the client device.

The third aspect provides the same advantages as the first network node corresponding to the first aspect.

According to a fourth aspect of the present invention, the above and other objects are achieved by a method for a client device, comprising

The method provided by the fourth aspect has the same advantages as the corresponding client device of the second aspect.

The invention also relates to a computer program comprising code means which, when run on a processing means, causes the processing means to perform any of the methods provided by the invention. Further, the invention also relates to a computer program product comprising a computer readable medium and a computer program as described above, wherein said computer readable medium comprises said computer program and comprises one or more of the following: read-only memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), flash memory, electrically Erasable EPROM (EEPROM), and a hard disk drive.

Other applications and advantages of the present invention will become apparent from the following detailed description.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification:

fig. 1 is a schematic diagram of a first network node according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a method for corresponding to a first network node according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a client device according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a method corresponding to a client device according to an embodiment of the present invention;

fig. 5 is a diagram of a wireless communication system according to an embodiment of the present invention;

FIG. 6 is a schematic flow chart provided by an embodiment of the present invention;

FIG. 7 is a schematic flow chart provided by an embodiment of the present invention;

FIG. 8 is a schematic flow chart provided by an embodiment of the present invention; and

fig. 9 is a schematic flow chart provided in the embodiment of the present invention.

Detailed Description

Fig. 1 is a schematic diagram of a first network node 100 according to an embodiment of the present invention. In the embodiment shown in fig. 1, the first network node 100 in this example comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 is coupled to the transceiver 104 and the memory 106 by communication means 108 as is known in the art. The first network node 100 may be used for wireless and wired communication in a wireless and wired communication system. The wireless communication capability is provided by an antenna 110 coupled to the transceiver 104 and the wired communication capability is provided by a wired communication interface 112 coupled to the transceiver 104. The first network node 100 may be part of a network of a wireless communication system.

It should be understood that in the present invention the first network node 100 is used to perform certain actions, meaning that the first network node 100 comprises suitable means for performing the described operations, such as the processor 102 and the transceiver 104.

The first network node 100 here is configured to control at least one first cell 402 (as shown in fig. 5) operating in at least one of an uplink mobility mode and a downlink mobility mode. In the uplink mobility mode, the mobility decision uses uplink measurements, and in the downlink mobility mode, the mobility decision uses downlink measurements. The first network node 100 is further configured to generate a first mobility mode information message MMIM1 including the current mobility mode of the first cell 402. The current mobility pattern of the first cell 402 is at least one of an uplink mobility pattern and a downlink mobility pattern. Further, the first network node 100 is configured to send the first mobility mode information message MMIM1 to at least one second network node 200 (shown in fig. 5) for managing at least one second cell 404 (shown in fig. 5). In fig. 1 it is illustrated how the first network node 100 sends the first mobility mode information message MMIM1 over the wired communication interface 112. However, in another example, the first mobility mode information message MMIM1 is sent over a wireless interface. It should be understood that the first network node 100 may communicate with the second network node 200 and the client device by any combination of wired and wireless communication.

For example, the first network node 100 may send the first mobility mode information message MMIM1 to the second network node 200 when first configuring the first cell 402 or when reconfiguring the mobility mode of the first cell 402, i.e. when the mobility mode is changed. Thus, the first network node 100 in an embodiment may be configured to send said first mobility mode information message MMIM1 in response to changing the current mobility mode of the first cell 402, as will be described below in connection with fig. 6. The first network node 100 in an embodiment may send said first mobility mode information message MMIM1 upon receiving a request from the second network node 200, as will be described below in connection with fig. 7.

The first mobility mode information message MMIM1 may be defined as a new message type or may carry a message type existing in the wireless communication system, transmitted between different network nodes. For example, in an LTE network, the first mobility mode information message MMIM1 may be carried in an existing X2 message and transmitted over the X2 interface.

Mobility patterns here refer to how wireless channel properties are determined to decide which network nodes and cells each client device should connect to. In particular, downlink mobility refers to a client device measuring the received signal power or received signal quality of a reference signal transmitted by a network node. The client device measures the radio signals received from the cells and reports them to the currently connected serving cell if the measurements satisfy certain conditions that may be configured by the network node. Since the client device measures signals from nearby cells, these nearby cells need to be configured in a downlink mobility mode. Based on the measurement report of the client device, the serving network node may determine whether to handover the client device to another cell.

In the uplink mobility mode, the ue is configured to transmit a reference signal in the uplink. The multiple network nodes can measure the received signal power and signal quality of the reference signal, and report the measured value to the serving network node if the signal meets some measurement reporting requirements. The serving network node may then decide which network nodes and cells are best suited to provide service to the client device. Since reference signals are measured by nearby cells, these nearby cells need to be configured in an uplink mobility mode to measure the reference signals sent by the client device.

Thus, in general, mobility decisions for client devices connected to a cell are made based on measurements of wireless channels between the client device and nearby cells. Hence, the mobility pattern of the nearby cell is most important for the mobility decision made by the first network node. The measurements are compared to measurements of a serving cell to which the client device is connected. However, the channel measurements of the serving cell may be made in other transmissions, and thus the mobility pattern of the serving cell configuration is of less importance. In case different nearby cells have different mobility configurations, it may be necessary to use both uplink and downlink mobility patterns.

Mobility mode here may also refer to how mobility measurements are made for a client device in a mobile state where no conventional handover is made. This may apply in particular to client devices in an inactive or lightweight connected mode. Downlink mobility mode may also refer to a procedure in which a client device determines a cell to camp on without notifying a network node each time a different cell is selected. The client device only needs to notify the network when it is determined from the measurements of the downlink signals that it has moved into a cell defined by the network as a different tracking area. The uplink mobility mode of an inactive client device requires the client device to send a reference signal, and the network will track the location of the client device based on the reference signal with sufficient accuracy to send downlink transmissions, such as paging messages, to the client device.

Fig. 2 shows a flow chart of a corresponding method 500 that may be performed by the first network node 100 shown in fig. 1, for example. The method 500 here includes controlling 502 at least one first cell 402 operating in at least one of an uplink mobility mode and a downlink mobility mode. In the uplink mobility mode, the mobility decision uses uplink measurements, and in the downlink mobility mode, the mobility decision uses downlink measurements. The method 500 further comprises generating 504 a first mobility mode information message MMIM1 comprising a current mobility mode of the first cell 402. The current mobility pattern of the first cell 402 is at least one of an uplink mobility pattern and a downlink mobility pattern. Further, the method 500 further comprises sending 506 said first mobility mode information message MMIM1 to at least one second network node 200 for controlling at least one second cell 404.

Fig. 3 is a schematic diagram of a client device 300 according to an embodiment of the present invention. In the embodiment shown in fig. 3, client device 300 includes a processor 302, a transceiver 304, and a memory 306. The processor 302 is coupled to the transceiver 304 and the memory 306 by communication means 308 as is known in the art. The client device 300 may be used for wireless communication in a wireless communication system. The wireless communication capability is provided by an antenna 310 coupled to the transceiver 304.

It should be understood that in the present invention, the client device 300 is used to perform certain actions, meaning that the client device 300 includes suitable components, such as a processor 302 and a transceiver 304, for performing the described operations.

The client device 300 herein is configured to operate in at least one of an uplink mobility mode and a downlink mobility mode. The client device 300 is configured to send an uplink reference signal for the mobility decision of the first cell 402 in the uplink mobility mode, and the client device 300 is configured to send a downlink reference signal for the mobility decision of the first cell 402 in the downlink mobility mode. The client device 300 is further arranged to receive a mobility mode configuration message MMCM from the network node 100. The mobility mode configuration message MMCM comprises an instruction to operate in dual mobility mode, the valid time period value of dual mobility mode indicating the instruction. Operating in dual mobility mode refers to the client device 300 operating concurrently/simultaneously in both uplink mobility mode and downlink mobility mode. Further, the client device 300 is adapted to operate in dual mobility mode in response to receiving the mobility mode configuration message MMCM.

Fig. 4 is a flow chart illustrating a corresponding method 600 that may be performed by a client device 300, such as that shown in fig. 3. The method 600 herein includes operating 602 in at least one of an uplink mobility mode and a downlink mobility mode. The client device 300 is configured to send an uplink reference signal for the mobility decision of the first cell 402 in the uplink mobility mode, and the client device 300 is configured to send a downlink reference signal for the mobility decision of the first cell 402 in the downlink mobility mode. The method 600 further comprises receiving 604 a mobility mode configuration message MMCM from the network node 100. The mobility mode configuration message MMCM comprises an instruction to operate in dual mobility mode, the valid time period value of dual mobility mode indicating the instruction. Operating in dual mobility mode is concurrent/simultaneous operating in uplink mobility mode and downlink mobility mode. Further, the method 600 comprises operating 606 in dual mobility mode in response to receiving a mobility mode configuration message MMCM.

Fig. 5 is a diagram of a wireless communication system 400 according to an embodiment. The wireless communication system 400 comprises a first network node 100, a second network node 200 and a client device 300. In the embodiment shown in fig. 5, the first network node 100 controls a first cell 402 and the second network node 200 controls a second cell 404. However, in some embodiments, the first network node 100 and the second network node 200 may also control more than one cell. Further, the client device 300 is located in the first cell 402 and exchanges wireless transmissions with the first network node 100, i.e. the client device is served by the first network node 100. The first network node 100 and the second network node 200 are connected by a wireless link 406, wherein mobility pattern information in the present invention can be transmitted. The mobility mode information sent from the first network node 100 to the second network node 200 may be sent via a first mobility mode information message MMIM1, and the mobility mode information sent from the second network node 200 to the first network node 100 may be sent via a second mobility mode information message MMIM 2. The mobility pattern information in the present invention may provide information of the mobility pattern of each cell, i.e. the granularity may be cell-level. The granularity can also be finer, and individual Transmission and Reception Points (TRPs) within a cell can be used for different mobility modes.

By exchanging the first mobility mode information message MMIM1 and the second mobility mode information message MMIM2 between the first network node 100 and the second network node 200, the first network node 100 may know that the second cell 404 of the second network node 200 is using the uplink mobility mode and/or the downlink mobility mode, and vice versa. Thus, the first network node 100 configures the mobility behavior of the client device 300 accordingly. For example, the first network node 100 may configure the client device 300 by making mobility measurements on downlink reference signals transmitted within the second cell 404, and or configure the client device 300 for transmitting uplink reference signals. Thus, the client device 300 may be used to support mobility between the coverage of the first network node 100 and the coverage of the second network node 200, i.e. between the first cell 402 and the second cell 404 in the embodiment shown in fig. 5.

For simplicity of description, the wireless communication system 400 shown in fig. 5 comprises only one first network node 100, one second network node 200 and one client device 300. However, the wireless communication system 400 may include any number of first and second network nodes and client devices without departing from the scope of the present invention.

As described above, in some embodiments, the sending of the first mobility mode information message MMIM1 may be triggered by a current mobility mode change of the first cell 402. Fig. 6 is a flowchart of the present embodiment. In step I of fig. 6, the mobility pattern of the first cell 402 in the first network node 100 is changed. In accordance with the changed mobility pattern of the first cell 402, the first network node 100 generates and sends a first mobility pattern information message MMIM1 to the second network node 200, as shown in step II in fig. 6. The first mobility mode information message MMIM1 may include information such as an Identification (ID) of the first cell 402 and mobility modes (i.e., uplink and/or downlink) supported in various states of the client device 300, such as Wideband Code Division Multiple Access (WCDMA), New Radio (NR), and Radio Resource Control (RRC) connection, RRC inactivity, or RRC idle in Long Term Evolution (LTE). In fig. 6 step III, the second network node 200 evaluates the information received in the first mobility mode information message MMIM1 and determines whether any client devices served by the second network node 200 need to be reconfigured to support the changed mobility mode of the first cell 402. If the mobility pattern of the first cell 402 has changed to the downlink mobility pattern, the second network node 200, for example, needs to reconfigure the client device 300 through downlink measurements. On the other hand, if the mobility pattern of the first cell 402 has changed to the uplink mobility pattern, the second network node 200 may need to reconfigure the client device 300 to send the uplink reference signal to be measured by the first network node 100. The mobility pattern information exchange may be ended by an acknowledgement message ACK sent by the second network node 200 to the first network node 100, as shown in fig. 6 at step IV. In one embodiment, the mobility reconfiguration of the actual client device may occur after step IV.

According to embodiments of the present invention, the mobility mode change of a cell may be triggered in different ways. For example, the first network node 100 may be configured and reconfigured by the network management system by a particular mobility pattern; alternatively, the first network node 100 may decide to reconfigure the mobility pattern of its cell, i.e. the first cell 402 in the embodiment shown in fig. 5, depending on the traffic situation. For example, it is preferable to use uplink measurements when traffic is very limited to reduce the energy consumption for transmitting downlink reference signals. The first network node 100 may also reconfigure the mobility pattern of the first cell 402 upon discovering that a neighboring cell is changing mobility pattern and satisfying other requirements. For example, other conditions may be: client devices in neighbouring cells that are not connected need to be served with the current mobility pattern and the network node has the resources needed to change mobility pattern.

Furthermore, a request from a neighboring network node, such as the second network node 200, may trigger a change of the mobility pattern of the first cell 402. For example, when the client device 300 served by the second network node 200 does not support the uplink mobility mode, the second network node 200 may send a request to the first network node 100 requesting the first network node 100 to configure the first cell 402 to use the downlink mobility mode. Mobility mode change requests from neighboring network nodes may also be used when different measurement modes are needed to collect wireless measurement information. The radio measurement information may be used for optimization or for discovery of neighboring cells.

Fig. 7 is a flow chart illustrating an embodiment wherein a request from the second network node 200 triggers a change of mobility pattern of the first cell 402. In step I of fig. 7, the first network node 100 receives a second mobility pattern change request message MMCRM2 from the second network node 200. The second mobility pattern change request message MMCRM2 comprises a request to change the current mobility pattern of the first cell 402. As shown in fig. 7, step II, the first network node 100 determines the current mobility pattern of the first cell 402 from the received second mobility pattern change request message MMCRM 2. The determined current mobility pattern of the first cell 402 may be the same as the mobility pattern requested by the second network node 200. However, the first network node 100 may also decide not to change the mobility pattern of the first cell 402, since the mobility pattern configuration of the first cell 402 may affect the mobility measurements of the client device 300 in a plurality of neighboring network nodes.

In step III shown in fig. 7, the first network node 100 informs the second network node 200 of the determined current mobility mode of the first cell 402 by sending a first mobility mode information message MMIM 1. As shown in fig. 7 steps IV and V, in response to the first mobility mode information message MMIM1, the second network node 200 determines whether any client devices served by the second network node 200 need to be reconfigured and sends an acknowledgement message ACK to the first network node 100.

In a similar way, the first network node 100 may request to change the current mobility mode of the second cell 404 by means of a first mobility mode change request message MMCRM 1. Thus, if the first network node 100 identifies that the current mobility pattern of the second cell 404 needs to be changed, the first network node 100 may generate a first mobility pattern change request message MMCRM 1. The first mobility mode change request message MMCRM1 includes a request to change the current mobility mode of the second cell 404. The first network node 100 also sends a first mobility pattern change request message MMCRM1 to the second network node 200.

According to further embodiments of the present invention, the transmission periodicity of reference signals associated with at least one of the uplink measurements and the downlink measurements indicates the request to change the current mobility pattern of the first cell 402 or the second cell 404. For example, by requesting that the transmission periodicity of the downlink reference signals be set to zero or infinite, it may be indirectly indicated that there are no downlink reference signals to transmit and thus the uplink mobility mode is to be used. It should be noted, however, that even if the uplink reference signal is used for mobility, the transmission of the downlink reference signal is usually not completely turned off, because the downlink reference signal can also be used for other purposes, such as synchronization.

The mobility mode change request messages MMCRM1 and MMCRM2 may include IDs of

cells

402 and 404 requested to be reconfigured, and mobility modes to be configured for each client device state. The mobility pattern change request messages MMCRM1 and MMCRM2 may also include information of resources to be used, such as resources for uplink reference signals to be received by neighboring network nodes. The network node may then configure the client devices connected thereto to use these resources to transmit upstream reference signals measurable by neighboring network nodes. The mobility mode change request messages MMCRM1 and MMCRM2 may also include an indication of downlink reference signal resources available to neighboring network nodes without causing interference if the network node is requested to configure a downlink mobility mode.

To make mobility pattern management more granular than cell level, the mobility pattern change request messages MMCRM1 and MMCRM2 may also include IDs of specific sending and receiving points in a cell to be reconfigured to different mobility patterns. Therefore, uplink mobility measurement or downlink reference signal transmission can be limited to a small number of transmission and reception points within a cell, thereby saving resources.

In a similar manner, in some embodiments, the mobility mode information messages MMIM1 and MMIM2 may include IDs for particular sending and receiving points. Thus, the first mobility mode information message MMIM1 may also include one or more IDs of a transmitting point and a receiving point associated with the first cell 402, and/or the second mobility mode information message MMIM2 may also include one or more IDs of a transmitting point and a receiving point associated with the second cell 404.

According to an embodiment of the present invention, the first and second mobility mode information messages MMIM1, MMIM2, and the first and second mobility mode change request messages MMCRM1, MMCRM2 may comprise one or more of the following information types or corresponding parameters:

cell ID, e.g. physical cell ID or global cell ID. The above-mentioned IDs are used to identify which cells controlled by the network node have a specific configuration. The cell ID needs to be unambiguous within a defined area and thus may not need to use a globally unique cell ID. Even the physical cell ID can be used if the network node is able to determine which cells to refer to.

IDs indicating transmission and reception points used by the transmission and reception points for downlink mobility and/or uplink mobility. In particular, some of the transmission and reception points of a cell boundary may be configured using downlink reference signal transmission, while others are configured to measure only uplink reference signals.

Mobility patterns of client device states. The mobility pattern may be applied to the client device in a particular state. For example, in LTE, a client device in an RRC connected state may use an uplink mobility mode, while a client device in an RRC inactive (or light connected) or RRC idle state may use a downlink mobility mode.

Notification and/or tracking area information. This information informs neighboring network nodes, such as the second network node 200, to which notification or tracking area the cell belongs.

Radio resources used for reference signals or radio resources available for reference signals. The radio resources may relate to resource blocks, time-frequency resources, reference signal definitions, reference signal indices, etc. For example, this information may be used for neighboring network nodes to configure uplink reference signals or to reject mobility mode reconfiguration if the indicated resources conflict with resources in the cell. The radio resource information may also include periodicity of downlink reference signal transmissions.

The point in time to perform the proposed mobility mode change. For example, this time point may be represented using a coordinated Universal Time (UTC) or as an efficient time reference, such as a system frame number, for a network node in the wireless communication system. This time information helps the network node to synchronize mobility pattern changes over a larger area and to reconfigure the client node at the correct time to cope with the mobility pattern changes.

According to an embodiment of the invention, a network node may request information of a mobility pattern of a cell associated with a neighboring network node from the neighboring network node. This mobility pattern information request may comprise a list of IDs of mobility pattern configured cells that the network node wants to know. This flow may be used, for example, in a network node configuration when the network node is turned on.

Fig. 8 is a flow chart illustrating an embodiment wherein the first network node 100 requests mobility pattern information from the second network node 200. In fig. 8 step I, the first network node 100 generates a first mobility mode information request MMIR 1. The first mobility mode information request MMIR1 includes a request for mobility mode information for the second cell 404. As shown in fig. 8, step II, the first network node 100 sends a first mobility mode information request MMIR1 to the second network node 200. As shown in step III of fig. 8, the first network node 100 receives a second mobility mode information message MMIM2 from the second network node 200 in response to sending the first mobility mode information request MMIR 1. The second mobility mode information message MMIM2 comprises the current mobility mode of the second cell 404 controlled by the second network node 200.

The second mobility mode information message MMIM2 also includes a current mobility mode change proposal for the second cell 404, according to an embodiment of the present invention. In this embodiment, the first network node 100 determines whether a client device connected to the first network 100 is affected by a service level degradation according to the current mobility mode change proposal for the second cell 404. If the first network node 100 determines that the current mobility mode change proposal for the second cell would degrade the service level experienced by a client device 300 connected to the first network node 100, the first network node 100 sends a negative acknowledgement message NACK to the second network node 200 in response to the current mobility mode change proposal for the second cell 404. Otherwise, the first network node 100 sends an acknowledgement message ACK to said second network node 200 in response to the current mobility mode change proposal for the second cell 404.

To determine whether there is a client device 300 connected to the first network node 100 that would be affected by the service level degradation due to the current mobility mode change proposal for the second cell 404, the first network node 100 may, for example, check whether there are conflicting resources or whether the client device 300 to be handed over to the second cell 404 does not support the mobility mode proposing the second cell 404 change.

The first network node 100 may use different mechanisms to avoid any client device 300 being affected by a service level degradation, e.g. a disconnection or a service degradation in case the neighboring cell changes mobility pattern. For example, the first network node 100 may check whether all connected client devices have the capabilities required to support the proposed mobility mode. For a client device without these capabilities, the first network node 100 may evaluate possible scenarios, e.g. whether other cells having overlapping coverage with the cell for which the mobility pattern is to be changed may provide service to the client device; as another example, different frequency carriers or different Radio Access Technologies (RATs). Otherwise, the client device may disconnect in the event of a cell reconfiguration and move into a coverage area serviced only by the reconfigured cell. Thus, the first network node 100 may take into account which client devices are moving towards the coverage area of the cell for which reconfiguration is proposed when determining whether the service level of any client device will be affected by reconfiguration.

The first network node 100 may also evaluate whether, in case of reconfiguration, active services of connected client devices would be supported. If a service with high requirements on data rate, low latency or high reliability is used, the client device may need to connect to a specific cell that is considered for reconfiguring the mobility pattern. This may occur in situations where the traffic load in the alternative cell is high. If the service requirements cannot be met after reconfiguration, the first network node 100 may send a negative acknowledgement message NACK.

Changing the mobility pattern may cause the mobility of the client device 300 to become less robust. For example, downlink mobility requires measurement reports sent by the client device 300 and handover instructions received by the client device 300 before performing a handover. This results in a fast moving client device that is less robust and may not meet the requirements for communication reliability. Thus, if the first network node 100 has client devices that are unable to meet all the quality of service requirements, e.g. with respect to communication reliability or throughput, the proposed change may be rejected by sending a negative acknowledgement message NACK.

If the second network node 200 receives a negative acknowledgement message NACK from the first network node 100 in response to the current mobility mode change proposal for the second cell 404, the second network node 200, for example, selects further resources. In some embodiments, the first network node 100 may indicate in the negative acknowledgement message NACK that the mobility mode change proposal is available for other resources that may be indicated in the message. The second network node 200 may send a new second mobility mode information message MMIM2 to the first network node 100 with updated information. The first network node 100 evaluates the new mobility mode change proposal for the second cell 404 and sends an acknowledgement message ACK or a negative acknowledgement message NACK depending on the evaluation result.

If the second network node 200 wants to know the mobility pattern of the cell of the first network node 100, the second network node 200 may send a second mobility pattern information request MMIR2 to the first network node 100. The first network node 100 receives the second mobility mode information request MMIR2 from the second network node 200. The second mobility mode information request MMIR2 includes a request for mobility mode information for the first cell 402. In response to receiving the second mobility mode information request MMIR2, the first network node 100 sends a first mobility mode information message MMIM 1.

Similar to the second mobility mode information message MMIM2, the first mobility mode information message MMIM1 may also include a current mobility mode change proposal for the first cell 402. In response to sending the current mobility mode change proposal for the first cell 402, the first network node 100 may receive an acknowledgement message ACK or a negative acknowledgement message NACK from the second network node 200. The negative acknowledgement message NACK indicates that the current mobility mode change proposal for the first cell 402 may cause the client device 300 connected to the second network node 200 to experience a service level degradation. The acknowledgement message ACK then indicates that performing the current mobility mode change proposal for the first cell 402 does not cause any unacceptable service level degradation.

As described above (e.g. in step III of fig. 6), the second network node 200 may reconfigure the client device 300 it controls to support the mobility procedures required for the client device 300 to move to a neighbouring cell, such as to the first cell 402. In the reconfiguration of the client device 300, mobility-related parameters are reconfigured. Reconfiguring mobility of the client device 300, according to an embodiment of the present invention, includes: the client device 300 is instructed to use both the uplink mobility mode and the downlink mobility mode, referred to herein as a time period of dual mobility mode. In the indicated dual mobility mode time period, downlink measurements and uplink reference signal transmissions are configured for the same client device 300 at the same time. When the dual mobility mode time period expires, the client device 300 cancels the downlink measurement or uplink reference signal transmission. The parallel downlink measurements and uplink reference signal transmissions by the client device 300 may also be cancelled for other reasons, such as the client device 300 receiving a new configuration at the time of handover.

In some embodiments, the mobility mode configuration message MMCM from the first network node 100 indicates the dual mobility mode time period to the client device 300. The first network node 100 generates a mobility mode configuration message MMCM for a client device 300 served by the first network node 100 within the first cell 402. The mobility mode configuration message MMCM comprises an instruction to run in dual mobility mode, i.e. in both uplink mobility mode and downlink mobility mode, the valid time period value of the dual mobility mode indicating the instruction. The first network node 100 also sends a mobility mode configuration message MMCM to the client device 300. As described below in connection with fig. 9, the first network node 100 may determine the mobility mode configuration message MMCM for the client device 300 based on the second mobility mode information message MMIM 2.

Fig. 9 is a flow diagram illustrating an embodiment in which the client device 300 reconfigures from a downlink mobility mode to an uplink mobility mode. The client device 300 served by the first network node 100 is initially configured to make downlink mobility measurements. In fig. 9 step I, the second network node 200 evaluates the possibility to change the mobility pattern of the second cell 404 to an uplink mobility pattern. Thus, as shown in fig. 9, step II, the second network node 200 sends a second mobility mode information message MMIM2 to the first network node 100, including the current mobility mode change proposal for the second cell 404. In step III of fig. 9, the first network node 100 evaluates the possibility to handle the client device connected to the first cell 402 if the mobility mode of the second cell 404 changes to the uplink mobility mode. As shown in step IV of fig. 9, if the mobility mode change is considered feasible, the first network node 100 sends a positive response, i.e. an acknowledgement message ACK, to indicate that the second network node 200 may perform the mobility mode change; otherwise, a negative acknowledgement message NACK is sent. In fig. 9 step V, the first network node 100 determines to reconfigure the client device 300. In this embodiment, the reconfiguration involves reconfiguring the client device 300 to send the uplink reference signal such that the second network node 200 can measure the uplink reference signal and determine whether service can be provided to the client device 300. Further, the reconfiguration involves reconfiguring the client device 300 to remove measurement objects associated with the second cell 404 to be reconfigured to the uplink mobility mode. The first network node 100 may configure the client device 300 to use both uplink and downlink mobility simultaneously within a specified time period. During this time period, the client device 300 may measure the downlink reference signal and report it as needed, and send the uplink reference signal to be measured by the second network node 200. This is particularly useful when the second mobility mode information message MMIM2 includes time information indicating when a mobility mode change of the second cell 404 is to be performed. Since the client device 300 continues to measure and report the downlink reference signal, the first network node 100 may obtain the measurement report directly from the client device 300 before the second network node 200 starts to forward the measurement information obtained by measuring the uplink reference signal of the client device 300.

In fig. 9 step VI, the first network node 100 sends a mobility mode configuration message MMCM to the client device 300 to reconfigure the client device 300. The mobility mode configuration message MMCM includes instructions to operate in dual mobility mode for a period of time. As shown in step VII of fig. 9, in response to the mobility mode configuration message MMCM, the client device 300 starts sending uplink reference signals according to the reconfiguration. In fig. 9 step VIII, the dual mobility mode time period expires and the client device 300 cancels the downlink measurement configuration. Thus, the client device 300 saves measurement resources.

In some embodiments, the result of the evaluation by the first network node 100 in step III of fig. 9 may be: if the mobility mode of the second cell 404 changes to the uplink mobility mode, the ue 300 connected to the first cell 402 cannot be processed. This may occur, for example, if there is a client device 300 connected to the first cell 402 that does not support the uplink mobility mode. In this case, the first network node 100 may check whether there are alternative cells that can be handed over by these client devices 300. Whether suitable alternative cells are available may depend, for example, on the frequency bands supported by the client device 300. If there is no suitable alternative cell, the first network node 100 may send a negative acknowledgement message NACK to inform the second network node 200 of unsupported client devices and may disconnect if a proposed mobility mode change to the second cell 404 is made. The negative acknowledgement message NACK may indicate which frequency bands need to retain the downlink mobility pattern so as not to disconnect the subsequent client device 300 served by the first network node 100.

The first network node 100 here may also be denoted as a Radio network node, an access point or a Base Station, e.g. a Radio Base Station (RBS), which in some networks may be referred to as transmitter, "eNB", "eNodeB", "gNB", "NodeB" or "B node". Depending on the technology and terminology used. The class of radio network nodes may differ depending on the transmission power as well as the cell size, e.g. macro eNodeB, indoor eNodeB or pico base station. A wireless network node may be a Station (STA), which is any device that includes a Media Access Control (MAC) compliant IEEE 802.11 specification and a physical layer (PHY) interface for the wireless medium. The radio network node may also be a base station corresponding to a fifth generation (5G) radio system.

The client device 300 may be referred to herein as a User Equipment (UE), a mobile station, an internet of things (IoT) device, a sensor device, a wireless terminal, and/or a mobile terminal, and may be capable of wireless communication in a wireless communication system, sometimes referred to as a cellular wireless system. The UE may also be referred to as a mobile phone, a cellular phone, a tablet, or a wireless enabled laptop. For example, in the present context, a UE may be a portable, pocket, hand-held, computer-included, or vehicle-mounted mobile device capable of voice and/or data communication with other entities, such as other receivers or servers, via a radio access network. The UE may be a Station (STA), which is any device including a Medium Access Control (MAC) compliant with IEEE 802.11 specifications and a physical layer (PHY) interface of a wireless medium. The UE may also be used for communication in LTE and LTE-Advanced related 3GPP, WiMAX and its evolution, and fifth generation wireless technologies such as communication in new radio.

Further, any of the methods provided by the embodiments of the invention may be implemented in a computer program having code means which, when run on a processing tool, causes the processing tool to perform the steps of the methods described above. A computer program product comprises the computer program in a computer readable medium. The computer-readable medium may include essentially any memory, such as Read-only memory (ROM), programmable Read-only memory (PROM), Erasable Programmable ROM (EPROM), flash memory, Electrically Erasable Programmable ROM (EEPROM), or a hard drive.

Furthermore, the skilled person may realize that embodiments of the first network node 100 and the client device 300 comprise necessary communication capabilities, e.g. in the form of functions, means, units, elements, etc. to perform the present solution. Other examples of such means, units, elements and functions include: processors, memories, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multiplexers, decision units, selection units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, transmitter atmosphere, receiving units, transmitting units, DSPs, MSDs, TCM encoders, TCM decoders, power supply units, power feeders, communication interfaces, communication protocols, etc., are suitably placed together to perform the present scheme.

In particular, the processors of the first network node 100 and the client device 300 may include, for example, one or more Central Processing Unit (CPU) instances, processing units, processing circuits, processors, Application Specific Integrated Circuits (ASICs), microprocessors, or other processing logic that may interpret and execute instructions. Accordingly, the expression "processor" may represent processing circuitry, including a plurality of processing circuits, such as any, some, or all of the above. The processing circuitry may also perform data processing functions for inputting, outputting, and processing data, including data caching and device control functions, such as call processing control or user interface control.

Finally, it is to be understood that the invention is not limited to the embodiments described above, but relates to and encompasses all embodiments within the scope of the following independent claims.

Claims

1. A first network node (100) for a wireless communication system (400), characterized in that the first network node (100) is configured to

Controlling at least one first cell (402) operating in at least one of an uplink mobility mode, in which a mobility decision uses uplink measurements, and a downlink mobility mode, in which a mobility decision uses downlink measurements;

generating a first mobility mode information message (MMIM1) comprising a current mobility mode of the first cell (402), wherein the current mobility mode of the first cell (402) is at least one of the uplink mobility mode and the downlink mobility mode; and

sending the first mobility mode information message (MMIM1) to at least one second network node (200) for controlling at least one second cell (404).

2. First network node (100) according to claim 1, configured to

Sending the first mobility mode information message (MMIM1) in response to changing the current mobility mode of the first cell (402).

3. First network node (100) according to claim 1 or 2, configured to

Generating a first mobility pattern change request message (MMCRM1), wherein the first mobility pattern change request message (MMCRM1) comprises a request to change a current mobility pattern of the second cell (404); and

sending the first mobility mode change request message (MMCRM1) to the second network node (200).

4. First network node (100) according to any of the preceding claims, configured to

Receiving a second mobility pattern change request message (MMCRM2) from the second network node (200), wherein the second mobility pattern change request message (MMCRM1) comprises a request to change the current mobility pattern of the first cell (402); and

determining the current mobility mode of the first cell (402) in accordance with the received second mobility mode change request message (MMCRM 2).

5. The first network node (100) according to claim 3 or 4, wherein a transmission periodicity of a reference signal associated with at least one of the uplink measurements and the downlink measurements indicates the request to change the current mobility pattern of the first cell (402) or the second cell (404).

6. First network node (100) according to any of the preceding claims, configured to

Receiving a second mobility mode information message (MMIM2) from the second network node (200), wherein the second mobility mode information message (MMIM2) comprises a current mobility mode of the second cell (404) controlled by the second network node (200).

7. First network node (100) according to claim 6, configured to

Generating a first mobility mode information request (MMIR1), wherein the first mobility mode information request (MMIR1) comprises a request for mobility mode information of the second cell (404);

sending the first mobility mode information request (MMIR1) to the second network node (200); and

receiving the second mobility mode information message (MMIM2) from the second network node (200) as a response to transmitting the first mobility mode information request (MMIR 1).

8. The first network node (100) according to claim 6 or 7, wherein the second mobility mode information message (MMIM2) further comprises a current mobility mode change proposal for the second cell (404); and the first network node (100) is configured to

Sending a negative acknowledgement message (NACK) to the second network node (200) as a response to the current mobility mode change proposal for the second cell (404) if the current mobility mode change proposal for the second cell (404) would cause a client device (300) connected to the first network node (100) to experience a service level degradation; otherwise

Sending an acknowledgement message (ACK) to the second network node (200) as a response to the current mobility mode change proposal for the second cell (404).

9. First network node (100) according to any of the preceding claims, configured to

Receiving a second mobility mode information request (MMIR2) from the second network node (200), wherein the second mobility mode information request (MMIR2) comprises a request for mobility mode information of the first cell (404); and

transmitting the first mobility mode information message (MMIM1) in response to receiving the second mobility mode information request (MMIR 2).

10. The first network node (100) according to any of the preceding claims, wherein the first mobility mode information message (MMIM1) further comprises a current mobility mode change proposal for the first cell (402); and the first network node (100) is configured to

Receiving a negative acknowledgement message (NACK) from the second network node (200) in response to transmitting a current mobility mode change proposal for the first cell (402), wherein the negative acknowledgement message (NACK) indicates that the current mobility mode change proposal for the first cell (404) is experiencing a service level degradation for a client device (300) connected to the second network node (200); otherwise

Receiving an acknowledgement message (ACK) from the second network node (200) in response to transmitting the current mobility mode change proposal for the first cell (402).

11. The first network node (100) according to any of the preceding claims, wherein at least one of the first mobility mode information messages (MMIM1) further comprises an identification of a transmission and reception point associated with the first cell (402), and wherein the second mobility mode information message (MMIM2) further comprises an identification of a transmission and reception point associated with the second cell (404).

12. First network node (100) according to any of the preceding claims, configured to

Generating a Mobility Mode Configuration Message (MMCM) for a client device (300) served by a first network node (100) in a first cell (402), wherein the Mobility Mode Configuration Message (MMCM) comprises an instruction for dual mobility mode operation, as in the uplink mobility mode and the downlink mobility mode at the same time, a valid time period value of the dual mobility mode indicating the instruction; and

-sending the Mobility Mode Configuration Message (MMCM) to the client device (300).

13. First network node (100) according to claim 12 and as dependent on claim 6, configured to perform

-generating the Mobility Mode Configuration Message (MMCM) for a client device (300) in accordance with the second mobility mode information message (MMIM 2).

14. A client device (300) for a wireless communication system (400), the client device (300) being configured to

Operating in at least one of an uplink mobility mode in which the client device (300) is configured to transmit uplink reference signals for a first cell (402) mobility decision and a downlink mobility mode in which the client device (300) is configured to transmit downlink reference signals for the first cell (402) mobility decision;

receiving a Mobility Mode Configuration Message (MMCM) from a network node (100), wherein the Mobility Mode Configuration Message (MMCM) comprises an instruction to operate in a dual mobility mode, a valid time period value of the dual mobility mode indicating the instruction, the operation in the dual mobility mode being to operate in the uplink mobility mode and the downlink mobility mode simultaneously; and

operating in the dual mobility mode in response to receiving the Mobility Mode Configuration Message (MMCM).

15. A method (500) for use in a first network node (100) of a wireless communication system (400), the method (500) comprising:

controlling (502) at least one first cell (402) operating in at least one of an uplink mobility mode, in which a mobility decision uses uplink measurements, and a downlink mobility mode, in which a mobility decision uses downlink measurements;

generating (504) a first mobility mode information message (MMIM1) comprising a current mobility mode of the first cell (402), wherein the current mobility mode of the first cell (402) is at least one of the uplink mobility mode and the downlink mobility mode; and

sending (506) the first mobility mode information message (MMIM1) to at least one second network node (200) for controlling at least one second cell (404).

16. A method (600) for use in a client device (300) of a wireless communication system (400), the method (600) comprising:

operating (602) in at least one of an uplink mobility mode in which the client device (300) is configured to transmit uplink reference signals for a first cell (402) mobility decision and a downlink mobility mode in which the client device (300) is configured to transmit downlink reference signals for the first cell (402) mobility decision;

receiving (604) a Mobility Mode Configuration Message (MMCM) from a network node (100), wherein the Mobility Mode Configuration Message (MMCM) comprises an instruction to operate in a dual mobility mode, a validity time period value of the dual mobility mode indicating the instruction, operation in dual mobility mode being to operate in the uplink mobility mode and the downlink mobility mode simultaneously; and

operating (606) in the dual mobility mode in response to receiving a Mobility Mode Configuration Message (MMCM).

17. A computer program product comprising a computer program with program code for performing the method according to claim 15 or 16.