Method, device and computer program

Abstract

A device is provided, the device comprising a means for: transmitting a data unit to a network node, the data unit conveying data from a logical channel LCH configured with a set of logical channel parameters; starting a first timer when transmitting the data unit to the network node; determining based on a state of the first timer to configure the logical channel using a modified set of logical channel parameters; configuring the logical channel using the modified set of physical channel parameters based on the determination; and transmitting a data unit to the network node, the data unit conveying data from a logical channel configured with the modified set of logical channel parameters.

Description

Technical Field

[0001] The present application relates to a method, apparatus, system and computer program, and in particular, but not exclusively, to dynamic modification of LCH mapping restrictions when a cg retransmission timer expires. Background Art

[0002] A communication system may be viewed as a facility for enabling communication sessions between two or more entities such as user terminals, base stations and / or other nodes by providing carriers between the various entities involved in the communication path. For example, a communication system may be provided by means of a communication network and one or more compatible communication devices (also referred to as stations or user equipment) and / or application servers. A communication session may include, for example, communications for carrying data for communication, such as voice, video, electronic mail (email), text messages, multimedia, content data, time-sensitive network (TSN) streams and / or data in industrial applications such as critical system messages between actuators and controllers, critical sensor data (such as measurements, video feeds, etc.) toward control systems, etc. Non-limiting examples of the services provided include two-way or multi-way calls, data communications or multimedia services, and access to data network systems such as the Internet.

[0003] In a wireless communication system, at least a portion of a communication session, e.g. between at least two stations or between at least one station and at least one application server (e.g. for video), takes place over a wireless link. Examples of wireless systems include public land mobile networks (PLMNs) operating based on 3GPP radio standards such as E-UTRA, new air interfaces, satellite-based communication systems, and different wireless local area networks such as wireless local area networks (WLANs). Wireless systems can typically be divided into cells and are therefore often referred to as cellular systems.

[0004] A user can access the communication system with the aid of an appropriate communication device or terminal. The user's communication device may be referred to as a user equipment (UE) or a user device. The communication device is provided with an appropriate signal receiving and transmitting device for implementing communication, for example, implementing access to a communication network or communicating directly with other users. The communication device can access one or more carriers provided by a network such as a base station of a cell, and transmit and / or receive communications on one or more carriers. In carrier aggregation (CA), two or more carriers are combined into one channel. In dual connectivity (DC), two carriers from different sites are combined, that is, the user equipment can be dual (or multi) connected to two (or more) sites.

[0005] Communication systems and related equipment typically operate according to a given standard or specification that arranges what the various entities associated with the system are allowed to do and how it should be achieved. Communication protocols and / or parameters that should be used for the connection are also typically defined. An example of a communication system is UTRAN (3G radio). Other examples of communication systems are the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) based on the E-UTRAN radio access technology, and the so-called 5G System (5GS), which includes a 5G or Next Generation Core (NGC) and a 5G access network based on the New Radio (NR) radio access technology. 5GS, including NR, is being standardized by the Third Generation Partnership Project (3GPP). Summary of the invention

[0006] In a first aspect, a device is provided, comprising a means for performing the following at a terminal device: transmitting a data unit to a network node, the data unit transmitting data from a logical channel LCH configured with a set of logical channel parameters; starting a first timer when transmitting the data unit to the network node; determining based on a state of the first timer to configure the logical channel using a modified set of logical channel parameters; configuring the logical channel using the modified set of logical channel parameters based on the determination; and transmitting a data unit to the network node, the data unit transmitting data from a logical channel configured with the modified set of logical channel parameters.

[0007] The set of logical channel parameters and the modified set of logical channel parameters may include at least one of at least one LCH mapping restriction, LCH priority, prioritized bit rate, bucket size duration, and channel access priority category.

[0008] The at least one LCH mapping restriction may indicate a list of allowed configuration authorizations.

[0009] The at least one LCH mapping restriction may indicate a list of allowed serving cells.

[0010] The apparatus may include means for receiving at least one configuration message from a network node, the configuration message indicating at least one of a set of logical channel parameters and a modified set of logical channel parameters.

[0011] The first timer may be a cg retransmission timer.

[0012] The status of the first timer may include expiration of the first timer.

[0013] The apparatus may include means for reverting to a configuration of a set of logical channel parameters for a logical channel based on at least one condition.

[0014] The at least one condition may include at least one of expiration of a second timer, receipt of a control signal from a network node, confirmation that the data unit has been successfully transmitted and received, and generation of a data unit.

[0015] The apparatus may include means for receiving an indication of at least one condition from a network node.

[0016] In a second aspect, a method is provided, the method comprising: at a terminal device: transmitting a data unit to a network node, the data unit transmitting data from a logical channel LCH configured with a set of logical channel parameters; starting a first timer when transmitting the data unit to the network node; determining based on a state of the first timer to configure the logical channel using a modified set of logical channel parameters; configuring the logical channel using the modified set of logical channel parameters based on the determination; and transmitting a data unit to the network node, the data unit transmitting data from a logical channel configured with the modified set of logical channel parameters.

[0017] The set of logical channel parameters and the modified set of logical channel parameters may include at least one of at least one LCH mapping restriction, LCH priority, prioritized bit rate, bucket size duration, and channel access priority category.

[0018] The at least one LCH mapping restriction may indicate a list of allowed configuration authorizations.

[0019] The at least one LCH mapping restriction may indicate a list of allowed serving cells.

[0020] The method may include receiving at least one configuration message from a network node, the configuration message indicating at least one of a set of logical channel parameters and a modified set of logical channel parameters.

[0021] The first timer may be a cg retransmission timer.

[0022] The status of the first timer may include expiration of the first timer.

[0023] The method may include reverting to a configuration of a set of logical channel parameters for the logical channel based on at least one condition.

[0024] The at least one condition may include at least one of expiration of a second timer, receipt of a control signal from a network node, confirmation that the data unit has been successfully transmitted and received, and generation of a data unit.

[0025] The method may include receiving an indication of at least one condition from a network node.

[0026] In a third aspect, a device is provided, comprising at least one processor and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to use the at least one processor to enable the device, at least at a terminal device, to: transmit a data unit to a network node, wherein the data unit transmits data from a logical channel LCH configured with a set of logical channel parameters; start a first timer when transmitting the data unit to the network node; determine based on a state of the first timer to configure the logical channel using a modified set of logical channel parameters; configure the logical channel based on the determination to use the modified set of logical channel parameters; and transmit a data unit to the network node, wherein the data unit transmits data from a logical channel configured with the modified set of logical channel parameters.

[0027] The set of logical channel parameters and the modified set of logical channel parameters may include at least one of at least one LCH mapping restriction, LCH priority, prioritized bit rate, bucket size duration, and channel access priority category.

[0028] The at least one LCH mapping restriction may indicate a list of allowed configuration authorizations.

[0029] The at least one LCH mapping restriction may indicate a list of allowed serving cells.

[0030] The apparatus may be configured to receive at least one configuration message from a network node, the configuration message indicating at least one of a set of logical channel parameters and a modified set of logical channel parameters.

[0031] The first timer may be a cg retransmission timer.

[0032] The status of the first timer may include expiration of the first timer.

[0033] The apparatus may be configured to revert to a configuration of a set of logical channel parameters for a logical channel based on at least one condition.

[0034] The at least one condition may include at least one of expiration of a second timer, receipt of a control signal from a network node, confirmation that the data unit has been successfully transmitted and received, and generation of a data unit.

[0035] The apparatus may be configured to receive an indication of at least one condition from a network node.

[0036] In a fourth aspect, a computer-readable medium comprising program instructions is provided, wherein the program instructions are used to cause an apparatus to perform at least the following operations at a terminal device: transmit a data unit to a network node, wherein the data unit transmits data from a logical channel LCH configured with a set of logical channel parameters; start a first timer when transmitting the data unit to the network node; determine based on a state of the first timer to configure the logical channel using a modified set of logical channel parameters; configure the logical channel using the modified set of logical channel parameters based on the determination; and transmit a data unit to the network node, wherein the data unit transmits data from a logical channel configured with the modified set of logical channel parameters.

[0037] The modified set of logical channel parameters may include at least one of at least one LCH mapping restriction, LCH priority, prioritized bit rate, bucket size duration, and channel access priority category.

[0038] The at least one LCH mapping restriction may indicate a list of allowed configuration authorizations.

[0039] The at least one LCH mapping restriction may indicate a list of allowed serving cells.

[0040] The apparatus may be caused to perform receiving at least one configuration message from a network node, the configuration message indicating at least one of a set of logical channel parameters and a modified set of logical channel parameters.

[0041] The first timer may be a cg retransmission timer.

[0042] The status of the first timer may include expiration of the first timer.

[0043] The apparatus may be caused to perform reverting to configuration of a set of logical channel parameters for the logical channel based on at least one condition.

[0044] The at least one condition may include at least one of expiration of a second timer, receipt of a control signal from a network node, confirmation that the data unit has been successfully transmitted and received, and generation of a data unit.

[0045] The apparatus may be caused to perform receiving an indication of at least one condition from a network node.

[0046] In a fifth aspect, a non-transitory computer-readable medium is provided, comprising program instructions for causing an apparatus to at least perform the method according to the second aspect.

[0047] In the above, many different embodiments have been described. It should be understood that further embodiments can be provided by combining any two or more of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0049] Figure 1 shows a schematic diagram of an example 5G communication system;

[0050] Figure 2 A schematic diagram of an example mobile communication device is shown;

[0051] Figure 3 A schematic diagram of an example control arrangement is shown;

[0052] Figure 4 shows a flow chart of a method according to an example embodiment;

[0053] Figure 5 shows a signaling flow according to an example embodiment;

[0054] Figure 6 shows a logic flow diagram at a terminal according to an example embodiment;

[0055] Figure 7 A schematic diagram of a first configuration authorization CG1 and a second configuration authorization CG2 is shown. DETAILED DESCRIPTION

[0056] Before explaining the examples in detail, we will refer to Figures 1 to 3 Certain general principles of wireless communication systems and mobile communication devices are briefly explained to assist in understanding the technology behind the described examples.

[0057] An example of a suitable communication system is a 5G system (5GS). The network architecture in 5GS may be similar to that of Advanced LTE. The base stations of the NR system may be referred to as Next Generation Node Bs (gNBs). Changes to the network architecture may depend on the need to support various radio technologies and more sophisticated QoS support, as well as on-demand requirements for, for example, QoS levels to support the user's QoE. In addition, network-aware services and applications, as well as service- and application-aware networks, may bring changes to the architecture. These are all related to information-centric networks (ICNs) and user-centric content delivery networks (UC-CDN) approaches. NR may use multiple-input multiple-output (MIMO) antennas, many more base stations or nodes than LTE, including macro sites operating in cooperation with smaller stations (the so-called small cell concept), and may also use various radio technologies to achieve better coverage and enhanced data rates.

[0058] 5G networks may utilize network function virtualization (NFV), a network architecture concept that proposes virtualizing network node functions into "building blocks" or entities that are operably connected or linked together to provide services. Virtualized network functions (VNFs) may include one or more virtual machines that use standard or general-purpose servers rather than custom hardware to run computer program code. Cloud computing or data storage may also be utilized. In radio communications, this may mean that node operations are performed at least in part in a server, host, or node that is operably coupled to a remote radio head. It is also possible that node operations are distributed among multiple servers, nodes, or hosts. It should also be understood that the distribution of labor between core network operations and base station operations may be different from that of LTE, or even non-existent.

[0059] Figure 1 A schematic diagram of a 5G system (5GS) 100 is shown. The 5GS may include a user equipment (UE) 102 (also referred to as a communication device or terminal), a 5G radio access network (5GRAN) 104, a 5G core network (5GCN) 106, one or more application functions (AFs) 108, and one or more data networks (DNs) 110.

[0060] An example 5G core network (CN) includes functional entities. The 5GCN 106 may include one or more access and mobility management functions (AMFs) 112, one or more session management functions (SMFs) 114, an authentication server function (AUSF) 116, a unified data management (UDM) 118, one or more user plane functions (UPFs) 120, a unified data repository (UDR) 122, and / or a network exposure function (NEF) 124. The UPF is controlled by the SMF (session management function) which receives policies from the PCF (policy control function).

[0061] The CN is connected to the terminal device via a radio access network (RAN). A 5G RAN may include one or more gNodeB (GNB) distributed unit functions, which are connected to one or more gNodeB (GNDB) centralized unit functions. The RAN may include one or more access nodes.

[0062] The UPF (User Plane Function) whose role is called PSA (PDU Session Anchor) may be responsible for forwarding frames back and forth between the DN (Data Network) and the tunnel established on 5G to the UE exchanging services with the DN.

[0063] Now refer to Figure 2 Describe the possible terminal devices in more detail, Figure 2A schematic partial cutaway view of a communication device 200 is shown. Such a communication device is generally referred to as a user equipment (UE). Suitable communication equipment may be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a mobile station (MS) or mobile device, such as a mobile phone or so-called "smart phone", a computer provided with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal data assistant (PDA), or a tablet computer provided with wireless communication capabilities, or any combination of these or similar devices. For example, a communication device may provide data communications for carrying communications such as voice, e-mail (email), text messages, multimedia, etc. Therefore, many services may be provided to a user via the user's communication device. Non-limiting examples of these services include two-way or multi-way calls, data communications or multimedia services, or simply access to a data communication network system such as the Internet. Broadcast or multicast data may also be provided to the user. Non-limiting examples of content include downloads, television and radio programs, videos, advertisements, various warnings, and other information.

[0064] The device is typically provided with at least one data processing entity 201, at least one memory 202 and possibly other components 203 for software and hardware assistance in performing the tasks it is designed to perform, including controlling access to and communication with access systems and other communication devices. Data processing, storage and other related control devices may be provided on appropriate circuit boards and / or in chipsets. This feature is represented by reference numeral 204. The user may control the operation of the mobile device with the aid of a suitable user interface such as a keyboard 205, voice commands, a touch-sensitive screen or touchpad, a combination thereof. A display 208, a speaker and a microphone may also be provided. In addition, the mobile communication device may include appropriate connectors (wired or wireless) to other devices and / or for connecting external accessories such as hands-free devices to it.

[0065] The apparatus 200 may receive signals over the air or radio interface 207 via appropriate means for receiving, and may transmit signals via appropriate means for transmitting radio signals. Figure 2 In the mobile device, the transceiver arrangement is schematically represented by block 206. The transceiver arrangement 206 may be provided, for example, by means of a radio component and an associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[0066] Figure 3An example embodiment of a control device for a communication system is shown, for example, for coupling to and / or controlling a station of an access system, such as a RAN node, such as a base station, eNB or gNB, a relay node or a core network node, such as an MME or S-GW or P-GW, or a core network function, such as an AMF / SMF, or a server or host. The method may be implanted in a single control device, or span more than one control device. The control device may be integrated with a node or module of a core network or RAN or external to a node or module of a core network or RAT. In some embodiments, the base station includes a separate control device unit or module. In other embodiments, the control device may be another network element, such as a radio network controller or a spectrum controller. In some embodiments, each base station may have such a control device and a control device provided in a radio network controller. The control device 300 may be arranged to provide control of communications in a service area of ​​the system. The control device 300 includes at least one memory 301, at least one data processing unit 302, 303 and an input / output interface 304. Via the interface, the control device may be coupled to a receiver and a transmitter of the base station. The receiver and / or transmitter may be implemented as a radio front end or a remote radio head.

[0067] In 3GPP Rel-17, it is expected that Industrial Internet of Things (IIoT) / Ultra-Reliable Low Latency Communications (URLLC) should be supported in the unlicensed New Radio Band (NR-U), with a focus on enhancements related to provisioning authorization. In addition, 3GPP should address new requirements for time to live. The following provides some context for these aspects.

[0068] There is an ongoing work item for IIoT / URLLC enhancements in 3GPP Rel-17. The following goals are listed in the approved WID RP-201310:

[0069] 2. Uplink Enhancement for URLLC in Unlicensed Controlled Environment [RAN1, RAN2]:

[0070] a. Specify support for UE-initiated Channel Occupancy Time (COT) for Frame-Based Equipment (FBE) with minimal specification effort

[0071] b. Coordinate the enhancement of UL configuration authorization in NR-U and URLLC introduced in Rel-16 to apply to unlicensed spectrum

[0072] 5. RAN enhancements based on new Quality of Service (QoS) related parameters (if any) determined in SA2 such as time to live, burst extension. [RAN2, RAN3]

[0073] Time-sensitive communications (TSC) for IIoT have some unique requirements and characteristics compared to traditional cellular communications where UEs are primarily mobile phones. For example, the traffic pattern of TSC is typically periodic with fixed burst sizes, which allows the scheduler to determine resource allocation in a more informed manner. It has been agreed in Rel-16 that the gNB can determine certain information related to the traffic flow based on TSC assistance information (TSCAI) from the core network, so the gNB can allocate configured scheduling resources (e.g., semi-persistent scheduling (SPS) and configuration grant (CG)) with appropriate parameters such as periodicity and transport block size to meet the needs of the TSC flow. For the uplink, configuration grant (CG) is particularly important for TSC traffic due to its periodicity.

[0074] Industrial applications may have a requirement called a time-to-live, which means the time interval during which an application can still run without receiving an expected message. More formally, the time-to-live is defined in TS 22.104 as the time an application consuming a communication service can continue without an expected message.

[0075] The Time to Live indicates to the communication service how long it will take to recover from a failure. The Time to Live can be expressed as a time period or, for example, for cyclic services, as the maximum number of consecutive incorrectly received or lost messages. Since the Time to Live has now been approved as a new QoS requirement by SA2, how the RAN should be enhanced to achieve Time to Live protection (i.e. avoid consecutive message losses) is a key topic in Rel-17.

[0076] NR-U has further limitations compared to conventional operation in licensed bands due to potential listen-before-talk (LBT) failures. Therefore, some mechanisms have been introduced for NR-U to facilitate its operation. In particular, for a configuration grant (CG), the UE may perform autonomous retransmissions of pending medium access control (MAC) protocol data units (PDUs). This is controlled by the cg retransmission timer, which is started when the CG-PUSCH is transmitted. If the UE does not receive any downlink feedback information (DFI) from the gNB indicating the status of pending MAC PDUs in different hybrid automatic repeat request (HARQ) processes before the timer expires, the UE may assume that the CG physical uplink shared channel (CG-PUSCH) was not successfully transmitted and then perform an autonomous retransmission on subsequent CG resources.

[0077] In 5G NR, there are logical channel (LCH) mapping restrictions that force the (UE's) MAC layer to map data from the LCH to resources that are only suitable for certain characteristics. This allows data from the DRB to be transmitted on appropriate radio resources according to their QoS requirements. For example, multiple concurrently active CGs per bandwidth part (BWP) can be supported in Rel-16, and a new LCH mapping restriction called the allowed CG list can be configured for the LCH so that data from the LCH can only be transmitted by the CG resources indicated on the list. More details on this feature can be found in Section 5.4.3.1.2 in TS 38.321.

[0078] The Rel-17 WI for IIoT / URLLC enhancements considers operation in NR-U, as well as RAN enhancements to meet time-to-live requirements. In this context, it would be useful to enhance the NR-U mechanisms to support time-to-live requirements (i.e. reduce the probability of consecutive message losses).

[0079] The following concepts have been developed for RAN functions to meet the time-to-live requirements:

[0080] Two approaches for time to live have been proposed: (1) adaptive LCH mapping restriction rules based on the sequence number of the packet via, for example, an LCH that alternates over time, and (2) configured scheduling including two types of resource allocation (eg, CG / SPS).

[0081] Another proposal is to implicitly activate the packet data convergence protocol (PDCP) duplication of dedicated radio bearers (DRBs) based on negative HARQ feedback. For example, if the UE receives a non-switched new data indicator (NDI) in an uplink grant, the UE will automatically duplicate the next packet at higher layers to prevent continuous errors.

[0082] The lifetime requirements for unlicensed band operation have been considered. One proposed approach is to perform periodic adaptation of the channel access priority class (CAPC) configured with the grant to ensure that every Nth packet can access the unlicensed channel with a low probability of LBT failure. The transmission reliability issue has not been resolved.

[0083] Figure 4 A flow chart of a method according to an example embodiment is shown. The method may be performed at a terminal device.

[0084] In a first step S1 , the method comprises transmitting a data unit to a network node, the data unit conveying data from an LCH configured with a set of logical channel parameters.

[0085] In a second step S2, the method comprises starting a first timer when transmitting a data unit to the network node.

[0086] In a third step S3, the method comprises configuring the LCH with a modified set of logical channel parameters based on the state of the first timer.

[0087] In a fourth step S4, the method comprises configuring the LCH with a modified set of logical channel parameters based on the determination.

[0088] In a fifth step S5, the method transmits a data unit to the network node, the data unit conveying data from the logical channel configured with the modified set of logical channel parameters.

[0089] The modified set of logical channel parameters may provide a more reliable resource for the logical channel.

[0090] The set of logical channel parameters and the set of modified logical channel parameters may include at least one LCH mapping restriction. The at least one LCH mapping restriction may indicate a list of allowed configuration authorizations.

[0091] The set of logical channel parameters may be referred to as a default set of logical channel parameters. The set of modified logical channel parameters may be referred to as an adaptive set of logical channel parameters. The set of logical channel parameters may be a logical channel prioritization (LCP) setting.

[0092] The state of the first timer may include expiration of the first timer. The first timer may be a cg transmit timer.

[0093] Alternatively or additionally, the method may comprise determining to configure the logical channel with a modified set of logical channel parameters based on receiving an indication from the network node that the transmission was not successfully received. The indication may comprise a DFI or a retransmission grant.

[0094] A data unit may include a transport block (TB).

[0095] The method may provide a MAC mechanism for dynamically modifying the LCH mapping restrictions configured for an LCH based on the state of the cg retransmission timer associated with data transmitted on the PUSCH from the LCH. Alternatively or additionally, if the UE receives a signal indicating that the gNB did not successfully receive a previous transmission associated with the LCH (e.g., a DFI or retransmission grant), the UE may dynamically modify the LCH mapping restrictions configured for the LCH. This may help meet the time-to-live requirements of IIoT / TSC applications in NR-U.

[0096] For example, when the cg retransmission timer expires (i.e., the UE does not receive any DFI while the timer is running), the UE may assume that the PUSCH was not successfully transmitted and (at least temporarily) change the LCH mapping restrictions configured for at least one LCH associated with the transmitted PUSCH, for example, so that the grant of a specific configuration is the only resource on the CG list allowed in the LCH mapping restrictions for the LCH. This forces the UE to transmit subsequent data from the same LCH on more reliable radio resources, thereby reducing the probability of consecutive transmission errors.

[0097] The method may include receiving at least one configuration message from a network node, the configuration message indicating at least one of a set of logical channel parameters and a modified set of logical channel parameters. For example, at least one configuration message may be provided from a gNB to a UE. The at least one configuration message may include a default LCH mapping restriction for at least one LCH and a modified LCH mapping constraint for at least one LCH based on a state of a cg retransmission timer (e.g., when the timer expires). In one example, the default LCH mapping restriction does not impose any restrictions (i.e., data from the LCH can be mapped to any resource), while the modified LCH mapping constraint imposes certain restrictions on how to map data from the LCH. That is, the LCH mapping restriction is only imposed when the timer expires, otherwise the LCH mapping constraint is released.

[0098] If the logical channel has an associated time-to-live requirement, the network node (e.g., gNB) may determine to provide a modified set of logical channel parameters for the logical channel to the UE. The UE may determine whether the logical channel has a time-to-live requirement (and therefore whether it should retransmit the data unit using the modified set of logical channel parameters) based on both whether the logical channel is configured with the set of logical channel parameters and the modified set of logical channel parameters.

[0099] The UE may modify the LCH mapping restrictions of at least one LCH (from the default setting to the modified setting) based on the state of the cg retransmission timer. The UE may also restore the LCH mapping restrictions from the adapted setting back to the default setting of at least one LCH.

[0100] The method may include reverting to a configuration of a set of logical channel parameters for the LCH based on at least one condition. The at least one condition may include at least one of expiration of a second timer, receiving a control signal from a network node, confirming that the data unit has been successfully transmitted and received, and generation of the data unit.

[0101] The second timer may be referred to as an LCP adaptation timer.

[0102] The control signal from the network node may include a MAC CE or a DCI. For example, in some embodiments, upon receiving a control signal (e.g., a MAC CE or a DCI) from the gNB, the UE may fall back to a default set of logical channel parameters. Alternatively, once at least one TB is generated using the adapted LCH mapping restrictions, or when the UE has confirmed that the TB is successfully transmitted and / or received, the UE may fall back to a default set of logical channel parameters.

[0103] The method may include receiving an indication of the condition from the network node. For example, the condition (e.g., the value of the LCP adaptation timer) for the UE to fall back to the default set of logical channel parameters may be pre-configured by the gNB. The at least one configuration message may include instructions regarding when to fall back to the default set of logical channel parameters for the at least one LCH.

[0104] Figure 5 A signaling flow according to an example embodiment is shown. Initially, the gNB configures the UE with default LCH mapping restrictions and adapted LCH mapping constraints for the LCH (e.g., via radio resource control (RRC)). A CG-PUSCH associated with the LCH is transmitted based on the default LCH mapping restrictions, and the cg retransmission timer is started accordingly. When the cg retransmission timer expires (e.g., because no downlink feedback information (DFI) is received at the UE), the UE changes the LCH mapping restrictions for the LCH.

[0105] A new CG-PUSCH is transmitted based on the adapted LCH mapping restrictions.

[0106] When the UE changes the LCH mapping restrictions for LCH, it may further start another timer, such as a so-called LCP adaptation timer. When the LCP adaptation timer expires, the UE changes the LCH mapping restrictions for LCH back to the default settings.

[0107] Figure 6 UE logic according to an example embodiment is shown for determining whether the UE should change the LCH mapping restrictions for a LCH when the cg retransmission timer expires. When no DFI is received and the cg retransmission timer expires, the UE may check whether any LCH mapped to the TB whose transmission triggered the timer has a lifetime requirement. This may be implied based on whether the LCH is configured with both default and adapted LCH mapping restrictions (typically, the gNB should only configure an LCH with both settings if the service corresponding to that LCH has a lifetime requirement). If so, the UE may change the LCH mapping restriction settings. Otherwise, it will operate as usual, i.e., only perform autonomous retransmissions of that TB.

[0108] Figure 7An example embodiment is shown in which a UE has a service flow with a lifetime requirement. The service flow is mapped to a DRB. The gNB configures at least two CGs, CG1 and CG2, in the BWP.

[0109] CG1 is configured to have a reliability target that meets the QoS requirements (e.g., packet error rate (PER)) of the services transmitted by the DRB.

[0110] CG2 is configured to have a higher reliability target than CG1, such as having a lower modulation and coding scheme (MCS) and / or more repetitions at each CG opportunity.

[0111] In the MAC layer, the LCH corresponding to this DRB is configured with a default LCH mapping restriction, where CG1 is on the allowed CG list. This means that by default, data from this LCH can be mapped to the radio resources associated with CG1.

[0112] In addition to this default LCH mapping restriction setting, the gNB also configures an adaptation setting where only CG2 is on the allowed CG list (i.e., in this adaptation setting, CG1 is removed from the list). The UE shall switch to this adaptation setting for this LCH when the associated cg retransmission timer expires (i.e., no DFI has been received).

[0113] When transmitting PUSCH on CG1 which triggers the cg retransmission timer to start as per current specification, the UE observes whether it receives a DFI from the gNB while the timer is running. If the UE does not receive a DFI and the timer expires, the UE further checks whether the pending TB contains any data from an LCH configured with adapted settings (meaning that the data from this LCH has a time to live requirement). If yes, the UE shall switch the LCH mapping restriction for this LCH from the default setting to the adapted setting.

[0114] With the LCH mapping restrictions switched, the upcoming data from this LCH should follow the new mapping restriction rules to generate new TBs for new transmissions. In this example, subsequent data from this LCH should only be mapped to CG2 (no longer mapped to CG1) until it is switched back to the default settings again (e.g., when the LCP adaptation timer expires).

[0115] In an alternative embodiment, the at least one LCH mapping restriction may indicate a list of allowed serving cells.For example, the proposed scheme may be applied to LCH mapping restrictions related to allowed serving cells.

[0116] For example, in the case where the UE has both licensed and unlicensed bands, for LCH, it may have a default LCH mapping restriction with allowed serving cells in both licensed and unlicensed bands, and a modified LCH mapping restriction with allowed serving cells only in the licensed band.

[0117] Therefore, in this example embodiment, upon, for example, the first expiration of the cg retransmission timer or receipt of an indication of unsuccessful transmission from a network node, the UE is caused to transmit subsequent data from the LCH using only resources in the licensed band to ensure that the next packet is not unsuccessfully transmitted due to, for example, an LBT failure in an unlicensed band, and thereby reducing the probability of consecutive errors.

[0118] The method can be extended to the adaptation of other parameters in the LCP settings, including LCH priority, prioritized bit rate (PBR), bucket size duration (BSD), and channel access priority class (CAPC). That is, in an alternative example embodiment, the set of logical channel parameter settings may include LCH priority, PBR, BSD, and CAPC.

[0119] In some embodiments, only a default set of logical channel parameters is configured by the network node, without requiring additional configuration of a modified set of logical channel parameters. In this case, the modified set of logical channel parameters may be known settings (e.g., fixed in a specification), and thus no explicit configuration is required. Alternatively, or in addition, the default set of logical channel parameters may be known settings (e.g., fixed in a specification), and thus no explicit configuration is required.

[0120] In addition to changing the set of logical channel parameters, other types of adaptation may be performed upon expiration of the cg retransmission timer, such as CAPC upgrade for the LCH or activation of PDCP duplication of DRBs associated with the LCH.

[0121] The advantage of this method is that when transmitting a data unit of a service with a lifetime requirement in the NR unlicensed spectrum, if the UE detects that the data unit may not be successfully received by the gNB (i.e., the cg retransmission timer expires), the UE can be forced to transmit subsequent data in a more reliable manner. Therefore, the probability of consecutive transmission failures that may lead to lifetime violations can be reduced.

[0122] This method can be found in reference Figure 2 The method is implemented in the user equipment described.

[0123] A device may include a means for performing the following at a terminal device: transmitting a data unit to a network node, the data unit transmitting data from a logical channel LCH configured with a set of logical channel parameters; starting a first timer when transmitting the data unit to the network node; determining based on a state of the first timer to configure the logical channel using a modified set of logical channel parameters; configuring the logical channel using the modified set of logical channel parameters based on the determination; and transmitting a data unit to the network node, the data unit transmitting data from a logical channel configured with the modified set of logical channel parameters.

[0124] It should be understood that these devices may include or be coupled to other units or modules, such as radio components or radio heads for transmission and / or reception. Although the device has been described as one entity, the different modules and memories may be implemented in one or more physical or logical entities.

[0125] Note that while embodiments have been described with respect to LTE and 5G NR, similar principles may be applied to other networks and communication systems. Thus, while certain embodiments are described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, the embodiments may be applied to any other suitable form of communication system in addition to the communication system shown and described herein.

[0126] It is also noted herein that while exemplary embodiments are described above, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0127] In general, the various example embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device, but the invention is not limited thereto. Although various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other illustrations, it should be clearly understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof.

[0128] Embodiments of the present invention may be implemented by computer software executable by a data processor of a mobile device, for example in a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs, also referred to as program products, include software routines, applets and / or macros, which may be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. A computer program product may include one or more computer executable components that are configured to perform an embodiment when the program is run. One or more computer executable components may be at least one software code or a portion thereof.

[0129] Further in this regard, it should be noted that any blocks of the logic flow as shown in the figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on physical media such as memory chips or memory blocks implemented within a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and their data variants CDs. Physical media are non-transitory media.

[0130] The memory may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. As non-limiting examples, the data processor may be of any type suitable for the local technical environment and may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an FPGA, a gate-level circuit, and a processor based on a multi-core processor architecture.

[0131] Example embodiments of the present invention may be practiced in various components such as integrated circuit modules. In general, the design of integrated circuits is a highly automated process. Complex and powerful software tools are available to convert logic-level designs into semiconductor circuit designs ready to be etched and formed on semiconductor substrates.

[0132] The above description has provided by way of non-limiting examples a complete and informative description of exemplary embodiments of the present invention. However, various modifications and adaptations may become apparent to those skilled in the relevant art in view of the foregoing description when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the present teachings will still fall within the scope of the present invention as defined in the appended claims. Indeed, there are further embodiments including combinations of one or more embodiments with any other embodiments previously discussed.

Claims

1. A device for communication, the device being used at a terminal device, the device comprising: means for transmitting a data unit to a network node, the data unit conveying data from a logical channel LCH configured with a set of logical channel parameters; means for starting a first timer when transmitting the data unit to the network node, wherein the first timer is a cg retransmission timer; means for determining, when it is determined that the first timer expires and no downlink feedback information DFI is received, to configure the logical channel with a modified set of logical channel parameters based on checking whether the transmitted data unit includes data from an LCH with a time-to-live requirement; means for configuring the logical channel with a modified set of logical channel parameters based on the determination; as well as Means for transmitting a data unit to the network node, the data unit conveying data from a logical channel configured with the modified set of logical channel parameters.

2. The apparatus according to claim 1, comprising means for receiving from the network node at least one configuration message indicating at least one of the set of logical channel parameters and the set of modified logical channel parameters.

3. The device according to claim 1 or claim 2, wherein: The set of logical channel parameters and the modified set of logical channel parameters include at least one of at least one LCH mapping restriction, LCH priority, prioritized bit rate, bucket size duration, and channel access priority.

4. The device according to claim 3, wherein: The at least one LCH mapping restriction indicates a list of allowed configuration authorizations.

5. The device according to claim 3, wherein: The at least one LCH mapping restriction indicates a list of allowed serving cells.

6. An apparatus as claimed in claim 1, 2, 4 or 5, comprising means for reverting to the configuration of the set of logical channel parameters for the logical channel based on at least one condition.

7. The device according to claim 6, wherein: The at least one condition comprises at least one of expiration of a second timer, receipt of a control signal from the network node, confirmation that the data unit has been successfully transmitted and received, and generation of the data unit.

8. The apparatus of claim 7, comprising receiving an indication of the at least one condition from the network node.

9. A method for communication, comprising: at a terminal device: transmitting a data unit to a network node, the data unit conveying data from a logical channel LCH configured with a set of logical channel parameters; starting a first timer when transmitting the data unit to the network node, wherein the first timer is a cg retransmission timer; When it is determined that the first timer expires and no downlink feedback information DFI is received, determining to configure the logical channel with a modified set of logical channel parameters based on checking whether the transmitted data unit includes data from an LCH with a lifetime requirement; configuring the logical channel using the modified set of logical channel parameters based on the determination; as well as A data unit is transmitted to the network node, the data unit conveying data from the logical channel configured with the modified set of logical channel parameters.

10. An apparatus for communication, comprising: At least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus at a terminal device to at least: transmitting a data unit to a network node, the data unit conveying data from a logical channel LCH configured with a set of logical channel parameters; starting a first timer when transmitting the data unit to the network node, wherein the first timer is a cg retransmission timer; When it is determined that the first timer expires and no downlink feedback information DFI is received, determining to configure the logical channel with a modified set of logical channel parameters based on checking whether the transmitted data unit includes data from an LCH with a lifetime requirement; configuring the logical channel using the modified set of logical channel parameters based on the determination; as well as A data unit is transmitted to the network node, the data unit conveying data from a logical channel configured with the modified set of logical channel parameters.

11. A computer-readable medium comprising program instructions for causing an apparatus to perform at least the following operations at a terminal device: transmitting a data unit to a network node, the data unit conveying data from a logical channel LCH configured with a set of logical channel parameters; starting a first timer when transmitting the data unit to the network node, wherein the first timer is a cg retransmission timer; When it is determined that the first timer expires and no downlink feedback information DFI is received, determining to configure the logical channel with a modified set of logical channel parameters based on checking whether the transmitted data unit includes data from an LCH with a lifetime requirement; configuring the logical channel using the modified set of logical channel parameters based on the determination; as well as A data unit is transmitted to the network node, the data unit conveying data from a logical channel configured with the modified set of logical channel parameters.

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