CELL, A WIRELESS CLIENT DEVICE AND METHODS THEREOF

Technical Field

The invention relates to a first network node and a client device. Furthermore, the invention also relates to corresponding methods and a computer program.

Background

In cellular wireless communication systems, such as GSM, UMTS, and LTE, a multitude of cells are used to provide coverage over a large area. To manage the mobility of client devices, such as User Equipments (UEs), the client devices must be allowed to move between the cells of the wireless communication system. In present wireless communication systems, the mobility is typically based on measurement on downlink channels performed by the client devices and reported by the client devices to the network. A client device detects cells in its vicinity and performs measurements on downlink channels of the detected cells. The measurement results are reported to the network node currently serving the client device, e.g. as a metric identifying the quality of the measured downlink channels. The mobility decisions are made by the serving network node and communicated to the client device. Depending on the system architecture, the serving network node may e.g. be a radio access node or a radio access node controller.

One likely solution for future wireless communication systems is that the mobility is not always based on measurements on downlink channels. Instead the mobility may be based on measurements on uplink channels. Downlink based mobility requires that each cell frequently broadcasts cell reference signals on which the client devices can perform measurements. This is not the case in uplink based mobility as the measurements on uplink channels are performed by the network nodes. Hence, with uplink based mobility the frequency of the cell reference signals can be reduced, thereby reducing the amount of radio resources needed for cell reference signals. It is therefore preferable to configure each cell to either use downlink based mobility or uplink based mobility, so that the cells which use uplink based mobility can save radio resources that would otherwise be used for cell reference signal transmissions.

Summary

An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

Another objective of embodiments of the invention is to provide a solution with lower overhead signalling and more flexible mobility handling compared to conventional techniques. The above and further objectives are solved by the subject matter of the independent claims. Further advantageous implementation forms of the present invention can be found in the dependent claims.

Embodiments of the invention are based on the observation that problems arise when different types of mobility are used in neighbouring cells as the previously defined methods for mobility cannot be directly reused when switching from downlink based mobility to uplink based mobility. Hence, there is a need to address how to support the use of different types of mobility in neighbouring cells.

According to a first aspect of the invention, the above mentioned and other objectives are achieved with a first network node for a wireless communication system, the first network node being configured to

control at least one first cell which operates in at least one of an uplink mobility mode and a downlink mobility mode, wherein in the uplink mobility mode uplink measurements are used for mobility decisions and in the downlink mobility mode downlink measurements are used for mobility decisions;

generate a first mobility mode information message comprising a current mobility mode of the first cell, wherein the current mobility mode of the first cell is at least one of the uplink mobility mode and the downlink mobility mode;

transmit the first mobility mode information message to at least one second network node configured to control at least one second cell. The first network node may in this disclosure e.g. be a radio access node or a radio access node controller or any other suitable network node. In particular, the first network node and in general a network node in this disclosure may be a base station, a combination of a Base Station (BS) and a Base Station Controller (BSC). It is further realised that the first network node may inter-work with a plurality of second network nodes.

Uplink measurements and downlink measurements may in this disclosure be understood to mean measurements on uplink channels and measurements on downlink channels, respectively. That the current mobility mode of the first cell is at least one of the uplink mobility mode and the downlink mobility mode may in this disclosure mean 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 the uplink mobility mode or in the downlink mobility mode, as well as operate in both the uplink mobility mode and in the downlink mobility mode concurrently/simultaneously.

A first network node according to the first aspect provides a number of advantages over conventional solutions. An advantage of the first network node is that the second network node is informed about the mobility mode of the first cell, which allows the second network node to properly configure mobility measurements and reference signal transmissions in its cells. This allows the second network node to handle mobility procedures, e.g. handovers to the first cell. By informing neighbouring network nodes about the mobility mode in its own cells, the handover between cells using different mobility modes can be handled in an efficient manner. Also, other mobility procedures, such as cell reselection or network based client device tracking, may be configured according to the specific mobility mode of the cell. This means that different mobility modes can coexist in the same network and allow a cell to support a single mobility mode. Thereby, the necessary cell reference signal transmission can be reduced in cells using the uplink mobility mode. In an implementation form of a first network node according to the first aspect, the first network node is further configured to

transmit the first mobility mode information message in response to a change of the current mobility mode of the first cell. An advantage with this implementation form is that the mobility information message only needs to be exchanged when changes to the mobility configuration is made, which reduces the overhead signalling between the network nodes.

In an implementation form of a first network node according to the first aspect, the first network node is further configured to

generate a first mobility mode change request message, wherein the first mobility mode change request message comprises a request for a change of a current mobility mode of the second cell;

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

An advantage with this implementation form is that a first network node can request that a neighbour cell changes mobility mode to support mobility for client devices that are connected to cells of the first network node. That allows the first network node to support client devices that do not have the capability to use a specific mobility mode.

In an implementation form of a first network node according to the first aspect, the first network node is further configured to

receive a second mobility mode change request message from the second network node, wherein the second mobility mode change request message comprises a request for change of the current mobility mode of the first cell;

determine the current mobility mode of the first cell based on the received second mobility mode change request message.

An advantage with this implementation form is that the first network node can determine whether the requested mobility mode change is possible considering the available resources. For example, downlink mobility requires that downlink reference signals are transmitted without causing high interference to neighbour cells, the first network node therefore needs to determine if there are sufficient resources available to configure downlink mobility in a cell. Since the second network node may not know all the neighbour cells of the cells belonging to first network node the first network node is more suitable to determine the mobility mode and respond to the second mobility mode with the configured mobility mode.

In an implementation form of a first network node according to the first aspect, the request for change of the current mobility mode of the first cell or the second cell is indicated by a transmission periodicity for reference signals associated with at least one of the uplink measurements and the downlink measurements.

An advantage with this implementation form is that a flexible signalling scheme can be implemented where the reference signal periodicity can be adopted to implicitly support client devices with different mobility requirements in a specific mobility mode. For example, in an area where client devices tend to have low mobility speeds the periodicity of reference signals may be longer. It may also be possible to support downlink mobility measurements for client devices in energy saving modes with less reference signal transmissions, hence signalling of transmission periodicity allows the first network node to request change the mobility mode implicitly for specific client device modes. With a request for infinite periodicity it is also possible to request a single mobility mode in a cell.

In an implementation form of a first network node according to the first aspect, the first network node is further configured to receive a second mobility mode information message from the second network node, wherein second mobility mode information message comprises a current mobility mode of the second cell controlled by the second network node. An advantage with this implementation form is that the first network node is informed about the mobility mode of the second cell and can configure the mobility measurements accordingly for client devices connected to the first network node.

In an implementation form of a first network node according to the first aspect, the first network node is further configured to

generate a first mobility mode information request, wherein the first mobility mode information request comprises a request for mobility mode information of the second cell; transmit the first mobility mode information request to the second network node;

receive the second mobility mode information message from the second network node in response to the transmission of the first mobility mode information request.

An advantage with this implementation form is that the first network node can request information about the configuration of neighbour cells at specific occasions when it needs to configure its own mobility mode. For example, it may send a mobility mode information request when it is being rebooted, or when it is deployed as part of a mobile network.

In an implementation form of a first network node according to the first aspect, the second mobility mode information message further comprises a current mobility mode change proposal for the second cell, and the first network node is further configured to

transmit a negative acknowledge message to the second network node in response to the current mobility mode change proposal for the second cell if a client device connected to the first network node will experience service level deterioration due to the current mobility mode change proposal for the second cell, else

transmit an acknowledge message to the second network node in response to the current mobility mode change proposal for the second cell.

Therefore, the first network node can be configured to determine whether a client device connected to the first network will suffer from a service level deterioration based on the current mobility mode change proposal for the second cell. Service level deterioration may in this context relate to quality of service level not met, e.g. the radio link failure probability may be too high, the handover service interruption time may be too high, the throughput may be too low, the packet transmission delay may be too high, the packet drop rate may be too high, energy consumption may increase, etc. Such service level deterioration may occur if the client devices need to rely on mobility procedures with worse performance or if they need to refrain from using cells that are configured with a certain mobility mode. An advantage with this implementation form is that the first network node can determine whether the proposed mobility mode change of the second cell is acceptable for the service level of its connected client devices. If the mobility mode change is not acceptable the first network node can prevent the second node from changing its mobility mode and thereby the first network node can maintain the service level of its connected client devices also if they need to handover to the second cell.

In an implementation form of a first network node according to the first aspect, the first network node is further configured to

receive a second mobility mode information request from the second network node, wherein the second mobility mode information request comprises a request for mobility mode information of the first cell;

transmit the first mobility mode information message in response to the reception of the second mobility mode information request. An advantage with this implementation form is that the second network node can be informed about the mobility mode of the first cell when the information is needed by the second network node, e.g. if the second network node is being rebooted or added to the network.

In an implementation form of a first network node according to the first aspect, the first mobility mode information message further comprises a current mobility mode change proposal for the first cell, and the first network node is further configured to

receive a negative acknowledge message from the second network node in response to the transmission of the current mobility mode change proposal for the first cell, wherein the negative acknowledge message indicates that a client device connected to the second network node will experience a service level deterioration due to the current mobility mode change proposal for the first cell, else

receive an acknowledge message from the second network node in response to the transmission of the current mobility mode change proposal for the first cell. An advantage with this implementation form is that the first network node and the second network node can jointly find a mobility mode configuration that work for both network nodes. This mechanism can be a part of a negotiation procedure that aligns the mobility mode configurations of a larger number of cells. For example, all cells of a certain carrier frequency in a larger area can be configured with the same mobility mode by coordination between multiple network nodes. In an implementation form of a first network node according to the first aspect, at least one of the first mobility mode information message further comprises identities of transmission and reception points associated with the first cell and the second mobility mode information message further comprises identities of transmission and reception points associated with the second cell.

Therefore, the following alternatives are possible: the first mobility mode information message comprises identities of transmission and reception points associated with the first cell, or the second mobility mode information message further comprises identities of transmission and reception points associated with the second cell, or the first mobility mode information message further comprises identities of transmission and reception points associated with the first cell and the second mobility mode information message further comprises identities of transmission and reception points associated with the second cell.

An advantage with this implementation form is that the configuration of the mobility modes can be made with a finer granularity than a cell. For example, it is possible to configure some transmission and reception points located at the edge of a cell to transmit downlink reference signals so that client devices can measure those reference signals when they enter the coverage area of the cell. This can make the transition between areas with uplink mobility and downlink mobility simpler.

In an implementation form of a first network node according to the first aspect, the first network node is further configured to

generate a mobility mode configuration message for a client device served by the first network node in the first cell, wherein the mobility mode configuration message comprises an instruction for operation in a dual mobility mode, i.e. concurrently in the uplink mobility mode and in the downlink mobility mode, indicated by a valid time period value for the dual mobility mode;

transmit the mobility mode configuration message to the client device. An advantage with this implementation form is that the mobility of the client device can be handled based on either uplink measurements or downlink measurements or a combination thereof during a transitional period when the mobility modes are being reconfigured for one or more cells in the vicinity of the client device.

In an implementation form of a first network node according to the first aspect, the first network node is further configured to

generate the mobility mode configuration message for the client device based on the second mobility mode information message.

An advantage with this implementation form is that the network node configures the client device according to the mobility mode configuration in the neighbour cell. In particular, it may reconfigure the mobility mode of the client device so that it transmits uplink reference signals if the neighbour cells are configured with uplink mobility, or it may configure the client device to measure and report reference signals of neighbour cells if the neighbour cells are configured with downlink mobility, etc.

According to a second aspect of the invention, the above mentioned and other objectives are achieved with a client device for a wireless communication system, the client device being configured to

operate in at least one of an uplink mobility mode and a downlink mobility mode, wherein the client device in the uplink mobility mode uplink is configured to transmit uplink reference signals for mobility decisions in a first cell, and wherein the client device in the downlink mobility mode is configured to measure downlink reference signals for mobility decisions in the first cell;

receive a mobility mode configuration message from a network node, wherein the mobility mode configuration message comprises an instruction for operation in a dual mobility mode indicated by a valid time period value for the dual mobility mode, wherein the operation in the dual mobility mode is concurrent operation in the uplink mobility mode and in the downlink mobility mode;

operate in the dual mobility mode in response to the reception of the mobility mode configuration message.

A client device according to the second aspect provides a number of advantages over conventional solutions. An advantage of the present client device is that the mobility of the device can be handled by a combination of uplink and downlink measurements during a time interval, therefore it is not necessary for all cells in an area to support the same mobility mode. The change of mobility mode of cells can therefore be implemented with lower requirements on synchronization of the configuration change, without causing loss of connectivity for the client devices.

According to a third aspect of the invention, the above mentioned and other objectives are achieved with a method for a first network node, the method comprises

controlling at least one first cell which operates in at least one of an uplink mobility mode and a downlink mobility mode, wherein in the uplink mobility mode uplink measurements are used for mobility decisions and in the downlink mobility mode downlink measurements are used for mobility decisions;

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

transmitting the first mobility mode information message to at least one second network node configured to control at least one second cell.

In an implementation form of a method according to the third aspect, the method further comprises

transmitting the first mobility mode information message in response to a change of the current mobility mode of the first cell.

In an implementation form of a method according to the third aspect, the method further comprises

generating a first mobility mode change request message, wherein the first mobility mode change request message comprises a request for a change of a current mobility mode of the second cell;

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

In an implementation form of a method according to the third aspect, the method further comprises

receiving a second mobility mode change request message from the second network node, wherein the second mobility mode change request message comprises a request for change of the current mobility mode of the first cell;

determining the current mobility mode of the first cell based on the received second mobility mode change request message. In an implementation form of a method according to the third aspect, the request for change of the current mobility mode of the first cell or the second cell is indicated by a transmission periodicity for reference signals associated with at least one of the uplink measurements and the downlink measurements.

In an implementation form of a method according to the third aspect, the method further comprises

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

In an implementation form of a method according to the third aspect, the method further comprises

generating a first mobility mode information request, wherein the first mobility mode information request comprises a request for mobility mode information of the second cell; transmitting the first mobility mode information request to the second network node; receiving the second mobility mode information message from the second network node in response to the transmission of the first mobility mode information request. In an implementation form of a method according to the third aspect, the second mobility mode information message further comprises a current mobility mode change proposal for the second cell, and the method further comprises

transmitting a negative acknowledge message to the second network node in response to the current mobility mode change proposal for the second cell if a client device connected to the first network node will experience service level deterioration due to the current mobility mode change proposal for the second cell, else

transmitting an acknowledge message to the second network node in response to the current mobility mode change proposal for the second cell. In an implementation form of a method according to the third aspect, the method further comprises

receiving a second mobility mode information request from the second network node, wherein the second mobility mode information request comprises a request for mobility mode information of the first cell;

transmitting the first mobility mode information message in response to the reception of the second mobility mode information request. In an implementation form of a method according to the third aspect, the first mobility mode information message further comprises a current mobility mode change proposal for the first cell, and the method further comprises

receiving a negative acknowledge message from the second network node in response to the transmission of the current mobility mode change proposal for the first cell, wherein the negative acknowledge message indicates that a client device connected to the second network node will experience a service level deterioration due to the current mobility mode change proposal for the first cell, else

receiving an acknowledge message from the second network node in response to the transmission of the current mobility mode change proposal for the first cell.

In an implementation form of a method according to the third aspect, at least one of the first mobility mode information message further comprises identities of transmission and reception points associated with the first cell and the second mobility mode information message further comprises identities of transmission and reception points associated with the second cell.

In an implementation form of a method according to the third aspect, the method further comprises

generating a mobility mode configuration message for a client device served by the first network node in the first cell, wherein the mobility mode configuration message comprises an instruction for operation in a dual mobility mode, i.e. concurrently in the uplink mobility mode and in the downlink mobility mode, indicated by a valid time period value for the dual mobility mode;

transmitting the mobility mode configuration message to the client device.

In an implementation form of a method according to the third aspect, the method further comprises

generating the mobility mode configuration message for the client device based on the second mobility mode information message.

The advantages of the methods according to the third aspect are the same as those for the corresponding first network node claims according to the first aspect.

According to a fourth aspect of the invention, the above mentioned and other objectives are achieved with a method for a client device, the method comprises

operating in at least one of an uplink mobility mode and a downlink mobility mode, wherein the client device in the uplink mobility mode uplink is configured to transmit uplink reference signals for mobility decisions in a first cell, and wherein the client device in the downlink mobility mode is configured to measure downlink reference signals for mobility decisions in the first cell;

receiving a mobility mode configuration message from a network node, wherein the mobility mode configuration message comprises an instruction for operation in a dual mobility mode indicated by a valid time period value for the dual mobility mode, wherein the operation in the dual mobility mode is concurrent operation in the uplink mobility mode and in the downlink mobility mode;

operating in the dual mobility mode in response to the reception of the mobility mode configuration message.

The advantages of the methods according to the fourth aspect are the same as those for the corresponding client device claims according to the second aspect. The invention also relates to a computer program, characterized in code means, which when run by processing means causes said processing means to execute any method according to the present invention. Further, the invention also relates to a computer program product comprising a computer readable medium and said mentioned computer program, wherein said computer program is included in the computer readable medium, and comprises of one or more from the group: ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically EPROM) and hard disk drive.

Further applications and advantages of the present invention will be apparent from the following detailed description.

Brief Description of the Drawings

The appended drawings are intended to clarify and explain different embodiments of the present invention, in which:

- Fig. 1 shows a first network node according to an embodiment of the invention.

- Fig. 2 shows a method for a first network node according to an embodiment of the invention.

- Fig. 3 shows a client device according to an embodiment of the invention.

- Fig. 4 shows a method for a client device according to an embodiment of the invention.

- Fig. 5 shows a wireless communication system according to an embodiment of the invention.

- Fig. 6 shows a flow chart according to an embodiment of the invention. - Fig. 7 shows a flow chart according to an embodiment of the invention.

- Fig. 8 shows a flow chart according to an embodiment of the invention.

- Fig. 9 shows a flow chart according to an embodiment of the invention. Detailed Description

Fig. 1 shows a first network node 100 according to an embodiment of the 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 known in the art. The first network node 100 can be configured for any of wireless and wired communications in wireless and wired communication systems, respectively. The wireless communication capability is provided with an antenna 1 10 coupled to the transceiver 104, while the wired communication capability is provided with a wired communication interface 1 12 coupled to the transceiver 104. The first network node 100 may be part of a network of a wireless communication system.

That the first network node 100 is configured to perform certain actions should in this disclosure be understood to mean that the first network node 100 comprises suitable means, such as e.g. the processor 102 and the transceiver 104, configured to perform said actions. The first network node 100 herein is configured to control at least one first cell 402 (as shown in Fig. 5) which operates in at least one of an uplink mobility mode and a downlink mobility mode. In the uplink mobility mode uplink measurements are used for mobility decisions and in the downlink mobility mode downlink measurements are used for mobility decisions. The first network node 100 is further configured to generate a first mobility mode information message MMIM1 comprising a current mobility mode of the first cell 402. The current mobility mode of the first cell 402 is at least one of the uplink mobility mode and the downlink mobility mode. Furthermore, the first network node 100 is configured to transmit the first mobility mode information message MMIM1 to at least one second network node 200 (shown in Fig. 5) configured to control at least one second cell 404 (shown in Fig. 5). In Fig. 1 it is illustrated how the first network node 100 transmits the first mobility mode information message MMIM1 over the wired communication interface 1 12. However, in another example the first mobility mode information message MMIM1 is transmitted over a wireless interface. It is understood that the first network node 100 may communicate with the second network node 200 and client devices using any combination of wired or wireless communications.

The first network node 100 may transmit the first mobility mode information message MMIM1 to the second network node 200, e.g. when the first cell 402 is configured for the first time or when the mobility mode of the first cell 402 is reconfigured, i.e. the mobility mode is changed. Thus, the first network node 100 may in embodiments be configured to transmit the first mobility mode information message MMIM1 in response to a change of the current mobility mode of the first cell 402, as will be described below with reference to Fig. 6. In embodiments, the first network node 100 may transmit the first mobility mode information message MMIM1 upon a request from the second network node 200, as will be described below with reference to Fig. 7.

The first mobility mode information message MMIM1 may be defined as a new message type or could be added to an existing message type of a wireless communication system which is transmitted between different network nodes. In an LTE network, the first mobility mode information message MMIM1 may e.g. be added to an existing X2 message and transmitted over the X2 interface. The mobility mode herein refers to how the radio channel properties are determined to make a decision about which network nodes and cells each client device shall be connected to. In particular, the downlink mobility refers to the scenario when the client device measures the received signal power or received signal quality of reference signals that are transmitted by the network nodes. A client device measures the received radio signals from multiple cells, and reports those to the serving cell where it is currently connected if the measurement fulfils some criteria which may be configured by the network nodes. Since the client device measures the signals from neighbour cells, it requires that those neighbour cells are configured with downlink mobility mode. Based on the measurement reports from the client device the serving network node can determine if the client device shall make a handover to another cell or not.

In the uplink mobility mode the client device is instead configured to transmit reference signals in the uplink. Multiple network nodes can measure the received signal power and signal quality of the reference signals and report the measured values to the serving network node if the signal fulfils some measurement report requirements. The serving network node can then make a decision about which network nodes and cells are the most suitable to serve the client device. Since the reference signals are measured by neighbour cells, those neighbour cells need to be configured with uplink mobility mode to measure the reference signals transmitted by the client device. Hence, in general the mobility decisions for a client device connected to a cell is taken based on measurements of the radio channel between the client device and the neighbour cells. Therefore, the mobility mode of the neighbour cells are the most important for the mobility decisions taken by a first network node. Those measurements are compared to measurements of the serving cell where the client device is connected. However, the measurements of the channel to the serving cell can be made from other transmissions and it is therefore of less importance what mobility mode is configured in the serving cell. In cases where different neighbour cells have different mobility configurations it may be necessary to use both uplink and downlink mobility in parallel.

The mobility mode herein may also refer to how the mobility measurements are made for client devices that are in mobility states where no traditional handover is performed. In particular it can apply to client devices in an inactive or lightly connected mode. Downlink mobility mode may then refer to a procedure where the client device determines which cell it is camping on, without informing the network node every time it selects a different cell. The client device only needs to inform the network when it determines based on measurements of downlink signals that it has moved to a cell that the network has defined as a different tracking area. Uplink mobility mode for an inactive client device would require the client device to transmit a reference signal, and the network would 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 which may be executed in a first network node 100, such as the one shown in Fig. 1. The method 500 comprises controlling 502 at least one first cell 402 which operates in at least one of an uplink mobility mode and a downlink mobility mode. In the uplink mobility mode uplink measurements are used for mobility decisions and in the downlink mobility mode downlink measurements are used for mobility decisions. 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 mode of the first cell 402 is at least one of the uplink mobility mode and the downlink mobility mode. Furthermore, the method 500 comprises transmitting 506 the first mobility mode information message MMIM1 to at least one second network node 200 configured to control at least one second cell 404.

Fig. 3 shows a client device 300 according to an embodiment of the invention. In the embodiment shown in Fig. 3, the client device 300 comprises 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 known in the art. The client device 300 can be configured for wireless communications in wireless communication systems. The wireless communication capability is provided with an antenna 310 coupled to the transceiver 304. That the client device 300 is configured to perform certain actions should in this disclosure be understood to mean that the client device 300 comprises suitable means, such as the processor 302 and the transceiver 304, configured to perform said actions.

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 in the uplink mobility mode is configured to transmit uplink reference signals for mobility decisions in a first cell 402, and the client device 300 in the downlink mobility mode is configured to measure downlink reference signals for mobility decisions in the first cell 402. The client device 300 is further configured to receive a mobility mode configuration message MMCM from a network node 100. The mobility mode configuration message MMCM comprises an instruction for operation in a dual mobility mode indicated by a valid time period value for the dual mobility mode. The operation in the dual mobility mode means that the client device 300 operates concurrently/simultaneously in the uplink mobility mode and in the downlink mobility mode. Furthermore, the client device 300 is configured to operate in the dual mobility mode in response to the reception of the mobility mode configuration message MMCM.

Fig. 4 shows a flow chart of a corresponding method 600 which may be executed in a client device 300, such as the one shown in Fig. 3. The method 600 comprises operating 602 in at least one of an uplink mobility mode and a downlink mobility mode. The client device 300 in the uplink mobility mode uplink is configured to transmit uplink reference signals for mobility decisions in a first cell 402, and the client device 300 in the downlink mobility mode is configured to measure downlink reference signals for mobility decisions in the first cell 402. The method 600 further comprises receiving 604 a mobility mode configuration message MMCM from a network node 100. The mobility mode configuration message MMCM comprises an instruction for operation in a dual mobility mode indicated by a valid time period value for the dual mobility mode. The operation in the dual mobility mode is concurrent/simultaneous operation in the uplink mobility mode and in the downlink mobility mode. Furthermore, the method 600 comprises operating 606 in the dual mobility mode in response to the reception of the mobility mode configuration message MMCM.

Fig. 5 shows 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, while the second network node 200 controls a second cell 404. However, the first network node 100 and the second network node 200 may in some embodiments control more than one cell each. Furthermore, the client device 300 is located in the first cell 402 and exchange 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 via a communication link 406, over which mobility mode information according to the invention may be transmitted. Mobility mode information from the first network node 100 to the second network node 200 may be transmitted using a first mobility mode information message MMIM1 , while mobility mode information from the second network node 200 to the first network node 100 may be transmitted using a second mobility mode information message MMIM2. The mobility mode information according to the invention may provide information about the mobility mode per cell, i.e. the granularity may be on cell level. It may also be on a finer granularity, where individual transmission and reception points (TRPs) within a cell may be configured with different mobility modes.

The first mobility mode information messages MMIMI s and second mobility mode information messages MMIM2s exchanged between the first network node 100 and the second network node 200 allows the first network node 100 to know whether the second cell 404 of the second network node 200 are using uplink mobility mode and/or downlink mobility mode, and vice versa. Thereby, the first network node 100 may configure the mobility behaviour of the client device 300 accordingly. The first network node 100 may e.g. configure the client devices 300 with mobility measurements on the downlink reference signals transmitted in the second cell 404 and/or configure the client devices 300 to transmit uplink reference signals. Hence, the client device 300 may be configured 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, the wireless communication system 400 shown in Fig. 5 only comprises one first network node 100, one second network node 200 and one client device 300. However, the wireless communication system 400 may comprise any number of first and second network nodes and client devices without deviating from the scope of the invention.

As described above the transmission of a first mobility mode information message MMIM1 may in some embodiments be triggered by a change of the current mobility mode of the first cell 402. Fig. 6 shows a flow chart according to such an embodiment. In step I in Fig. 6, the mobility mode of the first cell 402 of the first network node 100 is changed. Based on the mobility mode change of the first cell 402, the first network node 100 generates and transmits a first mobility mode 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 comprise information such as e.g. the identity (ID) of the first cell 402 and the mobility mode (i.e. in the uplink and/or in the downlink) supported in each client device 300 state, e.g. radio resource control (RRC) connected, RRC inactive, or RRC idle in wideband code division multiple access (WCDMA), new radio (NR) and long term evolution (LTE). In step III in Fig. 6, 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 in order to support the changed mobility mode of the first cell 402. If the mobility mode of the first cell 402 has been changed to the downlink mobility mode, the second network node 200 may e.g. need to reconfigure client devices 300 with downlink measurements. On the other hand, if the mobility mode of the first cell 402 has been changed to the uplink mobility mode, the second network node 200 may need to reconfigure client devices 300 to send uplink reference signals that the first network node 100 may measure. The mobility mode information exchange may be terminated by an acknowledge message ACK transmitted from the second network node 200 to the first network node 100, as shown in step IV in Fig. 6. In one embodiment, the actual mobility reconfiguration of the client devices may occur after step IV.

According to embodiments of the invention a change of the mobility mode of a cell may be triggered in different ways. The first network node 100 may e.g. be configured and reconfigured with a specific mobility mode by a network management system, or the first network node 100 may decide to reconfigure the mobility mode of its cells, i.e. the first cell 402 in the embodiment shown in Fig. 5, based on the traffic situation. For example, it may be preferred to use uplink measurements when the traffic is very limited to reduce the energy consumption used for transmitting downlink reference signals. The first network node 100 may also reconfigure the mobility mode of the first cell 402 when it notices that neighbouring cells are changing their mobility modes, and other necessary criteria are met. Such criteria may e.g. be that there are no connected client devices in neighbour cells that need to be served with the current mobility mode, and that the network node has the required resources to change the mobility mode. In addition, a change of the mobility mode of the first cell 402 may be triggered by a request from a neighbouring network node, such as the second network node 200. The second network node 200 may e.g. transmit such a request to the first network node 100 when a client device 300 served by the second network node 200 does not support the uplink mobility mode, to request the first network node 100 to configure the first cell 402 to use the downlink mobility mode. The mobility mode change request from a neighbouring network node may also be used when a different measurement mode is needed to collect radio measurement information, which may be used for optimization or to discover neighbouring cells. Fig. 7 shows a flow chart of an embodiment where a change of the mobility mode of the first cell 402 is triggered by a request from the second network node 200. In step I in Fig. 7, the first network node 100 receives a second mobility mode change request message MMCRM2 from the second network node 200. The second mobility mode change request message MMCRM2 comprises a request for change of the current mobility mode of the first cell 402. Based on the received second mobility mode change request message MMCRM2 the first network node 100 determines the current mobility mode of the first cell 402, as shown in step II in Fig. 7. The determined current mobility mode of the first cell 402 may be the same as the mobility mode requested by the second network node 200. However, the first network node 100 may also decide to not change the mobility mode of the first cell 402 since the configuration of the mobility mode of the first cell 402 has an impact on the mobility measurements for client devices 300 in multiple neighbouring network nodes. In step III in Fig. 7, the first network node 100 informs the second network node 200 about the determined current mobility mode of the first cell 402 by transmitting a first mobility mode information message MMIM1. 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 transmits an acknowledge message ACK to the first network node 100, as shown in step IV and V in Fig. 7.

In a similar way, the first network node 100 may request a change of the current mobility mode of the second cell 404 using a first mobility mode change request message MMCRM1 . Hence, if the first network node 100 identifies that a change of the current mobility mode of the second cell 404 is required, the first network node 100 may generate a first mobility mode change request message MMCRM1. The first mobility mode change request message MMCRM1 comprises a request for a change of a current mobility mode of the second cell 404. The first network node 100 further transmits the first mobility mode change request message MMCRM1 to the second network node 200.

According to further embodiments of the invention the request for change of the current mobility mode of the first cell 402 or the second cell 404 is indicated by a transmission periodicity for reference signals associated with at least one of the uplink measurements and the downlink measurements. For example, by requesting that the transmission periodicity of downlink reference signals is set to zero or infinity it may be implicitly indicated that no downlink reference signals should be transmitted and hence the uplink mobility mode should be used. It should be noted however that even if uplink reference signals are used for mobility the downlink reference signal transmissions can typically not be completely switched off, as the downlink reference signals may also be used for other purposes, e.g. synchronization, etc.

The mobility mode change request messages MMCRM1 , MMCRM2 may comprise the ID of the cell 402, 404 requested to be reconfigured, and the mobility mode that should be configured for each client device state. The mobility mode change request messages MMCRM1 , MMCRM2 may further comprise information about resources to be used, such as e.g. resources for uplink reference signals that the neighbouring network node will receive. The network node may then configure its connected client devices to use these resources to send uplink reference signals that the neighbouring network node can measure. If the network node is requested to configure downlink mobility mode the mobility mode change request messages MMCRM1 , MMCRM2 may further comprise an indication of downlink reference signal resources that can be used by the neighbouring network node without causing interference. To allow a finer granularity of the mobility mode management than on the cell level the mobility mode change request messages MMCRM1 , MMCRM2 may further comprise IDs of specific transmission and reception points of a cell that should be reconfigured with a different mobility mode. Thereby, uplink mobility measurements or downlink reference signal transmission may be limited to a few transmission and reception points within a cell, which can save resources.

In a similar way, the mobility mode information messages MMIM1 , MMIM2 may in some embodiments comprise IDs of specific transmission and reception points. Hence, the first mobility mode information message MMIM1 may further comprise one or more IDs of transmission and reception points associated with the first cell 402 and/or the second mobility mode information message MMIM2 may further comprise one or more IDs of transmission and reception points associated with the second cell 404.

According to embodiments of the invention the first mobility mode information message MMIM1 and the second mobility mode information message MMIM2, as well as the first mobility mode change request message MMCRM1 and the second mobility mode change request message MMCRM2 may comprise one or more of the following types of information or corresponding parameters:

• Cell IDs, e.g. physical cell IDs or global cell IDs. Mentioned IDs are used to identify which cells controlled by a network node have a specific configuration. The cell IDs need to be unambiguous within a limited area, therefore it may not be necessary to use globally unique cell IDs, even physical cell IDs may be used if the network nodes can determine which cells are referred to. • IDs of transmission and reception points which indicate transmission and reception points configured for downlink mobility and/or uplink mobility. In particular some transmission and reception points at cell borders may be configured with downlink reference signal transmissions, while others are configured to only measure uplink reference signals.

• Mobility mode for a client device state. A mobility mode may apply to a client device in a specific state, e.g. in LTE the uplink mobility mode may be used for a client device in RRC connected state, while the downlink mobility mode may be used for a client device in RRC inactive (or light connection) or RRC idle state.

· Notification and/or tracking area information. This information informs the neighboring network node (such as the second network node 200) about which notification or tracking area a cell belongs to.

• Radio resources used for reference signals or resources available for reference signals. The radio resources may relate to any of resource blocks, time-frequency resources, reference signal definitions, reference signal indexes, etc. This information is useful for the neighboring network node, e.g. to configure uplink reference signals or to reject the mobility mode reconfiguration if the indicated resources are in conflict with the resources in a cell. The radio resource information may also include the periodicity of the downlink reference signal transmission. · A point in time when a proposed mobility mode change will be executed. This point in time may be expressed e.g. in coordinated universal time (UTC) or as a time reference valid for the network nodes in the wireless communication system, e.g. a system frame number. This time information helps the network nodes to synchronize a change of the mobility mode in a larger area and to reconfigure the client nodes at the right time to handle the change in mobility mode.

According to embodiments of the invention a network node may request information from a neighbouring network node about the mobility mode of the cell(s) associated with the neighbouring network node. Such a mobility mode information request may contain a list of cell IDs for which the network node would like to know the configured mobility mode. This procedure may e.g. be used during configuration of a network node at the start-up of the network node.

Fig. 8 shows a flow chart of an embodiment where the first network node 100 requests mobility mode information from the second network node 200. In step I in Fig. 8, the first network node 100 generates a first mobility mode information request MMIR1. The first mobility mode information request MMIR1 comprises a request for mobility mode information of the second cell 404. The first network node 100 transmits the first mobility mode information request MMIR1 to the second network node 200, as shown in step II in Fig. 8. In response to the transmission of the first mobility mode information request MMIR1 , the first network node 100 receives a second mobility mode information message MMIM2 from the second network node 200, as shown in step III in Fig. 8. The second mobility mode information message MMIM2 comprises a current mobility mode of the second cell 404 controlled by the second network node 200. According to embodiments of the invention the second mobility mode information message MMIM2 further comprises a current mobility mode change proposal for the second cell 404. In such an embodiment, the first network node 100 determines whether a client device connected to the first network 100 will suffer from a service level deterioration based on the current mobility mode change proposal for the second cell 404. If the first network node 100 determines that a client device 300 connected to the first network node 100 will experience a service level deterioration due to the current mobility mode change proposal for the second cell, the first network node 100 transmits a negative acknowledge message NACK to the second network node 200 in response to the current mobility mode change proposal for the second cell 404. Else, the first network node 100 transmits an acknowledge message ACK to the second network node 200 in response to the current mobility mode change proposal for the second cell 404 in response to the current mobility mode change proposal for the second cell 404.

To determine whether any client device 300 connected to the first network node 100 will suffer from a service level deterioration due to the current mobility mode change proposal for the second cell 404, the first network node 100 may e.g. check if there are any conflicting resources or if a client device 300, which may need to be handed over to the second cell 404, cannot support the mobility mode to which the second cell 404 is proposed to change. The first network node 100 may use different mechanisms to avoid that the any client device 300 suffers from service level deterioration, such as lost connectivity or deteriorated service in case of a mobility mode change in a neighbor cell. For example, the first network node 100 may check if all the connected client devices have the required capabilities to support the proposed mobility mode. For client devices that do not have the capabilities, the first network node 100 may evaluate possible solutions, e.g. if the client devices can be served by other cells with overlapping coverage with the cell that would change mobility mode, e.g. on a different frequency carrier or different radio access technology (RAT). Otherwise the client devices could lose the connectivity in case the cell is reconfigured and they move into an area where coverage is only provided by the cell that is being reconfigured. The first network node 100 may therefore take into account which client devices are moving towards the coverage area of the cell that is proposed to be reconfigured when it determines if the service level to any client device may be affected by the reconfiguration.

The first network node 100 may also evaluate whether the active services of the connected client devices can be supported in case of a reconfiguration. Client devices with services that have high demands on data rate, low latency or high reliability may need to be connected to the specific cells that are being considered for mobility mode reconfiguration. This may be the case if the traffic load is high on alternative cells. If the service requirements may not be fulfilled after a reconfiguration the first network node 100 may send a negative acknowledgement message NACK. The change of mobility mode may result in lower robustness of the mobility procedure for a client device 300. For example, downlink mobility requires that a measurement report is transmitted from the client device 300 and a handover command is received by the client device 300 before a handover is executed. This may lead to lower robustness for fast moving client devices, and the requirements on communication reliability may not be fulfilled. The first network node 100 may therefore reject the proposed change by sending a negative acknowledgement message NACK if it has connected client devices that may not fulfil all of its quality of service requirements, e.g. related to communication reliability or throughput.

If the second network node 200 receives a negative acknowledge message NACK from the first network node 100 in response to its current mobility mode change proposal for the second cell 404, the second network node 200 may e.g. select other resources. According to some embodiments the first network node 100 may in the negative acknowledge message NACK indicate that the mobility mode change proposal is possible with other resources that can be indicated in the message. The second network node 200 may transmit a new second mobility mode information message MMIM2 with updated information to the first network node 100. The first network node 100 evaluates the new mobility mode change proposal for the second cell 404 and transmits an acknowledge message ACK or a negative acknowledge message NACK depending on the outcome of the evaluation. If the second network node 200 would like to know the mobility mode of the cells of the first network node 100, the second network node 200 may send a second mobility mode 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 comprises a request for mobility mode information of the first cell 402. In response to the reception of the second mobility mode information request MMIR2 the first network node 100 transmits the first mobility mode information message MMIM1 .

Similar to the second mobility mode information message MMIM2, the first mobility mode information message MMIM1 may further comprises a current mobility mode change proposal for the first cell 402. In response to the transmission of the current mobility mode change proposal for the first cell 402 the first network node 100 may receive an acknowledge message ACK or a negative acknowledge message NACK from the second network node 200. The negative acknowledge message NACK indicates that a client device 300 connected to the second network node 200 will experience deteriorated service level due to the current mobility mode change proposal for the first cell 402, while the acknowledge message ACK indicates that the current mobility mode change proposal for the first cell 402 can be executed without any unacceptable service level deterioration.

As previously described (e.g. in step III in Fig. 6) the second network node 200 may reconfigure a client device 300 under its control to support the mobility procedure required to allow the client device 300 to move to a neighbouring cell, e.g. the first cell 402. The client device 300 reconfiguration reconfigures parameters that are relevant for the mobility. According to embodiments of the invention the client device 300 mobility reconfiguration, may involve indicating a time period during which the client device 300 should use both the uplink mobility mode and the downlink mobility mode in parallel, herein called a dual mobility mode. During the indicated time period for the dual mobility mode both downlink measurements and uplink reference signal transmissions are configured at the same time for the same client device 300. When the time period for the dual mobility mode expires the client device 300 cancels the downlink measurement or the uplink reference signal transmissions, respectively. The parallel downlink measurement and uplink reference signal transmissions for a client device 300 may also be cancelled for other reasons, e.g. if the client device 300 receives a new configuration at handover.

In some embodiments, the time period for the dual mobility mode is indicated to a client device 300 in a mobility mode configuration message MMCM from the first network node 100. The first network node 100 generates a mobility mode configuration message MMCM for a client device 300 served by the first network node 100 in the first cell 402. The mobility mode configuration message MMCM comprises an instruction for operation in a dual mobility mode, i.e. concurrently in the uplink mobility mode and in the downlink mobility mode, indicated by a valid time period value for the dual mobility mode. The first network node 100 further transmit the mobility mode configuration message MMCM to the client device 300. 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 MMIM2, as will be described below with reference to Fig. 9.

Fig. 9 shows a flow chart according to an embodiment where a client device 300 is reconfigured from the downlink mobility mode to the uplink mobility mode. A client device 300 served by the first network node 100 is initially configured to make downlink mobility measurements. In step I in Fig. 9, the second network node 200 evaluates the possibility to change to mobility mode of the second cell 404 to the uplink mobility mode. Hence, the second network node 200 transmits a second mobility mode information message MMIM2 comprising a current mobility mode change proposal for the second cell 404 to the first network node 100, as shown in step II in Fig. 9. In step III in Fig. 9, first network node 100 evaluates the possibility to handle the client devices connected to the first cell 402 if the mobility mode of the second cell 404 is changed to the uplink mobility mode. If the mobility mode change is considered possible, the first network node 100 will send a positive response, an acknowledge message ACK, to indicate that the second network node 200 can execute the mobility mode change, as shown in step IV in Fig. 9; else a negative acknowledge message NACK is sent. In step V in Fig. 9 the first network node 100 determines the reconfiguration of the client device 300. The reconfiguration in this embodiment involves reconfiguring the client device 300 to transmit uplink reference signals so that the second network node 200 can measure the uplink reference signals and determine if the client device 300 can be served. In addition, the reconfiguration involves reconfiguring the client device 300 to remove the measurement objects associated with the second cell 404 that will be reconfigured to the uplink mobility mode. The first network node 100 may configure the client device 300 to use both downlink and uplink mobility during a specified time period. During this time period the client device 300 may both measure downlink reference signals and report as needed and transmit uplink reference signals for the second network node 200 to measure. This may be particularly useful when the second mobility mode information message MMIM2 contains time information indicating when the mobility mode change of the second cell 404 will be executed. Since the client device 300 continues to measure and report the downlink reference signals, the first network node 100 will get measurement reports directly from the client device 300 during a transition period before the second network node 200 starts forwarding measurement information from its measurements of the uplink reference signals of the client device 300. In step VI in Fig. 9 the first network node 100 transmits a mobility mode configuration message MMCM to the client device 300 to reconfigure the client device 300. The mobility mode configuration message MMCM comprises an instruction for operation in a dual mobility mode during a time period. In response to the mobility mode configuration message MMCM the client device 300 starts to transmit uplink reference signals according to the reconfiguration, as shown in step VII in Fig. 9. In step VIII in Fig. 9, the time period for the dual mobility mode expires and the client device 300 cancels the downlink measurement configuration. Thereby, the client device 300 is saving measurement resources. In some embodiments, the evaluation by the first network node 100 in step III in Fig. 9 may result in that it is not possible to handle the client devices 300 connected to the first cell 402 if the mobility mode of the second cell 404 is changed to the uplink mobility mode. This is e.g. the case if there are client devices 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 if there are alternative cells that those client devices 300 can be handed over to instead. The availability of suitable alternative cells may e.g. depend on the supported frequency bands of the client devices 300. If no suitable alternative cells exist, the first network node 100 may transmit a negative acknowledge message NACK to inform the second network node 200 that it has client devices that cannot be supported and may lose connectivity if the proposed mobility mode change for the second cell 404 is performed. The negative acknowledge message NACK may indicate which frequency bands would need to keep the downlink mobility mode in order to not lose connectivity to any client devices 300 served by the first network node 100.

The first network node 100 herein may also be denoted as a radio network node, an access 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 radio network nodes may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. The radio network node can be a Station (STA), which is any device that contains an IEEE 802.1 1 -conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM). The radio network node may also be a base station corresponding to the fifth generation (5G) wireless systems.

The client device 300 herein may be denoted as a user device, a User Equipment (UE), a mobile station, an internet of things (loT) device, a sensor device, a wireless terminal and/or a mobile terminal, is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability. The UEs in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another receiver or a server. The UE can be a Station (STA), which is any device that contains an IEEE 802.1 1 - conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM). The UE may also be configured for communication in 3GPP related LTE and LTE-Advanced, in WiMAX and its evolution, and in fifth generation wireless technologies, such as New Radio.

Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive.

Moreover, it is realized by the skilled person that embodiments of the first network node 100 and the client device 300 comprises the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing the present solution. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the present solution. Especially, the processor(s) of the first network node 100 and the client device 300 may comprise, e.g., one or more instances of a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The expression "processor" may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as processing control, user interface control, or the like.

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