Network node in wireless communication network, first user equipment and methods therein

Abstract

The present disclosure provides a method performed by a first UE for handling a multicast session between a network node and a group of UEs comprising at least the first UE in a wireless communication network. The first UE operates in a second discontinuous reception (DRX) configuration. The first UE detects (201) that the multicast session is activated by receiving (201-1) a group paging message transmitted to the group of UEs indicating that the multicast session is activated, or by receiving (201-2) session data for the multicast session. In response to detecting (201) that the multicast session is activated, the first UE switches (202) from the second DRX configuration to the first DRX configuration. The first DRX configuration indicates that the first UE should monitor all session data transmitted in the multicast session. The second DRX configuration indicates that the first UE should monitor a subset of all session data transmitted in the multicast session.

Description

Technical Field

[0001] Embodiments herein relate to user equipment (UE), network nodes, and methods therein. In some aspects, they relate to handling multicast sessions between network nodes and groups of UEs in a wireless communication network. Background Art

[0002] In a typical wireless communication network, wireless devices (also referred to as wireless communication devices), mobile stations, stations (STAs), and / or user equipment communicate with one or more core networks (CNs) via a local area network (e.g., a Wi-Fi network or a radio access network (RAN)). The RAN coverage is divided into geographical areas that are service areas or cell areas, which may also be referred to as beams or beam groups, where each service area or cell area is served by a radio network node such as a radio access node (e.g., a Wi-Fi access point or a radio base station (RBS)), which may also be denoted as, for example, NodeB, eNodeB (eNB), or gNB as represented in fifth generation (5G) telecommunications. A service area or cell area is a geographical area where radio coverage is provided by a radio network node. The radio network node communicates with wireless devices within the range of the radio network node via an air interface operating at radio frequencies.

[0003] Within the 3rd Generation Partnership Project (3GPP), the specifications for the Evolved Packet System (EPS) (also known as the Fourth Generation (4G) network) have been completed, and this work continues in upcoming 3GPP system releases, such as the development of the 5G network (also known as 5G New Radio (NR)). EPS includes the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as the Long Term Evolution (LTE) radio access network, and the Evolved Packet Core (EPC), also known as the System Architecture Evolution (SAE) core network. E-UTRAN / LTE is a variant of the 3GPP radio access network, where radio network nodes are directly connected to the EPC core network, rather than the RNC used in 3G networks. Generally, in E-UTRAN / LTE, the functions of the 3G RNC are distributed between radio network nodes (such as eNodeB in LTE) and the core network. Thus, the RAN of EPS has a substantially "flat" architecture, consisting of radio network nodes directly connected to one or more core networks, i.e., they are not connected to an RNC. To compensate for this, the E-UTRAN specification defines a direct interface between radio network nodes, which is called the X2 interface.

[0004] Multiple antenna techniques can significantly improve the data rate and reliability of wireless communication systems. Performance is particularly enhanced if both the transmitter and receiver are equipped with multiple antennas, forming a Multiple-Input Multiple-Output (MIMO) communication channel. Such systems and / or related technologies are generally referred to as MIMO.

[0005] When a 3GPP System Release 17 (Rel-17) Multicast Broadcast System (MBS) session (also known as a multicast session) is activated, deactivated, or released, the core network (CN) notifies each Next Generation RAN (NG-RAN) node providing the multicast session of the corresponding session state change. Each NG-RAN node can then perform group paging within its own cell.

[0006] In Rel-17, the group paging message includes the Temporary Mobile Group Identity (TMGI) of the MBS session and no other information. A given group paging message can include one or more such TMGIs, depending on which MBS session(s) require group paging.

[0007] Since the UEs that need to be group-paged for a given TMGI / MBS session can be configured to monitor different Paging Occasions (POs), the same TMGI can be transmitted in multiple or possibly all POs. This enables group paging for each MBS UE while still monitoring its legacy PO. The UE identity for legacy unicast paging can be included in the same paging message as the paging message for group paging, i.e., each PO can contain any combination of UE identities (for single-UE paging) and / or TMGIs (for group paging).

[0008] In Rel-17, the full-length TMGI is transmitted in each PO for group paging. SUMMARY OF THE INVENTION

[0009] The inventors have identified problems in handling multicast sessions and will discuss them first. To be able to receive relevant data in a multicast session, a UE may need to continuously monitor all session data. And if the multicast session and the UE are in an inactive state, the network node needs to iteratively transmit group paging indicating the activation of the multicast session until it can be ensured that all UEs have received the group paging and are ready to receive session data. This process consumes a large amount of resources, especially in terms of power consumption.

[0010] The object of the embodiments herein is to improve the performance of handling multicast sessions.

[0011] According to a first aspect, there is provided a method performed by a first UE for handling a multicast session between a network node and a group of UEs including at least the first UE in a wireless communication network. The first UE operates in a second Discontinuous Reception (DRX) configuration. The second DRX configuration indicates that the first UE should monitor a subset of all session data transmitted in the multicast session. The first UE detects that the multicast session is activated by any of the following: receiving a group paging message transmitted to the group of UEs indicating that the multicast session is activated, or receiving session data of the multicast session. In response to detecting that the multicast session is activated, the first UE switches from the second DRX configuration to a first DRX configuration. The first DRX configuration indicates that the first UE should monitor all session data transmitted in the multicast session.

[0012] According to a second aspect, there is provided a method performed by a network node for handling a multicast session between the network node and a UE group including at least a first UE in a wireless communication network. The first UE operates under a second DRX configuration. The network node transmits a group paging message indicating that the multicast session is activated to the UE group. The network node transmits session data associated with the multicast session. The session data is transmitted to be at least partially receivable by the first UE operating under the second DRX configuration, thereby further indicating to the first UE that the multicast session is activated.

[0013] According to a third aspect, there is provided a first UE configured to handle a multicast session between a network node and a UE group including at least the first UE in a wireless communication network. The first UE is configured to operate under a second DRX configuration. The first UE is configured to:

[0014] - detect that the multicast session is activated by any of the following: receiving a group paging message transmitted to the UE group indicating that the multicast session is activated, or receiving session data of the multicast session.

[0015] - in response to detecting that the multicast session is activated, switch from the second DRX configuration to a first DRX configuration, where the first DRX configuration is adapted to indicate that the first UE should monitor all session data transmitted in the multicast session, and where the second DRX configuration is adapted to indicate that the first UE should monitor a subset of all session data transmitted in the multicast session.

[0016] According to a fourth aspect, there is provided a network node configured to handle a multicast session between the network node and a UE group including at least a first UE in a wireless communication network. The first UE is adapted to operate under a second DRX configuration. The network node is configured to:

[0017] - transmit a group paging message indicating that the multicast session is activated to the UE group, and

[0018] - transmit session data associated with the multicast session, the session data being transmitted to be at least partially receivable by the first UE operating under the second DRX configuration, thereby further indicating to the first UE that the multicast session is activated.

[0019] Since the first UE can detect the activation of a multicast session by group paging or by monitoring session data sent from a network node in a session while the first UE is using a second DRX configuration, the first UE can detect session activation without monitoring each session data. In addition, there is no need to repeat the group paging message because if the group paging message is not detected, the first UE can also detect the transmitted session data under the second DRX configuration. Thus, more efficient processing of multicast session activation is achieved, while also improving the power efficiency of the first UE and the network node. This is because the network node will not need to send repeated paging signals, and the UE can reduce power by operating under the second DRX configuration, which reduces power compared to operating normally without DRX and / or operating under the first DRX configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Examples of embodiments herein are described in more detail with reference to the accompanying drawings, in which:

[0021] Figure 1 is a schematic block diagram showing an embodiment of a wireless communication network.

[0022] Figure 2 is a flowchart depicting an embodiment of a method performed by a first UE.

[0023] Figure 3 is a flowchart depicting an embodiment of a method performed by a network node.

[0024] Figure 4 is a diagram depicting an example scenario of an embodiment.

[0025] Figure 5 is a timing diagram depicting an example scenario of an embodiment.

[0026] Figure 6a and Figure 6b is a schematic block diagram showing an embodiment of a first UE.

[0027] Figure 7a and Figure 7b is a schematic block diagram showing an embodiment of a network node.

[0028] Figures 8 - 10 schematically shows a communication system according to some embodiments. DETAILED DESCRIPTION

[0029] As part of the development of the embodiments herein, the inventors have identified the problem of multicast sessions as described in the Summary of the Invention, which will be discussed in more detail below. In the embodiments herein, the term "multicast session" may refer to an MBS session or an MBS multicast session, and these terms may be used interchangeably to define the same type of multicast session. Unless otherwise explicitly stated, a session as used herein may be a multicast session.

[0030] In 3GPP Rel-17, for a multicast session (e.g., a multicast MBS session), when a Rel-17 UE operates in an inactive mobility state (e.g., a Radio Resource Control (RRC) inactive state, or also referred to as an RRC inactive state (RRC INACTIVE)), multicast reception is not supported. Thus, in Rel-17, there is no need to notify the Rel-17 UE of the corresponding session state via group paging. Instead, group paging is only used to restore the UE to a connected mobility state, such as an RRC connected state (RRC CONNECTED). Typically, this is achieved due to MBS session activation, so the UE can receive the MBS session in the RRC connected state, but in principle, there can be other reasons for the RAN to perform group paging for an RRC inactive state UE.

[0031] However, Release 18 (Rel-18) will support multicast reception in the RRC inactive state. In one scenario, when a session is deactivated, a Rel-18 UE is released from the RRC connected state to the RRC inactive state. Thus, the Rel-18 UE can wait in the RRC inactive state for the session to be activated to start receiving multicast data. A Rel-18 UE as used herein may represent a UE having the capabilities compliant with the Release-18 3GPP specification.

[0032] If an explicit session activation notification is not provided to a Rel-18 UE in the RRC inactive state, the Rel-18 UE will have to continuously monitor the session in the RRC inactive state as if the session were always active. In this way, the Rel-18 UE can receive multicast in the RRC inactive state, but this method will unnecessarily consume the UE's power during the period when the session is deactivated.

[0033] If an explicit session activation notification is provided to a Rel-18 UE in the RRC inactive state (which is expected to remain in the RRC inactive state and receive multicast when the session is activated), it is important that the Rel-18 UE receives the notification or at least detects in some way that the session has been activated.

[0034] If session activation notification is provided via single-group paging, it is possible that Rel-18 UEs may miss the group paging for various reasons (e.g., due to poor radio conditions). For traditional unicast and Rel-17 multicast, a paged UE in RRC Inactive state is expected to resume to the RRC connected state, which means that the network node will obtain feedback on whether the UE has received the paging, e.g., as part of the RRC resume operation. For UEs that miss the paging, the network node can send repeated paging messages until all UEs have resumed, or any remaining missed UEs can be considered out of coverage.

[0035] However, if Rel-18 UEs are expected to remain in RRC Inactive state, neither the Rel-18 UEs nor the network nodes will detect the missed paging, and thus the Rel-18 UEs will continue to wait for the session activation notification message that may never arrive. This means that Rel-18 UEs may face the risk of losing all data sent in a multicast session (e.g., an MBS session).

[0036] For a network node (e.g., a gNB), one solution is to repeat the group paging until it believes that the residual probability of the Rel-18 UEs not receiving the notification is low enough. This solution requires a trade-off between the overhead caused by the repeated group paging and the residual probability of the Rel-18 UEs missing the notification being low enough.

[0037] Embodiments of the present disclosure will be further discussed, which solve and overcome at least some of the above problems.

[0038] Figure 1 FIG. 1 is a schematic overview of a wireless communication network 100 in which embodiments of the present disclosure may be implemented. The wireless communication network 100 includes one or more RANs and one or more CNs. The wireless communication network 100 may use 5G NR, but may also use many other different technologies, such as Wi-Fi, Long-Term Evolution (LTE), LTE-Advanced, Wideband Code Division Multiple Access (WCDMA), Global System for Mobile communication / enhanced Data rate for GSM Evolution (GSM / EDGE), Ultra Mobile Broadband (UMB), to mention just a few possible implementations.

[0039] A network node, such as network node 110, operates in a wireless communication network 100. The network node 110 can provide multiple referenced cells and can use these cells to communicate with any one or more suitable UEs operating in these cells. The network node 110 can be a transmission and reception point, for example, a radio access network node such as a base station, for example, a radio base station such as NodeB, evolved Node B (eNB, eNodeB, eNode B), NR Node B (gNB), base transceiver station, radio remote unit, access point base station, base station router, transmission device of a radio base station, stand-alone access point, Wireless Local Area Network (WLAN) access point, Access Point Station (AP STA), access controller, a UE acting as an access point or peer in Device to Device (D2D) communication, or any other network unit capable of communicating with a UE within any cell served by the network node 110, for example, depending on the radio access technology and terminology used. In particular, the first network node 110 is capable of sending a group paging message including a multicast session identifier (such as TMGI) to a UE.

[0040] A user equipment operates in the wireless communication network 100, such as the first UE 121. In the wireless communication network 100, the second UE 122 can also operate. The first UE 121 and the second UE 122 can provide radio coverage respectively through multiple antenna beams (also referred to as beams in this document).

[0041] The first UE 121 and the second UE 122 can be, respectively, for example, an NR device, a mobile station, a wireless terminal, an NB-IoT device, an eMTC device, an NR RedCap device, a CAT-M device, a Wi-Fi device, an LTE device, and a non-Access Point (non-AP) STA, a STA that communicates with one or more core networks (CN) via a base station (such as network node 110), one or more access networks (AN) (such as RAN). Those skilled in the art should understand that UE is a non-restrictive term that refers to any UE, terminal, wireless communication terminal, user equipment, device to device (D2D) terminal or node, such as a smart phone, a laptop computer, a mobile phone, a sensor, a relay, a mobile tablet, or even a small base station that communicates within a cell.

[0042] The first UE 121 can be a Rel-18-capable UE, i.e., a Rel-18 UE. The second UE 122 can be a Rel-17 UE or a Rel-18 UE. Any one or both of the first UE 121 and the second UE 122 can be part of one or more UE groups (not shown), and the corresponding UE groups can be part of the same session (e.g., a multicast MBS session) between the corresponding groups and the network node 110.

[0043] The first UE 121 is capable of operating in any suitable mobility state (e.g., RRC inactive state) while receiving multicast session data. The first UE 121 is capable of operating with different DRX configurations, e.g., different DRX configurations can be switched by the first UE 121.

[0044] A CN node (e.g., CN node 130) operates in the radio communication network 100. The CN node 130 can be configured to notify (e.g., signal) each network node (e.g., network node 110) where the session (e.g., a multicast MBS session) is provided (e.g., between which one or more UEs and which network node), and / or of a change in the session state of the session. In this way, each network node (e.g., network node 110) can be triggered to perform group paging to the UE groups associated with the session (e.g., the first UE 121 and / or the second UE 122).

[0045] In one aspect, the methods herein can be performed by the network node 110, and in another aspect, by the first UE 121. As an alternative, for example, as Figure 1 shown, distributed nodes (DNs) and functions included in the cloud 140 can be used to perform or partially perform the methods and embodiments herein.

[0046] In embodiments of the present disclosure, a UE (e.g., the first UE 121) may be configured with two alternative DRX configurations. These will be used for receiving MBS sessions and include a first DRX configuration (also referred to as DRX1) and a second DRX configuration (also referred to as DRX2). In some embodiments of the present disclosure, the first DRX configuration may also be referred to as normal DRX or standard DRX. In some embodiments of the present disclosure, the second DRX configuration may be referred to as a sparse DRX configuration. Each DRX configuration may be a low-power configuration for the UE (e.g., the first UE 121). For example, the DRX configuration may determine how long to sleep and / or how long not to listen or monitor certain radio transmissions (e.g., multicast transmissions). The sleep duration, the duration configured in the low-power mode, and / or the duration of not listening or monitoring at least a certain type of radio (e.g., multicast session data) may be defined by corresponding periods. In this regard, the period of the second DRX configuration may be longer than that of the first DRX configuration, i.e., the second DRX configuration monitors fewer multicast transmissions than the first DRX configuration. DRX may additionally or alternatively be defined as any suitable way of configuring the UE (e.g., the first UE 121) to monitor a subset of all logically possible monitoring occasions (MOs) (e.g., one or more repeating radio frames). In this context, the first DRX configuration includes monitoring a larger subset than the second DRX configuration. In this context, a longer period may mean that the second DRX configuration monitors fewer MOs than the first DRX configuration.

[0047] In some embodiments of the present disclosure, the UE (e.g., the first UE 121) may selectively use the first DRX configuration or the second DRX configuration. When using the second DRX configuration, the UE (e.g., the first UE 121) may consider the session state of a multicast session (e.g., an MBS session) as deactivated. In other words, the second DRX configuration may be used for inactive multicast sessions. In these embodiments, the UE may monitor paging messages and at least a part of the multicast session according to the second DRX configuration (DRX2). In other words, the UE (e.g., the first UE 121) may monitor paging messages, and may power off according to the second DRX configuration and monitor certain monitoring occasions related to the multicast session. This may apply only to UEs in the RRC connected state, only to UEs in the RRC inactive state, or to UEs in both RRC states, such as the first UE 121 and / or the second UE 122. When the UE (e.g., the first UE 121) considers the session state as active, the UE may monitor paging messages and the multicast session according to the first DRX configuration.

[0048] In some embodiments, for a session activation notification, a single group paging may be transmitted. However, it is possible that a UE (e.g., the first UE 121) fails to detect the group paging.

[0049] In some embodiments, if a UE (e.g., the first UE 121) receives a single group paging message, the UE may immediately apply its first DRX configuration and then receive the multicast as expected without data loss. In some embodiments, if a UE (e.g., the first UE 121) misses a single group paging message, the UE may still detect that the session is activated by receiving the multicast session data via its second DRX. That is, the UE will periodically monitor the session data transmitted in the multicast session according to the second DRX configuration, for example, to detect whether the session is activated. When an active multicast session is detected, the UE may immediately switch to the first DRX configuration and continue the multicast reception using the first DRX configuration.

[0050] Therefore, in some embodiments herein, a UE (e.g., the first UE 121 and / or the second UE 122) may detect a multicast session activation by the first occurrence of the following two events: "detecting group paging" and "self-detection using the second DRX configuration". When a UE (e.g., the first UE 121) detects group paging, the UE detects that the multicast session is activated, and thus self-detection is not needed and may not be used.

[0051] A network node (e.g., network node 110, e.g., gNB) according to embodiments herein may need to ensure that the second DRX configuration has monitoring opportunities (MOs) such that a UE (e.g., the first UE 121) can detect the session data in the multicast session when using the second DRX configuration. In other words, the network node 110 may need to schedule and / or transmit session data in the multicast session such that the UE, by operating under the second DRX and listening to the session data in the multicast session (e.g., monitoring the multicast session), will necessarily detect the data transmitted therein, thereby implying that the multicast session has been activated. Otherwise, for example, no session data can be transmitted in the multicast session.

[0052] Since the second DRX configuration has a longer period and / or requires less monitoring than the first DRX configuration, a UE (e.g., the first UE 121) will reduce its power consumption because it can be in the second DRX configuration for a longer time and is still able to receive session data when the multicast session is activated, for example, in an inactive mobility state, e.g., RRC inactive state).

[0053] It should be noted that the session used herein may represent a multicast session between the network node 110 and a group of UEs 121, 122. The session may be a multicast MBS session.

[0054] It should also be noted that, for any embodiment herein, the session activation notification can be any transmitted indication or information indicating that the corresponding multicast session has been activated.

[0055] It should also be noted that, for any embodiment herein, the session identifier can refer to the TMGI. However, when using the TMGI, it can only be used as an example, and any suitable session identifier for the general multicast session is also applicable.

[0056] Since the UE (e.g., the first UE 121) of the embodiments herein can detect that the multicast session has been activated either through group paging or by monitoring session data in the session using the second DRX configuration, the robustness of the session activation notification will be improved without imposing overhead on the UE (e.g., through repeated group paging repetitions). In addition, the embodiments herein allow the UE (e.g., the first UE 121) to operate under the second DRX configuration when the session is deactivated, thereby reducing UE power consumption, e.g., compared to normal operation without DRX and / or compared to operation under the first DRX configuration.

[0057] By configuring two DRXs (DRX1, DRX2) for the UE (e.g., the first UE 121 or the second UE 122) by the network, the UE can self-detect that the multicast MBS session has been activated. This is because, if the UE (e.g., the first UE 121 or the second UE 122) misses the first set of paging messages, the UE can "self-detect" that the multicast session has been activated by detecting the session data in the multicast session. This implies that the multicast session has been activated. This can be achieved with much lower power consumption compared to using only DRX1, and the power consumption is only slightly higher compared to only monitoring group paging. This configuration can be applicable only to the RRC connected state, only to the RRC inactive state, or to both RRC states, i.e., the RRC connected state and the RRC inactive state.

[0058] Self-detection can be used as a reliable fallback method for the primary session notification method (i.e., group paging), and then the primary session notification method can be used without repetition. The self-detection method can also be used in the absence of group paging (more data is lost), or the self-detection method can be combined with repeated group paging (to improve reliability).

[0059] Some embodiments will now be described, where some embodiments can be considered alternatives, and some embodiments can be used in combination.

[0060] Figure 2An example embodiment of a method performed by a first UE 121 for handling a multicast session between a network node 110 and a group of UEs 121, 122 including at least the first UE 121 in a wireless communication network 100 is shown. The multicast session may be a multicast MBS session. The first UE 121 is, for example, at least initially operating under a second DRX configuration. The method includes the following actions, which may be performed in any suitable order. Figure 2 The dashed boxes in may include optional actions.

[0061] Action 201

[0062] The first UE 121 detects that the multicast session is activated by any one of the following actions 201-1 or 201-2. If detected by any one action, no other action is required to detect that the multicast session is activated.

[0063] Action 201 - 1

[0064] In some embodiments, the first UE 121 detects that the multicast session is activated by receiving a group paging message transmitted to the group of UEs 121, 122 indicating that the multicast session is activated. The first UE 121 may receive the group paging message from the network node 110 in any suitable manner.

[0065] Action 201 - 2

[0066] In some embodiments, the first UE 121 detects that the multicast session is activated by receiving session data of the multicast session.

[0067] In some embodiments, the first UE 121 does not receive a group paging message transmitted to the group of UEs 121, 122, for example, as in action 201-1. In these embodiments, when the first UE 121 receives session data of the multicast session, the received session data implies to the first UE 121 that the multicast session has been activated. This may further imply that the first UE 121 has failed to receive the group paging message. In this way, even if the group paging message is missed, the first UE 121 can detect that the multicast session has been activated.

[0068] In some embodiments, the network node 110 transmits at least some session data during a monitoring occasion of a second DRX configuration run by the UE 121 such that the first UE 121 can receive the session data shortly after the group paging message, for example, if the first UE 121 misses the group paging message. This may mean that after the first network node 110 transmits the group paging message, the first UE 121 receives the session data within a pre-determined maximum number of time slots.

[0069] Action 202

[0070] In response to detecting that a multicast session is activated, the first UE 121 switches from a second DRX configuration to a first DRX configuration, as described above for example. This switch enables the first UE 121 to receive session data in the multicast session transmitted by the network node 110. This is because when the UE 121 operates using the first DRX configuration, the network node 110 can transmit all receivable session data, while when the UE 121 operates using the second DRX configuration, the network node 110 can transmit only a part of the receivable session data.

[0071] When the first UE 121 operates under the first DRX configuration, the first DRX configuration indicates that the first UE 121 should monitor all session data transmitted in the multicast session. The second DRX configuration indicates that the first UE 121 should monitor a subset of all session data transmitted in the multicast session.

[0072] Additionally or alternatively, when the first UE 121 operates under the first DRX configuration, the first UE 121 can monitor the multicast session during a first set of monitoring opportunities (MOs) and can avoid monitoring the multicast session within a first period.

[0073] When the first UE 121 operates under the second DRX configuration, the first UE 121 can monitor the session during a second set of MOs and can avoid monitoring the multicast session within a second period. The second period is longer than the first period. The first set of MOs includes the second set of MOs. In this example, this means that the monitoring performed by the second DRX configuration is also performed by the first DRX configuration. This further means that the MOs of the second DRX configuration are a subset of the MOs of the first DRX configuration. In other words, when operating under the first DRX configuration, the first UE 121 can receive the same or even more data than when operating under the second DRX configuration.

[0074] In some embodiments, the second set of MOs is configured to include at least a part of the MOs mapped to adjacent time slots in a radio frame. This enables the network node 110 to be more flexible in terms of when / where to transmit session data.

[0075] In some embodiments, the first UE 121 is configured to operate in an inactive mobility state, for example, the radio resource control (RRC) inactive state. The first UE 121 can detect session activation and receive session data in the inactive mobility state.

[0076] Action 203

[0077] In some embodiments, when the first UE 121 has switched to the first DRX configuration, the first UE 121 receives session data of a multicast session while operating in an inactive mobility state (e.g., RRC inactive state).

[0078] Figure 3 An example embodiment of a method performed by a network node 110 for handling a multicast session between the network node 110 and a UE group 121, 122 including at least the first UE 121 in a wireless communication network 100 is shown. The multicast session may be a multicast MBS session. The first UE 121, for example, initially operates at least in a second DRX configuration. The method includes the following actions, which may be performed in any suitable order. Figure 3 The dashed boxes in represent optional actions.

[0079] Action 301

[0080] The network node 110 transmits a group paging message indicating that the multicast session is activated to the UE group 121, 122.

[0081] Action 302

[0082] The network node 110 transmits session data associated with the multicast session to the UE group 121, 122. The session data is transmitted to be at least partially receivable by the first UE 121 operating in the second DRX configuration, thereby further indicating to the first UE 121 that the multicast session is activated.

[0083] In some embodiments, transmitting the session data associated with the multicast session implies to the first UE 121 that the multicast session has been activated, e.g., if the first UE 121 fails to receive the transmitted group paging message in 301. In other words, if the first UE 121 misses the transmission of the group paging message in action 301, then receiving the transmitted session data associated with the multicast session implies to the first UE 121 that the multicast session has been activated, e.g., otherwise the session data would not be transmitted in the session.

[0084] The first UE 121 may be configured to be able to selectively operate in the first DRX configuration or the second DRX configuration, e.g., as in actions 201 - 203.

[0085] When the first UE 121 operates in the first DRX configuration, the first UE 121 may monitor the multicast session during a first set of MOs and may avoid monitoring the multicast session during a first period.

[0086] When the first UE 121 operates under the second DRX configuration, the first UE 121 can monitor sessions during the second set of MOs and can avoid monitoring multicast sessions within the second period. The second period is longer than the first period. The first set of MOs includes the second set of MOs. In this example, this means that the monitoring performed by the second DRX configuration is also performed by the first DRX configuration. This further means that the MOs of the second DRX configuration are a subset of the MOs of the first DRX configuration. In other words, when operating under the first DRX configuration, the first UE 121 can receive the same or even more data as when operating under the second DRX configuration.

[0087] In some embodiments, the second set of MOs is configured to include at least a portion of the MOs mapped to adjacent time slots in a radio frame. This enables the network node 110 to be more flexible in terms of when / where to transmit session data.

[0088] In some embodiments, the first UE 121 is configured to operate in an inactive mobility state, e.g., the radio resource control (RRC) inactive state. The first UE 121 can detect session activation and receive session data in the inactive mobility state.

[0089] These methods will now be further explained and illustrated in the following embodiments. These embodiments can be combined in any suitable manner.

[0090] The first UE 121 can be configured with two alternative DRX configurations for receiving session data in a multicast session (e.g., a multicast MBS session), the first DRX configuration is also referred to as DRX1, and the second DRX configuration is also referred to as DRX2. The second DRX configuration can have a longer period than the first DRX configuration. The first UE 121 is capable of switching between the first DRX configuration and the second DRX configuration, e.g., as in action 202. When the multicast session is deactivated, the first UE 121 can switch to the second DRX configuration. When it is detected that the multicast session is activated, e.g., as in action 201, the first UE 121 can switch to the first DRX configuration.

[0091] In some embodiments, when the first UE 121 believes (e.g., detects) that the session state of the multicast session is deactivated or will be deactivated, the first UE 121 monitors the group paging of the multicast session (e.g., as in action 201-1), and also monitors the session data indicating that the multicast session is activated for the multicast session itself (e.g., as in action 201-2). The multicast session can be monitored according to the second DRX configuration.

[0092] In some embodiments, when the first UE 121 believes (e.g., detects) that the session state of a multicast session is activated or will be activated, the first UE 121 may monitor the multicast session according to the first DRX configuration.

[0093] For session activation notification, a single group paging may be transmitted from the network node 110 to the first UE 121, e.g., as in action 301. The session activation notification may be sent as a group paging message to a group of UEs including the first UE 121 and optionally the second UE 122. The group of UEs 121, 122 may include any suitable combination of Rel-17 UEs and Rel-18 UEs. Rel-17 UEs may always switch to the RRC connected state when seeing the group paging message. If the first UE 121 receives a single group paging, e.g., as in action 201-1, the first UE 121 may immediately apply its first DRX configuration and then may receive multicasts in the multicast session, e.g., in the RRC inactive state, as expected.

[0094] If the first UE 121 misses the single group paging, it may still indirectly detect that the session is activated from receiving multicast session data using its second DRX configuration, e.g., as in action 201-2. When implementing such indirect detection, the first UE 121 may immediately switch to the first DRX configuration, e.g., as in action 202. Then, the first UE 121 may continue multicast reception using the first DRX configuration, e.g., in the RRC inactive state.

[0095] The network node 110 may need to ensure the coordination of the scheduling of multicast session data and the configuration of the second DRX configuration such that the first UE 121, when using the second DRX configuration, can detect at least some session data when the multicast session is activated and session data is transmitted in the multicast session. In other words, the network node 110 (e.g., as part of action 302) may need to schedule the multicast session data (e.g., MBS session data) such that the first UE 121 operating with the second DRX configuration should detect the transmitted session data.

[0096] The first UE 121 under the first DRX configuration or the second DRX configuration may be in the RRC inactive state, while the RRC connected state is an option. Using the RRC inactive state reduces the power consumption of the first UE 121 but will be slightly higher than just monitoring group paging. When using the second DRX configuration, the power consumption of the first UE 121 is reduced compared to using the first DRX configuration.

[0097] As an example scenario of the embodiments herein, the cycle time of the second DRX configuration can be much greater than the cycle time of the first DRX configuration, e.g., greater than a threshold. For an example application (e.g., Mission Critical PushTo Talk (MCPTT)), which typically uses one transmitted audio frame every 20 milliseconds (ms), corresponding to an average of one transmitted Transport Block (TB) every 20 ms, the cycle time of the first DRX configuration can be, e.g., 10 ms, e.g., when the first UE 121 is in a power saving state and / or not monitoring certain radios. This allows scheduling one TB containing an audio frame every 20 ms and allows for an alternative scheduling of + / - 10 ms so that the first UE 121 can receive the audio frame. In contrast, the second DRX configuration can be on the order of 500 ms, and when considering the monitoring of radio frames (e.g., in addition to monitoring the PO for group paging, this may increase power consumption when monitoring a multicast session according to the first DRX configuration and the second DRX configuration), the power consumption can be reduced by 50 times compared to using the first DRX configuration. As an example, if the cycle time of the PO for monitoring group paging messages (e.g., as transmitted in action 301) is, e.g., 100 ms, this means that the total power consumption due to monitoring according to the second DRX configuration and group paging monitoring is only slightly higher than just monitoring paging. This is because the second DRX configuration rarely monitors the session data of the multicast session, and the PO for group paging is the majority of the monitoring opportunities.

[0098] When the first UE 121 receives a (single) group paging (e.g., as in action 201-1), there is no data loss because the UE 121 can directly start monitoring the session data in the multicast session (e.g., using the first configuration), as in actions 202-203. If the first UE 121 misses the group paging (e.g., sent by the network node 110 in action 301), but detects session activation via the second DRX configuration (e.g., as in action 201-2), the multicast session may have lasted for the maximum time of the cycle time of the second DRX configuration. It can be assumed that in the subsequent monitoring opportunity of the second DRX configuration, the first UE 121 is unlikely to miss the group paging (e.g., as transmitted in action 301) and subsequent multicast session data (e.g., as transmitted in action 302). This is because when the first UE 121 is within the coverage area of the network node 110, the probability of missing the group paging and subsequent session data is extremely low, e.g., below a threshold.

[0099] In some scenarios, in order to allow time when UEs in UE groups 121, 122 (e.g., other than the first UE 121) are in the RRC inactive state and are paged in a group (e.g., as in action 301), and at least some UEs are expected to resume to the RRC connected state before receiving session data (e.g., as transmitted in action 302), the network node 110 may delay the session data transmission (e.g., as in action 302) until one or more UEs in UE groups 121, 122 are ready to receive data in the RRC connected state. This delay may be pre-determined. If the delay is 200 ms, it means that when the first UE 121 in the RRC inactive state misses the group paging, the time to receive data will not be more than 300 ms later than the UEs in UE groups 121, 122 that receive the group paging and resume to the RRC connected state. This is because, if the cycle time of the monitoring occasion of the second DRX configuration (e.g., as operated by the first UE 121) is 500 ms, that is, the first UE 121 checks the session data in the multicast session every 500 ms, then the first UE 121 can check the session data in the multicast session before the group paging message, and then after 200 ms, start the session data of the multicast session, and then after an additional 300 ms (500 ms has passed since the last monitoring), the first UE 121 can thus receive the session data of the multicast session, e.g., as in action 201-2. In other words, the difference between the cycle time of the second DRX configuration and the pre-determined delay can be the longest transmission time missed by the first UE 121, and the network node 110, the first UE 121, and / or the applications they use can take this into account, e.g., when planning how and when to send critical data to the first UE 121.

[0100] However, if the group paging is performed at a time independent of the monitoring occasion of the second DRX configuration, and if the cycle of the second DRX configuration is 500 ms, the first UE 121 in the RRC inactive state that has missed the group paging will, on average, receive the session data only 50 ms later than the resumed UEs. This is because, on average, the paging occasion is in the middle of the cycle time of the second DRX configuration. It should be noted that this amount of missed data only affects the UEs that miss the group paging. In the examples in this article, the first UE 121 is mainly discussed. However, those skilled in the art understand that this also applies to any number of UEs with similar or identical configurations.

[0101] In some embodiments, the network node 110 may coordinate the start of session data transmission (e.g., as in action 302) with the second DRX configuration monitoring occasion such that the second DRX configuration monitoring occasion will occur simultaneously with the first transmission data of the session data transmitted by the network node 110 (e.g., as in action 302), or as soon as possible after the first transmission, e.g., the time is less than a threshold.

[0102] It may also be noted that UEs in UE groups 121, 122 that are paged in a group to resume to the RRC connected state may also miss the group paging, at least to the same extent as UEs expected to remain in the RRC inactive state (e.g., the first UE 121). The network node 110 may know which UEs are expected to resume to the RRC connected state. Since there will be a delay before the network node 110 detects the missed UEs, assuming these UEs will receive repeated paging, they may also miss some data at the start of the activation period. This means that the amount of lost data of the first UE 121 that performs self-detection as in action 201-1 or 201-2 is not necessarily greater than that of UEs that need to resume to the RRC connected state. In some scenarios, in fact, the first UE 121 may on average lose less data than UEs that are always expected to resume to the RRC connected state. This is because even if the first UE 121 misses the group paging, it may be possible to quickly detect session activation. However, UEs that are always expected to resume to the RRC connected state will always have a significant delay before resuming to the RRC connected state.

[0103] Figure 4 Example scenarios of the embodiments herein are illustrated by comparing UEs in UE groups 121, 122 in three example cases. The first example scenario 401, where the DRX1 UEs in UE groups 121, 122 receive a group paging message transmitted by the network node 110, e.g., as in action 301, and resume to the RRC connected state to receive session data, i.e., Figure 4 the upper part of the illustration. The DRX1 UEs may initially be in the RRC inactive state, and when paged in a group, the DRX1 UEs may resume to the RRC connected state to operate under the first DRX configuration. Subsequently, after sending session activation 404, the network node 110 may send a group paging message 405, e.g., as in action 301, and since the network node 110 knows that the DRX1 UEs need to resume to the RRC connected state, the network node 110 may need to delay the transmission of session data in the multicast session. Then, the network node 110 may transmit the first data 406 as part of the multicast session data within a time period T1 after session activation 404.

[0104] Second example scenario 402, where the first UE 121 is in group paging and remains in the RRC inactive state to receive data, i.e., Figure 4 the middle part shown in the figure. The first UE 121 receives the group paging message 405 in one or more monitoring occasions 410, for example, as in action 201-1. The monitoring occasion 410 can be the monitoring occasion of the second DRX configuration and / or the paging occasion of the paging message. The first UE 121 switches to the first DRX configuration, for example, as in action 202, and when the network node 110 subsequently transmits the first data 406 as part of the multicast session data, the first UE 121 will receive the data as it is under the first DRX configuration and monitor the transmission occasion of the session data of the multicast session.

[0105] Third example scenario 403, where the first UE 121 misses the group paging but self-detects session activation, i.e., Figure 4 the lower part shown in the figure. The first UE 121 misses the group paging message 405 (transmitted by the network node 110 in action 301, for example).

[0106] In this third scenario 403, after the network node 110 has transmitted the first data 406, the first UE 121 will subsequently notice the existence of session data being transmitted in the multicast session during one or more monitoring occasions 420, for example, as in action 201-2. Then, the first UE 121 can switch to the first DRX configuration, for example, as in action 202, and continue to receive the multicast data in the RRC inactive state, for example, as in action 203.

[0107] To give the network node 110 a certain degree of scheduling flexibility while still ensuring that the first UE 121 can self-detect session activation only using its second DRX configuration (for example, as in action 201-2), the second DRX configuration can be configured to take this into account. In one embodiment, the second DRX configuration can be configured with a structure of monitoring occasions (MOs) that has MOs in several adjacent time slots (e.g., in a radio frame), followed by a larger gap (e.g., the cycle time of the second DRX configuration), and then again several such adjacent time slots, for example, as a pattern repetition. In this way, the network node 110 has the flexibility to adjust the scheduling from the nominal default time slots to any adjacent time slots. This embodiment does not exclude other second DRX configuration patterns, and any other DRX configuration can be applied, for example, where the power saving of the second DRX configuration is greater than that of the first DRX configuration. The configuration of the second DRX configuration can be flexible enough to allow any but at least multiple different second DRX configuration patterns.

[0108] Figure 5An example scenario of an embodiment herein is shown, and the communication between the first UE 121 and the network node 110 is shown as a combined flowchart and timing diagram.

[0109] In the example scenario, the first UE 121 monitors a multicast session 501 using a second DRX configuration.

[0110] In the example scenario, the network node 110 transmits a group paging message 502 to a UE group including the first UE 121, for example, as in action 301. This group paging message is associated with the activated multicast session. In other words, this group paging message indicates that the multicast session is activated.

[0111] In the example scenario, the first UE 121 misses the group paging message. In other words, the first UE 121 neither receives nor detects the group paging message.

[0112] In the example scenario, the network node 110 transmits session data 503a - c, for example, as in action 302, such that it can be received by UEs operating in a first DRX configuration.

[0113] The first UE 121 receives session data from transmission 503a, which can also be received by the second DRX configuration, and thus can detect session activation 504, for example, as in actions 201 - 2.

[0114] In the example scenario, the first UE 121 then switches 505 to the first DRX configuration, for example, as in action 202.

[0115] In the example scenario, the first UE 121 then operates in the first DRX configuration and can receive session data from transmissions 503b - c, which may not be receivable when operating in the second DRX configuration.

[0116] To perform the above method actions, the first UE 121 may include Figure 6a and Figure 6b the apparatus depicted therein. The first UE 121 is configured to handle a multicast session between the network node 110 and a UE group 121, 122 including at least the first UE 121 in a wireless communication network 100. This multicast session may be a multicast MBS session. The first UE 121 is configured to operate (e.g., at least initially) in a second DRX configuration.

[0117] The first UE 121 may include an input / output interface 600, which is configured to communicate with any suitable entity described herein (e.g., the network node 110). The input / output interface 600 may include a wireless receiver (not shown) and a wireless transmitter (not shown).

[0118] The first UE 121 may further include any one or more of the following: a receiving unit, a switching unit, a detecting unit, for example, for performing the above actions.

[0119] The first UE 121 is configured to detect that a multicast session is activated in any of the following ways: receiving a group paging message indicating that the multicast session is activated and transmitted to the UE group 121, 122, or receiving session data of the multicast session.

[0120] The first UE 121 is configured to switch from a second DRX configuration to a first DRX configuration in response to detecting that the multicast session is activated, where the first DRX configuration is adapted to indicate that the first UE 121 should monitor all session data transmitted in the multicast session. The second DRX configuration is applicable to indicate that the first UE 121 should monitor a subset of all session data transmitted in the multicast session.

[0121] In some embodiments, the first DRX configuration is adapted to include: monitoring the multicast session during a first set of monitoring opportunities (MOs) and avoiding monitoring the session within a first cycle time. In some of these embodiments, the second DRX configuration is adapted to include: monitoring the session during a second set of MOs and avoiding monitoring the session within a second cycle time. The second cycle time may be adapted to be longer than the first cycle time. The first set of MOs may be adapted to include the second set of MOs.

[0122] In some embodiments, the second set of MOs is adapted to be configured to include at least a portion of the MOs mapped to adjacent time slots in a radio frame.

[0123] In some embodiments, the first UE 121 is configured to operate in an inactive mobility state and is further configured to: receive session data of the multicast session when operating in the inactive mobility state when the first UE 121 has switched to the first DRX configuration.

[0124] In some embodiments, the first UE 121 is configured to: when the first UE 121 has not received a group paging message transmitted to the UE group 121, 122, receiving session data of the multicast session implies that the multicast session has been activated. Embodiments herein may be implemented by a processor or one or more processors (e.g., Figure 6aThe at least one processor 640 of the processing circuitry in the first UE 121 depicted is implemented together with computer program code for performing the functions and actions of the embodiments herein. The above program code can also be provided as a computer program product, for example, in the form of a data carrier carrying the computer program code, which is for performing the embodiments herein when loaded into the first UE 121. One such carrier can be in the form of a CD ROM disk. However, this is feasible for other data carriers (such as a memory stick). The computer program code can also be provided as pure program code on a server and downloaded to the first UE 121.

[0125] The first UE 121 may also include a corresponding memory 650, which includes one or more memory units. The memory includes instructions executable by the processor in the first UE 121. The memory is arranged to store instructions, data, configurations, and application programs for performing the methods herein when executed in the first UE 121.

[0126] In some embodiments, the computer program 660 includes instructions that, when executed by the at least one processor, cause the at least one processor of the first UE 121 to perform the above actions.

[0127] In some embodiments, the corresponding carrier 890 includes a corresponding computer program, where the carrier is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electrical signal, a radio signal, a microwave signal, or a computer-readable storage medium.

[0128] Those skilled in the art will also understand that the functional modules in the above first UE 121 can refer to a combination of analog circuits and digital circuits, and / or one or more processors configured with software and / or firmware (for example, stored in the first UE 121 and, when executed by the corresponding one or more processors (such as the above at least one processor), cause the corresponding at least one processor to perform actions according to any of the above actions). One or more of these processors and other digital hardware can be included in a single Application-Specific Integrated Circuitry (ASIC), or multiple processors and various digital hardware can be distributed in multiple separate components, whether individually packaged or assembled into a System-On-a-Chip (SoC).

[0129] To perform the above method actions, the network node 110 may include Figure 7a and Figure 7bThe apparatus depicted. The network node 110 is configured to handle a multicast session between the network node 110 and a group of UEs 121, 122 including at least the first UE 121 in a wireless communication network 100. The multicast session may be a multicast MBS session. The first UE 121 may be adapted (e.g., at least initially) to operate under a second DRX configuration.

[0130] The network node 110 may include an input / output interface 700, which is configured to communicate with any suitable entity described herein (e.g., the network node 110). The input / output interface 700 may include a wireless receiver (not shown) and a wireless transmitter (not shown).

[0131] The network node 110 may also include any one or more of the following: a receiving unit, a deriving unit, a configuring unit, e.g., for performing the actions described above.

[0132] The network node 110 is configured to transmit a group paging message indicating that the multicast session is activated to the group of UEs 121, 122.

[0133] The network node 110 is configured to transmit session data associated with the multicast session. The session data is transmitted to be at least partially receivable by the first UE 121 operating under the second DRX configuration, thereby further indicating to the first UE 121 that the multicast session is activated.

[0134] In some embodiments, the first UE 121 is configured to be able to selectively operate under a first DRX configuration or a second DRX configuration. In some embodiments, when the first UE 121 operates under the first DRX configuration, the first UE 121 monitors the multicast session during a first set of MOs and avoids monitoring the session during a first cycle time. In some embodiments, when the first UE 121 operates under the second DRX configuration, the first UE 121 monitors the session during a second set of MOs and avoids monitoring the session during a second cycle time. The second cycle time may be adapted to be longer than the first cycle time. The first set of MOs may be adapted to include the second set of MOs.

[0135] In some embodiments, the second set of MOs is adapted to be constructed to include at least a portion of the MOs mapped to adjacent time slots in a radio frame.

[0136] In some embodiments, the first UE 121 is adapted to be configured to operate in an inactive mobility state.

[0137] In some embodiments, transmitting the session data associated with the multicast session implies to the first UE 121 that the multicast session has been activated.

[0138] Embodiments herein may be implemented by a processor or one or more processors (e.g., Figure 7ais implemented together with at least one processor 740 of the processing circuitry in the network node 110 depicted herein and computer program code for performing the functions and actions of the embodiments herein. The above program code may also be provided as a computer program product, for example in the form of a data carrier carrying the computer program code, which is for performing the embodiments herein when loaded into the network node 110. One such carrier may be in the form of a CD ROM disk. However, this is feasible for other data carriers (such as memory sticks). The computer program code may also be provided as pure program code on a server and downloaded to the network node 110.

[0139] The network node 110 may also include a corresponding memory 750, which includes one or more memory units. The memory includes instructions executable by the processor in the network node 110. The memory is arranged to store instructions, data, configurations, and application programs for performing the methods herein when executed in the network node 110.

[0140] In some embodiments, the computer program 760 includes instructions that, when executed by at least one processor, cause at least one processor of the network node 110 to perform the above actions.

[0141] In some embodiments, the corresponding carrier 890 includes a corresponding computer program, where the carrier is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electrical signal, a radio signal, a microwave signal, or a computer-readable storage medium.

[0142] Those skilled in the art will understand that the functional modules in the above network node 110 may refer to a combination of analog circuits and digital circuits, and / or one or more processors configured with software and / or firmware (e.g., stored in the first UE 121, which, when executed by the corresponding one or more processors (such as the above at least one processor), cause the corresponding at least one processor to perform actions according to any of the above actions). One or more of these processors and other digital hardware may be included in a single application-specific integrated circuit (ASIC), or multiple processors and various digital hardware may be distributed in multiple separate components, whether individually packaged or assembled into a system-on-chip (SoC).

[0143] Embodiments

[0144] Some example embodiments 1 - 20 are briefly described below. For example, see Figure 1 、 2 、3, 4, 5, 6a, 6b, 7a, and 7b.

[0145] Example 1. A method for handling a multicast session between a network node 110 and a UE group 121, 122 including at least a first UE 121 in a wireless communication network 100, performed by the first UE 121. For example, the multicast session is a multicast, multicast broadcast service (MBS) session, and the first UE 121 operates in a second discontinuous reception (DRX) configuration. The method includes any one or more of the following, for example:

[0146] - Detecting 201 that the multicast session is activated in any of the following ways: receiving 201-1 a group paging message indicating that the multicast session is activated and transmitted to the UE group 121, 122, or receiving 201-2 session data of the multicast session,

[0147] - In response to detecting 201 that the multicast session is activated, switching 202 from the second DRX configuration to the first DRX configuration, where the first DRX configuration indicates that the first UE 121 should monitor the session data transmitted in the multicast session, and where the second DRX configuration indicates that the first UE 121 should monitor a subset of all session data transmitted in the multicast session, All and where the second DRX configuration indicates that the first UE 121 should monitor a subset of all session data transmitted in the multicast session,

[0148] - Optionally, the first DRX configuration includes monitoring the multicast session during a first set of monitoring occasions (MO) and avoiding monitoring the session within a first cycle time, where the second DRX configuration includes monitoring the session during a second set of MO and avoiding monitoring the session within a second cycle time, where the second cycle time is longer than the first cycle time, and where the first set of MO includes the second set of MO.

[0149] Example 2. The method according to Example 1, where the second set of MO is configured to include at least a part of the MO mapped to adjacent time slots in a radio frame.

[0150] Example 3. The method according to any one of Examples 1 to 2, where the first UE 121 is configured to operate in an inactive mobility state, for example, a radio resource control (RRC) inactive state, and where the method further includes:

[0151] - Receiving 203 session data of the multicast session while operating in the inactive mobility state when the first UE 121 has switched 202 to the first DRX configuration.

[0152] Example 4. The method according to any one of Examples 1 to 3, where when the first UE 121 has not received 201-1 the group paging message transmitted to the UE group 121, 122, receiving 201-2 session data of the multicast session implies to the first UE 121 that the multicast session has been activated, and for example, also implies that the first UE 121 has failed to receive the group paging message.

[0153] Example 5. A method performed by a network node 110 for handling a multicast session between the network node 110 and a UE group 121, 122 including at least a first UE 121 in a wireless communication network 100. For example, where the multicast session is a multicast, multicast broadcast service (MBS) session, and where the first UE 121 operates in a second discontinuous reception (DRX) configuration, the method may include any one or more of the following:

[0154] - Transmitting 301 a group paging message indicating that the multicast session is activated to the UE group 121, 122, and

[0155] - Transmitting 302 session data associated with the multicast session to the UE group 121, 122, the session data being transmitted to be at least partially received by the first UE 121 operating in the second DRX configuration, thereby further indicating to the first UE 121 that the multicast session is activated,

[0156] - Optionally, the first UE 121 is configured to be able to selectively operate in a first DRX configuration or a second DRX configuration. When the first UE 121 operates in the first DRX configuration, the first UE 121 monitors the multicast session during a first set of monitoring occasions (MO) and avoids monitoring the session during a first cycle time. When the first UE 121 operates in the second DRX configuration, the first UE 121 monitors the session during a second set of MO and avoids monitoring the session during a second cycle time, where the second cycle time is longer than the first cycle time, and where the first set of MO includes the second set of MO.

[0157] Example 6. The method according to Example 5, wherein the second set of MO is configured to include at least a part of the MO mapped to adjacent time slots in a radio frame.

[0158] Example 7. The method according to any one of Examples 5 to 6, wherein the first UE 121 is configured to operate in an inactive mobility state, for example, a radio resource control (RRC) inactive state.

[0159] Example 8. The method according to any one of Examples 5 to 7, wherein transmitting 302 the session data associated with the multicast session implies to the first UE 121 that the multicast session has been activated, for example, if the first UE 121 fails to receive the transmitted 301 group paging message.

[0160] Example 9. A computer program 660 comprising instructions which, when executed by a processor 640, cause the processor 640 to perform the actions according to any one of Examples 1 to 4.

[0161] Example 10. A carrier 670, which includes the computer program 660 according to Example 9, wherein the carrier 670 is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electrical signal, a radio signal, a microwave signal, or a computer-readable storage medium.

[0162] Example 11. A computer program 760 containing instructions, which, when executed by a processor 740, cause the processor 740 to perform the actions according to any one of Examples 5 to 8.

[0163] Example 12. A carrier 770, which includes the computer program 760 according to Example 11, wherein the carrier 770 is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electrical signal, a radio signal, a microwave signal, or a computer-readable storage medium.

[0164] Example 13. A first UE 121, which is configured to handle a multicast session between a network node 110 and a UE group 121, 122 including at least the first UE 121 in a wireless communication network 100. For example, the multicast session is suitable for a multicast or multicast broadcast service (MBS) session, and the first UE 121 is configured to operate in a second discontinuous reception (DRX) configuration. The first UE 121 is also configured to perform any one or more of the following:

[0165] - Detect that the multicast session is activated by a detection unit in the first UE 121 in any of the following ways: For example, receive a group paging message indicating that the multicast session is activated transmitted to the UE group 121, 122 by a receiving unit in the first UE 121, or receive session data of the multicast session by the receiving unit in the first UE 121,

[0166] - In response to detecting that the multicast session is activated, switch from the second DRX configuration to the first DRX configuration by a switching unit in the first UE 121, where the first DRX configuration is suitable for indicating that the first UE 121 should monitor the The whole session data transmitted in the multicast session, and the second DRX configuration is suitable for indicating that the first UE 121 should monitor a subset of all session data transmitted in the multicast session.

[0167] - Optionally, the first DRX configuration is suitable for including: monitoring the multicast session during a first set of monitoring opportunities (MO) and avoiding monitoring the session within a first cycle time, and the second DRX configuration is suitable for including: monitoring the session during a second set of MO and avoiding monitoring the session within a second cycle time, where the second cycle time is suitable for being longer than the first cycle time, and the first set of MO is suitable for including the second set of MO.

[0168] Example 14. The first UE 121 according to Example 13, wherein the second set of MOs is adapted to be configured to include at least a portion of the MOs mapped to adjacent time slots in a radio frame.

[0169] Example 15. The first UE 121 according to any one of Examples 13 to 14, which is further configured to operate in an inactive mobility state, for example, a radio resource control (RRC) inactive state, and is further configured to:

[0170] - When the first UE 121 has switched to the first DRX configuration, receive session data of a multicast session when operating in the inactive mobility state, for example, by a receiving unit in the first UE 121.

[0171] Example 16. The first UE 121 according to any one of Examples 13 to 15, wherein when the first UE 121 has not received a group paging message transmitted to the UE group 121, 122, receiving the session data of the multicast session implies to the first UE 121 that the multicast session has been activated, for example, and further implies that the first UE 121 has failed to receive the group paging message.

[0172] Example 17. A network node 110, which is configured to handle a multicast session between the network node 110 and a UE group 121, 122 including at least the first UE 121 in a wireless communication network 100, for example, wherein the multicast session is a multicast, multicast broadcast service (MBS) session, and wherein the first UE 121 is adapted to operate in a second discontinuous reception (DRX) configuration, and the network node 110 is further configured to perform any one or more of the following:

[0173] - Transmit a group paging message indicating that the multicast session is activated to the UE group 121, 122, for example, by a transmission unit in the network node 110, and

[0174] - Transmit session data associated with the multicast session, for example, by a transmission unit in the network node 110, and the session data is transmitted to be at least partially received by the first UE 121 operating in the second DRX configuration, thereby further indicating to the first UE 121 that the multicast session is activated,

[0175] - Optionally, the first UE 121 is configured to be able to selectively operate under a first DRX configuration or a second DRX configuration, and when the first UE 121 operates under the first DRX configuration, the first UE 121 monitors the multicast session during a first set of monitoring occasions (MOs) and avoids monitoring the session during a first cycle time, and when the first UE 121 operates under the second DRX configuration, the first UE 121 monitors the session during a second set of MOs and avoids monitoring the session during a second cycle time, where the second cycle time is adapted to be longer than the first cycle time, and where the first set of MOs is adapted to include the second set of MOs.

[0176] Example 18. The network node 110 according to Example 17, wherein the second set of MOs is adapted to be constructed to include at least a portion of the MOs mapped to adjacent time slots in a radio frame.

[0177] Example 19. The network node 110 according to any one of Examples 17 to 18, wherein the first UE 121 is adapted to be configured to operate in an inactive mobility state, e.g., a Radio Resource Control (RRC) inactive state.

[0178] Example 20. The network node 110 according to any one of Examples 17 to 19, wherein transmitting session data associated with the multicast session implies to the first UE 121 that the multicast session has been activated, e.g., if the first UE 121 fails to receive a transmitted group paging message.

[0179] Figure 8 An example of a communication system 800 according to some embodiments is shown. The communication system 800 may be a wireless communication network 100.

[0180] In this example, the communication system 800 includes a telecommunications network 802, which includes an access network 804 (e.g., a Radio Access Network (RAN)) and a core network 806, and the core network 806 includes one or more core network nodes 808 (e.g., CN node 130). The access network 804 includes one or more access network nodes, such as network nodes 810a and 810b, such as network node 110 (one or more of which may be collectively referred to as network node 810), or any other similar 3rd Generation Partnership Project (3GPP) access node or non-3GPP access point. The network node 810 facilitates the direct or indirect connection of user equipment (UE), such as connecting UEs 812a, 812b, 812c, and 812d (one or more of which may be collectively referred to as UE 812) (e.g., first UE 121 and / or second UE 122) to the core network 806 through one or more wireless connections.

[0181] Example wireless communications via a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for transmitting information without using wires, cables, or other material conductors. Additionally, in different embodiments, the communication system 800 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that can facilitate or participate in data and / or signal communication (whether via a wired connection or a wireless connection). The communication system 800 may include any type of communication, telecommunications, data, cellular, radio network, and / or other similar types of systems, and / or be connected to any type of communication, telecommunications, data, cellular, radio network, and / or other similar types of systems.

[0182] The UE 812 can be any of a variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network node 810 and other communication devices. Similarly, the network node 810 is arranged, capable, configured, and / or operable to communicate directly or indirectly with the UE 812 and / or with other network nodes or devices in the telecommunications network 802 to enable and / or provide network access (e.g., wireless network access) and / or perform other functions (e.g., management in the telecommunications network 802).

[0183] In the depicted example, the core network 806 connects the network node 810 to one or more hosts, such as host 816. These connections can be direct connections or indirect connections via one or more intermediate networks or devices. In other examples, the network node can be directly coupled to the host. The core network 806 includes one or more core network nodes (e.g., core network node 808) composed of hardware and software components. The characteristics of these components can be generally similar to those described for the UE, network node, and / or host, such that their description generally applies to the corresponding components of the core network node 808. Example core network nodes include the functions of one or more of the following: Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing Function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or User Plane Function (UPF).

[0184] The host 816 can be owned or controlled by a service provider other than the operator or vendor of the access network 804 and / or the telecommunication network 802, and can be operated by the service provider or on behalf of the service provider. The host 816 can host various applications to provide one or more services. Examples of such applications include live and pre-recorded audio / video content, data collection services (e.g., retrieving and compiling data on various environmental conditions detected by multiple UEs), analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for alarm and monitoring centers, or any other such functions performed by a server.

[0185] Generally speaking, Figure 8The communication system 800 enables connections between UEs, network nodes, and hosts. In this sense, the communication system can be configured to operate according to predefined rules or procedures, such as including but not limited to the following specific standards: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long-Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standards (e.g., 6G); wireless local area network (WLAN) standards, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standards, such as Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC), ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards, such as LoRa and Sigfox.

[0186] In some examples, the telecommunications network 802 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 802 can support network slicing to provide different logical networks to different devices connected to the telecommunications network 802. For example, the telecommunications network 802 can provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or providing Massive Machine Type Communication (mMTC) / Massive IoT services to additional UEs.

[0187] In some examples, the UE 812 is configured to transmit and / or receive information without direct human interaction. For example, the UE can be designed to transmit information to the access network 804 according to a predetermined schedule when triggered by an internal or external event or in response to a request from the access network 804. Additionally, the UE can be configured to operate in a single RAT or multi-RAT or multi-standard mode. For example, the UE can operate using any one or combination of Wi-Fi, NR (New Radio), and LTE, i.e., be configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) New Radio–Dual Connectivity (EN-DC).

[0188] In this example, the hub 814 communicates with the access network 804 to facilitate indirect communication between one or more UEs (e.g., UE 812c and / or 812d) and a network node (e.g., network node 810b). In some examples, the hub 814 can be a controller, router, content source, and analysis tool, or any other communication device described herein with respect to the UE. For example, the hub 814 can be a broadband router that enables the UE to access the core network 806. As another example, the hub 814 can be a controller that sends commands or instructions to one or more actuators in the UE. The commands or instructions can be received from the UE, network node 810, or through executable code, scripts, processes, or other instructions in the hub 814. As another example, the hub 814 can be a data collector that acts as a temporary storage for UE data and, in some embodiments, can perform analysis or other processing of the data. As another example, the hub 814 can be a content source. For example, for a UE that is a VR headset, display, speaker, or other media transmission device, the hub 814 can retrieve VR resources, video, audio, or other media or data related to sensory information via the network node, and then the hub 814 directly provides it to the UE after performing local processing and / or adding additional local content. In yet another example, the hub 814 acts as a proxy server or orchestrator for the UE, especially in the case where one or more UEs are low-power IoT devices.

[0189] The hub 814 may have a constant / persistent or intermittent connection to the network node 810b. The hub 814 may also allow for different communication schemes and / or scheduling between the hub 814 and the UEs (e.g., UEs 812c and / or 812d), as well as between the hub 814 and the core network 806. In other examples, the hub 814 is connected to the core network 806 and / or one or more UEs via a wired connection. Additionally, the hub 814 may be configured to connect to an M2M service provider via the access network 804 and / or to another UE via a direct connection. In some scenarios, a UE may establish a wireless connection to the network node 810 while still being connected via the hub 814 via a wired or wireless connection. In some embodiments, the hub 814 may be a dedicated hub, i.e., its primary function is to route communications from the network node 810b to the UEs / to the network node 810b from the UEs. In other embodiments, the hub 814 may be a non-dedicated hub, i.e., a device that is capable of operating to route communications between the UEs and the network node 810b, but is also capable of operating as a communication origin and / or destination for certain data channels.

[0190] Figure 9 is a block diagram of a host 900 according to various aspects described herein, the host 900 may be Figure 8 an embodiment of the host 816. As used herein, the host 900 may be or include various combinations of hardware and / or software, including stand-alone servers, blade servers, cloud-implemented servers, distributed servers, virtual machines, containers, or processing resources in a server farm. The host 900 may provide one or more services to one or more UEs.

[0191] The host 900 includes a processing circuit 902, which is operatively coupled via a bus 904 to an input / output interface 906, a network interface 908, a power supply 910, and a memory 912. Other components may be included in other embodiments. The characteristics of these components may be substantially similar to those described for the devices of the previous figures, such that their description generally applies to the corresponding components of the host 900.

[0192] Memory 912 may include one or more computer programs, including one or more host applications 914 and data 916. The data 916 may include user data, e.g., data generated by the UE for the host 900, or data generated by the host 900 for the UE. Embodiments of the host 900 may use only a subset or all of the illustrated components. The host application 914 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAC, Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., mobile phones, desktop computers, wearable display systems, head-up display systems). The host application 914 may also provide user authentication and license checking and may periodically report health, routing, and content availability to a central node (e.g., a device in or at the edge of the core network). Thus, the host 900 may select and / or indicate different hosts for Over-the-Top services for the UE. The host application 914 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, the Real-Time Messaging Protocol (RTMP), the Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), etc.

[0193] Figure 10 A communication diagram is shown of a host 1002 communicating with a UE 1006 over a partial wireless connection via a network node 1004, according to some embodiments. Reference will now be made to Figure 10 Describe example implementations of the UE, network nodes (e.g., Figure 8 network node 810a) and hosts (e.g., Figure 8 host 816 and / or Figure 9 host 900) discussed in the previous paragraphs according to various embodiments.

[0194] Similar to host 900, embodiments of host 1002 include hardware such as a communication interface, processing circuitry, and memory. Host 1002 also includes software that is stored in or accessible by host 1002 and executable by the processing circuitry. The software includes host applications that are operable to provide services to remote users, such as UE 1006 connected via an over-the-top (OTT) connection 1050 extending between UE 1006 and host 1002. When providing services to remote users, the host applications may provide user data transmitted using OTT connection 1050.

[0195] Network node 1004 includes hardware that enables it to communicate with host 1002 and UE 1006. Connection 1060 may be direct or through a core network (such as Figure 8 core network 806) and / or one or more other intermediate networks (such as one or more public, private, or managed networks). For example, the intermediate network may be a backbone network or the Internet.

[0196] UE 1006 includes hardware and software that is stored in or accessible by UE 1006 and executable by the processing circuitry of the UE. The software includes client applications such as a web browser or a carrier-specific "application (APP)" that are operable to provide services to human or non-human users via UE 1006 with the support of host 1002. In host 1002, the executing host applications may communicate with the executing client applications via the OTT connection 1050 terminated at UE 1006 and host 1002. When providing services to users, the client applications of the UE may receive request data from the host applications of the host and provide user data in response to the request data. The OTT connection 1050 may transmit the request data and the user data. The client applications of the UE may interact with the users to generate user data that it provides to the host applications via the OTT connection 1050.

[0197] The OTT connection 1050 may extend via the connection 1060 between host 1002 and network node 1004 and via the wireless connection 1070 between network node 1004 and UE 1006 to provide a connection between host 1002 and UE 1006. The connection 1060 and the wireless connection 1070 (through which the OTT connection 1050 may be provided) have been abstractly drawn to illustrate the communication between host 1002 and UE 1006 via network node 1004 without explicitly referring to any intermediate devices and the exact routing of messages through these devices.

[0198] Taking the transmission of data via the OTT connection 1050 as an example, in step 1008, the host 1002 provides user data, which can be performed by executing a host application. In some embodiments, the user data is associated with a specific human user interacting with the UE 1006. In other embodiments, the user data is associated with the UE 1006, and the UE 1006 shares data with the host 1002 without explicit human-machine interaction. In step 1010, the host 1002 initiates a transmission carrying the user data to the UE 1006. The host 1002 can initiate the transmission in response to a request transmitted by the UE 1006. The request can be caused by human interaction with the UE 1006 or by the operation of a client application executed on the UE 1006. According to the teachings of the embodiments described throughout this disclosure, the transmission can be through the network node 1004. Thus, in step 1012, according to the teachings of the embodiments described throughout this disclosure, the network node 1004 transmits the user data carried in the transmission initiated by the host 1002 to the UE 1006. In step 1014, the UE 1006 receives the user data carried in the transmission, which can be performed by a client application executed on the UE 1006 and associated with the host application executed by the host 1002.

[0199] In some examples, the UE 1006 executes a client application that provides user data to the host 1002. The user data can be provided in response to or in reaction to data received from the host 1002. Accordingly, in step 1016, the UE 1006 can provide user data, which can be performed by executing the client application. When providing the user data, the client application can also consider user input received from the user via the input / output interface of the UE 1006. Regardless of the specific manner of providing the user data, in step 1018, the UE 1006 initiates a transmission of the user data to the host 1002 via the network node 1004. In step 1020, according to the teachings of the embodiments described throughout this disclosure, the network node 1004 receives the user data from the UE 1006 and initiates a transmission of the received user data to the host 1002. In step 1022, the host 1002 receives the user data carried in the transmission initiated by the UE 1006.

[0200] One or more of the various embodiments can improve the performance of the OTT service provided to the UE 1006 using the OTT connection 1050, where the wireless connection 1070 forms the final segment. More precisely, the teachings of these embodiments can improve power consumption and reduce traffic, thus providing benefits such as reduced user waiting time, better responsiveness, and extended battery life.

[0201] In an example scenario, the host 1002 can collect and analyze factory status information. As another example, the host 1002 can process audio and video data that has been retrieved from the UE for map creation. As another example, the host 1002 can collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1002 can store the monitoring videos uploaded by the UE. As another example, the host 1002 can store or control access to media content (e.g., video, audio, VR, or AR), and it can broadcast, multicast, or unicast it to the UE. As other examples, the host 1002 can be used for energy pricing, remote control of non-time-critical electrical loads to balance power generation demand, location services, presentation services (e.g., compiling charts based on data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing, and / or transmitting data.

[0202] In some examples, a measurement process can be provided for the purpose of monitoring data rate, latency, and other factors improved in one or more embodiments. There can also be optional network functionality for reconfiguring the OTT connection 1050 between the host 1002 and the UE 1006 in response to changes in the measurement results. The measurement process and / or network functionality for reconfiguring the OTT connection can be implemented in the software and hardware of the host 1002 and / or the UE 1006. In some embodiments, sensors (not shown) can be deployed in or associated with other devices through which the OTT connection 1050 passes; the sensors can participate in the measurement process by providing values of the monitored quantities exemplified above, or other physical quantities from which software can calculate or estimate the monitored quantities. The reconfiguration of the OTT connection 1050 can include message format, retransmission settings, preferred routing, etc.; the reconfiguration does not need to directly change the operation of the network node 1004. Such processes and functionality can be known and practiced in the art. In certain embodiments, the measurement can involve proprietary UE signaling that helps the host 1002 measure throughput, propagation time, latency, etc. The measurement can be achieved by software causing messages, especially empty messages or "dummy" messages, to be transmitted using the OTT connection 1050 while detecting propagation time, errors, etc.

[0203] When the words "comprising" or "including" are used, they should be understood as non-restrictive, meaning "consisting at least of...".

[0204] The embodiments herein are not limited to the above preferred embodiments. Various alternatives, modifications, and equivalents can be used.

Claims

1. A method performed by a first UE (121) for handling a multicast session between a network node (110) and a UE group (121, 122) including at least the first UE (121) in a wireless communication network (100), wherein, the first UE (121) operates under a second discontinuous reception DRX configuration, and the method includes: - detecting (201) activation of the multicast session by any of the following: receiving (201-1) a group paging message transmitted to the UE group (121, 122) indicating activation of the multicast session, or receiving (201-2) session data of the multicast session, - in response to detecting (201) activation of the multicast session, switching (202) from the second DRX configuration to a first DRX configuration, wherein the first DRX configuration indicates that the first UE (121) should monitor all session data transmitted in the multicast session, and wherein the second DRX configuration indicates that the first UE (121) should monitor a subset of all session data transmitted in the multicast session.

2. The method according to claim 1, wherein, the first DRX configuration includes monitoring the multicast session during a first set of monitoring occasions MO and avoiding monitoring the session within a first cycle time, wherein the second DRX configuration includes monitoring the session during a second set of MO and avoiding monitoring the session within a second cycle time, wherein the second cycle time is longer than the first cycle time, and wherein the first set of MO includes the second set of MO.

3. The method according to claim 2, wherein, the second set of MO is configured to include at least a portion of MOs mapped to adjacent time slots in a radio frame.

4. The method according to any one of claims 1 to 3, wherein, the first UE (121) is configured to operate in an inactive mobility state, and the method further includes: - when the first UE (121) has switched (202) to the first DRX configuration, receiving (203) session data of the multicast session while operating in the inactive mobility state.

5. The method according to any one of claims 1 to 4, wherein, when the first UE (121) has not received (201-1) a group paging message transmitted to the UE group (121, 122), receiving (201-2) session data of the multicast session implies to the first UE (121) that the multicast session has been activated.

6. A method performed by a network node (110) for handling a multicast session between the network node (110) and a UE group (121, 122) including at least the first UE (121) in a wireless communication network (100), wherein the first UE (121) operates under a second discontinuous reception DRX configuration, the method includes: - transmitting (301) to the UE group (121, 122) a group paging message indicating activation of the multicast session, and - Transmit (302) session data associated with the multicast session to the UE group (121, 122), the session data being transmitted to be at least partially receivable by a first UE (121) operating under a second DRX configuration, thereby further indicating to the first UE (121) that the multicast session is active.

7. The method according to claim 6, wherein, the first UE (121) is configured to be able to selectively operate under a first DRX configuration or under the second DRX configuration, and when the first UE (121) operates under the first DRX configuration, the first UE (121) monitors the multicast session during a first set of monitoring opportunities (MO) and avoids monitoring the session during a first cycle time, and when the first UE (121) operates under the second DRX configuration, the first UE (121) monitors the session during a second set of MO and avoids monitoring the session during a second cycle time, wherein the second cycle time is longer than the first cycle time, and wherein the first set of MO includes the second set of MO.

8. The method according to claim 7, wherein, the second set of MO is configured to at least include at least a portion of the MO mapped to adjacent time slots in a radio frame.

9. The method according to any one of claims 6 to 8, wherein, the first UE (121) is configured to operate in an inactive mobility state.

10. The method according to any one of claims 6 to 9, wherein, transmitting (302) session data associated with the multicast session implies to the first UE (121) that the multicast session has been activated.

11. A computer program (860) comprising instructions which, when executed by a processor (840), cause the processor (840) to perform the actions according to any one of claims 1 to 5.

12. A carrier (870) comprising the computer program (860) according to claim 11, wherein, the carrier (870) is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electrical signal, a radio signal, a microwave signal or a computer-readable storage medium.

13. A computer program (860) comprising instructions which, when executed by a processor (840), cause the processor (840) to perform the actions according to any one of claims 6 to 10.

14. A carrier (870) comprising the computer program (860) according to claim 13, wherein, the carrier (870) is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electrical signal, a radio signal, a microwave signal or a computer-readable storage medium.

15. A first UE (121) configured to handle a multicast session between a network node (110) and a UE group (121, 122) including at least the first UE (121) in a wireless communication network (100), and wherein the first UE (121) is configured to operate under a second discontinuous reception DRX configuration, the first UE (121) is further configured to: - Detect that the multicast session is activated in any of the following ways: receiving a group paging message transmitted to the UE group (121, 122) indicating that the multicast session is activated, or receiving session data of the multicast session, - In response to detecting that the multicast session is activated, switch from the second DRX configuration to a first DRX configuration, wherein the first DRX configuration is adapted to indicate that the first UE (121) should monitor all session data transmitted in the multicast session, and wherein the second DRX configuration is adapted to indicate that the first UE (121) should monitor a subset of all session data transmitted in the multicast session.

16. The first UE (121) according to claim 15, wherein, the first DRX configuration is adapted to include: monitoring the multicast session during a first set of monitoring opportunities MO and avoiding monitoring the session within a first periodic time, wherein the second DRX configuration is adapted to include: monitoring the session during a second set of MO and avoiding monitoring the session within a second periodic time, wherein the second periodic time is adapted to be longer than the first periodic time, and wherein the first set of MO is adapted to include the second set of MO.

17. The first UE (121) according to claim 16, wherein, the second set of MO is adapted to be constructed to include at least a portion of the MO mapped to adjacent time slots in a radio frame.

18. The first UE (121) according to any one of claims 15 to 17, further configured to operate in an inactive mobility state, and further configured to: - Receive session data of the multicast session when operating in the inactive mobility state when the first UE (121) has switched to the first DRX configuration.

19. The first UE (121) according to any one of claims 15 to 18, wherein, receiving session data of the multicast session implies to the first UE (121) that the multicast session has been activated when the first UE (121) has not received a group paging message transmitted to the UE group (121, 122).

20. A network node (110) configured to handle a multicast session between the network node (110) and a UE group (121, 122) including at least a first UE (121) in a wireless communication network (100), and wherein the first UE (121) is adapted to operate under a second discontinuous reception DRX configuration, the network node (110) is further configured to: - Transmit a group paging message indicating that the multicast session is activated to the UE group (121, 122), and - Transmit session data associated with the multicast session, the session data being transmitted to be at least partially receivable by the first UE (121) operating under a second DRX configuration, thereby further indicating to the first UE (121) that the multicast session is active.

21. The network node (110) according to claim 20, wherein, the first UE (121) is configured to be able to selectively operate under a first DRX configuration or under the second DRX configuration, and when the first UE (121) operates under the first DRX configuration, the first UE (121) monitors the multicast session during a first set of monitoring occasions (MO) and avoids monitoring the session during a first cycle time, and when the first UE (121) operates under the second DRX configuration, the first UE (121) monitors the session during a second set of MO and avoids monitoring the session during a second cycle time, wherein the second cycle time is adapted to be longer than the first cycle time, and wherein the first set of MO is adapted to include the second set of MO.

22. The network node (110) according to claim 21, wherein, the second set of MO is adapted to be constructed to at least include at least a portion of the MO mapped to adjacent time slots in a radio frame.

23. The network node (110) according to any one of claims 20 to 22, wherein, the first UE (121) is adapted to be configured to operate in an inactive mobility state.

24. The network node (110) according to any one of claims 20 to 23, wherein, transmitting session data associated with the multicast session implies to the first UE (121) that the multicast session has been activated.

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