METHOD FOR TRANSMITTING AND RECEIVING SIGNAL FOR TERMINAL IN WIRELESS COMMUNICATION SYSTEM

One embodiment of a method, which is for a terminal operating in a wireless communication system, comprises the steps of: received configured grant from a serving cell; and reporting radio link failure (RLF) with the serving cell, wherein the terminal, subsequent to the RLF, perform sidelink communication using the configured grant until a new configured grant is received.

TECHNICAL FIELD

The following description relates to a wireless communication system, and more specifically, to a method for performing sidelink communication by a UE using a configured grant.

BACKGROUND ART

A wireless communication system uses various radio access technologies (RATs) such as long term evolution (LTE), LTE-advanced (LTE-A), and wireless fidelity (WiFi). 5th generation (5G) is such a wireless communication system. Three key requirement areas of 5G include (1) enhanced mobile broadband (eMBB), (2) massive machine type communication (mMTC), and (3) ultra-reliable and low latency communications (URLLC). Some use cases may require multiple dimensions for optimization, while others may focus only on one key performance indicator (KPI). 5G supports such diverse use cases in a flexible and reliable way.

eMBB goes far beyond basic mobile Internet access and covers rich interactive work, media and entertainment applications in the cloud or augmented reality (AR). Data is one of the key drivers for 5G and in the 5G era, we may for the first time see no dedicated voice service. In 5G, voice is expected to be handled as an application program, simply using data connectivity provided by a communication system. The main drivers for an increased traffic volume are the increase in the size of content and the number of applications requiring high data rates. Streaming services (audio and video), interactive video, and mobile Internet connectivity will continue to be used more broadly as more devices connect to the Internet. Many of these applications require always-on connectivity to push real time information and notifications to users. Cloud storage and applications are rapidly increasing for mobile communication platforms. This is applicable for both work and entertainment. Cloud storage is one particular use case driving the growth of uplink data rates. 5G will also be used for remote work in the cloud which, when done with tactile interfaces, requires much lower end-to-end latencies in order to maintain a good user experience. Entertainment, for example, cloud gaming and video streaming, is another key driver for the increasing need for mobile broadband capacity. Entertainment will be very essential on smart phones and tablets everywhere, including high mobility environments such as trains, cars and airplanes. Another use case is augmented reality (AR) for entertainment and information search, which requires very low latencies and significant instant data volumes.

One of the most expected 5G use cases is the functionality of actively connecting embedded sensors in every field, that is, mMTC. It is expected that there will be 20.4 billion potential Internet of things (IoT) devices by 2020. In industrial IoT, 5G is one of areas that play key roles in enabling smart city, asset tracking, smart utility, agriculture, and security infrastructure.

URLLC includes services which will transform industries with ultra-reliable/available, low latency links such as remote control of critical infrastructure and self-driving vehicles. The level of reliability and latency are vital to smart-grid control, industrial automation, robotics, drone control and coordination, and so on.

Now, multiple use cases will be described in detail.

5G may complement fiber-to-the home (FTTH) and cable-based broadband (or data-over-cable service interface specifications (DOCSIS)) as a means of providing streams at data rates of hundreds of megabits per second to giga bits per second. Such a high speed is required for TV broadcasts at or above a resolution of 4K (6K, 8K, and higher) as well as virtual reality (VR) and AR. VR and AR applications mostly include immersive sport games. A special network configuration may be required for a specific application program. For VR games, for example, game companies may have to integrate a core server with an edge network server of a network operator in order to minimize latency.

The automotive sector is expected to be a very important new driver for 5G, with many use cases for mobile communications for vehicles. For example, entertainment for passengers requires simultaneous high capacity and high mobility mobile broadband, because future users will expect to continue their good quality connection independent of their location and speed. Other use cases for the automotive sector are AR dashboards. These display overlay information on top of what a driver is seeing through the front window, identifying objects in the dark and telling the driver about the distances and movements of the objects. In the future, wireless modules will enable communication between vehicles themselves, information exchange between vehicles and supporting infrastructure and between vehicles and other connected devices (e.g., those carried by pedestrians). Safety systems may guide drivers on alternative courses of action to allow them to drive more safely and lower the risks of accidents. The next stage will be remote-controlled or self-driving vehicles. These require very reliable, very fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, self-driving vehicles will execute all driving activities, while drivers are focusing on traffic abnormality elusive to the vehicles themselves. The technical requirements for self-driving vehicles call for ultra-low latencies and ultra-high reliability, increasing traffic safety to levels humans cannot achieve.

Smart cities and smart homes, often referred to as smart society, will be embedded with dense wireless sensor networks. Distributed networks of intelligent sensors will identify conditions for cost- and energy-efficient maintenance of the city or home. A similar setup can be done for each home, where temperature sensors, window and heating controllers, burglar alarms, and home appliances are all connected wirelessly. Many of these sensors are typically characterized by low data rate, low power, and low cost, but for example, real time high definition (HD) video may be required in some types of devices for surveillance.

The consumption and distribution of energy, including heat or gas, is becoming highly decentralized, creating the need for automated control of a very distributed sensor network. A smart grid interconnects such sensors, using digital information and communications technology to gather and act on information. This information may include information about the behaviors of suppliers and consumers, allowing the smart grid to improve the efficiency, reliability, economics and sustainability of the production and distribution of fuels such as electricity in an automated fashion. A smart grid may be seen as another sensor network with low delays.

The health sector has many applications that may benefit from mobile communications. Communications systems enable telemedicine, which provides clinical health care at a distance. It helps eliminate distance barriers and may improve access to medical services that would often not be consistently available in distant rural communities. It is also used to save lives in critical care and emergency situations. Wireless sensor networks based on mobile communication may provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly important for industrial applications. Wires are expensive to install and maintain, and the possibility of replacing cables with reconfigurable wireless links is a tempting opportunity for many industries. However, achieving this requires that the wireless connection works with a similar delay, reliability and capacity as cables and that its management is simplified. Low delays and very low error probabilities are new requirements that need to be addressed with 5G

Finally, logistics and freight tracking are important use cases for mobile communications that enable the tracking of inventory and packages wherever they are by using location-based information systems. The logistics and freight tracking use cases typically require lower data rates but need wide coverage and reliable location information.

A wireless communication system is a multiple access system that supports communication of multiple users by sharing available system resources (a bandwidth, transmission power, etc.). Examples of multiple access systems include a CDMA system, an FDMA system, a TDMA system, an OFDMA system, an SC-FDMA system, and an MC-FDMA system.

Sidelink (SL) refers to a communication scheme in which a direct link is established between user equipments (UEs) and the UEs directly exchange voice or data without intervention of a base station (BS). SL is considered as a solution of relieving the BS of the constraint of rapidly growing data traffic.

Vehicle-to-everything (V2X) is a communication technology in which a vehicle exchanges information with another vehicle, a pedestrian, and infrastructure by wired/wireless communication. V2X may be categorized into four types: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). V2X communication may be provided via a PC5 interface and/or a Uu interface.

As more and more communication devices demand larger communication capacities, there is a need for enhanced mobile broadband communication relative to existing RATs. Accordingly, a communication system is under discussion, for which services or UEs sensitive to reliability and latency are considered. The next-generation RAT in which eMBB, MTC, and URLLC are considered is referred to as new RAT or NR. In NR, V2X communication may also be supported.

FIG. 1is a diagram illustrating V2X communication based on pre-NR RAT and V2X communication based on NR in comparison.

For V2X communication, a technique of providing safety service based on V2X messages such as basic safety message (BSM), cooperative awareness message (CAM), and decentralized environmental notification message (DENM) was mainly discussed in the pre-NR RAT. The V2X message may include location information, dynamic information, and attribute information. For example, a UE may transmit a CAM of a periodic message type and/or a DENM of an event-triggered type to another UE.

For example, the CAM may include basic vehicle information including dynamic state information such as a direction and a speed, vehicle static data such as dimensions, an external lighting state, path details, and so on. For example, the UE may broadcast the CAM which may have a latency less than 100 ms. For example, when an unexpected incident occurs, such as breakage or an accident of a vehicle, the UE may generate the DENM and transmit the DENM to another UE. For example, all vehicles within the transmission range of the UE may receive the CAM and/or the DENM. In this case, the DENM may have priority over the CAM.

In relation to V2X communication, various V2X scenarios are presented in NR. For example, the V2X scenarios include vehicle platooning, advanced driving, extended sensors, and remote driving.

For example, vehicles may be dynamically grouped and travel together based on vehicle platooning. For example, to perform platoon operations based on vehicle platooning, the vehicles of the group may receive periodic data from a leading vehicle. For example, the vehicles of the group may widen or narrow their gaps based on the periodic data.

For example, a vehicle may be semi-automated or full-automated based on advanced driving. For example, each vehicle may adjust a trajectory or maneuvering based on data obtained from a nearby vehicle and/or a nearby logical entity. For example, each vehicle may also share a dividing intention with nearby vehicles.

Based on extended sensors, for example, raw or processed data obtained through local sensor or live video data may be exchanged between vehicles, logical entities, UEs of pedestrians and/or V2X application servers. Accordingly, a vehicle may perceive an advanced environment relative to an environment perceivable by its sensor.

Based on remote driving, for example, a remote driver or a V2X application may operate or control a remote vehicle on behalf of a person incapable of driving or in a dangerous environment. For example, when a path may be predicted as in public transportation, cloud computing-based driving may be used in operating or controlling the remote vehicle. For example, access to a cloud-based back-end service platform may also be used for remote driving.

A scheme of specifying service requirements for various V2X scenarios including vehicle platooning, advanced driving, extended sensors, and remote driving is under discussion in NR-based V2X communication.

DISCLOSURE

Technical Task

A technical task of embodiment(s) is how long configured grant resources will be used when a UE using the configured grant resources announces radio link failure (RLF).

The technical task to be achieved in the embodiment(s) are not limited to the technical task mentioned above, and other technical tasks that are not mentioned can be clearly understood by those skilled in the art to which the embodiment(s) belong from the description below.

Technical Solutions

One embodiment is a method for a UE operating in a wireless communication system, including receiving a configured grant from a serving cell, and announcing radio link failure (RLF) with respect to the serving cell, wherein the UE performs sidelink communication using the configured grant until receiving a new configured grant after the RLF.

One embodiment is a UE in a wireless communication system, including at least one processor, and at least one computer memory operably coupled to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include receiving a configured grant from a serving cell, and announcing radio link failure (RLF) with respect to the serving cell, wherein the UE performs sidelink communication using the configured grant until receiving a new configured grant after the RLF.

One embodiment is a processor for performing operations for a UE in a wireless communication system, wherein the operations include receiving a configured grant from a serving cell, and announcing radio link failure (RLF) with respect to the serving cell, wherein the UE performs sidelink communication using the configured grant until receiving a new configured grant after the RLF.

One embodiment is a computer-readable storage medium storing at least one computer program including instructions that, when executed by at least one processor, cause the at least one processor to perform operations for a UE, wherein the operations include receiving a configured grant from a serving cell, and announcing radio link failure (RLF) with respect to the serving cell, wherein the UE performs sidelink communication using the configured grant until a new configured grant is received after the RLF.

The method may further include starting a radio link failure recovery timer, wherein the radio link failure recovery timer may be stopped based on the new configured grant.

The configured grant may be released based on a release indication.

The method may further include starting a radio link failure recovery timer, wherein the radio link failure recovery timer may be stopped based on the release indication.

The method may further include starting a radio link failure recovery timer, wherein the radio link failure recovery timer may be stopped based on recovery of a radio link.

The configured grant may include at least one of a configured grant type 1 and a configured grant type 2.

The UE may operate in a resource allocation mode 1.

The UE may switch to a resource allocation mode 2 when radio link recovery fails after the RLF.

The UE may release the configured grant when radio link recovery fails after the RLF.

The UE may communicate with at least one of another UE, a UE related to an autonomous vehicle, a base station or a network.

Advantageous Effects

According to an embodiment, it is possible to perform sidelink communication seamlessly using configured grant resources even after RLF.

Effects that can be obtained in the embodiment(s) are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by those skilled in the art to which the embodiment(s) belong from the description below.

BEST MODE FOR DISCLOSURE

In various embodiments of the present disclosure, “or” should be interpreted as “and/or”. For example, “A or B” may include “only A”, “only B”, and/or “both A and B”. In other words, “or” should be interpreted as “additionally or alternatively”.

Techniques described herein may be used in various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier-frequency division multiple access (SC-FDMA), and so on. CDMA may be implemented as a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented as a radio technology such as global system for mobile communications (GSM)/general packet radio service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented as a radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved-UTRA (E-UTRA), or the like. IEEE 802.16m is an evolution of IEEE 802.16e, offering backward compatibility with an IRRR 802.16e-based system. UTRA is a part of universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS) using evolved UTRA (E-UTRA). 3GPP LTE employs OFDMA for downlink (DL) and SC-FDMA for uplink (UL). LTE-advanced (LTE-A) is an evolution of 3GPP LTE.

A successor to LTE-A, 5th generation (5G) new radio access technology (NR) is a new clean-state mobile communication system characterized by high performance, low latency, and high availability. 5G NR may use all available spectral resources including a low frequency band below 1 GHz, an intermediate frequency band between 1 GHz and 10 GHz, and a high frequency (millimeter) band of 24 GHz or above.

While the following description is given mainly in the context of LTE-A or 5G NR for the clarity of description, the technical idea of an embodiment of the present disclosure is not limited thereto.

FIG. 2shows a radio protocol architecture for SL communication according to an embodiment of the present disclosure. Specifically, (a) ofFIG. 2shows a user plane protocol stack of NR and (b) ofFIG. 2shows a control plane protocol stack of NR.

FIG. 3illustrates UEs performing V2X or SL communication according to one embodiment of the present disclosure.

Referring toFIG. 3, in V2X or SL communication, the term UE may mainly refer to a user's UE. However, when network equipment such as a BS transmits and receives signals according to a communication scheme between UEs, the BS may also be regarded as a kind of UE. For example, UE 1 may be the first device100, and UE 2 may be the second device200.

For example, UE 1 may select a resource unit corresponding to a specific resource in a resource pool, which represents a set of resources. Then, UE 1 may transmit an SL signal through the resource unit. For example, UE 2, which is a receiving UE, may receive a configuration of a resource pool in which UE 1 may transmit a signal, and may detect a signal of UE 1 in the resource pool.

Here, when UE 1 is within the connection range of the BS, the BS may inform UE 1 of a resource pool. On the other hand, when the UE 1 is outside the connection range of the BS, another UE may inform UE 1 of the resource pool, or UE 1 may use a preconfigured resource pool.

In general, the resource pool may be composed of a plurality of resource units, and each UE may select one or multiple resource units and transmit an SL signal through the selected units.

FIG. 4illustrates resource units for V2X or SL communication.

Referring toFIG. 4, the frequency resources of a resource pool may be divided into NF sets, and the time resources of the resource pool may be divided into NT sets. Accordingly, a total of NF*NT resource units may be defined in the resource pool.FIG. 8shows an exemplary case where the resource pool is repeated with a periodicity of NT subframes.

As shown inFIG. 4, one resource unit (e.g., Unit #0) may appear periodically and repeatedly. Alternatively, in order to obtain a diversity effect in the time or frequency domain, an index of a physical resource unit to which one logical resource unit is mapped may change in a predetermined pattern over time. In this structure of resource units, the resource pool may represent a set of resource units available to a UE which intends to transmit an SL signal.

Resource pools may be subdivided into several types. For example, according to the content in the SL signal transmitted in each resource pool, the resource pools may be divided as follows.

(1) Scheduling assignment (SA) may be a signal including information such as a position of a resource through which a transmitting UE transmits an SL data channel, a modulation and coding scheme (MCS) or a multiple input multiple output (MIMO) transmission scheme required for demodulation of other data channels, and timing advance (TA). The SA may be multiplexed with SL data and transmitted through the same resource unit. In this case, an SA resource pool may represent a resource pool in which SA is multiplexed with SL data and transmitted. The SA may be referred to as an SL control channel.

(2) SL data channel (physical sidelink shared channel (PSSCH)) may be a resource pool through which the transmitting UE transmits user data. When the SA and SL data are multiplexed and transmitted together in the same resource unit, only the SL data channel except for the SA information may be transmitted in the resource pool for the SL data channel. In other words, resource elements (REs) used to transmit the SA information in individual resource units in the SA resource pool may still be used to transmit the SL data in the resource pool of the SL data channel. For example, the transmitting UE may map the PSSCH to consecutive PRBs and transmit the same.

(3) The discovery channel may be a resource pool used for the transmitting UE to transmit information such as the ID thereof. Through this channel, the transmitting UE may allow a neighboring UE to discover the transmitting UE.

Even when the SL signals described above have the same content, they may use different resource pools according to the transmission/reception properties of the SL signals. For example, even when the SL data channel or discovery message is the same among the signals, it may be classified into different resource pools according to determination of the SL signal transmission timing (e.g., transmission at the reception time of the synchronization reference signal or transmission by applying a predetermined TA at the reception time), a resource allocation scheme (e.g., the BS designates individual signal transmission resources to individual transmitting UEs or individual transmission UEs select individual signal transmission resources within the resource pool), signal format (e.g., the number of symbols occupied by each SL signal in a subframe, or the number of subframes used for transmission of one SL signal), signal strength from a BS, the strength of transmit power of an SL UE, and the like.

Hereinafter, resource allocation in SL will be described.

FIG. 5shows a procedure in which a UE performs V2X or SL communication according to a transmission mode, according to an embodiment of the present disclosure. In various embodiments of the present disclosure, a transmission mode may be referred to as a mode or a resource allocation mode. Hereinafter, for convenience of description, a transmission mode in LTE may be referred to as an LTE transmission mode, and a transmission mode in NR may be referred to as an NR resource allocation mode.

For example, (a) ofFIG. 5shows a UE operation related to LTE transmission mode 1 or LTE transmission mode 3. For example, (a) ofFIG. 5shows a UE operation related to NR resource allocation mode 1. For example, LTE transmission mode 1 may be applied to general SL communication, and LTE transmission mode 3 may be applied to V2X communication.

For example, (b) ofFIG. 5shows a UE operation related to LTE transmission mode 2 or LTE transmission mode 4. For example, (b) ofFIG. 5shows a UE operation related to NR resource allocation mode 2.

Referring to (a) ofFIG. 5, in LTE transmission mode 1, LTE transmission mode 3 or NR resource allocation mode 1, a BS may schedule SL resources to be used by a UE for SL transmission. For example, the BS may perform resource scheduling for UE 1 through a PDCCH (more specifically, downlink control information (DCI)), and UE 1 may perform V2X or SL communication with UE 2 according to resource scheduling. For example, UE 1 may transmit SCI (sidelink control information) to UE 2 through a physical sidelink control channel (PSCCH), and then transmit data based on the SCI to UE 2 through a physical sidelink shared channel (PSSCH).

For example, in NR resource allocation mode 1, the BS may provide or allocate resources for one or more SL transmissions in one transport block (TB) to a UE through a dynamic grant. For example, the BS may use a dynamic grant to provide resources for transmission of a PSCCH and/or a PSSCH to the UE. For example, a transmitting UE may report SL hybrid automatic repeat request (HARQ) feedback received from a receiving UE to the BS. In this case, PUCCH resources and timing for reporting the SL HARQ feedback to the BS may be determined based on an indication in a PDCCH for the BS to allocate resources for SL transmission.

For example, DCI may indicate a slot offset between DCI reception and first SL transmission scheduled by DCI. For example, a minimum gap between DCI scheduling SL transmission resources and first scheduled SL transmission resources may not be less than a processing time of the corresponding UE.

For example, in NR resource allocation mode 1, the BS may periodically provide or allocate a resource set to the UE through a configured grant for a plurality of SL transmissions. For example, the configured grant may include configured grant type 1 or configured grant type 2. For example, the UE may determine a TB to be transmitted on each occasion indicated by a given configured grant.

For example, the BS may allocate SL resources to the UE on the same carrier and may allocate SL resources to the UE on different carriers.

For example, an NR BS may control LTE-based SL communication. For example, the NR BS may transmit NR DCI to a UE to schedule LTE SL resources. In this case, for example, a new RNTI for scrambling the NR DCI may be defined. For example, the UE may include an NR SL module and an LTE SL module.

For example, after the UE including the NR SL module and the LTE SL module receives an NR SL DCI from a gNB, the NR SL module may convert the NR SL DCI into LTE DCI type 5A, and the NR SL module may deliver LTE DCI type 5A to the LTE SL module in X ms. For example, upon reception of LTE DCI format 5A from the NR SL module, the LTE SL module may apply activation and/or release to the first LTE subframe after Z ms. For example, X may be dynamically indicated using a field of DCI. For example, a minimum value of X may depend on UE capability. For example, the UE may report a single value according to UE capability. For example, X may be a positive number.

Referring to (b) ofFIG. 5, in LTE transmission mode 2, LTE transmission mode 4 or NR resource allocation mode 2, a UE may determine SL transmission resources within SL resources configured by the BS/network or preset SL resources. For example, the configured SL resources or the preset SL resources may be a resource pool. For example, the UE may autonomously select or schedule resources for SL transmission. For example, the UE may perform SL communication by selecting resources by itself within a set resource pool. For example, the UE may select resources by itself within a selection window by performing a sensing and resource (re)selection procedure. For example, sensing may be performed in units of subchannels. In addition, UE 1, which has selected resources by itself within a resource pool, may transmit SCI to UE 2 through a PSCCH and transmit data based on the SCI to UE 2 through a PSSCH.

For example, a UE may help selection of SL resources for another UE. For example, in NR resource allocation mode 2, the UE may receive a configured grant for SL transmission. For example, in NR resource allocation mode 2, the UE may schedule SL transmission of another UE. For example, in NR resource allocation mode 2, the UE may reserve SL resources for blind retransmission.

For example, in NR resource allocation mode 2, a first UE may indicate the priority of SL transmission to a second UE using SCI. For example, the second UE may decode the SCI and perform sensing and/or resource (re)selection based on the priority. For example, the resource (re)selection procedure may include a step of identifying candidate resources in a resource selection window by the second UE and a step of selecting a resource for (re)transmission from among the identified candidate resources. For example, the resource selection window may be a time interval during which a UE selects a resource for SL transmission. For example, after the second UE triggers resource (re)selection, the resource selection window may start at T1≥0, and the resource selection window may be limited by a remaining packet delay budget. For example, in the step of identifying the candidate resources in the resource selection window by the second UE, the second UE may not determine a specific resource as a candidate resource if the specific resource is indicated by SCI received by the second UE from the first UE, and an L1 SL RSRP measurement value for the specific resource exceeds an SL RSRP threshold value. For example, the SL RSRP threshold value may be determined based on the priority of SL transmission indicated by the SCI received by the second UE from the first UE and the priority of SL transmission on the resource selected by the second UE.

For example, the L1 SL RSRP may be measured based on an SL demodulation reference signal (DMRS). For example, one or more PSSCH DMRS patterns may be configured or preset for each resource pool in the time domain. For example, PDSCH DMRS configuration type 1 and/or type 2 may be the same as or similar to the frequency domain pattern of the PSSCH DMRS. For example, the exact DMRS pattern may be indicated by SCI. For example, in NR resource allocation mode 2, a transmitting UE may select a specific DMRS pattern from among DMRS patterns configured or preset for a resource pool.

For example, in NR resource allocation mode 2, the transmitting UE may perform initial transmission of a transport block (TB) without reservation based on the sensing and resource (re)selection procedure. For example, the transmitting UE may reserve an SL resource for initial transmission of the second TB using SCI associated with the first TB based on the sensing and resource (re)selection procedure.

For example, in NR resource allocation mode 2, a UE may reserve resources for feedback-based PSSCH retransmission through signaling related to previous transmission of the same TB. For example, the maximum number of SL resources reserved by one transmission including current transmission may be 2, 3, or 4. For example, the maximum number of SL resources may be the same regardless of whether HARQ feedback is enabled. For example, the maximum number of HARQ (re)transmissions for one TB may be limited by configuration or pre-configuration. For example, the maximum number of HARQ (re)transmissions may be up to 32. For example, if there is no configuration or pre-configuration, the maximum number of HARQ (re)transmissions may be unspecified. For example, the configuration or pre-configuration may be for a transmitting UE. For example, in NR resource allocation mode 2, HARQ feedback for releasing resources that are not used by a UE may be supported.

For example, in NR resource allocation mode 2, a UE may indicate one or more subchannels and/or slots used by the UE to another UE by using SCI. For example, the UE may indicate one or more subchannels and/or slots reserved by the UE for PSSCH (re)transmission to another UE by using SCI. For example, the minimum allocation unit of SL resources may be a slot. For example, the size of a subchannel may be set for the UE or may be preset.

Hereinafter, radio link monitoring (RLM) and radio link failure (RLF) of an LTE system will be described.

FIG. 6is a flowchart of a method of detecting radio link failure (RLF).

A UE in a carrier aggregation system including a plurality of serving cells performs radio link monitoring (RLM) for a serving cell.

In the case of RLM, the UE may monitor the downlink radio link quality of the serving cell (e.g., primary cell (PCell)) based on a CRS. Specifically, the UE may estimate the radio link quality in a single subframe based on the CRS and monitor/evaluate a radio link state (e.g., out-of-sync or in-sync) by comparing the estimated value (e.g., a signal-to-noise ratio (SNR) or a signal-to-interference plus noise ratio (SINR)) to threshold values (Qout and Qin). If the radio link state is in-sync, the UE can perform/maintain normal communication with a BS, and if the radio link state is out-of-sync, the UE can consider that the radio link has failed and perform operations such as RRC connection re-establishment, handover, cell reselection, and cell measurement.

The physical layer of the UE monitors the downlink radio link quality of the serving cell (e.g., PCell) and informs a higher layer (e.g., RRC) of the out-of-sync/in-sync state. Specifically, when the radio link quality is better than Qin, the physical layer of the UE indicates in-sync to the higher layer in a radio frame in which the radio link quality is evaluated. The physical layer of the UE evaluates the radio link quality in every radio frame in a non-DRX mode, and the physical layer of the UE evaluates the radio link quality at least once in every DRX cycle in a DRX mode. When higher layer signaling indicates subframe(s) for restricted RLM, evaluation of radio link quality is not performed in non-indicated subframes. Thereafter, when the radio link quality is worse than Qout, the physical layer of the UE indicates out-of-sync to the higher layer in the radio frame in which the radio link quality is evaluated.

When the radio link state is in-sync, the UE may normally perform/maintain communication with the BS. When the radio link state is out-of-sync, the UE considers that radio link failure (RLF) has occurred for the radio link. When radio link failure (RLF) occurs with respect to the PCell, the procedure of the UE is performed in the same manner as inFIG. 6. As shown inFIG. 6, an operation related to radio link failure is performed in two stages.

The first stage begins upon detection of a radio link problem. This leads to radio link failure detection. In the first stage, there is no UE-based mobility and operation is based on timer T1.

The second stage begins upon detection of radio link failure or handover failure. This leads to an RRC_IDLE state. In the second stage, UE-based mobility is present and operation is based on timer T2.

In the second stage, in order for a UE to resume RRC connection (state) and to avoid transition to the RRC_IDLE state, the following procedure may be applied when the UE returns to the same cell in which radio link failure is detected, selects a cell different from the cell in which radio link failure is detected in the same BS, or selects a cell from another BS.

1. The UE maintains the RRC_CONNECTED state for time T2.

2. The UE accesses a cell through a random access procedure.

3. The BS identifies the UE using identification information or identity of the UE (e.g., C-RNTI of the UE in the cell in which RLF has occurred, the identity of the physical layer of the corresponding cell, a short MAC-I based on a security key of the corresponding cell, etc.) used in a collision resolution random access procedure and checks whether a stored context belongs to the UE. In this case, the identification information of the UE used in the collision resolution random access procedure may be information used for random access preamble transmission in the collision resolution random access procedure.

When the BS discovers that the stored context matches the identity of the corresponding UE in 3, the BS informs the UE that RRC connection of the UE can be restarted. On the other hand, when the BS does not discover the context, RRC connection between the UE and the BS is released, and the UE may start a procedure for establishing a new RRC connection. In this case, the UE switches to the RRC_IDLE state.

In summary, in the LTE system, the PDCCH/PCFICH is defined as a reference channel for RLM, and a communication quality threshold value for defining the In-Sycn/Out-of-sync state through the defined reference channel. At this time, since the PDCCH serving as the reference channel is not always transmitted, the UE performs RLM through a procedure of predicting the quality of the PDCCH through the SNR of the region in which the PDCCH is transmitted and comparing the same with a threshold value.

EMBODIMENTS

In resource allocation mode 1, a dynamic grant, configured grant type 1, and configured grant type 2 for sidelink communication of a UE are supported. The UE may be allocated sidelink resources from a BS through the dynamic grant, configured grant type 1, or configured grant type 2. For example, the dynamic grant may be received through DCI by transmitting a scheduling request (SR)/buffer status report (BSR) of the UE. In addition, the UE may be provided or allocated a periodic resource set for transmission of a plurality of SLs from the BS through the configured grant type 1 and the configured grant type 2. For example, configured grant type 1 sidelink transmission may be semi-permanently scheduled by a higher layer signal without an activation process by DCI. Further, configured grant type 2 sidelink transmission may be activated or deactivated by DCI.

When a problem (e.g., beam failure or radio link failure) occurs in a Uu link between the UE and the BS in NR (New Radio) V2X (Vehicle-to-everything), the Uu radio link problem may also affect sidelink communication between V2X devices. If a problem occurs in the Uu radio link while a V2X UE is performing sidelink communication by receiving resources allocated from the BS in mode 1 method (i.e., mode 1 dynamic scheduling), the UE cannot normally perform “mode 1 resource allocation request (i.e., SR/BSR procedure)” for sidelink communication to the BS. In other words, if there is a problem in a link between the UE and the BS, the UE cannot perform a dynamic grant request operation by transmitting the SR/BSR.

Therefore, according to the embodiment (s) of the present disclosure, there are provided a method for managing sidelink transmission resources of a UE, a channel coding operation, and an apparatus supporting the same when a Uu radio link problem occurs in NR V2X.

Hereinafter, a radio link problem in a Uu link can be considered to have occurred in the following situations.Uu beam failureUu physical layer problem (e.g., occurrence of continuous out of sync indication events)Occurrence of one Uu physical layer problem event (e.g., occurrence of one out of sync indication event)Uu radio link failure

Hereinafter, a Uu radio link recovery timer may be one of the timers below.Uu beam failure recovery timerUu physical layer problem recovery timerUu radio link failure recovery timer

1. First Embodiment

When a UE that performs sidelink communication by receiving sidelink transmission resources allocated from a BS based on SR/BSR transmission detects a Uu radio link problem, the UE can cancel all BSRs/SRs triggered for sidelink transmission.

If a UE that performs sidelink communication by receiving sidelink transmission resources allocated from a BS based on SR/BSR transmission detects a Uu radio link problem, the UE can use configured grant type 2 to continue sidelink communication ceaselessly if the BS has configured grant type 2 resources for the UE through RRC signaling before detection of the Uu radio link problem, and the use of the configured grant type 2 resources is indicated (e.g., the BS activates the use of the configured grant type 2 resources through a physical layer, that is, DCI) before detection of the Uu radio link program (for example, a state in which the use of the configured grant type 2 resources has been instructed but SR/BSR-based SL resources are being used).

If a UE that performs sidelink communication by receiving sidelink transmission resources allocated from a BS based on SR/BSR transmission detects a Uu radio link problem, the UE can use configured grant type 1 to continue sidelink communication ceaselessly until the following period if the BS has configured grant type 1 resources for the UE through RRC signaling before detection of the Uu radio link problem (e.g., a state in which the use of the configured grant type 1 resources has been configured but SR/BSR-based SL resources are being used).

For example, the UE may continue to perform sidelink communication using the configured grant type 1 resources even if the Uu radio link problem is recovered. The UE may perform sidelink communication using the configured grant type 1 resources, and if the configured grant type 1 resources do not satisfy the QoS (e.g., latency) and reliability of newly generated sidelink data, perform sidelink communication by being allocated SR/BSR-based SL transmission resources without using the configured grant type 1 resources.

In another embodiment, the UE uses the configured grant type 1 resources until recovery from the Uu radio link problem, and after recovery of the Uu radio link problem, the UE may request resources again based on SR/BSR and receive sidelink transmission resources from the BS. If the Uu radio link is not recovered before the Uu radio link recovery timer expires, the UE may perform sidelink transmission using an exception TX pool after the Uu radio link recovery timer expires.

When a UE that performs sidelink communication by receiving sidelink transmission resources allocated from a BS based on SR/BSR transmission detects a Uu radio link problem, the UE can use configured grant type 2 to continue sidelink communication ceaselessly until the following period if the BS has configured grant type 2 resources for the UE through RRC signaling before detection of the Uu radio link problem, and the use of the configured grant type 2 resources is indicated (e.g., the BS activates the use of the configured grant type 2 resources through a physical layer, that is, DCI) before detection of the Uu radio link program (for example, a state in which the use of the configured grant type 2 resources has been instructed but SR/BSR-based SL resources are being used).

For example, the UE may continue to use the configured grant type 2 resources even if the Uu radio link problem is recovered to continue sidelink communication. The UE performs sidelink communication using the configured grant type 2 resources, and if the configured grant type 2 resources do not satisfy the QoS (e.g., latency and reliability) of newly generated sidelink data, the UE may perform sidelink communication by being allocated SR/BSR-based SL transmission resources without using the configured grant type 2 resources.

In another embodiment, the UE may use the configured grant type 2 resources until recovery from the Uu radio link problem, and after recovery from the Uu radio link problem, request resources again based on SR/BSR to be allocated sidelink transmission resources from the BS. If the Uu radio link is not recovered before the Uu radio link recovery timer expires, the UE may perform sidelink transmission using an exception TX pool after the Uu radio link recovery timer expires.

When a radio link problem (e.g., Uu beam failure, Uu physical layer problem, or Uu radio link failure) occurs in a Uu link between a mode-1 UE and a BS and thus the radio link recovery procedure is performed, if a transmitting UE (TX UE) has sidelink data for transmission to a receiving UE (RX UE), BSR triggered for sidelink data transmission is canceled without pending until the radio link is recovered. In addition, when the radio link problem is recovered, a new BSR is triggered for sidelink data that has not been previously transmitted. If new sidelink data is generated while the radio link problem is recovered from, a new BSR in which the BSR for the previously unsent sidelink data and the BSR for the new sidelink data transmission are aggregated can be transmitted.

FIG. 7is a diagram for illustrating embodiment(s) of the above-described proposal.

1. A transmitting UE may send a request for mode-1 sidelink transmission resources to a BS (based on SR/BSR) and receive the mode-1 resources to perform sidelink communication.

2. BSR may be triggered because new data to be transmitted by the transmitting UE to a receiving UE is generated.

3. The sidelink transmitting UE may detect a radio link problem in the Uu link (between the UE and the BS) and at the same time start a “Uu radio link recovery timer (e.g., a Uu beam failure recovery timer, a Uu physical layer problem recovery timer, or a Uu radio link failure recovery timer)”.

4. The transmitting UE may cancel the BSR triggered for sidelink data transmission.

5. The Uu radio link between the transmitting UE and the BS can be recovered.

6. The transmitting UE may trigger a new BSR for sidelink data that has not been transmitted.

7. The transmitting UE may recover from the Uu radio link problem and transmit a new BSR to the BS to receive a grant for sidelink data transmission from the BS.

FIG. 8is a diagram for illustrating embodiment(s) of the above-described proposal.

1. The transmitting UE may request mode-1 sidelink transmission resources from the BS (based on SR/BSR) and receive the mode-1 resources to perform sidelink communication.

2. New data to be transmitted by the transmitting UE to the receiving UE is generated, and thus a BSR may be triggered.

3. The sidelink transmitting UE may detect a radio link problem in the Uu link (between the UE and the BS) and at the same time start “Uu radio link recovery timer (e.g., Uu beam failure recovery timer, Uu physical layer problem recovery timer, or Uu radio link failure recovery timer)”.

4. The transmitting UE may cancel the BSR triggered for sidelink data transmission.

5. The Uu radio link between the transmitting UE and the BS station can be recovered.

6. When the transmitting UE triggers a new BSR for sidelink data transmission that has not been performed, if new sidelink data is generated during Uu radio link recovery or after Uu radio link recovery, the transmitting UE may trigger a new BSR in which BSR information for sidelink data that has not been transmitted and BSR information for newly generated new sidelink data are aggregated.

For example, at the time of aggregating BSR information, BSR information for a plurality of pieces of sidelink data delivered to the same destination ID (e.g., new sidelink data to be transmitted to the same receiving UE (same destination ID) to which sidelink data that has not been previously transmitted) may be aggregated to trigger a new BSR.

In another embodiment, even if newly generated sidelink data is sidelink data delivered to a receiving UE having a different destination ID, BSR information for a plurality of pieces of sidelink data (e.g., new sidelink data for transmission to a different receiving UE (different destination ID) from the receiving UE to which sidelink data has not been previously transmitted) may be triggered to trigger a new BSR.

7. After Uu radio link recovery, the transmitting UE may transmit a new BSR to the BS to receive a grant for sidelink data transmission from the BS.

When a radio link problem (e.g., Uu beam failure, Uu physical layer problem, or Uu radio link failure) occurs in a Uu link between a UE and a BS, mode-1 resource allocation is switched to mode-2 resource allocation only when proposed conditions are satisfied.

If there is sidelink data to be transmitted from a mode-1 transmitting UE to a receiving UE when a radio link problem occurs in the Uu link between the mode-1 UE and a BS, the transmitting UE may determine whether to continuously use mode-1 resources to perform sidelink communication or to switch mode 1 to mode 2 for sidelink communication using mode-2 resources according to the following conditions.

The transmitting UE may determine whether to continuously use the mode-1 resources or to switch to mode 2 to use the mode-2 resources by comparing a delay budget of data to be transmitted to the receiving UE with the duration of a Uu radio link recovery timer (e.g., a timer started by the UE because the Uu radio link recovery procedure is started due to the Uu radio link problem).Condition used to determine whether to continuously use mode-1 resource allocation method or switch to mode-2 resource allocation method

1) Delay budget of arrival data of transmitting UE>Duration of Uu radio link recovery timer

(If (latency budget of arrival data of TX UE>Uu radio link recovery timer's duration))

For example, when a Uu radio link problem is detected and thus the Uu radio link recovery procedure is triggered and the Uu radio link recovery timer is started, if a latency budget of sidelink data is longer than the Uu radio link recovery timer duration (that is, it is determined that there is a margin in delay for transmission of sidelink data), the transmitting UE can process the triggered BSR of sidelink arrival data as a pending BSR until recovery from the Uu radio link problem. In addition, the transmitting UE may hold the resource allocation process (mode-1 resource allocation and mode-2 resource allocation) until the Uu radio link is recovered. That is, the UE may not use the mode-2 TX exception pool as in the prior art (because there is a margin in the delay of the arrival data: that is, in that condition, latency requirement can be satisfied even if sidelink communication is resumed using mode-1 resources after recovery of the Uu radio link). In addition, when the Uu radio link is recovered, the transmitting UE may resume the pending BSR of the previous sidelink arrival data and perform a “mode-1 resource allocation request process (SR/BSR)” for the BS.

In another embodiment, when a Uu radio link problem is detected and thus the Uu radio link recovery procedure is triggered and at the same time the Uu radio link recovery timer is started, if a latency budget of sidelink data is longer than the Uu radio link recovery timer duration (that is, it is determined that there is a margin in delay for transmission of sidelink data), the transmitting UE may cancel the triggered BSR of sidelink arrival data. In addition, the transmitting UE may hold the resource allocation process (mode-1 resource allocation and mode-2 resource allocation) until the Uu radio link is recovered. That is, the UE may not use the mode-2 TX exception pool as in the prior art (because there is a margin in the delay of the arrival data: that is, in that condition, latency requirement can be satisfied even if sidelink communication is resumed using mode-1 resources after recovery of the Uu radio link). When the Uu radio link is recovered, the transmitting UE may perform a “mode-1 resource allocation request process (SR/BSR)” by newly triggering the canceled BSR for transmission of previous sidelink arrival data.

In another embodiment, if a latency budget of sidelink data is longer than the Uu radio link recovery timer duration (that is, it is determined that there is a margin in delay for transmission of sidelink data) when a Uu radio link problem is detected and thus the Uu radio link recovery procedure is triggered and at the same time the Uu radio link recovery timer is started, if sidelink data is generated after Uu radio link recovery starts, the transmitting UE may not trigger a BSR for the generated sidelink data. In addition, the transmitting UE may hold the resource allocation process (mode-1 resource allocation and mode-2 resource allocation) until recovery from the Uu radio link problem. That is, the UE may not use the mode-2 TX exception pool as in the prior art (because there is a margin in the delay of the arrival data: that is, in that condition, latency requirement can be satisfied even if sidelink communication is resumed using mode-1 resources after recovery of the Uu radio link). In addition, when the Uu radio link is recovered, the transmitting UE may perform a “mode-1 resource allocation request process (SR/BSR)” by triggering a BSR for transmission of previous sidelink arrival data.

In the above-described embodiment(s), if the Uu radio link is not recovered during the “Uu radio link recovery timer”, the UE may switch to mode 2, sense and select mode-2 resources, and transmit data to the receiving UE.

Referring toFIG. 9, the transmitting UE may operate as follows.

1. The transmitting UE may request mode-1 sidelink transmission resources from the BS (through SR/BSR) and receive the mode-1 resources to perform sidelink communication.

2. Data to be transmitted by the transmitting UE to the receiving UE is generated and thus a BSR may be triggered.

3. The sidelink transmitting UE may detect a radio link problem in the Uu link (between the UE and the BS), trigger Uu radio link recovery and at the same time start the “Uu radio link recovery timer”.

4. The transmitting UE may compare a delay budget of the generated sidelink data with the Uu radio link recovery timer duration, and when the delay budget of the sidelink data is longer than the Uu radio link recovery timer duration (that is, it is determined that there is a margin in the delay), process the triggered BSR as a pending BSR.

5. The transmitting UE may resume the pending BSR of previous sidelink data to resume the mode-1 resource allocation request process when the Uu radio link is recovered.

6. If the Uu radio link is not recovered during the Uu radio link recovery timer in the corresponding condition, the transmitting UE may switch to mode 2, sense and select mode-2 resources, and transmit sidelink data to the receiving UE.

Referring toFIG. 10, the transmitting UE may operate as follows.

1. The transmitting UE may request mode-1 sidelink transmission resources from the BS (through SR/BSR) and receive the mode-1 resources to perform sidelink communication.

2. Data to be transmitted by the transmitting UE to the receiving UE is generated and thus a BSR may be triggered.

3. The sidelink transmitting UE may detect a radio link problem in the Uu link (between the UE and the BS), trigger Uu radio link recovery and at the same time start the Uu radio link recovery timer.

4. The transmitting UE may compare a delay budget of the generated sidelink data with the Uu radio link recovery timer, and when the delay budget of the sidelink data is longer than the Uu radio link recovery timer duration (that is, it is determined that there is a margin in the delay), cancel the triggered BSR.

5. The transmitting UE may trigger a new BSR for transmission of sidelink data that has not been transmitted to the previous receiving UE to perform the mode-1 resource allocation request process when the Uu radio link is recovered.

6. If the Uu radio link is not recovered during the Uu radio link recovery timer in the corresponding condition, the transmitting UE may switch to mode 2, sense and select mode-2 resources, and transmit sidelink data to the receiving UE.

Referring toFIG. 11, the transmitting UE may operate as follows.

1. The transmitting UE may request mode-1 sidelink transmission resources from the BS (through SR/BSR) and receive the mode-1 resources to perform sidelink communication.

2. The sidelink transmitting UE may detect a radio link problem in the Uu link (between the UE and the BS), trigger Uu radio link recovery and at the same time start the “Uu radio link timer”.

3. Sidelink data that needs to be transmitted from the transmitting UE to the receiving UE may be generated.

4. The transmitting UE may compare a delay budget of the generated sidelink data with the Uu radio link recovery timer duration, and when the delay budget of the sidelink data is longer than the Uu radio link recovery timer duration (that is, it is determined that there is a margin in the delay), hold sidelink data transmission until the Uu radio link is recovered without triggering Uu radio link recovery for transmission of the generated sidelink data.

5. The transmitting UE may trigger a BSR for transmission of sidelink data that has not been transmitted to the previous receiving UE to perform the mode-1 resource allocation request process when the Uu radio link is recovered.

6. If the Uu radio link is not recovered during the Uu radio link recovery timer in the corresponding condition, the transmitting UE may switch to mode 2, sense and select mode-2 resources, and transmit sidelink data to the receiving UE.

2) Delay budget of arrival data of the TX UE<duration of Uu radio link recovery timer

(If (latency budget of arrival data of TX UE<Uu Radio Link Recovery Timer's duration))

When a Uu radio link problem is detected and thus the Uu radio link recovery procedure is triggered, if a latency budget of sidelink data is shorter than the Uu radio link recovery timer duration (that is, it is determined that delay for transmission of sidelink data is short), the transmitting UE may cancel a triggered BSR of sidelink arrival data. In addition, when this condition is satisfied, the transmitting UE may use the mode-2 TX exception pool until the Uu radio link is recovered (because delay of arrival data is short: that is, in that state, latency requirement cannot be satisfied if sidelink communication is resumed using mode-1 resources after recovery of the Uu radio link). When the Uu radio link is recovered, the transmitting UE may resume the “mode-1 resource allocation request process (SR/BSR)” for transmission of new sidelink arrival data to transmit sidelink data to the receiving UE.

Referring toFIG. 12, the transmitting UE may operate as follows.

1. The transmitting UE may request mode-1 sidelink transmission resources from the BS (through SR/BSR) and receive the mode-1 resources to perform sidelink communication.

2. The sidelink transmitting UE may detect a radio link problem in the Uu link (between the UE and the BS), trigger Uu radio link recovery and at the same time start the “Uu radio link timer”.

3. Data to be transmitted from the transmitting UE to the receiving UE may be generated.

4. The transmitting UE may compare a delay budget of the generated sidelink data with the Uu radio link recovery timer, and when the delay budget of the sidelink data is shorter than the Uu radio link recovery timer duration (that is, it is determined that delay is short), use “mode-2 TX exception pool” until the Uu radio link is recovered.

5. When the Uu radio link is recovered, the transmitting UE may resume “mode-1 resource allocation request process (SR/BSR)” for transmission of new sidelink arrival data to transmit sidelink data to the receiving UE.

When a V2X transmitting UE detects a Uu radio link problem (e.g., Uu beam failure, a Uu physical layer problem, or Uu radio link failure) and fails to use mode-1 resources and thus needs to perform a sensing operation in order to use “sensing based mode 2 resources” during Uu radio link recovery, “validity criterion (i.e., a reference time used for the transmitting UE to determine that corresponding resources are valid only when sensing is performed for a predefined time)” is applied differently.

For example, when the long-term sensing-based mode 2 resource selection method is used, it can be defined that only results of sensing performed by a transmitting UE for at least a time “M” are valid. On the other hand, when the short-term sensing-based mode 2 resource selection method is used, it can be defined that only results of sensing performed by a transmitting UE for at least a time “N” (N being defined as a time shorter than M. N<M. That is, it is defined that sensing results are determined to be valid even if sensing is performed for a shorter time than the sensing time applied to long-term sensing) are valid. That is, it can be defined such that the validity criterion of sensing results can be different depending on long-term sensing and short-term sensing.

In the present disclosure, as a criterion for the transmitting UE to determine that a sensing result for using “mode-2 TX normal pool resource” is valid, “sensing should have been performed for a predefined sensing validity reference time (long-term sensing validity period or short-term sensing validity period), and at the same time, the corresponding sensing operation should be completed within a sidelink packet delay budget generated by the transmitting UE”.

In the following, a criterion for a UE to determine whether to use the “mode-2 TX exceptional pool” or the “mode-2 TX normal pool” during Uu radio link recovery by applying the aforementioned proposals 7 and 8 is proposed.

When a V2X transmitting UE detects a radio link problem in a Uu link and fails to use mode-1 resources and thus needs to use mode-2 resources during Uu radio link recovery, if the transmitting UE has performed sensing during the validity criterion of proposal 1 and sensing is completed within a delay budget of sidelink data, “sensing-based mode-2 resources” can be used instead of random selection-based “mode-2 TX exception pool” during Uu radio link recovery.

When a V2X transmitting UE detects a radio link problem in a Uu link and fails to use mode-1 resources and thus needs to use mode-2 resources during Uu radio link recovery, if the transmitting UE has performed sensing during the validity criterion of proposal 1 and sensing is not completed within a delay budget of sidelink data, random selection-based “mode-2 TX exception pool” can be used during Uu radio link recovery.

FIG. 13andFIG. 14illustrate embodiments in which a transmitting UE determines whether to use “sensing-based TX normal pool (mode-2 resource)” or “random selection-based TX exceptional pool (mode-2 resource)” during Uu radio link recovery to perform sidelink communication based on the proposals when the transmitting UE detects a radio link problem in a Uu link and thus starts the Uu radio link recovery procedure.

FIG. 13is a diagram illustrating the above-mentioned proposal 9.

Referring toFIG. 13, when the Uu radio link recovery procedure starts, the transmitting UE may perform sidelink communication using “mode-2 TX normal pool” (i.e., by selecting and using sensing-based TX normal pool) during the Uu radio link recovery procedure when the transmitting UE has performed sensing for “sensing validity criterion of TX normal pool” proposed in the present disclosure, and completes sensing within a delay budget of sidelink data. The embodiment ofFIG. 13may be an embodiment in which the UE uses short-term sensing. The Uu radio link recovery timer mentioned inFIG. 13may be a Uu beam failure recovery timer, a Uu physical layer problem recovery timer, or a Uu RLF recovery timer.

FIG. 14is a diagram illustrating the above-mentioned proposal 10.

Referring toFIG. 14, when the Uu radio link recovery procedure starts, the transmitting UE may perform sidelink communication using “mode-2 TX exceptional pool” (i.e., by randomly selecting and using TX exceptional pool) during the Uu radio link recovery procedure when the transmitting UE cannot perform sensing for “sensing validity criterion of TX normal pool” proposed in the present disclosure (that is, when the transmitting UE cannot perform sensing for the validity reference time because execution of sensing for the sensing validity reference time exceeds the delay budget). The embodiment ofFIG. 14may be an embodiment in which the UE uses long-term sensing. The Uu radio link recovery timer mentioned inFIG. 14may be a Uu beam failure recovery timer, a Uu physical layer problem recovery timer, or a Uu RLF recovery timer.

When a radio link problem (e.g., Uu beam failure, a Uu physical layer problem, or Uu radio link failure) occurs in a Uu link between a mode-1 UE operating in the dynamic scheduling mode and a BS, if there is a configured grant resource configured by the BS, SL communication can be performed using the configured grant resource during Uu radio link recovery.

When the proposal is further extended, it can be applied as follows.

Method of using configured grant type-1 resources in order to continue sidelink communication when Uu radio link problem occurs

A mode-1 UE may include information on a sidelink service or sidelink data thereof (QoS information of sidelink data (priority), latency requirement, reliability requirement, destination UE address information, etc.) in a sidelinkUEInformation message and transmit the same to the BS for sidelink communication. The BS transmits grant type-1 resource information (e.g., resource location (time/frequency), resource period/offset information, etc.) configured for the UE based on the sidelinkUEInformation information received from the UE (through a dedicated RRC message). If the UE operating in the dynamic scheduling mode detects a Uu radio link problem, the UE may use the configured grant type-1 resource received from the BS through the dedicated RRC message in order to continue link communication.

FIG. 15is a diagram illustrating a method of using a configured grant type-1 resource when a radio link problem occurs in a Uu link.

Referring toFIG. 15, a transmitting UE may operate as follows.

1. The transmitting UE is allocated a configured grant type-1 resource from a BS through a dedicated RRC message.

2. The transmitting UE may perform sidelink communication in the dynamic scheduling mode.

3. A radio link problem may occur in the Uu link of the transmitting UE.

4. The transmitting UE may continuously perform sidelink communication using the configured grant type-1 resource received from the BS.

Method of using configured grant type-1 resources in order to continue sidelink communication when Uu radio link problem occurs

A mode-1 UE may include information on a sidelink service or sidelink data thereof (QoS information of sidelink data (priority), latency requirement, reliability requirement, destination UE address information, etc.) in a sidelinkUEInformation message and transmit the same to the BS for sidelink communication. The BS transmits grant type-2 resource information (e.g., resource location (time/frequency), resource period/power control parameter information, etc.) configured for the UE based on the sidelinkUEInformation information received from the UE (through a dedicated RRC message). If the BS detects a problem in the Uu radio link to the UE operating in the dynamic scheduling mode, the BS may transmit information (e.g., an offset with respect to the initial transmission timing, time/frequency resource allocation, a DMRS parameter, and MCS) to the UE operating in the dynamic scheduling mode through layer-1 signaling (DCI) to instruct the UE to perform sidelink communication using the configured grant type-2 resource. The BS may determine the Uu radio link problem based on a Uu measurement report value reported by the UE.

FIG. 16is a diagram illustrating a method of using a configured grant type-2 resource when a radio link problem occurs in a Uu link.

Referring toFIG. 16, a transmitting UE may operate as follows.

1. The transmitting UE may be allocated a configured grant type-2 resource from a BS through a dedicated RRC message.

2. The transmitting UE may perform sidelink communication in the dynamic scheduling mode.

3. The BS may detect a radio link problem in the Uu link.

4. The BS may activate use of the grant type-2 resource configured for the UE operating in the dynamic scheduling mode through Layer-1 signaling (DCI) via the Uu link from which the radio link problem has been detected.

5. The transmitting UE may continue to perform sidelink communication using the configured grant type-2 resource activated by the BS through L1 signaling.

As another embodiment,FIG. 17illustrates an embodiment in which a UE allocated a configured grant type-2 resource detects a radio link problem and reports the radio link problem to a BS, and the BS activates the grant type-2 resource configured for the UE. When a Uu radio link problem occurs, a UE operating in the dynamic scheduling mode, which has received the configured grant type-2 resource from the BS, cannot use the configured grant type-2 resource (because, if a Uu radio link problem occurs, the BS cannot activate the configured grant type-2 resource in the UE). In this proposal, upon detection of a Uu radio link problem, the UE that has received the configured grant type-2 resource reports the Uu radio link problem to the BS such that the BS can activate the grant type-2 resource configured for the UE.

Referring toFIG. 17, a transmitting UE may operate as follows.

1. The transmitting UE may be allocated a configured grant type-2 resource from a BS through a dedicated RRC message.

2. The transmitting UE may perform sidelink communication in the dynamic scheduling mode.

3. The UE may detect a radio link problem in the Uu link.

4. The UE that has received the configured grant type-2 resource may report the Uu radio link problem to the BS.

5. The BS may activate use of the configured grant type-2 resource for the UE through Layer-1 signaling (DCI).

6. The transmitting UE may continue to perform sidelink communication using the configured grant type-2 resource activated by the BS through L1 signaling.

According to the embodiment(s) of the present disclosure, even if a BS cannot allocate sidelink transmission resources to a UE due to detection of a Uu radio link problem (i.e., a problem in a radio link between the UE and the BS), the UE can perform sidelink communication ceaselessly using alternative resources mentioned in this proposal.

2. Second Embodiment

When there is a configured grant resource (configured grant type 1 or configured grant type 2) configured by a BS, a UE may continue to perform sidelink communication using the configured grant resource of mode 1. However, it is not yet defined how long grant resources configured in the standard will be used. In the present disclosure, how long a configured grant resource will be used when a Uu radio link problem occurs is defined, and a method of using the configured grant resource based thereon is proposed.

While a Uu radio link problem occurs and thus a Uu radio link is recovered (during a Uu radio link recovery timer operation), a UE may use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by a serving cell. According to the proposal of the present disclosure, the UE can operate using sidelink resources while the Uu radio link is recovered (i.e., during the Uu radio link recovery timer operation).

2.1.1. Proposal 1.1 While a Uu radio link problem occurs and thus a Uu radio link is recovered (during a Uu radio link recovery timer operation), a UE may use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by a serving cell.

2.1.2. Proposal 1.2 While a Uu radio link problem occurs and thus a Uu radio link is recovered (during a Uu radio link recovery timer operation), the UE may continuously use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by the serving cell until a new configured grant (configured grant type 1, or configured grant type 2) resource is received from the serving cell or a target cell. Even if the recovery timer is not set, the UE may continuously use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by the serving cell until a new configured grant (configured grant type 1, or configured grant type 2) resource is received from the serving cell or the target cell.

2.1.3. Proposal 1.3 While a Uu radio link problem occurs and thus a Uu radio link is recovered (during a Uu radio link recovery timer operation), the UE may use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by the serving cell, and when a new configured grant (configured grant type 1 or configured grant type 2) resource is configured by the serving cell or a target cell, stop the Uu radio link recovery timer and use the grant resource newly configured by the serving cell or the target cell.

2.1.4. Proposal 1.4 While a Uu radio link problem occurs and thus a Uu radio link is recovered (during a Uu radio link recovery timer operation), the UE may use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by the serving cell, and when the serving cell or the target cell indicates releases or deactivation of the configured grant (configured grant type 1, or configured grant type 2) resource previously configured by the serving cell (i.e., before the Uu radio link problem occurs), stop the Uu radio link recovery timer. When the timer is stopped, the UE may use a resource based on mode-1 dynamic scheduling (SR/BSR-based resource allocation) or may switch to mode 2 and use the Mode 2 TX pool.

2.1.5. Proposal 1.5 While a Uu radio link problem occurs and thus a Uu radio link is recovered (during a Uu radio link recovery timer operation), the UE may use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by the serving cell, and when a new configured grant (configured grant type 1 or configured grant type 2) resource is not configured by the serving cell or the target cell, stop the Uu radio link recovery timer, switch to the mode 2 and perform sidelink communication using the mode-2 TX pool.

2.1.6. Proposed 1.6 When a Uu radio link problem occurs and thus Uu radio link recovery is performed, but the Uu radio link is not recovered and recovery fails (i.e., during the Uu radio link recovery timer operation), the UE may deactivate or release the configured grant (configured grant type 1 or configured grant type 2) resource previously configured by the serving cell. Alternatively, the UE may switch to mode 2 and perform sidelink communication using the mode-2 TX pool (e.g., when there is a valid mode-2 TX resource pool) or perform sidelink communication using the exceptional pool (e.g., when there is no valid mode-2 TX resource pool).

Referring toFIG. 18, a transmitting UE may start a radio link recovery upon occurrence of a radio link problem. In addition, the transmitting UE may perform sidelink communication using a configured grant previously configured by a serving cell even after the radio link recovery timer starts. Thereafter, the transmitting UE may receive a newly configured grant resource from the serving cell or a target cell and stop the radio link recovery timer. In addition, the transmitting UE may perform sidelink communication using the newly configured grant resource.

Referring toFIG. 19, a transmitting UE may start a radio link recovery timer upon occurrence of a radio link problem. In addition, the transmitting UE may perform sidelink communication using a configured grant previously configured by a serving cell even after the radio link recovery timer starts. Thereafter, the transmitting UE may receive indication of release or deactivation of the previously configured grant. Then, the transmitting UE may stop the radio link recovery timer, use a resource based on dynamic allocation, or switch to mode 2 to perform sidelink communication.

While a Uu radio link problem occurs and thus a Uu radio link is recovered (during a Uu radio link recovery timer operation), a UE may use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by a serving cell. When the Uu radio link is recovered (the Uu radio link recovery timer is stopped: the timer can be stopped when the Uu radio link problem is recovered), the UE needs to determine whether to continuously use the configured grant resource that is being used or to use a resource based on dynamic scheduling (SR/BSR-based resource allocation). In the present disclosure, even if the Uu radio link is recovered, the UE can continuously use the configured grant (configured grant type 1 or configured grant type 2) resource that is being used before a new configured grant (configured grant type 1 or configured grant type 2) is received from the serving cell or a target cell.

2.2.1. Proposal 2.1 When a Uu radio link problem occurs, Uu radio link recovery (i.e., Uu radio link recovery timer operation) is performed, and a Uu radio link is recovered, a UE may stop the Uu radio link recovery timer and continuously use configured grant (configured grant type 1 or configured grant type 2) resources previously configured (before the Uu radio link problem occurs) by a serving cell.

2.2.2. Proposal 2.2 When a Uu radio link problem occurs, Uu radio link recovery (i.e., Uu radio link recovery timer operation) is performed, and a Uu radio link is recovered, a UE may stop the Uu radio link recovery timer. In addition, the UE may continuously use a configured grant resource previously configured (before the Uu radio link problem occurs) by a serving cell until a new configured grant (configured grant type 1 or configured grant type 2) resource is received from the serving cell or a target cell. Even if the recovery timer is not set, the UE may continuously use the configured grant resource previously configured (before the Uu radio link problem occurs) by the serving cell until a new configured grant (configured grant type 1 or configured grant type 2) resource is received from the serving cell or a target cell.

2.2.3. Proposal 2.3 When a Uu radio link problem occurs, Uu radio link recovery (i.e., Uu radio link recovery timer operation) is performed, and a Uu radio link is recovered, a UE may stop the Uu radio link recovery timer. Thereafter, the UE uses a configured grant resource previously configured (that is, before the Uu radio link problem occurs) by the serving cell, and when a new configured grant (configured grant type 1 or configured grant type 2) resource is received from the serving cell or a target cell, use the newly set configured grant resource received from the serving cell or the target cell.

2.2.4. Proposed 2.4 When a Uu radio link problem occurs, Uu radio link recovery (i.e., Uu radio link recovery timer operation) is performed, and a Uu radio link is recovered, a UE may stop the Uu radio link recovery timer. Thereafter, the UE may use a configured grant resource previously configured from the serving cell (that is, before the Uu radio link problem occurs). When the serving cell or a target cell indicates releases or deactivation of the configured grant (configured grant type 1 or configured grant type 2) resource previously configured by the serving cell (that is, before the Uu radio link problem occurs), the UE may use a resource based on mode-1 dynamic scheduling (SR/BSR-based resource allocation) or switch to mode 2 and use a mode-2 TX pool.

2.2.5. Proposal 2.5 When a Uu radio link problem occurs, Uu radio link recovery (i.e., Uu radio link recovery timer operation) is performed, and a Uu radio link is recovered, a UE may stop the Uu radio link recovery timer. If a new configured grant (configured grant type 1 or configured grant type 2) resource is not received from the serving cell or a target cell until the Uu radio link is recovered, the UE may switch to mode 2 and perform sidelink communication using the mode-2 TX pool. Alternatively, if a new configured grant (configured grant type 1 or configured grant type 2) resource is not received from the serving cell or a target cell until the Uu radio link is recovered, the UE may continuously use a configured grant resource previously configured (i.e., before the Uu radio link problem occurs) by the serving cell.

Referring toFIG. 20, a transmitting UE may start a radio link recovery timer upon occurrence of a radio link problem. In addition, the transmitting UE may perform sidelink communication using a configured grant previously configured by a serving cell even after the radio link recovery timer starts. After radio link recovery is completed, release or deactivation of the previously configured grant may be indicated. Then, the transmitting UE may perform sidelink communication by using a resource based on dynamic scheduling or by switching to mode 2.

According to the embodiment(s) of the present disclosure, even if a problem in a Uu radio link (that is, a radio link between a UE and a BS) is detected and thus the UE is no longer allocated a sidelink transmission resource from the BS, the UE may use an alternative resource (a mode 1 configured grant resource, or a mode 2 TX Pool) proposed in the present disclosure to continuously maintain sidelink communication.

Since examples of the above-described proposals can also be used as implementation methods of the present disclosure, it will also be apparent that the examples of the above-described proposals may be considered to be a kind of proposed methods. Although the above-described proposals can be implemented independently from each other, it should be noted that the above-described proposals can also be implemented as a combination (or a merged format) of some proposals. For example, although the proposed method has been disclosed based on the 3GPP NR system for convenience of description, a system to which the proposed method is applied may also be extended to another system other than the 3GPP NR system. For example, the proposed methods of the present disclosure may also be extendedly applied for D2D communication. Here, D2D communication indicates that a UE communicates with a different UE directly using a radio channel. Herein, although the UE refers to a user equipment (UE), when a network device such as a BS (or eNB) transmits and/or receives a signal according to a communication scheme between UEs, the UE may also be regarded as a sort of the UE. In addition, the proposed methods of the present disclosure may be limitedly applied only to MODE 3 V2X operation (and/or MODE 4 V2X operation). In addition, the proposed methods of the present disclosure may be limitedly applied only to a preconfigured (/signaled) (specific) V2X channel (/signal) transmission (e.g., PSSCH (and/or (interlinked) PSCCH and/or PSBCH)). In addition, the proposed methods of the present disclosure may be limitedly applied only to the case that a PSSCH and an (interlinked) PSCCH are adjacently (and/or non-adjacently) transmitted (on a frequency domain) (and/or a transmission based on a preconfigured (/signaled) MCS (and/or coding rate and/or resource block) (value (/range)) is performed). In addition, the proposed methods of the present disclosure may be limitedly applied only to MODE #3 (and/or MODE #4) V2X carrier (and/or (MODE #4 (/3) sidelink (/uplink) SPS (and/or sidelink (/uplink) dynamic scheduling) carrier). In addition, the proposed methods of the present document may be (limitedly) applied only if a synchronization signal (transmission (and/or reception)) resource position and/or a number (and/or V2X resource pool-related subframe position and/or number (and/or subchannel size and/or number)) are the same (and/or (some) different) between carriers. As an example, the proposed schemes of the present invention can be extended and applied to V2X communication between the BS and the UE. For example, the proposed schemes of the present disclosure may be limited only to UNICAST (sidelink) communication (and/or MULTICAST (or GROUPCAST) (sidelink) communication and/or BROADCAST (sidelink) communication).

Examples of Communication Systems Applicable to the Present Disclosure

FIG. 21illustrates a communication system applied to the present disclosure.

Example of Wireless Devices to which the Present Disclosure is Applied

FIG. 22illustrates wireless devices applicable to the present disclosure.

Here, wireless communication technologies implemented in the wireless devices (XXX, YYY) of the present disclosure may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low power communication. At this time, for example, the NB-IoT technology may be an example of a Low Power Wide Area Network (LPWAN) technology, and may be implemented in standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices (XXX, YYY) of the present disclosure may perform communication based on LTE-M technology. In this case, as an example, the LTE-M technology may be an example of LPWAN technology, and may be referred to by various names such as eMTC (enhanced machine type communication). For example, LTE-M technology may be implemented in at least one of a variety of standards, such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices (XXX, YYY) of the present disclosure is at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low power communication, and is not limited to the above-described names. As an example, ZigBee technology can generate personal area networks (PANs) related to small/low-power digital communication based on various standards such as IEEE 802.15.4, and may be called various names.

Example of a Signal Process Circuit to which the Present Disclosure is Applied

FIG. 23illustrates a signal process circuit for a transmission signal.

Referring toFIG. 23, a signal processing circuit1000may include scramblers1010, modulators1020, a layer mapper1030, a precoder1040, resource mappers1050, and signal generators1060. An operation/function ofFIG. 23may be performed, without being limited to, the processors102and202and/or the transceivers106and206ofFIG. 22. Hardware elements ofFIG. 23may be implemented by the processors102and202and/or the transceivers106and206ofFIG. 22. For example, blocks1010to1060may be implemented by the processors102and202ofFIG. 22. Alternatively, the blocks1010to1050may be implemented by the processors102and202ofFIG. 22and the block1060may be implemented by the transceivers106and206ofFIG. 22.

Application Example of a Wireless Device to which the Present Disclosure is Applied

FIG. 24illustrates another example of a wireless device applied to the present disclosure. The wireless device may be implemented in various forms according to a use-case/service (refer toFIG. 21).

The additional components140may be variously configured according to types of wireless devices. For example, the additional components140may include at least one of a power unit/battery, input/output (I/O) unit, a driving unit, and a computing unit. The wireless device may be implemented in the form of, without being limited to, the robot (100aofFIG. 21), the vehicles (100b-1and100b-2ofFIG. 21), the XR device (100cofFIG. 21), the hand-held device (100dofFIG. 21), the home appliance (100eofFIG. 21), the IoT device (100fofFIG. 21), a digital broadcast UE, a hologram device, a public safety device, an MTC device, a medicine device, a fintech device (or a finance device), a security device, a climate/environment device, the AI server/device (400ofFIG. 21), the BSs (200ofFIG. 21), a network node, etc. The wireless device may be used in a mobile or fixed place according to a use-example/service.

Hereinafter, an example of implementingFIG. 24will be described in detail with reference to the drawings.

Example of Hand-Held Device to which the Present Disclosure is Applied

Example of a Vehicle or an Autonomous Driving Vehicle to which the Present Disclosure is Applied

Examples of AR/VR and Vehicle to which the Present Disclosure is Applied

FIG. 27illustrates a vehicle applied to the present disclosure. The vehicle may be implemented as a transport means, an aerial vehicle, a ship, etc.

Referring toFIG. 27, a vehicle100may include a communication unit110, a control unit120, a memory unit130, an I/O unit140a, and a positioning unit140b. Herein, the blocks110to130/140aand140bcorrespond to blocks110to130/140ofFIG. 24.

The communication unit110may transmit and receive signals (e.g., data and control signals) to and from external devices such as other vehicles or BSs. The control unit120may perform various operations by controlling constituent elements of the vehicle100. The memory unit130may store data/parameters/programs/code/commands for supporting various functions of the vehicle100. The I/O unit140amay output an AR/VR object based on information within the memory unit130. The I/O unit140amay include an HUD. The positioning unit140bmay acquire information about the position of the vehicle100. The position information may include information about an absolute position of the vehicle100, information about the position of the vehicle100within a traveling lane, acceleration information, and information about the position of the vehicle100from a neighboring vehicle. The positioning unit140bmay include a GPS and various sensors.

As an example, the communication unit110of the vehicle100may receive map information and traffic information from an external server and store the received information in the memory unit130. The positioning unit140bmay obtain the vehicle position information through the GPS and various sensors and store the obtained information in the memory unit130. The control unit120may generate a virtual object based on the map information, traffic information, and vehicle position information and the I/O unit140amay display the generated virtual object in a window in the vehicle (1410and1420). The control unit120may determine whether the vehicle100normally drives within a traveling lane, based on the vehicle position information. If the vehicle100abnormally exits from the traveling lane, the control unit120may display a warning on the window in the vehicle through the I/O unit140a. In addition, the control unit120may broadcast a warning message regarding driving abnormity to neighboring vehicles through the communication unit110. According to situation, the control unit120may transmit the vehicle position information and the information about driving/vehicle abnormality to related organizations.

Examples of XR Device to which the Present Disclosure is Applied

FIG. 28illustrates an XR device applied to the present disclosure. The XR device may be implemented by an HMD, an HUD mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc.

Referring toFIG. 28, an XR device100amay include a communication unit110, a control unit120, a memory unit130, an I/O unit140a, a sensor unit140b, and a power supply unit140c. Herein, the blocks110to130/140ato140ccorrespond to the blocks110to130/140ofFIG. 24, respectively.

The communication unit110may transmit and receive signals (e.g., media data and control signals) to and from external devices such as other wireless devices, hand-held devices, or media servers. The media data may include video, images, and sound. The control unit120may perform various operations by controlling constituent elements of the XR device100a. For example, the control unit120may be configured to control and/or perform procedures such as video/image acquisition, (video/image) encoding, and metadata generation and processing. The memory unit130may store data/parameters/programs/code/commands needed to drive the XR device100a/generate XR object. The I/O unit140amay obtain control information and data from the exterior and output the generated XR object. The I/O unit140amay include a camera, a microphone, a user input unit, a display unit, a speaker, and/or a haptic module. The sensor unit140bmay obtain an XR device state, surrounding environment information, user information, etc. The sensor unit140bmay include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and/or a radar. The power supply unit140cmay supply power to the XR device100aand include a wired/wireless charging circuit, a battery, etc.

For example, the memory unit130of the XR device100amay include information (e.g., data) needed to generate the XR object (e.g., an AR/VR/MR object). The I/O unit140amay receive a command for manipulating the XR device100afrom a user and the control unit120may drive the XR device100aaccording to a driving command of a user. For example, when a user desires to watch a film or news through the XR device100a, the control unit120transmits content request information to another device (e.g., a hand-held device100b) or a media server through the communication unit130. The communication unit130may download/stream content such as films or news from another device (e.g., the hand-held device100b) or the media server to the memory unit130. The control unit120may control and/or perform procedures such as video/image acquisition, (video/image) encoding, and metadata generation/processing with respect to the content and generate/output the XR object based on information about a surrounding space or a real object obtained through the I/O unit140a/sensor unit140b.

The XR device100amay be wirelessly connected to the hand-held device100bthrough the communication unit110and the operation of the XR device100amay be controlled by the hand-held device100b. For example, the hand-held device100bmay operate as a controller of the XR device100a. To this end, the XR device100amay obtain information about a 3D position of the hand-held device100band generate and output an XR object corresponding to the hand-held device100b.

Examples of Robot to which the Present Disclosure is Applied

FIG. 29illustrates a robot applied to the present disclosure. The robot may be categorized into an industrial robot, a medical robot, a household robot, a military robot, etc., according to a used purpose or field.

Referring toFIG. 29, a robot100may include a communication unit110, a control unit120, a memory unit130, an I/O unit140a, a sensor unit140b, and a driving unit140c. Herein, the blocks110to130/140ato140ccorrespond to the blocks110to130/140ofFIG. 24, respectively.

The communication unit110may transmit and receive signals (e.g., driving information and control signals) to and from external devices such as other wireless devices, other robots, or control servers. The control unit120may perform various operations by controlling constituent elements of the robot100. The memory unit130may store data/parameters/programs/code/commands for supporting various functions of the robot100. The I/O unit140amay obtain information from the exterior of the robot100and output information to the exterior of the robot100. The I/O unit140amay include a camera, a microphone, a user input unit, a display unit, a speaker, and/or a haptic module. The sensor unit140bmay obtain internal information of the robot100, surrounding environment information, user information, etc. The sensor unit140bmay include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, a radar, etc. The driving unit140cmay perform various physical operations such as movement of robot joints. In addition, the driving unit140cmay cause the robot100to travel on the road or to fly. The driving unit140cmay include an actuator, a motor, a wheel, a brake, a propeller, etc.

Examples of AI Device to which the Present Disclosure is Applied

FIG. 30illustrates an AI device applied to the present disclosure. The AI device may be implemented by a fixed device or a mobile device, such as a TV, a projector, a smartphone, a PC, a notebook, a digital broadcast UE, a tablet PC, a wearable device, a Set Top Box (STB), a radio, a washing machine, a refrigerator, a digital signage, a robot, a vehicle, etc.

Referring toFIG. 30, an AI device100may include a communication unit110, a control unit120, a memory unit130, an I/O unit140a/140b, a learning processor unit140c, and a sensor unit140d. The blocks110to130/140ato140dcorrespond to blocks110to130/140ofFIG. 24, respectively.

The communication unit110may transmit and receive wired/radio signals (e.g., sensor information, user input, learning models, or control signals) to and from external devices such as other AI devices (e.g.,100x,200, or400ofFIG. 21) or an AI server (e.g.,400ofFIG. 21) using wired/wireless communication technology. To this end, the communication unit110may transmit information within the memory unit130to an external device and transmit a signal received from the external device to the memory unit130.

The control unit120may determine at least one feasible operation of the AI device100, based on information that is determined or generated using a data analysis algorithm or a machine learning algorithm. The control unit120may perform an operation determined by controlling constituent elements of the AI device100. For example, the control unit120may request, search, receive, or use data of the learning processor unit140cor the memory unit130and control the constituent elements of the AI device100to perform a predicted operation or an operation determined to be preferred among at least one feasible operation. The control unit120may collect history information including the operation contents of the AI device100and operation feedback by a user and store the collected information in the memory unit130or the learning processor unit140cor transmit the collected information to an external device such as an AI server (400ofFIG. 21). The collected history information may be used to update a learning model.

The memory unit130may store data for supporting various functions of the AI device100. For example, the memory unit130may store data obtained from the input unit140a, data obtained from the communication unit110, output data of the learning processor unit140c, and data obtained from the sensor unit140. The memory unit130may store control information and/or software code needed to operate/drive the control unit120.

The input unit140amay acquire various types of data from the exterior of the AI device100. For example, the input unit140amay acquire learning data for model learning, and input data to which the learning model is to be applied. The input unit140amay include a camera, a microphone, and/or a user input unit. The output unit140bmay generate output related to a visual, auditory, or tactile sense. The output unit140bmay include a display unit, a speaker, and/or a haptic module. The sensing unit140may obtain at least one of internal information of the AI device100, surrounding environment information of the AI device100, and user information, using various sensors. The sensor unit140may include a proximity sensor, an illumination sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and/or a radar.

The learning processor unit140cmay learn a model consisting of artificial neural networks, using learning data. The learning processor unit140cmay perform AI processing together with the learning processor unit of the AI server (400ofFIG. 21). The learning processor unit140cmay process information received from an external device through the communication unit110and/or information stored in the memory unit130. In addition, an output value of the learning processor unit140cmay be transmitted to the external device through the communication unit110and may be stored in the memory unit130.

INDUSTRIAL APPLICABILITY

The above-mentioned embodiments of the present disclosure are applicable to various mobile communication systems.