WO2023219537A1

WO2023219537A1 - Co-ordinating co-operative handover of a group of wireless devices as configured by source network node

Info

Publication number: WO2023219537A1
Application number: PCT/SE2022/050466
Authority: WO
Inventors: Jan Christoffersson; Mårten ERICSON; Majid GERAMI; Stefan WÄNSTEDT
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2023-11-16

Abstract

A coordinating wireless device and method therein for coordinating co-operative transmissions in a group of wireless devices located in a source cell served by a source network node in a wireless communications network is provided. The coordinating wireless device is arranged to obtain measurements of radio conditions towards at least 5one target cell in the wireless communications network that is indicative of the radio conditions towards the at least one target cell for the group of wireless devices. Thecoordinating wireless device is also arranged to determine if a co-operative handover from a source network node serving the source cell to a target network node serving a target cell is to be performed for the group of wireless devices based on the obtained 10measurements of radio conditions. A wireless device, a source network node and methods therein, as well as, computer program products and carriers are also provided.

Description

CO-ORDINATING CO-OPERATIVE HANDOVER OF A GROUP OF WIRELESS DEVICES AS CONFIGURED BY SOURCE NETWORK NODE

TECHNICAL FIELD

Embodiments herein relate to co-operative transmissions in a wireless communications network. In particular, embodiments herein relate to a coordinating wireless device and method therein for coordinating co-operative transmissions in a group of wireless devices located in a source cell served by a source network node in a wireless communications network. Also, embodiments herein relate to a wireless device, a source network node and methods therein for enabling co-operative transmissions in a group of wireless devices located in a source cell served by the source network node in a wireless communications network. Furthermore, the embodiments herein also relate to a computer program product and a carrier.

BACKGROUND

In wireless communications networks, a number of different technologies for enabling next generation of wireless communications networks is being implemented. Naturally, these next generation wireless communications networks, sometimes referred to as 6G or similar, are based upon and evolves from existing legacy telecom technologies, such as, New Radio (NR), Long Term Evolution (LTE), 5G/4G/3G etc.

A wireless communications network conventionally comprises different nodes. For example, network nodes, such as, e.g. eNB/gNBs, radio base stations, wireless access points, etc., provide radio coverage over at least one respective geographical area forming a cell. This may in some cases jointly be referred to as a Radio Access Network, RAN. Here, it should be noted that the definition of a “cell” may also incorporate frequency bands used for transmissions, which means that two different cells may cover the same geographical area but using different frequency bands. The wireless communications network may further comprise user nodes, also commonly referred to as wireless devices, User Equipments, UEs, mobile stations, and/or wireless terminals, that are served in the cells by its respective serving network node and communicating via its serving network node in the RAN. Commonly, the wireless devices transmit data over an air or radio interface to the network nodes in uplink, UL, transmissions and the network nodes transmit data over an air or radio interface to the wireless devices in downlink, DL, transmissions. In some wireless communication networks, for example, in future high frequency 5G/6G networks, a Device-to-Device/Sidelink, D2D/SL, co-operative group communication may be used in order to increase UL coverage and user bit rate. This is referred to herein and in the following simply as co-operative transmissions. Here, it should be noted that Sidelink, SL, transmission over NR is just one example of a D2D transmission. Examples of co-operative transmissions are also described in WO2017/182068 A1 and WG2021/071402A1.

Co-operative transmissions

Co-operative transmissions may be performed by a group of wireless devices that are D2D/SL capable. For example, in a first step, a wireless device with data to transmit will first distribute this data to its neighbouring wireless devices in the group over D2D/SL. In a second step, the wireless devices in the group will co-operatively transmit the data over the cellular UL. In this way, the co-operative transmission will increase the UL coverage, e.g. by combining transmissions from several wireless devices, and also be beneficial from a latency point of view compared to repeated transmissions for coverage, as used e.g. in LTE narrowband.

Figs. 1-2 illustrate the basic idea of co-operative transmission. In Fig. 1 , for example, when UE1 in the group of wireless devices 11 wants to transmit data through the group of wireless devices 11, UE1 may send its data over D2D/SL to UE2-UE4 in the group of wireless devices 11. Thereafter, as shown in Fig. 2, the data may be sent in a synchronized manner from UE1-UE4 in the group wireless devices 11 over the cellular UL to the network node, eNB/gNB, serving the cell 10. The latter may also be referred to as the second (2^nd) hop. In the DL, the eNB/gNB may transmit data to UE1-UE4 in group of wireless devices 11 as if it was a single wireless device. In this case, at least one of UE1- UE4, in the group of wireless devices 11 needs to be able to receive the DL data. If necessary, the DL data may be relayed to the other UE1-UE4 in the group of wireless devices 11 via D2D/SL. It should be noted that this is not an entirely new technique and may also be referred to as co-operative relaying or Virtual Antenna Array, WA. Also, there exists support for the co-operative transmissions to some extent already in LTE 3GPP. Here, it may, for example, be possible to create groups of UEs transmitting to each other. In 3GPP, this concept may be referred to as Proximity-based Services, ProSe. More details of how co-operative transmission may be setup and performed is described in WO2017/182068 A1 and WG2021/071402A1. Conditional handover, CHO

In combination with legacy handover procedures in the wireless communications network, Conditional Handover, CHO, may be performed by the wireless devices therein. The standard CHO procedure operates as described below.

First, the wireless device receives a handover command, e.g. an RRCReconfiguration message prepared by a target cell candidate, and stores it without applying it as it would have done in legacy handover. Together with the handover command, the wireless device also receives an associated condition to be monitored. When the associated condition is fulfilled, the wireless device applies the stored handover command as if the network would have just sent it. This instead of first sending a measurement report (that could fail to be transmitted) and then waiting to receive the handover command (which may fail to be received) as performed in a legacy handover situation. The associated condition that defines the criteria to apply the stored handover command is based on the signal quality in the serving cell(s) and neighbouring cells. This may be somewhat similar to the condition that in previous releases leads the mobile terminal to transmit a measurement report when the condition is fulfilled; for example, the network may configure the wireless device to transmit a measurement report when a neighbouring cell becomes an offset better than the serving cell, as a way to indicate to the network that a handover may be needed. In CHO, the associated condition may, instead of transmitting the measurement report, configure to the wireless device to apply the stored handover command.

One advantage of using CHO is that sending the handover command when the radio conditions are still favourable reduces the risk of failing the transmission of the measurement report and/or the reception of the handover command. It is also possible to configure two conditions for the wireless device and associate both to the stored handover command - i.e. the handover command is applied only if both conditions are fulfilled. To some extent, this may be viewed as attempting to replicate, in the wireless device, the criteria which the network would define for handover based on multiple measurement reports triggered by multiple conditions. These measurement reports may, for example, be measurement reports for different types of measurement quantities, such as, cell coverage represented by Radio Signal Received Power (RSRP), and/or signal quality represented by Radio Signal Received Quality (RSRQ).

On the network side, the serving network node may prepare one or more target cells, also referred to as target candidate cells, as it’s not certain if the wireless device will access a specific target cell. The CHO preparation procedure(s) has some similarities with the legacy handover preparation procedure, whereby the outcome is the creation of a handover command, i.e. an RRCReconfiguration message containing the target’s configuration, with the exception that the target network node does not expect the wireless device to access it immediately, and in some cases, not even to access it at all.

For example, in a best-case scenario, the wireless device will execute the handover in only one of the prepared target candidate cells. The target network node hosting this cell needs to inform the source network node that the wireless device successfully performed the handover in its cell, so that the source network node may cancel the resources reserved by the target network nodes of the remaining target candidate cells. Additionally, the time between the handover preparation, and thus the resource reservation, being unknown, the source network node is also able to release the reserved resources before the wireless device executes the handover.

If multiple cells need to be prepared to further increase robustness and the wireless device accesses one of them according to the best-case scenario, a set of resources would need to be reserved while the wireless device is monitoring the condition and does not perform the handover. The network therefore needs to carefully select the target candidate cells and keep the number of the target candidate cells to a reasonable amount, especially in resource constrained scenarios with high loads.

Another benefit of CHO is the fact that the wireless device has handover commands stored for multiple cells, which reduces interruption time even if a failure occurs. In a non-CHO case and as a failure, e.g. a radio link failure or handover failure, is detected while the wireless device is monitoring the condition, a wireless device may perform cell selection and continue with a re-establishment procedure. Contrary, in case of a CHO, the wireless device may prioritize a cell for which it has a stored handover command and, instead of performing re-establishment, it may perform a CHO. This will reduce the interruption time and the signalling over the air interface. More details regarding the conditional handover is found in the 3GPP standard document TS 38.300, version 17.0.0, section 9.2.3.4, which is hereby incorporated by reference.

Similar concepts to the CHO have also been suggested to optimize mobility in private networks, wherein the stored cell configuration of a wireless device only uses a so- called Special Cell Information Element, i.e. SpCell IE, instead of the full RRC configuration. This configuration is activated by the new target cell with a MAC CE transmission to support faster handover. One disadvantage with this concept is that it does not define the area of which cells to include in the spCell. Another disadvantage is that it requires inter-node signalling between the cells for each wireless device that is configured with more than one SpCell, such as, e.g. in CHO as described above. Yet another disadvantage is that this concept is only valid for handover and not also for a setup from IDLE mode.

SUMMARY

It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art to improve cooperative transmissions in a wireless communications network.

According to a first aspect there is provided a method performed by a coordinating wireless device for coordinating co-operative transmissions in a group of wireless devices located in a source cell served by a source network node in a wireless communications network. The method comprises obtaining measurements of radio conditions towards at least one target cell in the wireless communications network that is indicative of the radio conditions towards the at least one target cell for the group of wireless devices. The method also comprises determining if a co-operative handover from a source network node serving the source cell to a target network node serving a target cell is to be performed for the group of wireless devices based on the obtained measurements of radio conditions.

According to a second aspect there is provided a coordinating wireless device for coordinating co-operative transmissions in a group of wireless devices located in a source cell served by a source network node in a wireless communications network, wherein the coordinating wireless device comprises a processing circuitry and a memory. The processing circuitry is configured to obtain measurements of radio conditions towards at least one target cell in the wireless communications network that is indicative of the radio conditions towards the at least one target cell for the group of wireless devices. The processing circuitry is also configured to determine if a co-operative handover from a source network node serving the source cell to a target network node serving a target cell is to be performed for the group of wireless devices based on the obtained measurements of radio conditions.

According to a third aspect there is provided a method performed by a wireless device for enabling co-operative transmissions in a group of wireless devices located in a source cell served by a source network node in a wireless communications network. The method comprises performing measurements of radio conditions towards at least one target cell in the wireless communications network. The method also comprises transmitting, to a coordinating wireless device coordinating the co-operative transmissions in the group of wireless devices, a measurement report indicating its radio conditions towards at least one target cell in case the radio conditions fulfills determined triggering co-operative handover conditions or one or more configured radio condition threshold levels at which the wireless device is to transmit a measurement report to the coordinating wireless device.

According to a fourth aspect there is provided a wireless device for enabling cooperative transmissions in a group of wireless devices located in a source cell served by a source network node in a wireless communications network, wherein the wireless device comprises a processing circuitry and a memory. The processing circuitry is configured to perform measurements of radio conditions towards at least one target cell in the wireless communications network. The processing circuitry is also configured to transmit, to a coordinating wireless device coordinating the co-operative transmissions in the group of wireless devices, a measurement report indicating its radio conditions towards at least one target cell in case the radio conditions fulfills determined triggering co-operative handover conditions or one or more configured radio condition threshold levels at which the wireless device is to transmit a measurement report to the coordinating wireless device.

According to a fifth aspect there is provided a method performed by a source network node for enabling co-operative transmissions in a group of wireless devices located in a source cell served by the source network node in a wireless communications network. The method comprises obtaining configuration information indicating at least one target cell for the group of wireless devices and determined triggering co-operative handover conditions for radio conditions towards the at least one target cell for the group of wireless device. The method also comprises transmitting the obtained configuration information towards the group of wireless devices.

According to a sixth aspect there is provided a source network node for enabling co-operative transmissions in a group of wireless devices located in a source cell served by the source network node in a wireless communications network, wherein the source network node comprise a processing circuitry and a memory. The processing circuitry is configured to obtain configuration information indicating at least one target cell for the group of wireless devices and determined triggering co-operative handover conditions for radio conditions towards the at least one target cell for the group of wireless devices. The processing circuitry is also configured to transmit the obtained configuration information towards the group of wireless devices.

According to a seventh aspect of the embodiments herein, a computer program product is also provided configured to perform the method described above. Further, according to an eight aspect of the embodiments herein, carriers are also provided configured to carry the computer program product configured for performing the method described above.

By having a coordinating wireless device obtaining measurements indicative of the radio conditions for the group of wireless devices towards a target cell, the coordinating wireless device may determine if a co-operative handover of the group of wireless devices should be performed and, if so, ensuring that the co-operative handover is performed by all wireless devices in the group of wireless devices. Hence, a way to perform cooperative handovers, i.e. coordinated conditional handovers (CHOs), for a group of wireless devices configured for co-operative transmissions is enabled. Hence, cooperative transmissions in wireless communications networks are improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the embodiments will become readily apparent to those skilled in the art by the following detailed description of exemplary embodiments thereof with reference to the accompanying drawings, wherein:

Figs. 1-2 are schematic block diagrams illustrating co-operative transmissions, Fig. 3 is a schematic block diagram of a wireless communications network comprising wireless device and network nodes according to some embodiments,

Fig. 4 is a flowchart depicting embodiments of a method in a coordinating wireless device,

Fig. 5 is a flowchart depicting embodiments of a method in a wireless device,

Fig. 6 is a flowchart depicting embodiments of a method in a source network node, Fig. 7 is a signalling scheme depicting embodiments of methods in a coordinating wireless device, wireless device and a source network node,

Fig. 8 is another signalling scheme depicting embodiments of methods in a coordinating wireless device, a wireless device and a source network node, Figs. 9-12 are schematic block diagrams depicting in scenarios illustrating embodiments of a coordinating wireless device, a wireless device and a source network node,

Fig. 13 is a block diagram depicting embodiments of a coordinating wireless device,

Fig. 14 is a block diagram depicting embodiments of a wireless device,

Fig. 15 is a block diagram depicting embodiments of a source network node.

DETAILED DESCRIPTION

The figures are schematic and simplified for clarity, and they merely show details which are essential to the understanding of the embodiments presented herein, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts or steps.

Fig. 3 depicts a wireless communications network 100 in which embodiments herein may operate. In some embodiments, the wireless communications network 100 may be a radio communications network, such as, 6G, NR or NR+ telecommunications network. However, the wireless communications network 100 may also employ technology of any one of 3/4/5G, LTE, LTE-Advanced, Wideband Code Division Multiple Acces (WCDMA), EDGE, WiMax, Ultra Mobile Broadband (UMB), Global System of Mobil communication (GSM), or any other similar network or system. The wireless communications network 100 may also employ technology transmitting on millimetrewaves (mmW), such as, e.g. an Ultra Dense Network, UDN. In some embodiments, the wireless communications network 100 may also employ transmissions supporting WiFi transmissions, e.g. the wireless communications standard IEEE 802.11 ad or similar, or other non-cellular wireless transmissions.

The wireless communications network 100 comprises a first and a second network node 110, 111. The first and second network nodes 110, 111 may be configured to serve wireless devices in at least one cell or coverage area 115, 116, respectively. Also, the first and second network nodes 110, 111 may correspond to any type of network node or radio network node capable of communicating with wireless devices in the wireless communications network 100, such as, a base station (BS), a radio base station, gNB, eNB, eNodeB, a Home NodeB, a Home eNodeB, a femto Base Station (BS), or a pico BS in the wireless communications network 100. Further examples of the first network node 110 are repeaters, multi-standard radio (MSR) radio nodes such as MSR BSs, network controllers, radio network controllers (RNCs), base station controllers (BSCs), relays, donor node controlling relays, base transceiver stations (BTSs), access points (APs), transmission points, transmission nodes, Remote Radio Units (RRUs), Remote Radio Heads (RRHs) or nodes in distributed antenna system (DAS). It should be noted that the first and second network node 110, 111 may support different types of wireless communications technology, but may also be co-located at the same physical site or form part of a single network node site. In the scenarios described below and for illustrative purposes, the first network node 110 may be referred to as a source network node, while the second network node 111 may be referred to as a target network node. Thus, similarly, the cell 115 served by the first network node 110 may be referred to as a source cell, while the cell 116 served by the second network node 111 may be referred to as a target cell.

In the scenario shown in Fig. 3, a coordinating wireless device 121 and one or more wireless devices 122, 123, 124 are located within range of and is served by the first network node 110. The coordinating wireless device 121 and the wireless device 122, 123, 124 are configured to communicate within the wireless communications network 100 via a radio link to the first network node 110; that is, the coordinating wireless device 121 and the wireless devices 122, 123, 124 may be configured to transmit data over an air or radio interface to the first network node 110 in uplink, UL, transmissions, an receive data over the air or radio interface in downlink, DL, transmissions from the first network node 110. The coordinating wireless device 121 and the wireless devices 122, 123, 124 may be any type of wireless devices, mobile terminals or user equipments (UEs) capable of communicating in a cellular, mobile or radio communication network or system, such as, the wireless communications network 100. Examples of such wireless devices are mobile phones, cellular phones, Personal Digital Assistants (PDAs), smart phones, tablets, Laptop Mounted Equipment (LME) (e.g. USB), Laptop Embedded Equipments (LEEs), etc. Further examples of such wireless device are loT devices, sensors equipped with wireless communication capabilities, Machine Type Communication (MTC) devices, Machine to Machine (M2M) devices, Customer Premises Equipment (CPE), target devices, device-to-device (D2D) enabled wireless devices, wireless devices capable of machine to machine (M2M) communication, etc. According to the embodiments described herein, each of the coordinating wireless device 121 and the wireless devices 122, 123, 124 are device-to-device (D2D) enabled wireless devices capable of communicating directly with other neighbouring wireless devices using D2D, such as, e.g. Sidelink (SL) or similar. In the scenario shown in Fig. 3, the coordinating wireless device 121 and the wireless devices 122, 123, 124 form part of a group of wireless devices 120 configured for co-operative transmissions, e.g. as described above with reference to Figs. 1-2. Here, the coordinating wireless device 121 may be a coordinating wireless device for co-operative transmissions of the group of wireless devices 120. The coordinating wireless device 121 may thus be configured to communicate with the first network node 110, i.e. in LIL/DL communication, and with the wireless devices 122, 123, 124, e.g. over SL, in order to control and perform co-operative transmissions by the group of wireless devices 120. The wireless devices 122, 123, 124 are configured to perform co-operative transmissions in the group of wireless devices 120 that is coordinated by the coordinating wireless device 121.

As part of the developing of the embodiments described herein, it has been realized that in order to support mobility for groups of wireless devices configured for co-operative transmissions, such as, e.g. the group of wireless devices 120 in Fig. 3, some sort of coordinated conditional handover, CHO, should be supported. However, since legacy conditional handovers, CHOs, operates on a per-wireless-device basis, different wireless devices in the group of wireless devices 120 may perform handovers at different times. This may lead to different wireless devices in the group of wireless devices 120 being connected to different network nodes/base stations, and that the different wireless devices performs transmissions to different network nodes/base stations. This will significantly reduce the gain of co-operative transmissions, since the signal from all wireless devices in the group of wireless devices 120 then cannot be combined. It is therefore important that any handover of wireless devices in the group of wireless devices 120 is coordinated so that all wireless devices in the group of wireless devices 120 may transmit to or remain with the same network node/base station. This is issue is addressed by the embodiments described herein.

In accordance with the embodiments described herein, by configuring a group of wireless devices with a coordinated CHO wherein e.g. the wireless devices 122, 123, 124 in the group of wireless devices 120 transmits measurement reports to the coordinating wireless device 121 in the group of wireless devices 120, the coordinating wireless device 121 may determine when a coordinated CHO is to be performed and trigger the coordinated CHO for the group of wireless devices 120. This enables the group of wireless devices configured for co-operative transmission to perform seamless handovers and maintain the gain of their co-operative transmissions throughout a wireless communications network. In other words, a coordinated CHO from a source cell 115 to a new target cell 116 enables a seamless continuation of the coordinated transmissions by the group of wireless devices 120 even in the new target cell 116. Furthermore, this also means that wireless devices configured for co-operative transmissions using these coordinated CHOs are less likely to enter a Radio Link Failure, RLF, state, since the UL of the group of wireless devices 120 is more robust (e.g. compared to the DL) than for each single wireless device. Hence, coordinated transmissions in a wireless communications network is improved.

Examples of embodiments of a method performed by a coordinating wireless device 121 for coordinating co-operative transmissions in a group of wireless devices 120 located in a source cell 115 served by a source network node 110 in a wireless communications network 100, will now be described with reference to the flowchart depicted in Fig. 4. Fig. 4 is an illustrated example of actions or operations which may be taken by the coordinating wireless device 121 in the wireless communication network 100. The coordinating wireless device 121 may also be referred to as the coordinating wireless device or UE. The method may comprise the following actions.

Action 401. Optionally, the coordinating wireless device 121 may receive, from a source network node 110 serving the source cell 115, configuration information indicating the at least one target cell 111 and configured co-operative handover triggering conditions. This means, for example, that the coordinating wireless device 121 in the group of wireless devices 120 may be configured with a set of potential target cells, e.g. the at least one target cell 116, and triggering conditions for co-operative handover. Similarly as in legacy configuration signalling, this configuration information may be transmitted to the coordinating wireless device 121 by the source network node 110 serving the source cell 115 as part of an RRCReconfiguration message. However, there may also be other way in which the coordinating wireless device 121 may receive the configuration information, such as, pre-set or predefined configuration information or as part of other configuration messages.

According to some embodiments, the configuration information further indicates one or more of: radio condition threshold levels towards the at least one target cell 111 at which the wireless devices 122, 123, 124 in the group of wireless devices 120 are to transmit a measurement report to the coordinating wireless device 121 and/or information indicating one or more periodicities of measurement report transmissions. This means, for example, that the RRCReconfiguration message also may comprise additional parameters or thresholds which are not present in e.g. a legacy RRCReconfiguration message. In other words, the configuration information may comprise radio condition threshold levels which determines when the wireless devices 122, 123, 124 should transmit measurement reports to the coordinating wireless device 121. The configuration information may also comprise further information, such as, e.g. parameters indicating one or more periodicities for the transmission of measurement reports to the coordinating wireless device 121. Here, according to some embodiments, the RRCReconfiguration message may optionally be transmitted by the source network node 110 directly to each of the wireless devices 121 , 122, 123, 124 in the group of wireless devices 120. In this case, the additional parameters and thresholds are configured by the source network node 110.

As an alternative to the latter, the RRCReconfiguration message may be transmitted by the source network node 110 only to the coordinating wireless device 121. In this case, the coordinating wireless device 121 may forward the RRCReconfiguration message to each of the wireless devices 122, 123, 124 in the group of wireless devices 120. Additionally, in this case, the additional parameters may be configured by either the source network node 110 or the coordinating wireless device 121. In the latter case, the configured additional parameters may be inserted into the RRCReconfiguration message received from the source network node 110 by the coordinating wireless device 121 prior to forwarding the RRCReconfiguration message to the wireless devices 122, 123, 124 in the group of wireless devices 120.

Action 402. The coordinating wireless device 121 obtains measurements of radio conditions towards at least one target cell 116 in the wireless communications network 100 that is indicative of the radio conditions towards the at least one target cell 116 for the group of wireless devices 120. This means, for example, that the coordinating wireless device 121 and/or the wireless devices 122, 123, 124 in the group of wireless devices 120 may measures its radio condition towards its configured potential target cells, e.g. the at least one target cell 116, whereby one or more of these measurements may be taken into account by coordinating wireless device 121.

In some embodiments, the coordinating wireless device 121 may perform measurements of radio conditions towards the at least one target cell 116 in the wireless communications network 100, wherein the performed radio condition measurements are used as indicative of the radio conditions towards the at least one target cell 116 for the group of wireless devices 120. In this case, the coordinating wireless device 121 only considers its own radio condition measurements towards the at least one target cell 116 when determining the radio conditions towards the at least one target cell 116 for the group of wireless devices 120. This may, for example, be preferable when the coordinating wireless device 121 and the wireless devices 122, 123, 124 in the group of wireless devices 120 share the same mobility pattern. This may be advantageous in that no signalling is needed between the coordinating wireless device 121 and the wireless devices 122, 123, 124 in the group of wireless devices 120, thus conserves and save energy in the wireless devices 122, 123, 124 in the group of wireless devices 120. This is illustrated in further detail by the example scenario shown by signalling diagram in Fig. 8.

Alternatively, in some embodiment, the coordinating wireless device 121 may obtain measurement reports from each of the wireless devices in the group of wireless devices 120 indicating its radio conditions towards at least one target cell 116 in the wireless communications network 100. In this case, the coordinating wireless device 121 not only considers its own radio condition measurements towards the at least one target cell 116 when determining the radio conditions towards the at least one target cell 116 for the group of wireless devices 120, but also the radio condition measurements towards the at least one target cell 116 by the wireless devices 122, 123, 124 in the group of wireless devices 120. This is illustrated in further detail by the example scenario shown by signalling diagram in Fig. 7. According to some embodiments, the coordinating wireless device 121 may here optionally first receive a measurement report from at least one wireless device 122 in the group of wireless devices 120 indicating its radio conditions towards at least one target cell 116 in the wireless communications network 100. Secondly, the coordinating wireless device 121 may obtain measurement reports from each of the other wireless devices 123, 124 in the group of wireless devices 120 based on the measurement report from the at least one wireless device 122. This means, for example, that the reception of a measurement report from one of the wireless devices 122, 123, 124 in the group of wireless devices 120 may be used a trigger for the coordinating wireless device 121 to request measurement reports from the other wireless devices 122, 123, 124 in the group of wireless devices 120. This is because reception of a measurement report from one of the wireless devices 122, 123, 124 in the group of wireless devices 120 indicates that this wireless device may be close to, or is, meeting or satisfying one or more configured co-operative handover triggering conditions or a criteria to send a measurement reports to the coordinating wireless device 121 , e.g. one or more configured radio condition threshold levels for transmitting measurement reports to the coordinating wireless device 121 has been reached. Hence, it may be preferable for the coordinating wireless device 121 to request and collect measurement reports from the other wireless devices 122, 123, 123, 124 in the group of wireless devices 120 as well. Hence, for the obtaining of the measurement reports, the coordinating wireless device 121 may, in some embodiments, transmit, to each of the wireless devices 122, 123, 124 in the group of wireless devices 120, information requesting that each of the wireless devices

122, 123, 124 transmits measurement reports indicating its radio conditions towards at least one target cell 116 in the wireless communications network 100 to the coordinating wireless device 121. In other words, the coordinating wireless device 121 may configure the wireless devices 122, 123, 124 in the group of wireless devices 120 to transmit measurement reports to the coordinating wireless device 121. Here, for example, the coordinating wireless device 121 may send a broadcast message over SL to the wireless devices 122, 123, 124 in the group of wireless devices 120 to request measurement reports from the wireless devices 122, 123, 124 in the group of wireless devices 120. Thereafter, according to some embodiments, the coordinating wireless device 121 may receive measurement reports from each of the wireless devices 122, 123, 124 in the group of wireless devices 120.

Optionally, according to some embodiments, the wireless devices 122, 123, 124 in the group of wireless devices 120 may autonomously send measurement reports to the coordinating wireless device 121 when one or more configured co-operative handover triggering conditions is satisfied or reached. In this case, the coordinating wireless device 121 is aware of which wireless devices 122, 123, 124 are part of the group of wireless devices 120 and when it has received measurement reports from all of them. This means, for example, that after a certain time, e.g. upon the expiry of a dedicated timer in the coordinating wireless device 121, the coordinating wireless device 121 may assumes that all measurement reports from the group of wireless devices 120 have been received.

In some embodiments, the information requesting that the wireless devices 122,

123, 124 in the group of wireless devices 120 transmit measurement reports further indicates that the measurement reports are to be transmitted periodically. This means, for example, that the coordinating wireless device 121 may configure the wireless devices 122, 123, 124 in the group of wireless devices 120 to intermittently with a certain periodicity transmit measurement reports to the coordinating wireless device 121. Here, in case the wireless devices 122, 123, 124 in the group of wireless devices 120 has already been configured by the coordinating wireless device 121 to send periodic measurement reports to the coordinating wireless device 121 , the wireless devices 122, 123, 124 in the group of wireless devices 120 does not have to send an additional measurement report.

Action 403. After the obtaining in Action 402, the coordinating wireless device 121 determines if a co-operative handover from a source network node 110 serving the source cell 115 to a target network node 111 serving a target cell 116 is to be performed for the group of wireless devices 120 based on the obtained measurements of radio conditions. In some embodiments, the coordinating wireless device 121 may determine that a cooperative handover from a source network node 110 serving the source cell 115 to a target network node 111 serving a target cell 116 is to be performed for the group of wireless devices 120 based on the obtained measurements of radio conditions in case the radio condition measurements used as indicative of the radio conditions towards the at least one target cell 116 for the group of wireless devices 120 fulfills configured cooperative handover triggering conditions.

According to some embodiments, after obtaining measurements reports as described in Action 402, the coordinating wireless device 121 may determine that a cooperative handover from a source network node 110 serving the source cell 115 to a target network node 111 serving a target cell 116 is to be performed for the group of wireless devices 120 based on the obtained measurement reports from each of the wireless devices in the group of wireless devices 120. Here, the determination may be performed by the coordinating wireless device 121 by first estimate joint radio conditions for the group of wireless devices 120 towards the at least one target cell 116 in the wireless communications network 100 based on the radio conditions towards at least one target cell 116 comprised in the measurement reports from each of the wireless devices in the group of wireless devices 120. Then, the coordinating wireless device 121 may determine that a co-operative handover from the source network node 110 serving the source cell 115 to the target network node 111 serving the target cell 116 is to be performed for the group of wireless devices 120 based on the estimated joint radio conditions for the group of wireless devices 120. In some embodiments, this determination may be performed by the coordinating wireless device 121 in case the estimated joint radio conditions for the group of wireless devices 120 fulfills configured cooperative handover triggering conditions.

For example, in case the coordinating wireless device 121 only considers its own radio condition measurements towards the at least one target cell 116 when determining the radio conditions towards the at least one target cell 116 for the group of wireless devices 120, e.g. due to similar mobility pattern with the wireless devices 122, 123, 124 in the group of wireless devices 120, a configured co-operative handover triggering condition may be that the average RSRP or RSRQ of the target cell 116 for the coordinating wireless device 121 is: higher than the RSRP or RSRQ of the source cell 115, higher than the RSRP or RSRQ of the source cell 115 including hysteresis or delta value, higher than the RSRP or RSRQ of the source cell 115 for a certain period of time, or higher than the RSRP or RSRQ of the source cell 115 minus a delta value.

According to another example, in case the coordinating wireless device 121 not only considers its own radio condition measurements towards the at least one target cell 116 when determining the radio conditions towards the at least one target cell 116 for the group of wireless devices 120, but also the radio condition measurements towards the at least one target cell 116 by the wireless devices 122, 123, 124 in the group of wireless devices 120, a configured co-operative handover triggering condition may be that the average RSRP or RSRQ of the target cell 116 over the wireless devices 122, 123, 124 in the group of wireless devices 120 is: higher than the RSRP or RSRQ of the source cell 115, higher than the RSRP or RSRQ of the source cell 115 including hysteresis or delta value, higher than the RSRP or RSRQ of the source cell 115 for a certain period of time, or higher than the RSRP or RSRQ of the source cell 115, optionally minus a delta value, and that none of the wireless devices 122, 123, 124 in the group of wireless devices 120 has an RSRP below a determined threshold to the target cell 116.

Here, a further configured co-operative handover triggering condition may be that a certain percentage of the wireless devices 122, 123, 124 in the group of wireless devices 120 have a RSRP or RSRQ of the target cell 116 that is higher than the RSRP or RSRQ of the source cell 115. Here, it should be noted that the RSRP is the Reference Signal Received Power of the received signal from the source or target cell 115, 116, and the RSRQ is the Reference Signal Received Quality of the received signal from the source or target cell 115, 116.

In some embodiments, the coordinating wireless device 121 may also determine that the radio conditions towards the at least one target cell 116 of at least one wireless device 124 in the group of wireless devices 120 significantly differs from the radio conditions towards the at least one target cell 116 of the other wireless devices 122, 123 in the group of wireless devices 120. In this case, the coordinating wireless device 121 may detach the at least one wireless device 124 from the group of wireless devices 120. This means, for example, that when one or more of the wireless devices 122, 123, 124 in the group of wireless devices 120 has a noticeable different RSRP or RSRQ of the target cell 116 and the source cell 115 compared to a majority of the wireless devices 122, 123, 124 in the group of wireless devices 120, there may be a need to perform a handover of only the one or more of the wireless devices 122, 123, 124 to the target cell 116 and thus detach the one or more of the wireless devices 122, 123, 124 with different RSRP or RSRQ. For example, if one or more of the wireless devices 122, 123, 124 in the group of wireless devices 120 has a delta RSRP that is above a threshold level for the group of wireless devices 120, wherein delta RSRP is the RSRP of the source cell 115 minus the RSRP of target cell 116, the coordinating wireless device 121 may remove the one or more of the wireless devices 122, 123, 124 in the group of wireless devices 120. Here, the coordinating wireless device 121 may transmit a configuration message to the one or more of the wireless devices 122, 123, 124 in the group of wireless devices 120 indicating that they are detached from the group of wireless devices 120.

Action 404. Optionally, in case the determination in Action 403 results in that a cooperative handover is to be performed for the group of wireless devices 120, the coordinating wireless device 121 may transmits, to each of the wireless devices in the group of wireless devices 120, information indicating that a co-operative handover to the target network node 111 serving the target cell 116 is to be performed. This means, for example, that the coordinating wireless device 121 may configure the wireless devices 122, 123, 124 in the group of wireless devices 120 to perform a co-operative handover. In other words, when the evaluation of the measurement reports, e.g. according to some of the criteria in Action 403, indicates that a co-operative handover to the target cell 116 would be beneficial, the coordinating wireless device 121 may send a command comprising the selected target cell to the wireless devices 122, 123, 124 in the group of wireless devices 120 to trigger the co-operative handover to the target cell 116.

Alternatively, in case the determination in Action 403 results in that a co-operative handover is not to be performed for the group of wireless devices 120, the coordinating wireless device 121 may according to some embodiments transmit, to each of the wireless devices 122, 123, 124 in the group of wireless devices 120, information requesting that the wireless devices 122, 123, 124 stop transmitting the measurement reports when the estimated joint radio conditions for the group of wireless devices 120 does not fulfill the determined triggering co-operative handover conditions. This means, for example, that in case the measurement reports from the wireless devices 122, 123, 124 in the group of wireless devices 120 reveal that no wireless devices 122, 123, 124 in the group of wireless devices 120 satisfies the triggering criteria for transmitting measurement reports, the coordinating wireless device 121 may send a message to the wireless devices 122, 123, 124 in the group of wireless devices 120 to cancel any periodic measurement reports.

Action 405. Optionally, after the transmission in Action 404, the coordinating wireless device 121 may perform a co-operative handover from the source network node 110 serving the source cell 115 to the target network node 111 serving the target cell 116. This means, for example, that the coordinating wireless device 121 and the wireless devices 122, 123, 124 in the group of wireless devices 120 may apply a co-operative handover configuration of the target cell 116, synchronize to the target cell 116 and send the RRCReconfigurationComplete message to the target network node 111 serving the target cell 116.

Examples of embodiments of a method performed by a wireless device 122, 123, 124 for enabling co-operative transmissions in a group of wireless devices 120 located in a source cell 115 served by a source network node 110 in a wireless communications network 100, will now be described with reference to the flowchart depicted in Fig. 5. Fig. 5 is an illustrated example of actions or operations which may be taken by the wireless device 122, 123, 124 in the wireless communication network 100. The method may comprise the following actions.

Action 501. Optionally, the wireless device 122, 123, 124 may receive configuration information, originating from a source network node 110 serving the source cell 115, indicating the at least one target cell 111 and configured co-operative handover triggering conditions. This configuration information may, for example, be received from a coordinating wireless device 121 or directly from the source network node 110 serving the source cell 115 in e.g. an RRCReconfiguration message. This configuration information may be similar to or comprise parts of the configuration information received the coordinating wireless device 121 as described in Action 401. In some embodiments, the configuration information may further indicate one or more of: radio condition threshold levels towards the at least one target cell 111 at which the wireless device 122, 123, 124 is to transmit a measurement report to the coordinating wireless device 121 , and/or information indicating one or more periodicities of measurement report transmissions. This means, for example, that the RRCReconfiguration message also may comprise additional parameters or thresholds which are not present in e.g. a legacy RRCReconfiguration message. In other words, the configuration information may comprise radio condition threshold levels which determines when the wireless devices 122, 123, 124 should transmit measurement reports to the coordinating wireless device 121. The configuration information may also comprise further information, such as, e.g. parameters indicating one or more periodicities for the transmission of measurement reports to the coordinating wireless device 121.

Action 502. The wireless device 122, 123, 124 performs measurements of radio conditions towards at least one target cell 116 in the wireless communications network 100. This means, for example, that the wireless devices 122, 123, 124 in the group of wireless devices 120 may continuously measure their radio conditions towards the configured potential target cells for the group of wireless devices 120, e.g. the at least one target cell 116.

Action 503. Optionally, the wireless device 122, 123, 124 may receive, from the coordinating wireless device 121 , information requesting the wireless device 122, 123, 124 to transmit measurement reports indicating its radio conditions towards the at least one target cell 116 in the wireless communications network 100 to the coordinating wireless device 121. This means, for example, that the wireless devices 122, 123, 124 in the group of wireless devices 120 may be configured by the coordinating wireless device 121 to transmit its measurement reports to the coordinating wireless device 121. Here, for example, the wireless devices 122, 123, 124 may receive a broadcast message over SL from the coordinating wireless device 121 to requesting the measurement reports from the wireless devices 122, 123, 124 in the group of wireless devices 120. In some embodiments, the information requesting the wireless device 122, 123, 124 to transmit measurement reports further indicates that the measurement reports are to be transmitted periodically. This means, for example, that the wireless devices 122, 123, 124 in the group of wireless devices 120 may be configured by the coordinating wireless device 121 to intermittently with a certain periodicity transmit measurement reports to the coordinating wireless device 121. Here, in case the wireless devices 122, 123, 124 in the group of wireless devices 120 has already been configured by the coordinating wireless device 121 to send periodic measurement reports to the coordinating wireless device 121 , the wireless devices 122, 123, 124 in the group of wireless devices 120 does not have to send an additional measurement report. Action 504. After the measurements in Action 502, the wireless device 122, 123, 124 transmit, to the coordinating wireless device 121 coordinating the co-operative transmissions in the group of wireless devices 120, a measurement report indicating its radio conditions towards at least one target cell 116 in case the measured radio conditions fulfills the configured co-operative handover triggering conditions or one or more configured radio condition threshold levels at which the wireless device 122, 123, 124 is to transmit a measurement report to the coordinating wireless device 121. This means, for example, that the wireless devices 122, 123, 124 in the group of wireless devices 120 may be close to, or is, meeting or satisfying one or more configured cooperative handover triggering conditions or a criteria to send a measurement reports to the coordinating wireless device 121, e.g. one or more configured radio condition threshold levels for transmitting measurement reports to the coordinating wireless device 121 has been reached.

Optionally, after receiving the information in Action 503, the wireless device 122, 123, 124 may transmit measurement reports to the coordinating wireless device 121. This means, for example, that the wireless devices 122, 123, 124 in the group of wireless devices 120 may transmit its measurement reports to the coordinating wireless device 121 in response to the request from the coordinating wireless device 121 or intermittently with a certain periodicity according to the request from the coordinating wireless device

121.

Action 504. Optionally, after the transmission in Action 503, the wireless device

122, 123, 124 may receive information from the coordinating wireless device 121. In some embodiments, the information may comprise information requesting the wireless device 122, 123, 124 to stop transmitting the measurement reports. This may, for example, be indicative of that no wireless devices in the group of wireless devices 120 satisfies the triggering criteria for transmitting measurement reports. In some embodiments, the information may comprise information indicating that the wireless device 122, 123, 124 is detached from the group of wireless devices 120. This may, for example, indicated that the wireless devices 122, 123, 124 has a noticeable different RSRP or RSRQ of the target cell 116 and the source cell 115 compared to a majority of the wireless devices 122, 123, 124 in the group of wireless devices 120, hence the wireless devices 122, 123, 124 has been detached from the group of wireless devices 120. This may, for example, cause the wireless device 122, 123, 124 to perform a single handover to the target network node 111 serving the target cell 116. In some embodiments, the information may comprise information indicating that a co-operative handover to a target network node 111 serving the at least one target cell 116 is to be performed by the wireless device 122, 123, 124. This means, for example, that the wireless devices 122, 123, 124 in the group of wireless devices 120 may be configured to perform a co-operative handover. In other words, the wireless devices 122, 123, 124 in the group of wireless devices 120 may receive a command comprising the target cell triggering the co-operative handover to the target cell 116 according to Action 505.

Action 505. Optionally, in case the information received in Action 504 comprise information indicating that a co-operative handover to a target network node 111 serving the at least one target cell 116 is to be performed by the wireless device 122, 123, 124, the wireless device 122, 123, 124 may perform a co-operative handover from the source network node 110 serving the source cell 115 to the target network node 111 serving the target cell 116. This means, for example, that the wireless devices 122, 123, 124 in the group of wireless devices 120 may apply a co-operative handover configuration of the target cell 116, synchronize to the target cell 116, and send the RRCReconfigurationComplete message to the target network node 111 serving the target cell 116.

Examples of embodiments of a method performed by a source network node 110 for enabling co-operative transmissions in a group of wireless devices 120 located in a source cell 115 served by the source network node 110 in a wireless communications network 100, will now be described with reference to the flowchart depicted in Fig. 6. Fig. 6 is an illustrated example of actions or operations which may be taken by the source network node 110 in the wireless communication network 100. The method may comprise the following actions.

Action 601. Optionally, according to some embodiments, the source network node 110 may obtain information indicating a group of wireless devices 121 , 122, 123, 124 having the same mobility pattern for co-operative transmissions. According to one example, the source network node 110 may obtain the locations of each of the wireless devices 121 , 122, 123, 124 and their movements in the source cell 115. The source network node 110 may then determine that the wireless devices 121, 122, 123, 124 have the same pattern of movement or mobility, and thus may form a group of wireless devices 120 for co-operative transmissions. According to another example, the source network node 110 may, based on the list of the cells that the wireless devices 121 , 122, 123, 124 are connected for certain period of time, determine that the wireless devices 121 , 122, 123, 124 have the same pattern of movement or mobility. Optionally, the wireless devices

121 , 122, 123, 124 may have already formed a group of wireless devices 120, such as, e.g. wireless devices co-located in a car or similar, and then the wireless devices 121,

122, 123, 124 may inform the source network node 110 about their group ID. In this case, the wireless devices 121 , 122, 123, 124 may send their group ID to the source network node 110 through UCI, MAC-CE or data over PUCCH/PUSCH.

Action 602. The source network node 110 obtains configuration information indicating at least one target cell 116 for the group of wireless devices 120. Here, the source network node 110 also obtains configured co-operative handover triggering conditions towards the at least one target cell 116 for the group of wireless devices 120. This means, for example, that the source network node 110 may by itself determine or configure at least one target cell 116 for the group of wireless devices 120 and triggering co-operative handover conditions towards the at least one target cell 116 for the group of wireless devices 120, or collaboratively determine or configure at least one target cell 116 for the group of wireless devices 120 and triggering co-operative handover conditions towards the at least one target cell 116 for the group of wireless devices 120 together with one or more target network nodes 111 in the wireless communications network 100. In some embodiments, the configuration information indicates one or more of: radio condition threshold levels towards the at least one target cell 111 at which wireless devices 122, 123, 124 in the group of wireless devices 120 is to transmit a measurement report to a coordinating wireless device 121 in the group of wireless devices 120, and/or information indicating one or more periodicities of measurement report transmissions. This means, for example, that the source network node 110 may configure how the cooperative handover for the group of wireless devices 120 is performed in the wireless communications network 100.

Action 603. After obtaining the configuration information in Action 602, the source network node 110 may transmit the obtained configuration information towards the group of wireless devices 120. This configuration information may, for example, be transmitted to a coordinating wireless device 121 of the group of wireless devices 120 for forwarding to the wireless devices 122, 123, 124 in the group of wireless devices 120, and/or directly to each of the wireless devices 122, 123, 124 in the group of wireless devices 120, as well as, the coordinating wireless device 121 of the group of wireless devices 120. The configuration information may be transmitting in e.g. an RRCReconfiguration message. Fig. 7 shows a signalling diagram depicting an example scenario which illustrates the embodiments of methods in the coordinating wireless device 121, the wireless device 122, 123, 124 and a source network node 110 in a wireless communications network 100.

Action 701. The source network node 110 may start by transmitting group configurations for co-operative transmissions to the coordinating wireless device 121 and the wireless device 122, 123, 124 in the group of wireless devices 120.

Action 702. The source network node 110 may also transmit a request to the at least one target network node 111 for coordinated CHO for the group of wireless devices 120 configured for co-operative transmissions. This means that the source network node 110 may request CHO configurations with the at least one target network node 111 for the group of wireless devices 120 in a similar manner as the current standard for requesting CHO configuration for a single wireless device.

Action 703. In response to the request in Action 702, the source network node 110 may receive an acknowledgement from the at least one target network node 111.

Action 704. The source network node 110 may then transmit configuration information for the coordinated CHO to the group of wireless devices 120 configured for co-operative transmissions, i.e. the coordinating wireless device 121 and the wireless device 122, 123, 124 in the group of wireless devices 120. In other words, the source network node 110 configures the group of wireless devices 120 with the at least one target cell 116 and co-operative handover triggering conditions towards the at least one target cell 116 for the group of wireless devices 120. The configuration information may further comprise radio condition threshold levels towards the at least one target cell 111 at which wireless devices 122, 123, 124 in the group of wireless devices 120 is to transmit a measurement report to a coordinating wireless device 121 in the group of wireless devices 120 and/or information indicating one or more periodicities of measurement report transmissions.

Action 705. In response to the received configuration information from the source network node 110 in Action 704, the coordinating wireless device 121 and the wireless device 122, 123, 124 in the group of wireless devices 120 may measure and monitor the radio conditions towards the at least one target cell 116. This may be performed in view of configured co-operative handover triggering conditions and/or radio condition threshold levels comprised in the configuration information.

Action 706. In this scenario, the wireless device 122 in the group of wireless devices 120 may determine that its radio conditions towards the at least one target cell 116 is close to, or is, meeting or satisfying one or more configured co-operative handover triggering conditions or radio condition threshold levels for transmitting measurement reports to the coordinating wireless device 121. Hence, the wireless device 122 transmits a measurement report, MR, to the coordinating wireless device 121.

Action 707. In response to the measurement report from the wireless device 122 in the group of wireless devices 120, the coordinating wireless device 121 may transmit a request for measurement report to the each of the wireless devices 122, 123, 124 in the group of wireless devices 120.

Action 708. In response to the request from the coordinating wireless device 121 , each of the wireless devices 122, 123, 124 in the group of wireless devices 120 may transmit their measurement reports to the coordinating wireless device 121. This may be performed periodically by each of the wireless devices 122, 123, 124 in the group of wireless devices 120 if requested by the coordinating wireless device 121.

Action 709. In response to the measurement reports from each of the wireless devices 122, 123, 124 in the group of wireless devices 120, the coordinating wireless device 121 may determine if a co-operative handover from a source network node 110 serving the source cell 115 to a target network node 111 serving a target cell 116 is to be performed for the group of wireless devices 120 based on the obtained measurements reports.

Action 710. Optionally, in case the determination in Action 709 results in that a cooperative handover is not to be performed for the group of wireless devices 120, the coordinating wireless device 121 may transmit a request to each of the wireless devices

122, 123, 124 in the group of wireless devices 120 to stop transmitting the measurement reports.

Action 711. Optionally, in case the determination in Action 709 results in that a cooperative handover is to be performed for the group of wireless devices 120, the coordinating wireless device 121 may transmit information to the wireless devices 122,

123, 124 in the group of wireless devices 120 triggering a coordinated CHO for the group of wireless devices 120 configured for co-operative transmissions.

Action 712. In response to received information from the coordinating wireless device 121 in Action 711, the wireless devices 122, 123, 124 in the group of wireless devices 120 may apply the coordinated CHO towards the target network node 111 serving the target cell 116.

Action 713. In applying the coordinated CHO towards the target network node 111 serving the target cell 116 in Action 712, the wireless devices 122, 123, 124 in the group of wireless devices 120 may synchronize with the target network node 111 and then transmit an RRCReconfigurationComplete message to the target network node 111. This will conclude the coordinated CHO for the group of wireless devices 120 configured for co-operative transmissions in the wireless communications network 100.

Fig. 8 shows a signalling diagram depicting an example scenario which illustrates the embodiments of methods in the coordinating wireless device 121 , the wireless device

122, 123, 124 and a source network node 110 in a wireless communications network 100.

Actions 801-804. These actions may be identical or similar to Actions 701-704 described above with reference to Fig. 7.

Action 805. In response to the received configuration information from the source network node 110 in Action 804, the coordinating wireless device 121 may measure and monitor the radio conditions towards the at least one target cell 116. This may be performed in view of configured co-operative handover triggering conditions towards the at least one target cell 116 for the group of wireless devices 120 comprised in the configuration information.

Action 806. In response to the measurements of the radio conditions towards the at least one target cell 116 by the coordinating wireless device 121 in Action 805, the coordinating wireless device 121 may determine if a co-operative handover from a source network node 110 serving the source cell 115 to a target network node 111 serving a target cell 116 is to be performed for the group of wireless devices 120 based on the measurements.

Action 807. Optionally, in case the determination in Action 709 results in that a cooperative handover is to be performed for the group of wireless devices 120, the coordinating wireless device 121 may transmit information to the wireless devices 122,

Action 808. In response to received information from the coordinating wireless device 121 in Action 807, the wireless devices 122, 123, 124 in the group of wireless devices 120 may apply the coordinated CHO towards the target network node 111 serving the target cell 116.

Action 809. In applying the coordinated CHO towards the target network node 111 serving the target cell 116 in Action 808, the wireless devices 122, 123, 124 in the group of wireless devices 120 may synchronize with the target network node 111 and then transmit an RRCReconfigurationComplete message to the target network node 111. This will conclude the coordinated CHO for the group of wireless devices 120 configured for co-operative transmissions in the wireless communications network 100.

Figs. 9-12 show schematic block diagrams depicting scenarios illustrating some of the embodiments of a coordinating wireless device 121 , a wireless device 122, 123, 124, and a source network node 110.

In the scenario of Fig. 9, the group of wireless devices 120 moves in a general direction from the source cell 115 towards the target cell 116. Here, the wireless device 122 may determine that its radio conditions towards the target cell 116 is close to, or is, meeting or satisfying one or more configured co-operative handover triggering conditions and/or radio condition threshold levels for transmitting measurement reports to the coordinating wireless device 121. Hence, the wireless device 122 may transmits a measurement report, MR, to the coordinating wireless device 121 in the group of wireless devices 120, as seen in Fig. 9.

In the scenario of Fig. 10, the group of wireless devices 120 continues to move in the general direction from the source cell 115 towards the target cell 116. In response to the measurement report from the wireless device 122, the coordinating wireless device 121 may broadcast a request to the wireless devices 122, 123, 124 in the group of wireless devices 120 to send measurement reports (not shown). The wireless devices 122, 123, 124 in the group of wireless devices 120 may respond by sending measurement reports to the coordinating wireless device 121 , as seen in Fig. 10.

In the scenario of Fig. 11 , the group of wireless devices 120 continues to move further in the general direction from the source cell 115 and into the target cell 116. In response to the measurement reports from the wireless devices 122, 123, 124 in the group of wireless devices 120, the coordinating wireless device 121 may evaluate the joint radio conditions, such e.g. RSRP or RSRQ, from the wireless devices 122, 123, 124 to the source network node 110 and potential target network node 111 based on the measurement reports from the wireless devices 122, 123, 124 in the group of wireless devices 120. Here, based on the estimated joint radio conditions for the group of wireless devices 120, the coordinating wireless device 121 determines that the group of wireless devices 120 should handover to the target network node 111. Hence, the coordinating wireless device 121 sends a message to the wireless devices 122, 123, 124 in the group of wireless devices 120 to trigger a coordinated CHO to the target cell 116, as seen in Fig. 11. Optionally, in the scenario of Fig. 12, only the wireless device 122 continues to move in the general direction from the source cell 115 towards the target cell 116. Here, since the radio conditions towards the target cell 116 for the wireless device 122 will significantly differ from the radio conditions towards the target cell 116 for the other wireless devices 121, 123, 124 in the group of wireless devices 120, the coordinating wireless device 121 determines that the group of wireless devices 120 should not perform a handover to the target network node 111. Instead, the coordinating wireless device 121 may detach the wireless device 122 from the group of wireless devices 120, e.g. transmitting information to the wireless device 122 indicating that it has been removed from the group of wireless devices 120. This allows for the wireless device 122 perform a legacy handover for single wireless devices towards the target network node 111.

To perform the method actions in a coordinating wireless device 121 for coordinating co-operative transmissions in a group of wireless devices 120 located in a source cell 115 served by a source network node 110 in a wireless communications network 100, the coordinating wireless device 121 may comprise the following arrangement depicted in Fig 13. Fig 13 shows a schematic block diagram of embodiments of the coordinating wireless device 121. The embodiments of the coordinating wireless device 121 described herein may be considered as independent embodiments or may be considered in any combination with each other to describe nonlimiting examples of the example embodiments described herein. It should also be noted that, although not shown in Fig. 6, it should be noted that known conventional features of a wireless device, such as, for example, at least one antenna and a power source or battery, may be assumed to be comprised in the coordinating wireless device 121 but is not shown or described any further in regards to Fig. 13.

The coordinating wireless device 121 may comprise processing circuitry 1310 and a memory 1320. The processing circuitry 1310 may also comprise a receiving module 1311 and a transmitting module 1312. The receiving module 1311 and the transmitting module 1312 may comprise Radio Frequency, RF, circuitry and baseband processing circuitry capable of transmitting and receiving a radio signal in the wireless communications network 100. The receiving module 1311 and the transmitting module 1312 may also form part of a single transceiver. It should also be noted that some or all of the functionality described in the embodiments above as being performed by the coordinating wireless device 121 may be provided by the processing circuitry 1310 executing instructions stored on a computer-readable medium, such as, e.g. the memory 1320 shown in Fig. 13. Alternative embodiments of the coordinating wireless device 121 may comprise additional components, such as, for example, an obtaining module 1313, a determining module 1314, a performing module 1315, an estimating module 1316, and a detaching module 1315, each responsible for providing its functionality to support the embodiments described herein.

The coordinating wireless device 121 or processing circuitry 1310 is configured to, or may comprise the obtaining module 1313 configured to, obtain measurements of radio conditions towards at least one target cell 116 in the wireless communications network 100 that is indicative of the radio conditions towards the at least one target cell 116 for the group of wireless devices 120. Also, the coordinating wireless device 121 or processing circuitry 1310 is configured to, or may comprise the determining module 1314 configured to, determine if a co-operative handover from a source network node 110 serving the source cell 115 to a target network node 111 serving a target cell 116 is to be performed for the group of wireless devices 120 based on the obtained measurements of radio conditions.

In some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may be configured to, or may comprise the performing module 1315 configured to, perform measurements of radio conditions towards the at least one target cell 116 in the wireless communications network 100, wherein the performed radio condition measurements are used as indicative of the radio conditions towards the at least one target cell 116 for the group of wireless devices 120.

Alternatively, in some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may be configured to, or may comprise the obtaining module 1313 configured to, obtain measurement reports from each of the wireless devices in the group of wireless devices 120 indicating its radio conditions towards at least one target cell 116 in the wireless communications network 100. In this case, the coordinating wireless device 121 or processing circuitry 1310 may be configured to, or may comprise the determining module 1314 configured to, determine that a co-operative handover from a source network node 110 serving the source cell 115 to a target network node 111 serving a target cell 116 is to be performed for the group of wireless devices 120 based on the obtained measurement reports from each of the wireless devices in the group of wireless devices 120. Also, in some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may here be configured to, or may comprise the estimating module 1316 configured to, estimate joint radio conditions for the group of wireless devices 120 towards the at least one target cell 116 in the wireless communications network 100 based on the radio conditions towards at least one target cell 116 comprised in the measurement reports from each of the wireless devices in the group of wireless devices 120. In this case, the coordinating wireless device 121 or processing circuitry 1310 may be configured to, or may comprise the determining module 1314 configured to, determine that a co-operative handover from the source network node 110 serving the source cell 115 to the target network node 111 serving the target cell 116 is to be performed for the group of wireless devices 121 , 122, 123, 124 based on the estimated joint radio conditions for the group of wireless devices 120. Further, in some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may here be configured to, or may comprise the receiving module 1311 configured to, receive a measurement report from at least one wireless device 122 in the group of wireless devices 120 indicating its radio conditions towards at least one target cell 116 in the wireless communications network 100. In this case, the coordinating wireless device 121 or processing circuitry 1310 may be configured to, or may comprise the obtaining module 1313 configured to, obtain measurement reports from each of the other wireless devices 123, 124 in the group of wireless devices 120 based on the measurement report from the at least one wireless device 122. Here, according to some embodiment, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the transmitting module 1312 configured to, transmit, to each of the wireless devices 122, 123, 124 in the group of wireless devices 120, information requesting that each of the wireless devices 123 transmits measurement reports indicating its radio conditions towards at least one target cell 116 in the wireless communications network 100 to the coordinating wireless device 121. In this case, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the receiving module 1311 configured to, receive the measurement reports from each of the wireless devices 122, 123, 124 in the group of wireless devices 120. In some embodiment, the information requesting that the wireless devices 122, 123, 124 in the group of wireless devices 120 transmit measurement reports further indicates that the measurement reports are to be transmitted periodically. Also, in some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the determining module 1314 configured to, determine that the radio conditions towards the at least one target cell 116 of at least one wireless device 124 in the group of wireless devices 120 significantly differs from the radio conditions towards the at least one target cell 116 of the other wireless devices 121, 122, 123 in the group of wireless devices 120. In this case, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the detaching module 1317 configured to, detach the at least one wireless device 124 from the group of wireless devices 120.

Further, according to some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the determining module 1314 configured to, determine to perform the co-operative handover in case the radio condition measurements used as indicative of the radio conditions towards the at least one target cell 116 for the group of wireless devices 120, or the estimated joint radio conditions for the group of wireless devices 120, fulfills configured co-operative handover triggering conditions.

In some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may here be configured to, or may comprise the receiving module 1311 configured to, receive, from a source network node 110 serving the source cell 115, configuration information indicating the at least one target cell 111 and configured co-operative handover triggering conditions. Here, according to some embodiments, the configuration information may further indicate one or more of: radio condition threshold levels towards the at least one target cell 111 at which the wireless devices 122, 123, 124 in the group of wireless devices 120 are to transmit a measurement report to the coordinating wireless device 121 , and/or information indicating one or more periodicities of measurement report transmissions.

According to some embodiment, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the transmitting module 1312 configured to, transmit, to each of the wireless devices 122, 123, 124 in the group of wireless devices 120, information requesting that the wireless devices 122, 123, 124 stop transmitting the measurement reports when the estimated joint radio conditions for the group of wireless devices 120 does not fulfill the determined triggering co-operative handover conditions.

Further, in some embodiments, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the transmitting module 1312 configured to, transmit, to each of the wireless devices in the group of wireless devices 120, information indicating that a co-operative handover to the target network node 111 serving the target cell 116 is to be performed. In this case, the coordinating wireless device 121 or processing circuitry 1310 may also be configured to, or may comprise the performing module 1315 configured to, perform a co-operative handover from the source network node 110 serving the source cell 115 to the target network node 111 serving the target cell 116. Furthermore, the embodiments for coordinating co-operative transmissions in a group of wireless devices 120 located in a source cell 115 served by a source network node 110 in a wireless communications network 100 described above may be implemented through one or more processors, such as the processing circuitry 1310 in the coordinating wireless device 121 depicted in Fig. 13, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code or code means for performing the embodiments herein when being loaded into the processing circuitry 1310 in the coordinating wireless device 121. The computer program code may e.g. be provided as pure program code in the first node 110 or on a server and downloaded to the coordinating wireless device 121. Thus, it should be noted that the modules of the coordinating wireless device 121 may in some embodiments be implemented as computer programs stored in memory, e.g. in the memory modules 1320 in Fig. 13, for execution by processors or processing modules, e.g. the processing circuitry 1310 of Fig. 13. Those skilled in the art will also appreciate that the processing circuitry 1310 and the memory 1320 described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in a memory, that when executed by the one or more processors such as the processing circuitry 1310 perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single application-specific integrated circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system-on-a-chip (SoC).

To perform the method actions in a wireless device 122, 123, 124 for enabling cooperative transmissions in a group of wireless devices 120 located in a source cell 115 served by a source network node 110 in a wireless communications network 100, the wireless device 122, 123, 124 may comprise the following arrangement depicted in Fig 14. Fig 14 shows a schematic block diagram of embodiments of a wireless device 122, 123, 124. The embodiments of the wireless device 122, 123, 124 described herein may be considered as independent embodiments or may be considered in any combination with each other to describe non-limiting examples of the example embodiments described herein. It should also be noted that, although not shown in Fig. 14, it should be noted that known conventional features of a wireless device, such as, for example, at least one antenna and a power source or battery, may be assumed to be comprised in the wireless device 122, 123, 124 but is not shown or described any further in regards to Fig. 14.

The wireless device 122, 123, 124 may comprise processing circuitry 1410 and a memory 1420. The processing circuitry 1410 may also comprise a receiving module

1411 and a transmitting module 1412. The receiving module 1411 and the transmitting module 1412 may comprise Radio Frequency, RF, circuitry and baseband processing circuitry capable of transmitting and receiving a radio signal in the wireless communications network 100. The receiving module 1411 and the transmitting module

1412 may also form part of a single transceiver. It should also be noted that some or all of the functionality described in the embodiments above as being performed by the wireless device 122, 123, 124 may be provided by the processing circuitry 1410 executing instructions stored on a computer-readable medium, such as, e.g. the memory 1320 shown in Fig. 14. Alternative embodiments of the wireless device 122, 123, 124 may comprise additional components, such as, for example, a performing module 1413, responsible for providing its functionality to support the embodiments described herein.

The wireless device 122, 123, 124 or processing circuitry 1410 is configured to, or may comprise the performing module 1413 configured to, perform measurements of radio conditions towards at least one target cell 116 in the wireless communications network 100. Also, the wireless device 122, 123, 124 or processing circuitry 1410 is configured to, or may comprise the transmitting module 1412 configured to, transmit, to a coordinating wireless device 121 coordinating the co-operative transmissions in the group of wireless devices 120, a measurement report indicating its radio conditions towards at least one target cell 116 in case the radio conditions fulfills determined triggering co-operative handover conditions or one or more configured radio condition threshold levels at which the wireless device 122, 123, 124 is to transmit a measurement report to the coordinating wireless device 121.

In some embodiments, the wireless device 122, 123, 124 or processing circuitry 1410 may be configured to, or may comprise the receiving module 1411 configured to, receive, from the coordinating wireless device 121, information requesting the wireless device 122, 123, 124 to transmit measurement reports indicating its radio conditions towards the at least one target cell 116 in the wireless communications network 100 to the coordinating wireless device 121. In this case, the wireless device 122, 123, 124 or processing circuitry 1410 may be configured to, or may comprise the transmitting module 1412 configured to, transmit measurement reports to the coordinating wireless device 121. In some embodiments, the information requesting the wireless device 122, 123, 124 to transmit measurement reports further indicates that the measurement reports are to be transmitted periodically. In some embodiments, the wireless device 122, 123, 124 or processing circuitry 1410 may be configured to, or may comprise the receiving module 1411 configured to, receive, from the coordinating wireless device 121 , information requesting the wireless device 122, 123, 124 to stop transmitting the measurement reports.

In some embodiments, the wireless device 122, 123, 124 or processing circuitry 1410 may be configured to, or may comprise the receiving module 1411 configured to, receive, from the coordinating wireless device 121, information indicating that the wireless device 122, 123, 124 is detached from the group of wireless devices 120. Also, in some embodiments, the wireless device 122, 123, 124 or processing circuitry 1410 may be configured to, or may comprise the receiving module 1411 configured to, receive configuration information, originating from a source network node 110 serving the source cell 115, indicating the at least one target cell 111 and the determined triggering cooperative handover conditions. Here, in some embodiments, the configuration information further indicates one or more of: radio condition threshold levels towards the at least one target cell 111 at which the wireless device 122, 123, 124 is to transmit a measurement report to the coordinating wireless device 121 , and/or information indicating one or more periodicities of measurement report transmissions.

In some embodiments, the wireless device 122, 123, 124 or processing circuitry 1410 may be configured to, or may comprise the receiving module 1411 configured to, receive, from the coordinating wireless device 121, information indicating that a cooperative handover to a target network node 111 serving the at least one target cell 116 is to be performed by the wireless device 122, 123, 124. In this case, the wireless device

122, 123, 124 or processing circuitry 1410 may be configured to, or may comprise the performing module 1413 configured to, perform a co-operative handover from the source network node 110 serving the source cell 115 to the target network node 111 serving the target cell 116.

Furthermore, the embodiments for enabling co-operative transmissions in a group of wireless devices 120 located in a source cell 115 served by a source network node 110 in a wireless communications network 100 described above may be implemented through one or more processors, such as the processing circuitry 1410 in the wireless device 122,

123, 124 depicted in Fig. 14, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code or code means for performing the embodiments herein when being loaded into the processing circuitry 1410 in the wireless device 122, 123, 124. The computer program code may e.g. be provided as pure program code in the first node 110 or on a server and downloaded to the wireless device 122, 123, 124. Thus, it should be noted that the modules of the wireless device 122, 123, 124 may in some embodiments be implemented as computer programs stored in memory, e.g. in the memory modules 1420 in Fig. 14, for execution by processors or processing modules, e.g. the processing circuitry 1410 of Fig. 14. Those skilled in the art will also appreciate that the processing circuitry 1410 and the memory 1420 described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in a memory, that when executed by the one or more processors such as the processing circuitry 1410 perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single application-specific integrated circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system-on-a-chip (SoC).

To perform the method actions in a source network node 110 for enabling cooperative transmissions in a group of wireless devices 120 located in a source cell 115 served by the source network node 110 in a wireless communications network 100, the source network node 110 may comprise the following arrangement depicted in Fig 15. Fig 15 shows a schematic block diagram of embodiments of a source network node 110. The embodiments of the source network node 110 described herein may be considered as independent embodiments or may be considered in any combination with each other to describe non-limiting examples of the example embodiments described herein. It should also be noted that, although not shown in Fig. 15, it should be noted that known conventional features of network node, such as, for example, at least one antenna and a power source, e.g. a battery or main connection, may be assumed to be comprised in the source network node 110 but is not shown or described any further in regards to Fig. 15.

The source network node 110 may comprise processing circuitry 1510 and a memory 1520. The processing circuitry 1510 may also comprise a receiving module 1511 and a transmitting module 1512. The receiving module 1511 and the transmitting module 1512 may comprise Radio Frequency, RF, circuitry and baseband processing circuitry capable of transmitting and receiving a radio signal in the wireless communications network 100. The receiving module 1511 and the transmitting module 1512 may also form part of a single transceiver. It should also be noted that some or all of the functionality described in the embodiments above as being performed by the source network node 110 may be provided by the processing circuitry 1510 executing instructions stored on a computer-readable medium, such as, e.g. the memory 1520 shown in Fig. 15. Alternative embodiments of the first node 110 may comprise additional components, such as, for example, an obtaining module 1513, responsible for providing its functionality to support the embodiments described herein.

The source network node 110 or processing circuitry 1510 is configured to, or may comprise the obtaining module 1513 configured to, obtain configuration information indicating at least one target cell 116 for the group of wireless devices 120 and determined triggering co-operative handover conditions towards the at least one target cell 116 for the group of wireless devices 120. Also, the source network node 110 or processing circuitry 1510 is configured to, or may comprise the transmitting module 1512 configured to, transmit the obtained configuration information towards the group of wireless devices 120. In some embodiments, the configuration information may further indicate one or more of: radio condition threshold levels towards the at least one target cell 111 at which wireless devices 122, 123, 124 in the group of wireless devices 120 is to transmit a measurement report to a coordinating wireless device 121 in the group of wireless devices 120, and/or information indicating one or more periodicities of measurement report transmissions. In some embodiments, the source network node 110 or processing circuitry 1510 may be configured to, or may comprise the obtaining module

1513 configured to, obtain information indicating a group of wireless devices 121, 122, 123, 124 having the same mobility pattern for co-operative transmissions.

Furthermore, the embodiments for enabling co-operative transmissions in a group of wireless devices 120 located in a source cell 115 served by a source network node 110 in a wireless communications network 100 described above may be implemented through one or more processors, such as the processing circuitry 1510 in the source network node 110 depicted in Fig. 15, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code or code means for performing the embodiments herein when being loaded into the processing circuitry 1510 in the source network node 110. The computer program code may e.g. be provided as pure program code in the first node 110 or on a server and downloaded to the source network node 110. Thus, it should be noted that the modules of the source network node 110 may in some embodiments be implemented as computer programs stored in memory, e.g. in the memory modules 1520 in Fig. 15, for execution by processors or processing modules, e.g. the processing circuitry 1510 of Fig. 15. Those skilled in the art will also appreciate that the processing circuitry 1510 and the memory 1520 described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in a memory, that when executed by the one or more processors such as the processing circuitry 1510 perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single applicationspecific integrated circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system-on-a-chip (SoC).

The description of the example embodiments provided herein have been presented for purposes of illustration. The description is not intended to be exhaustive or to limit example embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various alternatives to the provided embodiments. The examples discussed herein were chosen and described in order to explain the principles and the nature of various example embodiments and its practical application to enable one skilled in the art to utilize the example embodiments in various manners and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products. It should be appreciated that the example embodiments presented herein may be practiced in any combination with each other.

It should be noted that the word “comprising” does not necessarily exclude the presence of other elements or steps than those listed and the words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. It should further be noted that any reference signs do not limit the scope of the claims, that the example embodiments may be implemented at least in part by means of both hardware and software, and that several “means”, “units” or “devices” may be represented by the same item of hardware.

It should also be noted that the various example embodiments described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer- readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), etc. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

The embodiments herein are not limited to the above described preferred embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be construed as limiting.

Abbreviations

ACK Acknowledgment

NACK Negative Acknowledgement

DCI Downlink Control Information

MAC Media Access Control

CE Control element

RSRP Reference Signal Received Power

RSSI Received Signal Strength Indicator

RSRQ Reference Signal Received Quality

UCI Uplink Control Information

MR Measurement Report

PUCCH Physical Uplink Control Channel

PUSCH Physical Uplink Shared Channel

RRC Radio Resource Control

IE Information Element

UE User Equipment gNB gNodeB

3G/4G/5G Third/Fourth/Fifth Generation

OFDM Orthogonal Frequency-Division Multiplexing

Claims

1 . A method performed by a coordinating wireless device (121) for coordinating cooperative transmissions in a group of wireless devices (120) located in a source cell (115) served by a source network node (110) in a wireless communications network (100), the method comprising obtaining (402; 705-708; 805) measurements of radio conditions towards at least one target cell (116) in the wireless communications network (100) that is indicative of the radio conditions towards the at least one target cell (116) for the group of wireless devices (120); determining (403; 709; 806) if a co-operative handover from a source network node (110) serving the source cell (115) to a target network node (111) serving a target cell (116) is to be performed for the group of wireless devices (120) based on the obtained measurements of radio conditions.

2. The method according to claim 1 , further comprising performing (805) measurements of radio conditions towards the at least one target cell (116) in the wireless communications network (100), wherein the performed radio condition measurements are used as indicative of the radio conditions towards the at least one target cell (116) for the group of wireless devices (120).

3. The method according to claim 1 , further comprising obtaining (705-708) measurement reports from each of the wireless devices (122, 123, 124) in the group of wireless devices (120) indicating its radio conditions towards at least one target cell (116) in the wireless communications network (100); determining (709) that a co-operative handover from a source network node (110) serving the source cell (115) to a target network node (111) serving a target cell (116) is to be performed for the group of wireless devices (120) based on the obtained measurement reports from each of the wireless devices (122, 123, 124) in the group of wireless devices (120).

4. The method according to claim 3, wherein the determining (709) further comprises estimating joint radio conditions for the group of wireless devices (120) towards the at least one target cell (116) in the wireless communications network (100) based on the radio conditions towards at least one target cell (116) comprised in the measurement reports from each of the wireless devices (122, 123, 124) in the group of wireless devices (120), and determining that a co-operative handover from the source network node (110) serving the source cell (115) to the target network node (111) serving the target cell (116) is to be performed for the group of wireless devices (121 , 122, 123, 124) based on the estimated joint radio conditions for the group of wireless devices (120). The method according to any of claim 3 or 4, further comprising receiving (706) a measurement report from at least one wireless device (122) in the group of wireless devices (120) indicating its radio conditions towards at least one target cell (116) in the wireless communications network (100); and obtaining (707-708) measurement reports from each of the other wireless devices (123, 124) in the group of wireless devices (120) based on the measurement report from the at least one wireless device (122). The method according to claim 5, further comprising transmitting (707), to each of the wireless devices (122, 123, 124) in the group of wireless devices (120), information requesting that each of the wireless devices (122, 123, 124) transmits measurement reports indicating its radio conditions towards at least one target cell (116) in the wireless communications network (100) to the coordinating wireless device (121); and receiving (708) the measurement reports from each of the wireless devices (122, 123, 124) in the group of wireless devices (120). The method according to claim 6, wherein the information requesting that the wireless devices (122, 123, 124) in the group of wireless devices (120) transmit measurement reports further indicates that the measurement reports are to be transmitted periodically. The method according to any of claims 3-7, further comprising determining that the radio conditions towards the at least one target cell (116) of at least one wireless device (124) in the group of wireless devices (120) significantly differs from the radio conditions towards the at least one target cell (116) of the other wireless devices (121, 122, 123) in the group of wireless devices (120), and detaching the at least one wireless device (124) from the group of wireless devices (120).

9. The method according to any of claims 1-8, wherein the determining (403) is performed in case the radio condition measurements used as indicative of the radio conditions towards the at least one target cell (116) for the group of wireless devices (120), or the estimated joint radio conditions for the group of wireless devices (120), fulfills configured co-operative handover triggering conditions.

10. The method according to claim 9, further comprising receiving (401; 704; 804), from a source network node (110) serving the source cell (115), configuration information indicating the at least one target cell (111) and configured co-operative handover triggering conditions.

11. The method according to claim 10, wherein the configuration information further indicates one or more of: radio condition threshold levels towards the at least one target cell (111) at which the wireless devices (122, 123, 124) in the group of wireless devices (120) are to transmit a measurement report to the coordinating wireless device (121), and/or information indicating one or more periodicities of measurement report transmissions.

12. The method according to any of claims 9-11, further comprising transmitting (710), to each of the wireless devices (122, 123, 124) in the group of wireless devices (120), information requesting that the wireless devices (122, 123, 124) stop transmitting the measurement reports when the estimated joint radio conditions for the group of wireless devices (120) does not fulfill the determined triggering co-operative handover conditions.

13. The method according to any of claims 1-12, further comprising transmitting (404; 711 ; 807), to each of the wireless devices (122, 123, 124) in the group of wireless devices (120), information indicating that a co-operative handover to the target network node (111) serving the target cell (116) is to be performed; and performing (405; 711- 713; 807-809) a co-operative handover from the source network node (110) serving the source cell (115) to the target network node (111) serving the target cell (116).

14. A coordinating wireless device (121) for coordinating co-operative transmissions in a group of wireless devices (120) located in a source cell (115) served by a source network node (110) in a wireless communications network (100), wherein the coordinating wireless device (121) comprise a processing circuitry (1110) and a memory (1120), the processing circuitry (1110) being configured to: obtain measurements of radio conditions towards at least one target cell (116) in the wireless communications network (100) that is indicative of the radio conditions towards the at least one target cell (116) for the group of wireless devices (120), determine if a co-operative handover from a source network node

(110) serving the source cell (115) to a target network node (111) serving a target cell (116) is to be performed for the group of wireless devices (120) based on the obtained measurements of radio conditions.

15. The coordinating wireless device (121) according to claim 14, wherein the processing circuitry (1110) is further configured to perform measurements of radio conditions towards the at least one target cell (116) in the wireless communications network (100), wherein the performed radio condition measurements are used as indicative of the radio conditions towards the at least one target cell (116) for the group of wireless devices (120).

16. The coordinating wireless device (121) according to claim 14, wherein the processing circuitry (1110) is further configured to obtain measurement reports from each of the wireless devices in the group of wireless devices (120) indicating its radio conditions towards at least one target cell (116) in the wireless communications network (100), and determine that a co-operative handover from a source network node (110) serving the source cell (115) to a target network node

(111) serving a target cell (116) is to be performed for the group of wireless devices (120) based on the obtained measurement reports from each of the wireless devices in the group of wireless devices (120).

17. The coordinating wireless device (121) according to claim 16, wherein the processing circuitry (1110) is further configured to estimate joint radio conditions for the group of wireless devices (120) towards the at least one target cell (116) in the wireless communications network (100) based on the radio conditions towards at least one target cell (116) comprised in the measurement reports from each of the wireless devices in the group of wireless devices (120), and determine that a cooperative handover from the source network node (110) serving the source cell (115) to the target network node (111) serving the target cell (116) is to be performed for the group of wireless devices (121 , 122, 123, 124) based on the estimated joint radio conditions for the group of wireless devices (120).

18. The coordinating wireless device (121) according to any of claim 16 or 17, wherein the processing circuitry (1110) is further configured to receive a measurement report from at least one wireless device (122) in the group of wireless devices (120) indicating its radio conditions towards at least one target cell (116) in the wireless communications network (100), and obtain measurement reports from each of the other wireless devices (123, 124) in the group of wireless devices (120) based on the measurement report from the at least one wireless device (122).

19. The coordinating wireless device (121) according to claim 18, wherein the processing circuitry (1110) is further configured to transmit, to each of the wireless devices (122, 123, 124) in the group of wireless devices (120), information requesting that each of the wireless devices (123) transmits measurement reports indicating its radio conditions towards at least one target cell (116) in the wireless communications network (100) to the coordinating wireless device (121), and receive the measurement reports from each of the wireless devices (122, 123, 124) in the group of wireless devices (120).

20. The coordinating wireless device (121) according to claim 19, wherein the information requesting that the wireless devices (122, 123, 124) in the group of wireless devices (120) transmit measurement reports further indicates that the measurement reports are to be transmitted periodically.

21. The coordinating wireless device (121) according to any of claims 16-20, wherein the processing circuitry (1110) is further configured to determine that the radio conditions towards the at least one target cell (116) of at least one wireless device (124) in the group of wireless devices (120) significantly differs from the radio conditions towards the at least one target cell (116) of the other wireless devices (121, 122, 123) in the group of wireless devices (120), and detach the at least one wireless device (124) from the group of wireless devices (120).

22. The coordinating wireless device (121) according to any of claims 14-21 , wherein the processing circuitry (1110) is further configured to determine to perform the cooperative handover in case the radio condition measurements used as indicative of the radio conditions towards the at least one target cell (116) for the group of wireless devices (120), or the estimated joint radio conditions for the group of wireless devices (120), fulfills configured co-operative handover triggering conditions.

23. The coordinating wireless device (121) according to claim 22, wherein the processing circuitry (1110) is further configured to receive, from a source network node (110) serving the source cell (115), configuration information indicating the at least one target cell (111) and configured co-operative handover triggering conditions.

24. The coordinating wireless device (121) according to claim 23, wherein the configuration information further indicates one or more of: radio condition threshold levels towards the at least one target cell (111) at which the wireless devices (122, 123, 124) in the group of wireless devices (120) are to transmit a measurement report to the coordinating wireless device (121), and/or information indicating one or more periodicities of measurement report transmissions.

25. The coordinating wireless device (121) according to any of claims 22-24, wherein the processing circuitry (1110) is further configured to transmit, to each of the wireless devices (122, 123, 124) in the group of wireless devices (120), information requesting that the wireless devices (122, 123, 124) stop transmitting the measurement reports when the estimated joint radio conditions for the group of wireless devices (120) does not fulfill the determined triggering co-operative handover conditions. The coordinating wireless device (121) according to any of claims 14-25, wherein the processing circuitry (1110) is further configured to transmit, to each of the wireless devices in the group of wireless devices (120), information indicating that a co-operative handover to the target network node (111) serving the target cell (116) is to be performed, and perform a co-operative handover from the source network node (110) serving the source cell (115) to the target network node (111) serving the target cell (116). A method performed by a wireless device (122, 123, 124) for enabling co-operative transmissions in a group of wireless devices (120) located in a source cell (115) served by a source network node (110) in a wireless communications network (100), the method comprising performing (502; 705) measurements of radio conditions towards at least one target cell (116) in the wireless communications network (100); and transmitting (503; 706), to a coordinating wireless device (121) coordinating the co-operative transmissions in the group of wireless devices (120), a measurement report indicating its radio conditions towards at least one target cell (116) in case the radio conditions fulfills determined triggering co-operative handover conditions or one or more configured radio condition threshold levels at which the wireless device (122, 123, 124) is to transmit a measurement report to the coordinating wireless device (121). The method according to claim 27, further comprising receiving (504; 707), from the coordinating wireless device (121), information requesting the wireless device (122, 123, 124) to transmit measurement reports indicating its radio conditions towards the at least one target cell (116) in the wireless communications network (100) to the coordinating wireless device (121); and transmitting (505; 708) measurement reports to the coordinating wireless device (121). The method according to claim 28, wherein the information requesting the wireless device (122, 123, 124) to transmit measurement reports further indicates that the measurement reports are to be transmitted periodically.

30. The method according to claim 29, further comprising receiving (710), from the coordinating wireless device (121), information requesting the wireless device (122, 123, 124) to stop transmitting the measurement reports.

31. The method according to any of claims 27-30, further comprising receiving, from the coordinating wireless device (121), information indicating that the wireless device (122, 123, 124) is detached from the group of wireless devices (120).

32. The method according to any of claims 27-31, further comprising receiving (501, 704) configuration information, originating from a source network node (110) serving the source cell (115), indicating the at least one target cell (111) and the determined triggering co-operative handover conditions.

33. The method according to claim 32, wherein the configuration information further indicates one or more of: radio condition threshold levels towards the at least one target cell (111) at which the wireless device (122, 123, 124) is to transmit a measurement report to the coordinating wireless device (121), and/or information indicating one or more periodicities of measurement report transmissions.

34. The method according to any of claims 27-33, further comprising receiving (711), from the coordinating wireless device (121), information indicating that a co-operative handover to a target network node (111) serving the at least one target cell (116) is to be performed by the wireless device (122, 123, 124); and performing (507; 712- 713) a co-operative handover from the source network node (110) serving the source cell (115) to the target network node (111) serving the target cell (116).

35. A wireless device (122, 123, 124) for enabling co-operative transmissions in a group of wireless devices (120) located in a source cell (115) served by a source network node (110) in a wireless communications network (100), wherein the wireless device (122, 123, 124) comprise a processing circuitry (1210) and a memory (1220), the processing circuitry (1210) being configured to: perform measurements of radio conditions towards at least one target cell (116) in the wireless communications network (100), and transmit, to a coordinating wireless device (121) coordinating the co-operative transmissions in the group of wireless devices (120), a measurement report indicating its radio conditions towards at least one target cell (116) in case the radio conditions fulfills determined triggering co-operative handover conditions or one or more configured radio condition threshold levels at which the wireless device (122, 123, 124) is to transmit a measurement report to the coordinating wireless device (121). The wireless device (122, 123, 124) according to claim 35, wherein the processing circuitry (1210) is further configured to receive, from the coordinating wireless device (121), information requesting the wireless device (122, 123, 124) to transmit measurement reports indicating its radio conditions towards the at least one target cell (116) in the wireless communications network (100) to the coordinating wireless device (121), and transmit measurement reports to the coordinating wireless device (121). The wireless device (122, 123, 124) according to claim 36, wherein the information requesting the wireless device (122, 123, 124) to transmit measurement reports further indicates that the measurement reports are to be transmitted periodically. The wireless device (122, 123, 124) according to claim 37, wherein the processing circuitry (1210) is further configured to receive, from the coordinating wireless device (121), information requesting the wireless device (122, 123, 124) to stop transmitting the measurement reports. The wireless device (122, 123, 124) according to any of claims 35-38, wherein the processing circuitry (1210) is further configured to receive, from the coordinating wireless device (121), information indicating that the wireless device (122, 123, 124) is detached from the group of wireless devices (120). The wireless device (122, 123, 124) according to any of claims 35-39, wherein the processing circuitry (1210) is further configured to receive configuration information, originating from a source network node (110) serving the source cell (115), indicating the at least one target cell (111) and the determined triggering cooperative handover conditions. The wireless device (122, 123, 124) according to claim 40, wherein the configuration information further indicates one or more of: radio condition threshold levels towards the at least one target cell (111) at which the wireless device (122, 123, 124) is to transmit a measurement report to the coordinating wireless device (121), and/or information indicating one or more periodicities of measurement report transmissions. The wireless device (122, 123, 124) according to any of claims 35-41 , wherein the processing circuitry (1210) is further configured to receive, from the coordinating wireless device (121), information indicating that a co-operative handover to a target network node (111) serving the at least one target cell (116) is to be performed by the wireless device (122, 123, 124), and perform a co-operative handover from the source network node (110) serving the source cell (115) to the target network node (111) serving the target cell (116). A method performed by a source network node (110) for enabling co-operative transmissions in a group of wireless devices (120) located in a source cell (115) served by the source network node (110) in a wireless communications network (100), the method comprising obtaining (602) configuration information indicating at least one target cell (116) for the group of wireless devices (120) and determined triggering cooperative handover conditions towards the at least one target cell (116) for the group of wireless devices (120); and transmitting (603) the obtained configuration information towards the group of wireless devices (120). The method according to claim 43, wherein the configuration information indicates one or more of: radio condition threshold levels towards the at least one target cell (111) at which wireless devices (122, 123, 124) in the group of wireless devices (120) is to transmit a measurement report to a coordinating wireless device (121) in the group of wireless devices (120), and/or information indicating one or more periodicities of measurement report transmissions. 5. The method according to claim 43 or 44, further comprising obtaining (601) information indicating a group of wireless devices (121, 122, 123, 124) having the same mobility pattern for co-operative transmissions. 6. A source network node (110) for enabling co-operative transmissions in a group of wireless devices (120) located in a source cell (115) served by the source network node (110) in a wireless communications network (100), wherein the source network node (110) comprises a processing circuitry (1310) and a memory (1320), the processing circuitry (1310) being configured to: obtain configuration information indicating at least one target cell (116) for the group of wireless devices (120) and determined triggering co-operative handover conditions towards the at least one target cell (116) for the group of wireless devices (120), and transmit the obtained configuration information towards the group of wireless devices (120). 7. The source network node (110) according to claim 46, wherein the configuration information further indicates one or more of: radio condition threshold levels towards the at least one target cell (111) at which wireless devices (122, 123, 124) in the group of wireless devices (120) is to transmit a measurement report to a coordinating wireless device (121) in the group of wireless devices (120), and/or information indicating one or more periodicities of measurement report transmissions. 8. The source network node (110) according to claim 46 or 47, wherein the processing circuitry (1310) is further configured to obtain information indicating a group of wireless devices (121 , 122, 123, 124) having the same mobility pattern for co-operative transmissions.

49. A computer program product comprising instructions which, when executed on at least one processing circuitry (1110, 1210, 1310), cause the at least one processing circuitry (1110, 1210, 1310) to carry out the methods according to any of claims 1-13, 27-34, or 43-45. A computer program carrier carrying a computer program product according to claim 49, wherein the computer program carrier is one of an electronic signal, optical signal, radio signal, or computer-readable storage medium.