Radio resource management for enhanced reliability in mobile scenarios

Abstract

A wireless communication system comprises one or more base stations and one or more user equipments UE for communicating with the base stations and / or another UE using allocated resources. In the event that the UE is out of coverage of a serving base station, at least some of the allocated resources of the serving cell are maintained or reserved for a predefined time interval T.

Description

Technical Field

[0001] The present application relates to the field of wireless communication systems or networks, and more particularly to methods for wireless communication between entities of a wireless communication system (e.g., communication between a base station and a user equipment or between user equipments). Embodiments relate to enhancements for situations where a user equipment is out of coverage of a serving base station for a limited period of time. Background Art

[0002] FIG. 1( a) and FIG. 1( b) are schematic diagrams of an example of a terrestrial wireless network 100. As shown in FIG. 1( a), the terrestrial wireless network 100 includes a core network 102 and one or more radio access networks RAN1, RAN2, ..., RAN N Figure 1(b) shows the radio access network RAN n Schematic diagram of an example of a radio access network RAN n One or more base stations gNB1 to gNB5 may be included, each serving a specific area around the base station, schematically represented by the corresponding cells 1061 to 1065. Base stations are provided to serve users within the cells. The term base station BS refers to gNB in ​​5G networks, eNB in ​​UMTS / LTE / LTE-A / LTE-A Pro, or simply BS in other mobile communication standards. Users can be fixed devices or mobile devices. Mobile or fixed IoT devices connected to base stations or users can also access the wireless communication system. Mobile devices or IoT devices may include physical devices, ground-based vehicles such as robots or cars, aircraft such as manned or unmanned aerial vehicles (UAVs) (the latter also known as drones), buildings, and other items or devices having embedded electronic devices, software, sensors, actuators, etc. and network connections that enable these devices to collect and exchange data across existing network infrastructure. Figure 1(b) shows an exemplary diagram of five cells, however the RAN n More or fewer such cells may be included, and the RAN nIt may also include only one base station. Figure 1(b) shows two users UE1 and UE2, also referred to as user equipment UE, served by base station gNB2 in cell 1062. Another user UE3 is shown in cell 1064, which is served by base station gNB4. Arrows 1081, 1082 and 1083 schematically represent uplink / downlink connections for sending data from users UE1, UE2 and UE3 to base stations gNB2, gNB4 or for sending data from base stations gNB2, gNB4 to users UE1, UE2, UE3. In addition, Figure 1(b) shows two IoT devices 1101 and 1102 in cell 1064, and IoT devices 1101 and 1102 may be fixed devices or mobile devices. IoT device 1101 accesses the wireless communication system via base station gNB4 to receive and send data, as schematically represented by arrow 1121. IoT device 1102 accesses the wireless communication system via user UE3, as schematically represented by arrow 1122. Each base station gNB1 to gNB5 may be connected to the core network 102, for example, via an S1 interface, via each backhaul link 1141 to 1145, which is schematically represented by an arrow pointing to "core" in Figure 1(b). The core network 102 may be connected to one or more external networks. In addition, some or all of the base stations gNB1 to gNB5 may be connected to each other, for example, via an S1 or X2 interface or an XN interface in NR, via corresponding backhaul links 1161 to 1165, which are schematically represented by an arrow pointing to "gNB" in Figure 1(b).

[0003] For data transmission, a physical resource grid may be used. The physical resource grid may include a set of resource elements to which various physical channels and physical signals are mapped. For example, a physical channel may include a physical downlink, uplink and sidelink shared channels (PDSCH, PUSCH, PSSCH) carrying user-specific data (also referred to as downlink, uplink and sidelink payload data), a physical broadcast channel (PBCH) carrying, for example, a master information block (MIB) and a system information block (SIB), a physical downlink, uplink and sidelink control channels (PDCCH, PUCCH, PSSCH) carrying, for example, downlink control information (DCI), uplink control information (UCI) and sidelink control information (SCI). For the uplink, the physical channel may also include a physical random access channel (PRACH or RACH) used by the UE to access the network after synchronization and obtaining the MIB and SIB. The physical signal may include a reference signal or symbol (RS), a synchronization signal, etc. The resource grid may include a frame or radio frame having a certain duration in the time domain and a given bandwidth in the frequency domain. A frame may have a certain number of subframes with a predetermined length (e.g., 1 ms). Each subframe may include one or more slots with 12 or 14 OFDM symbols, depending on the cyclic prefix (CP) length. A frame may also consist of a smaller number of OFDM symbols, such as when utilizing a shortened transmission time interval (sTTI) or a mini-slot / non-slot based frame structure containing only a few OFDM symbols.

[0004] The wireless communication system may be any single frequency or multi-carrier system using frequency division multiplexing, such as an orthogonal frequency division multiplexing (OFDM) system, an orthogonal frequency division multiple access (OFDMA) system, or any other IFFT-based signal with or without CP, such as DFT-S-OFDM. Other waveforms such as non-orthogonal waveforms for multiple access may be used, such as filter bank multi-carrier (FBMC), generalized frequency division multiplexing (GFDM), or universal filtered multi-carrier (UFMC). The wireless communication system may operate, for example, according to the advanced LTE pro standard or the 5G or NR new radio standard.

[0005] The wireless network or communication system depicted in Figures 1(a) and 1(b) may be composed of heterogeneous networks having different overlapping networks, for example, a network of macro cells in which each macro cell includes a macro base station (e.g., base stations gNB1 to gNB5) and a network of small cell base stations such as femto or pico base stations (not shown in Figures 1(a) and 1(b)).

[0006] In addition to the above-mentioned terrestrial wireless networks, there are also non-terrestrial wireless communication networks, including space-borne transceivers (e.g., satellites) and / or airborne transceivers (e.g., unmanned aircraft systems). Non-terrestrial wireless communication networks or systems can operate in a similar manner to the terrestrial systems described above with reference to Figures 1(a) and 1(b), for example, according to the advanced LTE pro standard or the 5G or NR new radio standard.

[0007] In a mobile communication network, for example, in a network as described above with reference to Figures 1(a) and 1(b), such as an LTE or 5G / NR network, there may be UEs that communicate directly with each other via one or more sidelink (SL) channels (e.g., using a PC5 interface). UEs that communicate directly with each other via sidelinks may include vehicles that communicate directly with other vehicles (V2V communication), vehicles that communicate with other entities of a wireless communication network (e.g., roadside entities such as traffic lights, traffic signs, or pedestrians) (V2X communication). Other UEs may not be vehicle-related UEs and may include any of the above-mentioned devices. Such devices may also communicate directly with each other (D2D communication) using SL channels.

[0008] When considering two UEs communicating with each other directly via a side link, the two UEs can be served by the same base station, so that the base station can provide side link resource allocation configuration or assistance to the UE. For example, both UEs can be within the coverage area of ​​a base station (such as one of the base stations depicted in Figures 1(a) and 1(b)). This is called an "in-coverage" scenario. Another scenario is called an "out-of-coverage" scenario. It should be noted that "out-of-coverage" does not mean that the two UEs are not within one of the cells depicted in Figures 1(a) and 1(b), but rather means that these UEs:

[0009] - may not be connected to the base station, e.g., they are not in RRC connected state, so the UE does not receive any sidelink resource allocation configuration or assistance from the base station, and / or

[0010] - may be connected to a base station, but, due to one or more reasons, the base station may not provide sidelink resource allocation configuration or assistance to the UE, and / or

[0011] -Can connect to base stations that do not support NR V2X services, such as GSM, UMTS, LTE base stations.

[0012] When considering two UEs communicating directly with each other via a side link (e.g. using a PC5 interface), one of the UEs may also be connected to a BS and may relay information from the BS to the other UE via the side link interface. Relaying may be performed in the same frequency band (in-band relaying), or another frequency band may be used (out-of-band relaying). In the first case, the communications on Uu and on the side link may be decoupled using different time slots, as in a time division duplex TDD system.

[0013] Figure 2 is a schematic diagram of an in-coverage scenario in which two UEs communicating directly with each other are both connected to a base station. The base station gNB has a coverage area schematically represented by a circle 200, which substantially corresponds to the cell schematically represented in Figures 1(a) and 1(b). The UEs communicating directly with each other include a first vehicle 202 and a second vehicle 204, both in the coverage area 200 of the base station gNB. Both vehicles 202, 204 are connected to the base station gNB, and furthermore, they are directly connected to each other via a PC5 interface. Scheduling and / or interference management of V2V traffic is assisted by the gNB via control signaling on the Uu interface, which is the radio interface between the base station and the UE. In other words, the gNB provides SL resource allocation configuration or assistance to the UE, and the gNB assigns resources to be used for V2V communication via the side link. This configuration is also referred to as Mode 1 configuration in NR V2X or Mode 3 configuration in LTE V2X.

[0014] Figure 3 is a schematic diagram of an out of coverage scenario, where UEs communicating directly with each other are not connected to a base station, although they may be physically within a cell of a wireless communication network, or some or all of the UEs communicating directly with each other are connected to a base station, but the base station does not provide SL resource allocation configuration or assistance. Three vehicles 206, 208, and 210 are shown communicating directly with each other via a side link (e.g., using a PC5 interface). Scheduling and / or interference management of V2V services is based on algorithms implemented between vehicles. This configuration is also referred to as a Mode 2 configuration in NR V2X or a Mode 4 configuration in LTE V2X. As described above, Figure 3 The scenario as out of coverage scenario does not necessarily mean that the corresponding Mode 2 UE (in NR) or Mode 4 UE (in LTE) is outside the coverage 200 of the base station, but rather it means that the corresponding Mode 2 UE (in NR) or Mode 4 UE (in LTE) is not served by the base station, is not connected to the base station in the coverage area, or is connected to the base station but does not receive SL resource allocation configuration or assistance from the base station. Therefore, the following scenarios may exist: Figure 2 In the coverage area 200 shown, in addition to NR mode 1 or LTE mode 3 UEs 202 and 204, NR mode 2 or LTE mode 4 UEs 206, 208, and 210 also exist.

[0015] In the above-mentioned scenario of the on-board user equipment UE, a plurality of such user equipments may form a user equipment group (also referred to as a group for short), and the communication within the group or between group members may be performed via a side link interface (such as a PC5 interface) between the user equipments. For example, the above-mentioned scenario using the on-board user equipment may be adopted in the field of the transportation industry, in which a plurality of vehicles equipped with on-board user equipments may be grouped together, for example, through a remote driving application. Other use cases in which a plurality of user equipments may be grouped together for performing side link communications with each other include, for example, factory automation and power distribution. In the case of factory automation, a plurality of mobile or fixed machines within a factory may be equipped with user equipments and grouped together for performing side link communications, for example, for controlling the operation of the machines, such as motion control of a robot. In the case of power distribution, entities within the power distribution network may be equipped with corresponding user equipments, which may be grouped together within a certain area of ​​the system so as to communicate with each other via side link communications, thereby allowing monitoring of the system and handling of power distribution network faults and interruptions.

[0016] Naturally, in the above use cases, the sidelink communication is not limited to intra-group communication. Instead, the sidelink communication can be between any UEs, such as between any UE pairs.

[0017] Note that the information in the above section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

[0018] Starting from the prior art as described above, there may be a need to improve or enhance the wireless communication between entities of a wireless communication system with respect to user equipment going out of coverage for a short or medium period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Now, embodiments of the present invention are described in further detail with reference to the accompanying drawings:

[0020] FIG. 1( a ) and FIG. 1( b ) are schematic diagrams showing examples of wireless communication systems;

[0021] Figure 2 is a schematic diagram of an in-coverage scenario where UEs communicating directly with each other are connected to a base station;

[0022] Figure 3 is a schematic diagram of an out-of-coverage scenario where UEs directly communicate with each other without receiving SL resource allocation configuration or assistance from a base station;

[0023] Figure 4 Schematically illustrates a scenario where a mobile UE temporarily enters out of coverage;

[0024] Figure 5is a schematic diagram of a wireless communication system, the wireless communication system comprising a transmitter (such as a base station) and one or more receivers (such as user equipment UE);

[0025] Figure 6 schematically illustrates a known RRS connection re-establishment process; and

[0026] Figure 7 An example of a computer system that can execute the units or modules described according to the method of the present invention and the steps of the method is shown. DETAILED DESCRIPTION

[0027] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings, wherein the same or similar elements have the same reference numerals designated therein.

[0028] As described above, in a wireless communication system and network, as shown in the above reference FIG. 1(a) and FIG. 1(b), Figure 2 or Figure 3 In the wireless communication systems and networks described herein, a mobile device may be served by a base station, for example to receive configuration regarding transmissions between the base station and the user equipment, or for configuration regarding communications with another user equipment, for example using a side link. In either case, the user equipment is said to be within coverage, as described above with reference to Figure 2 and Figure 3 The user equipment may be a mobile device, such as a vehicle, etc. Due to the mobility of the user equipment, the connection with the base station may change as the device moves, and there may be a situation where the connection with the base station is no longer provided, so the UE may enter out of coverage. However, in the case of a mobile user equipment, this out of coverage situation may only be temporary, i.e., may only exist for a limited period of time, because as the UE moves, a connection with the base station may become possible again.

[0029] Figure 4 An out of coverage situation for a highway scenario is shown. Figure 4 The cells are schematically shown, for example, as shown in FIG. 1( a ) and FIG. 1( b ) above. Figure 2 or Figure 3 Referring to a cell, the cell comprises a base station gNB serving multiple mobile UEs. In the depicted example, it is assumed that respective vehicles UE1, UE2 and UE3 are travelling along a highway and are served by the gNB. The respective UEs are Uu controlled by the base station gNB and are within coverage, i.e. operating in mode 1. However, as the respective UEs travel along the highway, there may be obstacles, such as a building B, that prevent the connection between the gNB and the UEs. Figure 4In the example of , UE3 is in a position where it can no longer connect to the gNB due to obstacle B. No Uu signaling, e.g. by RRC or RRC+L1 signaling, providing corresponding resources to be used for communication with the base station or communication via the sidelink is given any more. Thus, UE3 can be considered to be out of coverage, however, because UE3 is driving, e.g. at high speed along a highway, obstacle B only prevents connection to the gNB for a short period of time, and as soon as the vehicle passes obstacle B, connection to the base station gNB becomes possible again, so that UE3 is then in coverage again.

[0030] However, in the case where the UE is out of coverage in NR-V2X communication (similar to LTE-V2X communication), if UE3 is out of coverage on all frequencies in the supported frequency list, the RRC configuration for UE3 will be rewritten by the pre-configuration, that is, when UE3 switches to mode 2. The RRC configuration may include a configured authorized CG, which may no longer be available. As mentioned above, a typical reason for the UE to enter out of coverage for a short time is, for example, due to channel attenuation in the presence of obstacles (such as tunnels or buildings). This situation has an impact on ongoing unicast communications because the communication continuity between communication entities using the side link may no longer be guaranteed. Similarly, in the case of multicast communications, if one or more group members enter out of coverage within a short communication time, the continuity between the individual group members through the side link may no longer be guaranteed. Other issues associated with scenarios where a user equipment (such as a vehicle) is out of coverage for a short or medium period of time (i.e., if the UE loses connection to its serving cell or serving base station) are that, for example, handover may not be feasible or may not be successful because one or more neighboring cells or base stations may be missed, so that the handover takes longer than expected, and therefore a radio link failure RLF procedure is initiated. However, because the vehicle may move along the edge of the cell or because the obstacle that caused the radio link failure is passed by the vehicle quickly, the vehicle may return to coverage in a very short period of time (e.g., within a few milliseconds).

[0031] The present invention provides an improvement or enhancement in wireless communications between entities of a wireless communications system that addresses the above mentioned difficulties or problems with user equipment going out of coverage for only short or medium periods of time.

[0032] The embodiments of the present invention can be shown in FIG. 1(a) and FIG. 1(b), Figure 2 and Figure 3 The wireless communication system shown is implemented in the figure, and the wireless communication system includes a base station and a user, such as a mobile terminal or an IoT device. Figure 5 Schematic diagram of a wireless communication system, the wireless communication system includes a transmitter 300 (such as a base station) and one or more receivers 3021 to 302 n(eg, user equipment UE). The transmitter 300 and the receiver 302 may communicate via one or more wireless communication links or channels 304a, 304b, 304c (eg, radio links). The transmitter 300 may include one or more antennas ANT coupled to each other. T or an antenna array having a plurality of antenna elements, a signal processor 300a and a transceiver 300b. The receiver 302 includes one or more antennas ANT coupled to each other. R or an antenna array having multiple antennas, a signal processor 302a1, 302a n and transceivers 302b1, 302b n The base station 300 and the UE 302 may communicate via respective first wireless communication links 304a and 304b (e.g., radio links using a Uu interface), and the UE 302 may communicate with each other via a second wireless communication link 304c (e.g., a radio link using a PC5 interface). The UEs may communicate with each other via side links. The system, one or more UEs 302, and the base station may operate according to the teachings of the present invention as described herein.

[0033] Wireless communication system

[0034] The present invention provides a wireless communication system, comprising: one or more base stations; and one or more user equipments UE, for communicating with the base stations and / or another UE using allocated resources, wherein, when the UE is beyond the coverage of the serving base station, at least some of the allocated resources of the serving cell are maintained or reserved for a predefined time interval T.

[0035] According to an embodiment, at least some of the allocated resources include SL resources, wherein one or more of the following SL resource allocations may be maintained or retained:

[0036] Resource pool definitions, or

[0037] The resources being allocated, or

[0038] Other RRC configurations.

[0039] According to an embodiment, the wireless communication system will monitor the radio link between the UE and the serving base station to determine the short-term out-of-coverage of the UE, wherein the monitoring may include one or more of the following measurements:

[0040] ·Asynchronous,

[0041] Signal strength, such as RSSI,

[0042] CR error or block error rate,

[0043] • Radio link degradation or failure metrics or measurements.

[0044] According to an embodiment, short-term out-of-coverage is identified when one or more measurement results from the monitored radio link are below a predefined corresponding threshold, and wherein the corresponding threshold may depend on the communication in which the UE participates, for example, certain requirements to be met: such as a specific quality of service QoS, including, for example, latency, reliability and communication range; or a specific broadcast type, including, for example, unicast, multicast or broadcast; or a specific communication type, including, for example, initial transmission, retransmission and feedback, such as HARQ or CSI.

[0045] According to an embodiment, in response to determining that the coverage is out of coverage for a short period of time, the wireless communication system will indicate a timer for the allocated resources, such as a configured grant timer, wherein the timer may indicate a predefined time interval T as a specific time period or a specific number of subframes, wherein the timer may be defined based on:

[0046] - Single fixed value configured via signaling or preconfigured in the UE or preconfigured by the network

[0047] - More than one value configured via signaling or preconfigured in the UE or preconfigured by the network

[0048] - One or more values ​​configured via upper layer signaling, where the value conveys one or more Quality of Service (QoS) indicators

[0049] - One or more values ​​measured by the UE, wherein the UE may be requested to perform timing measurements, wherein the timing measurements may imply different criteria, such as speed, routing direction, location, packet priority, QoS.

[0050] According to an embodiment, a timer is provided for a specific UE or a UE group.

[0051] According to an embodiment, the predefined time interval T of the timer is selected as:

[0052] Avoiding, for example, upper layers from immediately considering the UE out of coverage in response to determining a short-term out of coverage, thereby avoiding dumping of allocated resources, and / or

[0053] Allow the UE to complete the handover procedure, and / or

[0054] Allows the UE to remain connected when performing a handover or when the HO stay is unsuccessful for a period of time (longer timer).

[0055] According to an embodiment, in response to the UE performing the following operations, the timer expires before reaching the predefined time interval T:

[0056] Joining a new cell / base station and receiving RRC configuration from the new cell / base station, e.g. in response to a successful handover, or

[0057] Rejoin the serving cell / base station and receive RRC reconfiguration.

[0058] According to an embodiment, the wireless communication system will start the timer in response to one or more of the following:

[0059] Out of coverage determination in the serving cell frequency list,

[0060] Out of coverage determination in the neighboring cell list,

[0061] UE initiates UE-assisted handover,

[0062] UE starts base station assisted handover, and

[0063] • The UE is in Mode 2 and determines that no interception results are available.

[0064] • The UE is in Mode 1 and changes to Mode 2.

[0065] According to an embodiment, where a timer is indicated to the UE in order to maintain the RRC / configuration during a short period of out of coverage,

[0066] If the timer is for out of coverage, the timer can be longer than RLF,

[0067] • If the UE is performing handover, the timer may be longer than the HO timer.

[0068] According to an embodiment, in case the UE switches from Mode 1 to Mode 2 due to a radio link failure RLF, the timer starts before the RLF and continues after the RLF.

[0069] According to an embodiment, the allocated resources are resources for a configured grant, wherein the configured grant may include: an RRC configured grant without any L1 signaling, RRC type 1; or an RRC configured grant with L1 signaling for activation or deactivation, RRC type 2.

[0070] According to an embodiment,

[0071] The configured authorizations include one or more of the following:

[0072] · Grant for configuration of TX resource pool for a specific UE,

[0073] Commonly configured authorized resources used by group UEs, configured via group common signaling

[0074] A commonly configured authorized resource used by all UEs, or

[0075] The configured granted resources may be configured via RRC and / or DCI signaling to operate in the following:

[0076] · Anomaly pool for use during radio failures and other radio abnormal conditions,

[0077] UL resources, if the UE is allowed to perform SL communication via the Uu configured resources,

[0078] X / Flexible / S resources or time slots, if the UE is allowed to perform SL communication via the Uu configured resources,

[0079] DL resources, if the UE is allowed to perform SL communication via the resources configured by Uu,

[0080] The SPS configuration configured by the LTE device for the UE.

[0081] According to an embodiment, for transmissions on a configured grant during a predefined time interval T, a timer shall maintain a period P of one or more configured grants.

[0082] According to an embodiment, the timer maintains the period P by referring to one or more of the following:

[0083] · The configured time offset that is synchronized only to the last detected SFN,

[0084] The configured time offset and correction from GNSS, the source UE or another cell, and

[0085] • If indicated by RRC message or upper layers, an arbitrarily selected time offset to an arbitrarily selected SFN, where the UE shall send an appropriate PSSS as synchronization source for the serving base station.

[0086] According to an embodiment, for transmissions on a configured grant during a predefined time interval T, the time domain resource period P will be reset to:

[0087] the original period P assigned by the base station via RRC and / or DCI before the short-term out-of-coverage,

[0088] a new period P_new that is faster than the original period P assigned by the base station via RRC and / or DCI before the short-term out-of-coverage, such as such that P_new=P / 2; or P_new=P / 3, or P_new=P / 4, ..., or P_new=P / N, where N is an integer,

[0089] A new period P_new that is slower than the original period P allocated by the base station via RRC and / or DCI before the short-term out of coverage, for example such that P_new=2P; or P_new=3P, or P_new=4P, ..., or P_new=N times P, where N is an integer.

[0090] According to an embodiment, for transmission on a configured grant during a predefined time interval T, the frequency domain resources will be reset to:

[0091] · The original frequency domain allocation for the in-coverage case allocation,

[0092] Short-term frequency domain allocation beyond coverage, short-term frequency domain allocation beyond coverage includes

[0093] o an allocation of 100% of the original frequency resources allocated via RRC or DCI before the short-term out-of-coverage, or

[0094] o Allocation of X% of the original frequency resources allocated via RRC or DCI before the short-term out-of-coverage, where X can be any value between 0 and 100, and where X can be configured by upper / high-layer signaling or can be pre-configured in the UE or selected by the UE high layers,

[0095] Among them, resources can be allocated from lower PRB / VRB / subchannel or from higher PRB / VRB / subchannel.

[0096] According to an embodiment, for transmissions on configured grants during a predefined time interval T, operating frequency domain and / or time domain hopping is configured, wherein the UE may be configured or preconfigured to perform hopping in a certain resource pattern.

[0097] According to an embodiment, time hopping is configured by defining a time hopping sequence via a shift relative to a predefined transmission period P as follows:

[0098] At transmission instance T(n), the transmission is performed at T(n) = T_from_last_TX + P,

[0099] At transmission instance T(n+1), the transmission is performed at T(n+1)=T_from_last_TX+P+deltashift1,

[0100] At transmission instance T(n+2), the transmission is performed at T(n+2)=T_from_last_TX+P+deltashift2,

[0101] ·…,

[0102] At transmission instance T(n+M), the transmission is performed at T(n+M)=T_from_last_TX+P+deltashiftM,

[0103] at T(mod(N,M+1)), where n=N transmission instances, M+1=end of shift count, the transmission is performed at T(mod(N,M+1))=T_from_last_TX+P,

[0104] where deltashiftX is a positive or negative shift from P to generate the time jump.

[0105] According to an embodiment, inter-slot or intra-slot frequency hopping is configured as follows:

[0106] By defining a frequency hopping sequence within a configured grant resource within a time slot and resource block RB, and / or

[0107] By defining a frequency hopping sequence between frequencies configured as one or more other configured grants, and / or

[0108] By defining a frequency hopping sequence between the frequencies of resources granted to one or more other grants,

[0109] Wherein, the UE may be requested, for example via an RRC message or in a configured grant information element, to perform hopping in a specific pattern and / or sequence in time and / or frequency, and / or

[0110] Therein, the UE may be requested to perform random hopping in time and / or frequency, for example, via an RRC message or in a configured authorization information element or in the UE or preconfigured by an upper layer.

[0111] According to an embodiment, frequency hopping and time hopping are configured by defining and signaling or by pre-configuring and indexing or by pre-configuring and enabling one or more time / frequency resource patterns as TFRPs, wherein

[0112] The UE may be requested to listen to each TFRP, for example via an RRC message, or

[0113] If a TFRP is used and the listening results show that the probability of collision is high, the UE may be requested to change one or more TX parameters, such as reducing power and / or MCS.

[0114] According to an embodiment, the wireless communication system will initialize a DMRS sequence for a predefined time interval T.

[0115] According to an embodiment, wherein the DMRS sequence for a predefined time interval T is initialized using:

[0116] DMRS sequence initialized by the serving base station, e.g., via a grant configured by RRC / DCI, and / or

[0117] Preconfigured sequences, and / or

[0118] • Randomly selected UEs, e.g. identified by upper layers, to override DMRS sequence generation during short-term out-of-coverage periods.

[0119] According to an embodiment, the DMRS positions are hopped in time and frequency, for example by identifying hopping DMRS symbol positions and different OFDM resource element positions.

[0120] According to an embodiment, if more than one pair of UEs are in short-term out-of-coverage selected from similar resources, DMRS sequence randomization is selected by the UEs to avoid DMRS collision.

[0121] According to an embodiment, the wireless communication system will provide an exception resource set and cause a switch to the exception resource set once the UE or base station identifies a short-term out-of-coverage and a predefined time interval T expires.

[0122] According to an embodiment, the abnormal resource set includes an abnormal pool, which includes time and frequency resources, wherein the time and frequency resources can be divided into:

[0123] Time-frequency modes, where the UE will listen to all different time-frequency modes and then select one or more modes to transmit, or

[0124] a time-frequency pattern, where the UE will listen to a dedicated time-frequency pattern in the time-frequency pattern, or

[0125] • Time-frequency mode, where the UE will use a dedicated time-frequency mode, which can be identified by specific RRC signaling, or by specific DCI signaling, or by group common RRC signaling, or by group common PDCCH / DCI signaling.

[0126] According to an embodiment, the exception resource set includes an exception pool, the exception pool includes time and frequency resources, wherein the exception pool includes one or more configured grants, wherein the exception pool including the one or more configured grants can be used when the channel shows a high congestion value (e.g., a high channel busy rate (CBR)) or a high data traffic load (e.g., a large number of scheduling requests (SRs) or buffer status reports (BSRs)), and wherein the UE can be requested to

[0127] Choose among all configured authorizations, and / or

[0128] · selecting among the authorizations of configurations, for example up to 8 or more configurations, which have a time offset and period P in time but have the same frequency, and / or

[0129] · selecting, for example, up to 8 or more configurations in the grant of configurations, which have different subchannel / subband / RB frequency offsets in frequency but have the same time offset and period P, and / or

[0130] · selecting, for example, up to 8 or more configurations in a configuration grant, with different subchannel / subband / RB frequency offsets in frequency and with time offsets and periods in time, and / or

[0131] • Only 1 configuration is selected, which is indicated by specific RRC signaling, or by specific DCI signaling, or by group-common RRC signaling for a UE group, or by group-common PDCCH / DCI signaling for a UE group.

[0132] According to an embodiment, the set of exception resources comprises an exception pool comprising time and frequency resources configured as configured grants.

[0133] According to an embodiment, the exception resource set includes a set of fixedly configured grants or a set of configured grants configured through multiple ConfiguredGrantConfig messages or only through rrc-ConfiguredUplinkGrant messages or rrc-ConfiguredSidelinkGrant messages, wherein the configured grant information may carry an exception timer allowing operation outside coverage.

[0134] According to an embodiment, the abnormal resource set includes an abnormally configured grant, such as only an RRC message or a UE-specific / group-specific RRC and / or DCI message.

[0135] According to an embodiment, the grant of exception configuration is configured in time / frequency via, for example, an (Exception)-ConfiguredGrantConfig message or only an (Exception)-rrc-ConfiguredUplinkGrant message.

[0136] According to an embodiment, the exception configuration is selected by the UE and may be used during in-coverage and during out-of-coverage until the timer expires one or more times.

[0137] According to an embodiment, when an out of coverage is triggered, a timer of the exception pool may define how long the exception resource pool is used during the out of coverage period.

[0138] According to an embodiment, if a configured authorized timer defined within an exception pool is defined, the configured authorized timer defined within the exception pool may be overwritten by the exception resource pool timer if the exception resource pool timer exists.

[0139] According to an embodiment, during the handover procedure, the UE shall use the configured grant in the exception pool of the target cell or serving cell.

[0140] According to an embodiment, when the UE is out of coverage for longer than a predefined time interval T, the UE will use the configured grant in the exception pool.

[0141] According to an embodiment, when the UE moves from a NR cell to an LTE cell and the UE triggers a SoC timer, the UE maintains the authorization of the configuration granted from the secondary NR cell, such as type 1, until the timer of the SoC is running, and once the timer expires, the UE starts using the SPS configuration provided by the LTE cell, wherein, via the X2 interface, the LTE cell learns the previously granted CG type 1 configuration, and when the UE moves from the LTE cell to the NR cell, via the X2 interface, the NR cell and the LTE cell align the SPS configuration granted to the UE, for example by storing the configuration of the SPS in the UE and providing it to the NR cell as UE capability information.

[0142] According to an embodiment, an exception-configured grant provided in an exception pool or a common TX pool may be adopted for handover between different RATs, and the UE may be configured by the NR serving cell and moved to the LTE target cell or vice versa by the LTE serving cell and moved to the NR target cell, and the CG may be defined for use in the target cell (e.g., including NR type 1 (such as CG), NR type 2 (such as CG, but with certain restrictions on LTE operation) or LTE (such as SPS)) and may be used within the following during handover:

[0143] - an abnormal pool of T cell or target cell (and T cell frequency) or S cell or serving cell (and S cell frequency), or

[0144] -TX pool of T cell (and T cell frequency) or S cell (and S cell frequency).

[0145] According to an embodiment, an exception-configured grant provided in an exception pool or a common TX pool may be adopted for handover between different RATs, and the UE may be configured by an LTE serving cell and moved to an NR LTE target cell, and the resource configuration may be defined for use in the target cell, for example as an SPS configuration, and may be used internally during handover in:

[0146] - an abnormal pool of T cell or target cell (and T cell frequency) or S cell or serving cell (and S cell frequency), or

[0147] -TX pool of T cell (and T cell frequency) or S cell (and S cell frequency).

[0148] According to an embodiment, the sidelink resource set and / or the sidelink resource subset includes a plurality of resources that are continuous or non-contiguous across the frequency domain and adjacent or non-adjacent across the time domain.

[0149] According to an embodiment, the side link resource set defines one or more of the following: a resource pool (RP), a mini resource pool (mRP) or a group common resource pool, a bandwidth part BWP in a resource pool, a resource pool in a BWP.

[0150] According to an embodiment, the multiple UEs include one or more of the following: a mobile terminal, or a fixed terminal, or a cellular IoT-UE, or a vehicle-mounted UE, or a group head UE (GL), or an IoT or narrowband IoT (NB-IoT) device, or a ground-based vehicle, or an aircraft, or a drone, or a mobile base station, or a roadside unit (RSU), or a building, or any other item or device provided with a network connection that enables the item / equipment to communicate using a wireless communication network, such as a sensor or actuator.

[0151] According to an embodiment, the base station includes one or more of the following: a macrocell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or a roadside unit, or a UE, or a scheduler UE, a group head (GL), a group head (GH), a cluster head (CH), or a relay or a remote radio head, or an AMF, or an SMF, or a core network entity, or a mobile edge computing entity, or a network slice as in the context of NR or 5G core, or any sending / receiving point TRP that enables an item or device to communicate using a wireless communication network, and the item or device is provided with a network connection to communicate using the wireless communication network.

[0152] Base Station

[0153] The present invention provides a base station used in the wireless communication system of the present invention.

[0154] The present invention provides a base station for a wireless communication system, which includes: one or more base stations; and one or more user equipment UE, which is used to communicate with the base station and / or another UE using allocated resources, wherein when the UE is beyond the coverage of the base station, the base station will maintain or reserve at least some of the allocated resources within a predefined time interval T.

[0155] User Equipment

[0156] The present invention provides a user equipment UE used in the wireless communication system of the present invention.

[0157] The present invention provides a user equipment UE for a wireless communication system, which wireless communication system includes one or more base stations and one or more user equipment UE, wherein the UE will use allocated resources to communicate with the base station and / or another UE, and wherein, when the UE is beyond the coverage of its serving base station, at least some of the allocated resources of the serving base station are maintained or reserved within a predefined time interval T.

[0158] method

[0159] The present invention provides a method for operating the wireless communication system of the present invention.

[0160] The present invention provides a method for operating a wireless communication system, which includes: one or more base stations; and one or more user equipment UE, which is used to communicate with the base station and / or another UE using allocated resources. The method includes maintaining or reserving at least some of the allocated resources of the serving cell within a predefined time interval T when the UE is out of the coverage of the serving base station.

[0161] Computer program product

[0162] The invention provides a computer program product comprising instructions which, when executed by a computer, cause the computer to carry out one or more methods according to the invention.

[0163] Therefore, according to the embodiments of the present invention described in more detail below, the situation in which a UE (such as a vehicle or another mobile UE) can switch to Mode 2 in a short or medium time period is solved. For example, in order to ensure the continuity of communication between group members and / or between unicast communication members on the side link, the embodiments of the present invention provide scheduling enhancements. Once the connection between the UE and the base station becomes possible again, other embodiments allow communication with the base station to be easily restored (this applies to the situation in which the UE performs SL communication with another UE and the situation in which the UE does not perform SL communication, that is, it has nothing to do with whether SL communication is performed). The embodiments of the present invention reduce latency issues and improve reliability while avoiding signaling overhead. According to an embodiment of the present invention, the above purpose is achieved by maintaining or retaining at least some of the resources (such as side link resources) previously allocated (i.e., before the UE enters out of coverage) for a short time interval. In the case of SL resource allocation, one or more resource pool definitions or other RRC configurations can be maintained without declaring a complete service or coverage failure. The SL resources to be maintained may include the authorized CG of the configuration of the last serving cell or TX pool of the base station. This allows a UE that temporarily loses connection with the base station (i.e., is out of coverage for a short period of time) to continue communicating with one or more other UEs via the side link using the maintained SL resources. In addition, while retaining resources for communicating with the base station, once the UE returns to the coverage of the previous serving cell, the UE can immediately reuse the previous resources without interruption and without the need for additional signaling exchange. The above situation where the UE is out of coverage for a short or medium period of time is also referred to as short out of coverage or short OoC hereinafter.

[0164] According to an embodiment, the radio link between the UE and the serving base station may be monitored to determine an out of coverage OoC situation or a short term out of coverage, for example based on one or more of the following measurements:

[0165] - not synchronized,

[0166] -Signal strength, such as RSSI,

[0167] -CR error or block error rate,

[0168] - Radio link degradation or failure metrics or measurements.

[0169] For example, in addition to or instead of the above references Figure 3 In the described situation, according to an embodiment, an out of coverage OoC situation may be identified when one or more of the measurement results from the monitored radio link is below a predefined corresponding threshold. The corresponding threshold may depend on:

[0170] The UE is involved in communications, e.g., certain requirements to be met, e.g., a specific quality of service QoS, including e.g. latency, reliability and communication range, or

[0171] A specific broadcast type, including, for example, unicast, multicast, or broadcast, or

[0172] Specific communication types, including, for example, initial transmissions, retransmissions, and feedback, such as HARQ or CSI.

[0173] According to an embodiment, retaining or maintaining at least some previously allocated resources may include: maintaining or retaining the authorization configuration of the RRC configuration for the SL so as to retain and obtain (without authorization) the configured authorizations in the RRC type 1 and RRC type 2 configurations during a situation where the user equipment temporarily exceeds the coverage of the radio signal or the radio link with the base station becomes weak (i.e., does not reach a predetermined threshold).

[0174] According to a further embodiment, during a short OoC, the reserved resources and / or reference signals may be randomized, ie, the UE may perform randomization to reduce interference. The randomization may be achieved by frequency hopping and / or time hopping.

[0175] According to another embodiment, the base station or the network may configure the UE with specific resources to overcome the short out of coverage moment, so as to maintain SL communication using the configured authorization when the UE moves into out of coverage for a short time. The above-mentioned specific resources to be used by the UE for the short out of coverage moment may be resources from a common resource pool. The common resource pool may be an enhanced version of the version-15 exception pool to alleviate the short out of coverage scenario. According to an embodiment, the specific resources to be used by the UE for the short out of coverage moment may include an exception pool to be used based on an OoC timer, which defines a predefined time period after the UE switches to mode 2 (i.e., enters out of coverage). In the exception pool, one or more configured authorizations may be defined. According to other embodiments, instead of providing an exception pool, an authorization for the exception configuration may be configured in one or more specific TX pools.

[0176] Embodiments of the present invention are advantageous because they provide communication continuity on the SL in the event of a short out-of-coverage moment of the UE. In addition, transitions or switches between Mode 1 and Mode 2 can be avoided. In addition, embodiments avoid the UE from quickly running into a radio link failure, such as during a switch. In addition, the method of the present invention allows maintaining communications for brief or short out-of-coverage moments (also referred to as quasi-out-of-coverage situations) of the UE according to Mode 1 operation. Additional embodiments may configure a persistent common resource pool (e.g., a Version-1 exception pool) for NR sidelink transmissions.

[0177] Embodiments of the invention are described in more detail, followed by examples or use cases where various embodiments of the invention are employed.

[0178] For the subsequent description, it is assumed that the UE may be configured to communicate with the base station using the Uu interface, or to communicate with one or more other UEs using the sidelink interface. The UE is considered to be in coverage and is thus controlled by the Uu to receive configuration of various resources to be used for communication via the Uu interface. The base station may be a NR base station (such as a gNB) or an LTE base station (such as an eNB).

[0179] According to an embodiment of the present invention, some or all resources (e.g., SL resources) (which have been allocated for use by UEs in coverage) may be maintained or reserved for a limited period of time after it has been determined that the UE has entered out of coverage. For example, the authorization configuration of the RRC configuration for SL communication may be retained. However, other resources may also be reserved to allow the UE to reconnect to the base station immediately after a temporary OoC moment.

[0180] Embodiments of the present invention may be employed, for example, in V2X, D2D, mMTC, URLLC, critical communications or in high traffic scenarios for V2X, where some / few / single UEs transmit on the same / multiple pools. The RX UE may have one or more RF chains.

[0181] Example 1

[0182] According to the first embodiment, the RRC-configured authorization configuration for SL communication can be retained during a short OoC period. The configured authorization (grant-free) can be retained and obtained in both the RRC type 1 configured authorization (which is based only on the RRC-configured authorization without any L1 signaling) and the type 2 configured authorization (which is based on the RRC configuration and the L1 signaling for activation or deactivation), for example, when the UE's connection with the base station shows a weak radio signal (e.g., a radio signal with an intensity lower than a predetermined threshold), indicating that the UE is out of coverage. Resources are reserved for a time period that does not extend the predefined time interval, and the UE can be referred to as being out of coverage for a short time or a medium time period. The time interval defining the short time or the medium time can be defined based on network capabilities. In contrast to short out of coverage, completely out of coverage may be referred to as long out of coverage hereinafter, that is, in this case, the predefined time interval may have expired, and after the expiration, the UE is considered to be completely out of coverage. A UE that is in long out of coverage or completely out of coverage can be considered to mean that the UE is out of coverage and may no longer retain the RRC configuration used during the coverage period. A UE in long out-of-coverage state dumps the RRC configuration.

[0183] Authorization can be configured using one or more of the following:

[0184] - a grant for the configuration of a TX resource pool for a specific UE,

[0185] - Commonly configured authorized resources used by group UEs, configured via group common signaling

[0186] - Commonly configured authorization resources used by all UEs.

[0187] The configured granted resources may be configured via RRC and / or DCI signaling to operate in or use one or more of the following:

[0188] - Anomaly pool for use during radio failures and other radio abnormal conditions,

[0189] -UL resources, if the UE is allowed to perform SL communication via the Uu configured resources,

[0190] -X / Flexible / S resources or time slots, if the UE is allowed to perform SL communication via the Uu configured resources,

[0191] -DL resources, if the UE is allowed to perform SL communication via the Uu configured resources,

[0192] -SPS configuration configured by the LTE device for the UE.

[0193] A timer may be provided for the entire resource configuration or for each configured resource, such as for each configured grant. The timer may be started in response to determining a short OoC situation and may indicate a specific predefined time interval or length T that may be measured in milliseconds, number of subframes, etc. During the predefined time interval T as defined by the timer, the RRC configuration may be maintained or retained. The timer may be referred to as a configured grant timer. For example, the configured grant timer may be included in the RRC configuration provided to the UE. According to other examples, the timer may be preconfigured. The configured / preconfigured timer may be started once:

[0194] - The UE determines that the serving cell frequency list is short out of coverage, and / or

[0195] - The UE determines that the neighbor cell frequency list is short out of coverage, and / or

[0196] -UE initiates UE-assisted handover, and / or

[0197] -UE initiates gNB / eNB-assisted handover, and / or

[0198] - The UE determines that no listening results are available in case Mode 2 is gNB / eNB assisted mode, and / or

[0199] - The UE is in Mode 1 and changes to Mode 2.

[0200] If the UE is performing a handover, this timer may be longer than the HO timer, again assuming that the UE is configured to maintain the RRC / configuration during HO.

[0201] If the timer is for out of coverage, the timer may be longer than RLF, assuming the UE is configured to maintain RRC / configuration during this event. For example, during the period or phase between switching from Mode 1 to Mode 2 due to Radio Link Failure RLF, the short OoC period may start before the RLF and continue after the RLF. For example, the short OoC may be based on a smaller number of out-of-sync signaling received at the UE (before RLF / high RSRP / RSSI).

[0202] According to an example, a timer may be provided for a specific UE, such as in the case of unicast or broadcast, or for a group of UEs, such as in the case of groupcast or broadcast.

[0203] The timer (like the configured grant timer) avoids that a UE entering the OoC state is considered to be in a long OoC state, i.e. a dump of the RRC configuration is avoided. Further, with the aid of the timer, the UE may comply with the requirements of a specific handover procedure, i.e. handover to a new cell and perform a new RRC configuration, and the timer may be provided to the UE together with the handover command, or after the handover command. The timer may allow the UE to remain connected while a handover is performed or when the HO stays for a period of time and is unsuccessful. Furthermore, a short OoC period as defined by the timer avoids that the current RRC configuration as used by the UE is cleared by the new RC configuration, which may occur in the case where the UE joins a new cell during the time defined by the timer and receives a complete and successful handover using the new RRC configuration, or in the case where the cell rejoins the primary cell or current cell and receives a new RRC reconfiguration.

[0204] Timers can be defined based on one or more of the following:

[0205] - Single fixed value configured via signaling or preconfigured in the UE or preconfigured by the network

[0206] - More than one value configured via signaling or preconfigured in the UE or preconfigured by the network

[0207] - One or more values ​​configured via upper layer signaling, where the value conveys one or more Quality of Service (QoS) indicators

[0208] - One or more values ​​measured by the UE, where the UE may be requested to perform timing measurements, where the timing measurements may imply different criteria, such as speed, routing direction, location, packet priority, QoS

[0209] Example 2

[0210] According to a second embodiment, during a short OoC period, a time domain alignment with a configured granted period may be performed. For example, for transmissions on one or more configured granted resources during a short OoC period, as indicated by a configured / preconfigured timer, the period P of one or more configured granted resources may be maintained by reference to:

[0211] - a configured time offset that can only be synchronized with the last detected SFN (subframe number),

[0212] - configured time offset + correction from GNSS or other source UE or another cell etc,

[0213] - If indicated by RRC message or upper layers, an arbitrarily chosen time offset to an arbitrarily chosen SFN, where the TXUE itself sends an appropriate PSSS (as configured or pre-configured) as synchronization source for the served UE.

[0214] Example 3

[0215] According to a third embodiment, the time domain allocation density may be performed during a short OoC period. For transmissions using the configured granted resources during a short OoC period as defined by a configured / preconfigured timer, the time domain resource period P may be as follows:

[0216] - the original period P allocated by the base station via RRC and / or DCI before the OoC situation,

[0217] - a new period P_new that is faster than the original period P allocated by the base station via RRC and / or DCI before the OoC situation, such as such that P_new=P / 2; or P_new=P / 3, or P_new=P / 4, ..., or P_new=P / N, where N is an integer,

[0218] - A new period P_new that is slower than the original period P allocated by the base station via RRC and / or DCI before the OoC situation, for example such that P_new=2P; or P_new=3P, or P_new=4P, ..., or P_new=N times P, where N is an integer.

[0219] The predefined time interval T (also referred to as short or medium out of coverage duration) may be configured or preconfigured with one or more values, and the UE may select or expect to receive one of these values.

[0220] Example 4

[0221] According to the fourth embodiment, during the short OoC period, frequency domain allocation may be performed. For transmission on the configured granted resources during the short OoC period, the frequency domain resources may be as follows:

[0222] - may use a frequency domain allocation (configured or preconfigured) that was specified in the grant configuration of the original configuration, (Type 1 or Type 2, resource allocation type 0 / 1 or dynamic), or

[0223] - A specific frequency domain allocation (configured / preconfigured) for OoC may be used. The specific frequency domain allocation may allocate 100% of the original frequency resources allocated via RRC or DCI before the last out-of-coverage. According to other examples, the specific frequency domain allocation may allocate X% of the original frequency resources via RRC or DCI before the last out-of-coverage. X may be any value between 0 and 100 and may be configured by upper or higher layer signaling or may be preconfigured in the UE or selected by the UE higher layer (UE behavior). Resources may be allocated from lower PRB-VRB-subchannels or from higher PRB-VRB-subchannels.

[0224] Example 5

[0225] According to the fifth embodiment, resources and / or reference signals may be randomized during a short OoC period. For example, frequency domain and / or time domain hopping for a configured grant may be performed during a short OoC period. The UE may be configured or preconfigured to perform hopping in a specific resource pattern.

[0226] For transmissions using the configured granted resources granted with the timer, operating frequency and time domain hopping during short OoC periods may be configured. For example, hopping may be configured using the RRC CG information element and may be activated via DCI.

[0227] Time jump

[0228] Time domain hopping can be applied by defining a time hopping sequence via a shift relative to a predefined transmission period, for example as follows:

[0229] - at a transmission instance T(n), the transmission is performed at T(n) = T_from_last_TX + P,

[0230] - at transmission instance T(n+1), the transmission is performed at T(n+1)=T_from_last_TX+P+deltashift1,

[0231] - at transmission instance T(n+2), the transmission is performed at T(n+2)=T_from_last_TX+P+deltashift2,

[0232] -…,

[0233] - at transmission instance T(n+M), the transmission is performed at T(n+M)=T_from_last_TX+P+deltashiftM,

[0234] - At T(mod(N,M+1)), n=N transmission instances, M+1=end of shift count, transmission is performed at T(mod(N,M+1))=T_from_last_TX+P, where deltashiftX is a positive or negative shift from P to generate a time jump.

[0235] Frequency and time hopping

[0236] Frequency domain and time domain hopping may be applied by using one or more time / frequency resource patterns TFRP that are defined or signaled, or preconfigured and indexed, or preconfigured and enabled, for example.

[0237] - The UE may be requested to listen to each TFRP, for example via an RRC message, or

[0238] - If a TFRP is used and the listening results show that the probability of collision is high, the UE may be requested to change one or more TX parameters, such as reducing power and / or MCS.

[0239] Frequency Hopping

[0240] Frequency hopping can be applied by defining a frequency hopping sequence, for example:

[0241] - by defining a frequency hopping sequence within a configured grant resource within a time slot and a resource block RB, and / or

[0242] - by defining a frequency hopping sequence among frequencies configured as one or more other configurations of the grant, and / or

[0243] - By defining a frequency hopping sequence between the frequencies of resources granted to one or more other grants.

[0244] The UE may be requested to perform hopping in a specific pattern and / or sequence in time and / or frequency, for example, via an RRC message or in a configured grant information element. The UE may be requested to perform random hopping in time and / or frequency, for example, via an RRC message or in a configured grant information element or in the UE or preconfigured by upper layers.

[0245] According to an example, it is assumed that a UE (eg, a UE in short OoC) and another terminal connected to the UE or in a connection broadcast by the UE are synchronous, quasi-synchronous, or operate in an asynchronous manner.

[0246] Example 6

[0247] According to the sixth embodiment, DMRS sequence initialization may be performed during a short OoC period.

[0248] According to an example, a DMRS sequence may be defined to be initialized during a short OoC period as follows:

[0249] - The gNB may initialize the same DMRS sequence via the RRC / DCI configured grant,

[0250] - a preconfigured sequence may be used, where the DMRS sequence is enabled by RRC during a short OoC period (e.g., DMRS_SeqInitialization_OoC or DMRS_SeqInitialization_OoC_index),

[0251] -The DMRS sequence is randomly selected by the UE or can be randomly identified by upper layers to provide coverage for DMRS sequence generation during short OoC periods.

[0252] Furthermore, DMRS positions that hop in time and frequency may be defined, for example, by identifying hopping DMRS symbol positions and different OFDM resource element positions.

[0253] Furthermore, if more than one pair of UEs are in a short OoC situation selecting from similar resources, DMRS sequence randomization may be defined to be selected by the UEs to avoid DMRS collision.

[0254] Example 7

[0255] According to an embodiment, predefined or special resources are provided to be used by the UE during short OoC moments or operations. Special resources are also called abnormal resources.

[0256] According to the seventh embodiment, the specific or abnormal resources can be defined as an abnormal pool, for example, through a corresponding RRC message or by using a pre-configuration. The abnormal pool can be, for example, one or more of the following:

[0257] -Exception pools with their own time-frequency resources, such as pools similar to those defined by SL-CommResourcePoolV2X-rXX. Exception pools can be divided into:

[0258] o time-frequency mode, where the UE is requested to listen to all different time-frequency modes and then the UE can select one or more modes to transmit, or

[0259] o time-frequency patterns, where the UE is requested to listen to some or dedicated time-frequency patterns and then selects one or more patterns to transmit, or

[0260] o Time-frequency mode, where the UE is requested to use a dedicated time-frequency mode for transmission. The dedicated time-frequency mode may be identified by specific RRC signaling, or by specific DCI signaling (selecting one or more exception resources among multiple configured / preconfigured exception resources), or by group common RRC signaling (for a UE group), or by group common PDCCH / DCI signaling (for a UE group).

[0261] - an exception pool with its own time-frequency resources, e.g. defined by SL-CommResourcePoolV2X-rXX. Within a pool, there may be one or more configured grants, e.g. if the channel shows high congestion values ​​(e.g. high channel busy rate (CBR)) or high data traffic load (e.g. a large number of scheduling requests (SR) or buffer status reports (BSR)). The UE may be requested to:

[0262] oSelect among all configured authorizations, or

[0263] o selection among a grant of configurations, e.g. up to 8 or more configurations, with a time offset and period P in time but with the same frequency, or

[0264] o Selection among the grants of configurations, e.g. up to 8 or more configurations, with different subchannel / subband / RB frequency offsets in frequency but with the same time offset and period P, or

[0265] o Select among a grant of configurations, e.g. up to 8 or more configurations, with different subchannel / subband / RB frequency offsets in frequency and with time offsets and periods in time, or

[0266] o Only 1 configuration is selected, which may be indicated by specific RRC signaling, by specific DCI signaling, by group-common RRC signaling (for a UE group), or by group-common PDCCH / DCI signaling (for a UE group).

[0267] Once the UE identifies or determines a short OoC situation, a handover to the abnormal resources may be performed. According to other examples, once the gNB identifies a possible out of coverage situation, a handover to the abnormal resources may be performed. The gNB may also provide a timer. In the event that a timer is defined, the abnormal resources may be used until the timer expires.

[0268] According to an example, the exception resource may be within an exception pool, and the corresponding time and frequency resources may be configured as a configured grant, for example using an RRC message or pre-configuration. The configured grant may be configured, for example, for:

[0269] - A UE with a requirement for an exception pool or a CG within an exception pool, or

[0270] - UEs in different modes (Mode 1 or Mode 2 (gNB / eNB assisted) or both), i.e. providing unusual resources for each of the different modes, or

[0271] -UE groups, for example, in cases where UEs initiate group communications and strict radio abnormality conditions are required. A UE group can have a group-common PDCCH or group-common RRC message, or

[0272] - Groups of UEs bound by the network based on network load or location specifications (geospatial location) of the UEs, or

[0273] - Cell-wide or area-wide exception pools, e.g., exception pools per cell or per area or validity area. The pools in each case can be configured via RRC or pre-configuration. Activation and deactivation of the pools can be via RRC signaling.

[0274] Example 8

[0275] According to the eighth embodiment, the exception resources may be defined by network configured resources within the normal TX resource pool, ie, the exception resource pool is not used.

[0276] According to the eighth embodiment, the exception resources can be defined as a set of fixed-configuration authorization resources, or defined as configured authorization resources with multiple active or inactive configurations (the authorization resources can be configured through the ConfiguredGrantConfig message, or only through the rrc-ConfiguredUplinkGrant message, or through the rrc-ConfiguredSidelinkGrant message, where the configured authorization information can carry an exception timer that allows operations outside the coverage).

[0277] Once the UE identifies or determines a short OoC situation, a handover to the abnormal resources may be performed. According to other examples, once the gNB identifies a possible out of coverage situation, a handover to the abnormal resources may be performed. The gNB may also provide a timer. In the case where a timer is defined, the abnormal resources may be used until the timer expires.

[0278] Example 9

[0279] According to the ninth embodiment, the exception resource definition may be configured as authorization of the exception configuration within the exception pool or within the normal TX pool.

[0280] The grant of abnormal configuration can be defined using only RRC messages or using UE-specific / group-specific RRC and / or DCI messages, or, if the grant of abnormal configuration is configured in time and frequency, the grant of abnormal configuration can be defined using the (abnormal)-ConfiguredGrantConfig message, or only the (abnormal)-rrc-ConfiguredUplinkGrant message, or the rrc-ConfiguredSidelinkGrant message, where the configured grant information can carry an abnormal timer that allows operation outside the coverage.

[0281] The exception configuration may be selected by the UE and may be used both in-coverage and out-of-coverage until the timer expires one or more times.

[0282] The exception pool's timer can define how long the exception resource pool is used during the out of coverage period when an out of coverage is triggered. If a configured authorized timer defined in the exception pool is defined, the configured authorized timer defined in the exception pool can be overwritten by the exception resource pool timer if the exception resource pool timer exists.

[0283] Once any of the previously configured / preconfigured timers expire, the UE may choose to switch to the preconfigured resources.Times may be defined for: short out of coverage, medium out of coverage, and any non-persistent out of coverage or non-deep out of coverage.

[0284] Example 10

[0285] According to the tenth embodiment, the authorization configured in the exception pool can be used for switching.

[0286] In the case of handover and other abnormal situations (such as RLF or lack of listening results), conventional LTE V2X communication uses an exception pool, which provides a random selection of resources on the target cell exception pool, assuming that the exception pool is included in the handover command. However, this implies a high risk of conflict, congestion and affects the reliability and latency of communication. Therefore, according to the tenth embodiment, during handover, the configured authorization can be used as follows:

[0287] - Authorization for configuration of the definition of exception pool - For switching case (similar to embodiment 9):

[0288] If the exception transmission resource pool is included in the handover command, the signaling exchange during the handover procedure may include authorization for the configuration of the exception pool for the target cell.

[0289] Starting from Release 16, the IE for NR sidelink exception pool V2X may be enhanced to add an IE with configured authorization.

[0290] - Authorization for configuration of the definition of exception pool - For switching case (similar to embodiment 9):

[0291] The signaling exchange during the handover procedure may include authorization for the configuration of an exception pool of serving cells.

[0292] Starting from Release 16, the IE for NR sidelink exception pool V2X may be enhanced to add an IE with configured authorization.

[0293] - Define configured grants in the common TX pool to be used as exception resources (similar to embodiment 8).

[0294] Similar to Embodiments 1 to 6 and Embodiment 8, fields may be added in IE ConfiguredGrantConfig to include timers and facilities as described in the embodiments.

[0295] Similar to Embodiments 1 to 6, during handover, if the timer and facilities are defined as in Embodiments 1 to 6, the configured grant of CommTxPool can be reused.

[0296] According to an embodiment, an exception-configured grant provided in an exception pool or a common TX pool may be used for handover between different RATs.

[0297] The UE may be configured by an NR serving cell and move to an LTE target cell or vice versa, and a CG may be defined for use in the target cell (e.g. including NR Type 1 (such as CG), NR Type 2 (such as CG, but with certain restrictions on LTE operation), or LTE (such as SPS)) and may be used during handover within:

[0298] - an abnormal pool of T cell or target cell (and T cell frequency) or S cell or serving cell (and S cell frequency), or

[0299] -TX pool of T cell (and T cell frequency) or S cell (and S cell frequency).

[0300] The UE may be configured by an LTE serving cell and move to an NR LTE target cell and the resource configuration may be defined for use in the target cell, e.g. as an SPS configuration and may be used during handover within:

[0301] - an abnormal pool of T cell or target cell (and T cell frequency) or S cell or serving cell (and S cell frequency), or

[0302] -TX pool of T cell (and T cell frequency) or S cell (and S cell frequency).

[0303] The CG(SPS) may be pre-configured with a timer for abnormal communication for normal communication, similar to Embodiment 1, or the CG(SPS) may be configured for abnormal communication, similar to Embodiment 9.

[0304] Embodiment 11

[0305] According to the eleventh embodiment, the abnormal resources can be used for deep or long out of coverage. According to the eleventh embodiment, the UE can be configured by the serving cell to use the abnormal pool as in embodiment 7, or the authorization configured in the abnormal pool as described in embodiment 8, or the TFRP as described in embodiment 5, or the authorization configured for abnormal situation abnormal configuration to be used during the actual out of coverage period. In this case, the configuration can be selected in the pool or on the pool (including the abnormal pool that allows the out of coverage pool), for example:

[0306] - Depending on the positioning information, some frequencies can be identified,

[0307] -depends on operator licensed and unlicensed access,

[0308] -Depends on dedicated frequencies for V2X / SL / D2D unlicensed access.

[0309] Other embodiments

[0310] Hereinafter, an example using the above-mentioned embodiment will be described. For example, when considering the above reference Figure 4 In the illustrated scenario, when it is determined that a UE (such as UE3) is out of coverage on the supported frequency list, the RRC / DCI configuration of the traditional V2X communication is removed or deleted and overwritten by the preconfiguration. This may not be sufficient for advanced V2X use cases, especially when out of coverage occurs frequently and only for a short time as described above. In this case, according to the present invention, RRC enhancements are introduced to allow, for example, a timer to be provided, which is configured to identify the UE as being out of coverage (short OoC) for a short time and can be measured in milliseconds, time slots, symbols, subframes, etc. During this period, the UE maintains the RRC / DCI configuration for the time of the identified timer. More details about the short OoC timer, RRC configuration, time and frequency allocation, and different time offsets and time periods are now described with reference to the above embodiments.

[0311] Short OoC treatment

[0312] For RRC-Connected / Active / Inactive or for RRC-Idle / Inactive, the RRC configuration configured for the configured grant may include a field to specify and / or configure one or more timers operating during a short OoC scenario, as described above with reference to Embodiment 1. For example, the timer may be defined as follows:

[0313] configuredGrantShortOoCTimer INTEGER (1..64 / or 128 / or 256 / etc.), or

[0314] configuredGrantTimer INTEGER (1..64 / or 128 / or 256 / etc.)

[0315] This definition can be included into the corresponding configuration, for example into the following configuration:

[0316] ConfiguredGrantConfig::=SEQUENCE{

[0317] or

[0318] -rrc-ConfiguredUplinkGrant SEQUENCE{

[0319] According to other embodiments, the timer may be identified in the RRC configuration broadcast by the SIB, which may include one or more of the timers to indicate how short OoC measured in milliseconds, slots, subframes or symbols may be handled.

[0320] The UE may identify a short OoC situation using one or more of the following, the UE may be RRC_IDLE or RRC_CONNECTED / Active or RRC_CONNECTED inactive:

[0321] - Overlay status and measurements, or

[0322] - Network structure and architecture, or

[0323] -Roadside unit information, or

[0324] - Network, gNB and / or eNB configuration (via specific RRC message or broadcast RRC message or early handover command (may have no measurement or handover timer trigger), or

[0325] - Preconfigured short exceedance override value, if identified by permanent provisioning or updated by the network.

[0326] According to other embodiments, short OoC may be identified by a base station (e.g., a gNB or an eNB) based on:

[0327] -RRC reconfiguration due to network load or other pre-configuration of the gNB, or

[0328] -DCI specific control information, or

[0329] - RRC broadcast information via, for example, SIB messages.

[0330] Once a short OoC is identified, the UE may continue to use the last or most recent configuration until a timer (such as a configured grant timer) expires. The UE may perform a cell search during a short OoC as follows:

[0331] - combine all occurrences of “out of coverage on frequencies used for V2X sidelink” with a timer, or

[0332] - Combine all occurrences of "UE could not detect any cell meeting S / SL / Sidelink criteria on this frequency" with a timer.

[0333] During short OoC, UEs connected to the primary cell and / or secondary cell may vacate resource configuration only when measurements indicate an out of coverage situation and when a timer expires.

[0334] Information about time domain alignment may be obtained as described above with reference to Example 2, and information about time domain period and time domain density during a short OoC period while acquiring a CG may be accomplished as described above with reference to Example 3. Information about frequency position and frequency resource selection during a short OoC period with a configured grant may be accomplished as described above with reference to Example 4.

[0335] Figure 6 A known RRS connection re-establishment process is schematically shown, and according to an embodiment, short OoC coverage may start before a radio link failure and once a radio link failure occurs until a defined short OoC timer expires or until the UE radio quality returns to a good state and receives a new RRC configuration. According to other embodiments, short OoC coverage may start once a handover command is triggered and until the handover command succeeds and the UE receives a new cell RRC configuration.

[0336] Randomization between UEs during short OoC periods

[0337] According to an embodiment, during a short OoC, the UE may perform randomized resource selection. Resources may be selected from multiple time / frequency resource patterns TFRP. The pattern may be configured or pre-configured for the UE during RRC connection / idle or during RRC disconnection. The UE may be configured for one TFRP or multiple TFRPs identified for the UE. In the case where multiple TFRPs are configured, during a short OoC (if identified), the UE performs listening on the configured TFRP.

[0338] Time and frequency resources may also be configured as multiple configured grants. The UE selects the active configured grant to be used for transmission among the active configured grants. The configuration may include a Type 1 configured grant, where the RRC configuration includes one or more configured grants and runs until the next RRC reconfiguration. In the case of maintaining the RRC configuration during a short OoC period, the UE may be configured to randomly select among the configured grants from the existing RRC configuration.

[0339] For type 2 configuration, the gNB may use DCI signaling to specify a frequency hopping sequence in a configured grant. DCI signaling may also be used to activate one or more configured grants or to deactivate one or more configured grants. The DCI signaling may be user-specific DCI signaling or group common, GC, PDCCH / DCI signaling. Time / frequency hopping may be performed in the manner described above with reference to Example 5.

[0340] Randomization may also be performed on the selected DMRS sequence generated by the UE for the sidelink transmission. The UE may randomly select one or more DMRS sequences during its SL transmission to minimize conflicts on the reference signal. The sequence may be configured or may be preconfigured, for example based on the operating mode and / or based on UE capabilities. In addition, based on signaling configuration or based on a preconfiguration that is again selected depending on the operating mode or UE capabilities, the UE may have different starting positions between symbols or different frequencies or resource elements or combinations of DMRS types / options. DMRS hopping and pattern selection may be performed in the manner described above with reference to Example 6.

[0341] Enhancements to abnormal resources

[0342] According to yet another embodiment, specific resources may be provided which are used by the UE during an OoC situation for a time specified, for example, by a timer. According to an embodiment, an exception pool, which is basically known in the art, may be employed for this purpose. More specifically, an embodiment provides an enhancement to an exception pool or exception resources to be used during a short OoC situation. According to an embodiment, an exception pool may also be used for a long OoC situation in order to define a specific set of resources used by all UEs that fall out of coverage. According to an example, once a short OoC situation is identified, the network or base station (such as a gNB) may define corresponding exception resources to be used by the UE.

[0343] According to an embodiment, the exception resources can be configured to use the version 15 exception pool of the normal SL-CommResourcePoolV2X-rXX, which can be divided into multiple exception pools, each for one or more UEs. Different exception pools can be configured, or different time / frequency rules can be configured. During a short OoC period, the resources of the exception pool can be randomly selected from multiple TFRPs using random selection or listening. If the UE is configured with an exception pool, once the UE enters OoC, the UE can monitor RRC specific / group common signaling or DCI / PDCCH specific / group common signaling for selecting one or more TFRPs, and can use it during the short OoC time, for example until the above-mentioned timer expires.

[0344] Additionally, resources in the exception pool may be configured as configured grants. The configured grants may be divided into one per UE or one per UE group. Dividing the configured grants into one per UE group may be used for group-bound communications or for any other geospatial requirements seen by the base station or network.

[0345] Multiple exception pools or exception pools with multiple configured authorizations can be used in one or more of the following situations where a particular set of exception resources is required:

[0346] - A UE that requires an exception pool or a CG in an exception pool, or

[0347] - UEs in different modes (1 or 2 (assisted by gNB / eNB) or both), i.e. abnormal resources for each or different modes, or

[0348] - A UE group (where they initiate group communication) and they require strict radio abnormality conditions. This UE group may have a group-common PDCCH or a group-common RRC message, or

[0349] - groups of UEs bound by the network based on network load or their location specifications (geospatial location), or

[0350] - Cell-wide or area-wide exception pools, e.g., exception pools per cell or per area or validity area. The pools in each case can be configured via RRC or pre-configuration. Activation and deactivation of the pools can be via RRC signaling.

[0351] The pre-configuration of additional specific resources may be handled according to Embodiment 7 as described in detail above.

[0352] In the case where the exception pool is not defined or signaled by SIB broadcast, the exception or specific resources can be configured as a configured grant or a set of configured grants configured within one or more normal TX resource pools. However, these resources can be used only for the above-mentioned situations where the above-mentioned exception pools can be used. This means that according to this embodiment, no additional pools are defined or configured on top of the TX pool, but one or more resources (such as configured grants) are determined, which can only be used in the case of determining an abnormal (such as RLF) situation, switching or listening to resources selected by the UE is not available, for example when the UE is in mode 2 or mode 4. The configured grants can be configured using specific RRC / TCI signaling for each UE or for all UEs in the group, as described in detail above with reference to Example 9.

[0353] According to yet another embodiment, the configured grant may be specifically configured to also be used for normal and abnormal situations. The UE may be configured to one of these CGs that may be used in situations where other conventional or normally configured grants cannot be recovered during a short OoC period, even if a short OoC timer is defined. This may be useful for type 2 configured grants, since normal CG resources within normal coverage operation need to always be connected in order to receive DCI messages and provide UE feedback. Therefore, in such a situation, for example in the case of a short OoC, the UE may be allowed to temporarily switch to one of the abnormally configured CGs within the UE list of multiple active configured grants, if defined. The fallback to the abnormal pool is described in embodiments 7 and 9 above and may be applied if the UE is not configured with one of the long-lasting CGs. As described above, the UE may identify the CG by configuring the configured grant timer in its configuration body. According to other examples, the configuration header (e.g., ConfiguredGrantConfig) may include another identifier, such as (SL_commV2X)_configured_GrantExceptional. In other words, the network or gNB may configure the UE with one or more abnormally configured grants and may use the abnormally configured grants in coverage or during a short OoC period as defined by a timer. The termination of the abnormally configured grants may be performed in the manner described above with reference to Embodiment 8.

[0354] Authorization with abnormal configuration

[0355] Further embodiments regarding the use of exception pools and authorization of exception configurations in TX pools are now described. The following embodiments provide improvements to the use of exception pools, which are often needed during latency critical scenarios, and both meet strict requirements such as defined by Release 16 and other use cases. Improvements may also be necessary due to the typical non-periodic traffic expected on the exception pools.

[0356] According to an embodiment, improvements regarding the use of an exception pool may include the introduction of a configured authorization in the manner described above with reference to Example 9. Therefore, according to Example 9, an authorization for a specific configuration of the exception pool may be provided, such as an authorization for a UE-specific or group-specific configuration of type 1 or type 2. A specific CG configured in the exception pool may be temporarily used during switching until the switching is successful, so as to also handle switching failures. For switching, according to an embodiment, a configured authorization may be defined in the exception pool in the manner described with reference to Example 9, which may also include a mechanism as described above with reference to Examples 1 to 6.

[0357] According to other embodiments, configured grants may be defined in the normal TX pool to be used abnormally during handover, for example by applying the method described above with reference to embodiment 8, which may also include additional mechanisms according to embodiments 1 to 6.

[0358] According to another embodiment, a configured or previously configured authorization that is still active or available for the UE (i.e., one or more configured authorizations dedicated to the UE) may be reused during switching, similar to the method described in Example 1, which may include mechanisms according to Examples 2 to 6.

[0359] Therefore, according to the above embodiment, resources can be defined / configured in a serving cell pool including a serving cell exception pool, or resources can be defined / configured in a target cell pool. These resources can be used temporarily until a successful handover ends with a new RRC configuration (including a new CG from the target cell), or once an unrecoverable complete out of coverage occurs. If the resources are configured in the target cell as a normal TX pool authorized as a normal configuration, they can be used for a longer timer or until a new RRC configuration is available, as described now.

[0360] During handover, the UE may use the target cell exception pool or normal TX pool resources according to an embodiment, or may use the serving cell exception pool or normal TX pool resources according to another embodiment.

[0361] When using T-cell pool resources, handover signaling, such as a handover command sent by a target cell, such as an RRC connection reconfiguration request, may include one or more of the following RRC configurations:

[0362] -RRC_ConfigGrantXXX in the exception pool during handover: (as in embodiment 9), i.e. configured in the T-cell exception pool.

[0363] The mechanisms according to Embodiments 1 to 7 and 9 can be applied.

[0364] Instead of configuring, one or more TFRPs may be configured similarly to Embodiment 5.

[0365] -RRC_ConfigGrant_Exeptionally during handover: (as in Embodiment 8) i.e., configured in the normal pool of T-cells

[0366] The mechanisms according to Embodiments 1 to 6 can be applied.

[0367] Instead of configuring, one or more TFRPs may be configured similarly to Embodiment 5.

[0368] The UE may temporarily use those CGs until it receives new configuration.

[0369] -RRC_ConfigGrant extended to / during handover; i.e., in this case, the target cell provides (e.g., included in the handover command) resources for the CG during handover and / or after a successful handover. The CG can be part of the target cell exception pool configuration IE included in the handover command or sent in a separate or different message or IE.

[0370] By allowing the CG to be in either the exception or common TX pool during the handover phase, latency and reliability will be enhanced and continuous connectivity can be provided without service interruption, which improves the handover process compared to Release 15 LTE V2X where resources are randomly selected on the exception pool.

[0371] In the case where the UE uses S-cell pool resources, the handover signaling, such as the handover command sent by the serving cell, such as the RRC connection reconfiguration request as a message sent from the target cell to the serving cell, may not include the target cell abnormal RRC configuration, i.e., the abnormal pool or CG used abnormally or normally during the handover. In this scenario, the UE may use the serving cell abnormal resources as follows:

[0372] -RRC_ConfigGrantXXX in the exception pool (as in embodiment 9), i.e.,

[0373] Configured in the S-cell exception pool.

[0374] The mechanisms according to Embodiments 1 to 8 can be applied.

[0375] Instead of configuring, one or more TFRPs may be configured similarly to Embodiment 5.

[0376] -RRC_ConfigGrant_Exeptionally (as in Embodiment 8), i.e., configured within the S-cell normal pool.

[0377] The mechanisms according to Embodiments 1 to 6 can be applied to Embodiment 8.

[0378] Instead of configuring, one or more TFRPs may be configured similarly to Embodiment 5.

[0379] The UE may temporarily use these CGs until it receives a new configuration from a new cell or declares depth out of coverage

[0380] - Extending the normal RRC_ConfiGrant usage (as in embodiment 1 and applying the mechanisms according to embodiments 2 to 6) during handover; i.e. in this case the serving cell provides for an unusual usage of the timer and the configured grant during handover.

[0381] According to an embodiment, for handover between different RATs, i.e., the UE moves from NR to LTE or vice versa, the UE may be configured by the NR Uu, including:

[0382] -Sidelink dynamic authorization

[0383] - Type 1 (RRC-based) sidelink configuration authorization

[0384] - Grant of sidelink configuration of type 2 (RRC+L1(DCI) activation / deactivation), and

[0385] The UE may be configured by LTE Uu, including:

[0386] -Sidelink dynamic authorization

[0387] - Type 1 (RRC based) sidelink configuration grant (adapted from SPS for sidelink)

[0388] In the case where the UE moves from an NR S-cell to an LTE T-cell, i.e., if the UE moves from an NR serving cell to an LTE target cell, during handover or when the short out of coverage timer is running, the UE may maintain the configured authorization type 1, i.e., configured by the serving NR cell. Once the timer expires, the UE may start using the SPS configuration provided by the target cell LTE cell, similar to Embodiment 1, Embodiment 9, and / or Embodiment 10. In this embodiment, the handover command from the NR serving cell to the LTE target cell may include the SPS to be used during handover. The SPS may use the cycles and resources of the target cell LTE frequency or NR frequency, for example, including an exception pool in any cell.

[0389] In the case where the UE moves from an LTE S-cell to an NR T-cell, i.e., when the UE moves from an LTE serving cell to an NR target cell, the handover command may indicate a configured grant, e.g., in the form of an SPS configured by LTE, assigned to the UE for exception use (e.g., according to Embodiment 1 or 9) or in an exception pool (see Embodiment 8). If necessary, the target gNB may override the last serving LTE configuration, e.g., the SPS configuration. In addition, the target cell may continue to use the same time and period on the same frequency or on the NR assigned frequency, including, e.g., a new PRB allocation. If necessary, the target cell may include an exception configured grant, e.g., in the handover command, for use during a handover from an LTE S-cell to an NR T-cell.

[0390] Long or deep beyond coverage

[0391] According to another embodiment, a process for deep out of coverage (also referred to as long out of coverage, for example, longer out of coverage than short-term out of coverage) may be implemented, for example after a timer expires. In such an embodiment, the UE may be configured by the serving cell to use an exception pool as described in Example 7 or an authorization configured in an exception pool as described in Example 8, or a TFRP as described in Example 5, or an authorization configured for an abnormal configuration for an abnormal situation during actual out of coverage. In this case, a configuration may be selected on a pool (including an exception pool that allows out of coverage pools). For example, some frequencies may be defined depending on positioning information or depending on operator licensed and unlicensed access. In addition, dedicated frequencies for V2X / SL / D2D unlicensed access may be used.

[0392] Modified Information Element IE

[0393] According to the method of the invention, all contents indicated (highlighted) in the table and in the following information elements can be changed.

[0394] For the V2X sidelink in LTE (R14 / A1), the sidelink (SL) resource pool configuration is sent in the system information block 21. The following table shows the relevant excerpt of the system information block 21 for reference information elements (IEs) and indicates where the enhancements according to the present invention may be reflected. More specifically, the underlined and bold printed information elements (IEs) may be modified or changed according to the inventive method described herein (see TS 36.331 on V2X, concerning exception pools):

[0395]

[0396]

[0397]

[0398] In the New Radio (NR) standard, the following are specified for the provisioning authorization:

[0399]

[0400] ConfiguredGrantConfig

[0401] The IE ConfiguredGrantConfig is used to configure uplink transmission without dynamic grant according to two possible schemes. The actual uplink grant can be configured via RRC (type 1) or provided via PDCCH (addressed to CS-RNTI) (type 2).

[0402]

[0403]

[0404]

[0405] Overview

[0406] The embodiments of the present invention have been described in detail above, and each embodiment and aspect may be implemented independently, or two or more embodiments may be implemented in combination.

[0407] Embodiments of the present invention have been described in detail above with reference to sidelink communications using a PC5 interface. However, the present invention is not limited to the use of a PC5 interface. Any other interface that allows direct communication between one or more UEs may be employed.

[0408] In some of the above embodiments, reference is made to a corresponding vehicle in a mode in which SL resource allocation configuration or assistance is provided by a base station (e.g., a connected mode, also known as an NR mode 1 or LTE mode 3 configuration), or a vehicle in a mode in which the base station does not provide SL resource allocation configuration or assistance (e.g., an idle mode, also known as an NR mode 2 or LTE mode 4 configuration). However, the present invention is not limited to V2V communication or V2X communication, but rather it is also applicable to any device-to-device communication, such as non-vehicle mobile users or fixed users performing side link communications, for example, via a PC5 interface. In addition, in such a scenario, the connection to the base station may be temporarily interrupted, for example due to a mobile obstacle, so that the UE may also be considered to be out of coverage. The above-mentioned aspects of the invention may also be adopted in such a scenario.

[0409] According to an embodiment, the wireless communication system may include a terrestrial network, or a non-terrestrial network, or a network or network segment using an airborne vehicle or a satellite vehicle as a receiver, or a combination thereof.

[0410] According to an embodiment, a receiver (such as a UE or a base station) may include one or more of the following: a mobile or fixed terminal, an IoT device, a ground-based vehicle, an aircraft, a drone, a building, or any other item or device with a network connection that enables the item / device to communicate using a wireless communication system, such as a sensor or actuator. According to an embodiment, a transmitter (such as a base station or a UE) may include one or more of the following: a macrocell base station, or a small cell base station, or a satellite-borne vehicle (such as a satellite or space), or an airborne vehicle (such as an unmanned aircraft system (UAS), such as a tethered UAS, a lighter-than-air UAS (LTA), a heavier-than-air UAS (HTA), and a high-altitude UAS platform (HAP)), or any transmission / reception point (TRP) that enables an item or device with a network connection to communicate using a wireless communication system.

[0411] Although some aspects of the described concepts have been described in the context of an apparatus, it is apparent that these aspects also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent a description of a corresponding block or item or a feature of a corresponding apparatus.

[0412] The various elements and features of the present invention can be implemented in hardware, software using analog and / or digital circuits, by executing instructions through one or more general or special processors, or as a combination of hardware and software. For example, embodiments of the present invention can be implemented in the environment of a computer system or another processing system. Figure 7 An example of a computer system 500 is shown. The units or modules and steps of the methods performed by the units may be executed on one or more computer systems 500. The computer system 500 includes one or more processors 502, such as a dedicated or general purpose digital signal processor. The processor 502 is connected to a communication infrastructure 504, such as a bus or a network. The computer system 500 includes: a main memory 506, such as a random access memory (RAM); and a secondary memory 508, such as a hard drive and / or a removable storage drive. The secondary memory 508 may allow computer programs or other instructions to be loaded into the computer system 500. The computer system 500 may also include a communication interface 510 to allow software and data to be transmitted between the computer system 500 and external devices. The communication may be in the form of electrical, electromagnetic, optical or other signals that can be processed by the communication interface. The communication may use wires or cables, optical fibers, telephone lines, cellular phone links, RF links and other communication channels 512.

[0413] The terms "computer program medium" and "computer readable medium" are generally used to refer to tangible storage media, such as a removable storage unit or a hard disk installed in a hard drive. These computer program products are devices for providing software to the computer system 500. Computer programs (also referred to as computer control logic) are stored in the main memory 506 and / or the auxiliary memory 508. The computer program can also be received via the communication interface 510. The computer program enables the computer system 500 to implement the present invention when executed. In particular, the computer program enables the processor 502 to implement the process of the present invention, such as any method described herein, when executed. Therefore, such a computer program can represent a controller of the computer system 500. In the case of implementing the present disclosure using software, the software can be stored in a computer program product and loaded into the computer system 500 using a removable storage drive, an interface (such as the communication interface 510).

[0414] The implementation in hardware or software can be performed using a digital storage medium, such as cloud storage, floppy disk, DVD, Blu-ray, CD, ROM, PROM, EPROM, EEPROM or FLASH memory, on which electronically readable control signals are stored, which cooperate (or can cooperate) with a programmable computer system to perform the corresponding method. Therefore, the digital storage medium can be computer readable.

[0415] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0416] Generally, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer.The program code may, for example, be stored on a machine readable carrier.

[0417] Other embodiments comprise a computer program stored on a machine readable carrier for performing one of the methods described herein. In other words, an embodiment of the inventive method is therefore a computer program having a program code for performing one of the methods described herein when the computer program runs on a computer.

[0418] Therefore, another embodiment of the method of the present invention is a data carrier (or a digital storage medium or a computer-readable medium) having a computer program recorded thereon, the computer program being used to perform one of the methods described herein. Therefore, another embodiment of the method of the present invention is a data stream or a signal sequence representing a computer program, the computer program being used to perform one of the methods described herein. The data stream or signal sequence can, for example, be configured to be transmitted via a data communication connection (for example, via the Internet). Another embodiment comprises a processing device, for example, a computer or a programmable logic device, the processing device being configured to or adapted to perform one of the methods described herein. Another embodiment comprises a computer having a computer program installed thereon, the computer program being used to perform one of the methods described herein.

[0419] In some embodiments, a programmable logic device (e.g., a field programmable gate array) can be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array can collaborate with a microprocessor to perform one of the methods described herein. Typically, the method is preferably performed by any hardware device.

[0420] The above embodiments are merely illustrative of the principles of the present invention. It should be understood that modifications and variations of the arrangements and details described herein will be apparent to other persons skilled in the art. Therefore, it is intended that the scope of the present invention be limited only by the scope of the appended patent claims and not by the specific details given by way of the description and explanation of the embodiments herein.

[0421] References

[0422]

[0423] Abbreviations

[0424]

Claims

1. A wireless communication system, comprising: one or more base stations, One or more user equipments UE, configured to communicate with the base station and / or another UE using the allocated resources, The UE is controlled by a serving base station using Uu, and the UE is configured to communicate with the serving base station using a Uu interface, or to communicate with one or more other UEs using a side link interface, The serving base station allocates resources for the UE to use for communication. Wherein, in the case where the UE is out of the coverage of the serving base station, the UE and the serving base station will maintain or retain at least some of the allocated resources within a predefined time interval T, thereby avoiding the UE from dumping the allocated resources and allowing the UE to continue to communicate via the side link or to reuse the allocated resources immediately after the UE returns to the coverage of the serving base station, wherein the UE monitors a radio link between the UE and the serving base station to determine that the UE is out of coverage, and In response to determining that the coverage is exceeded, the wireless communication system starts a timer for the allocated resources, wherein the timer indicates the predefined time interval T as a specific time period or a specific number of subframes, and wherein the timer is defined based on one or more of the following: - Single fixed value configured via signaling or preconfigured in the UE or preconfigured by the network - More than one value configured via signaling or preconfigured in the UE or preconfigured by the network - One or more values ​​configured via upper layer signaling, wherein the values ​​convey one or more Quality of Service (QoS) indicators - One or more values ​​measured by the UE, wherein the UE is requested to perform timing measurements, wherein the timing measurements imply different criteria, such as speed, routing direction, location, packet priority, QoS.

2. The wireless communication system according to claim 1, wherein: Monitoring the radio link between the UE and the serving base station comprises one or more of the following measurements: Not in sync, Signal strength, such as RSSI, CR error or block error rate, A radio link degradation or failure metric or measurement.

3. The wireless communication system according to claim 1, wherein: The timer is provided for a specific UE or for a UE group.

4. The wireless communication system according to claim 1, wherein: The predefined time interval T of the timer is selected as Avoiding, for example, upper layers immediately considering the UE to be out of coverage in response to determining the out of coverage, and / or allowing the UE to complete the handover procedure, and / or The UE is allowed to stay connected when performing a handover HO or when the HO stay is unsuccessful for a period of time.

5. The wireless communication system according to claim 1, wherein: In response to the UE performing the following operations, the timer is terminated before reaching the predefined time interval T: Joining a new cell / base station and receiving an RRC configuration from the new cell / base station, e.g. in response to a successful handover, or Rejoin the serving cell / base station and receive RRC reconfiguration.

6. The wireless communication system according to claim 1, wherein: The UE will start the timer in response to one or more of the following: Out of coverage determination in the serving cell frequency list, Out of coverage determination in the neighboring cell list, The UE initiates UE-assisted handover, The UE starts base station assisted handover, The UE operates in a first mode and changes to a second mode, and The UE is in the second mode and determines that no listening result is available, In which, in the first mode, the serving base station provides SL resource allocation configuration or assistance, and in the second mode, the serving base station does not provide SL resource allocation configuration or assistance.

7. The wireless communication system according to claim 1, wherein: In case the timer is used to maintain the RRC configuration during the out of coverage period, If the timer is for out of coverage, then the timer is longer than RLF, If the UE is performing handover, the timer is longer than the HO timer.

8. The wireless communication system according to claim 1, wherein: In case the UE switches from the first mode to the second mode due to a radio link failure RLF, the timer starts before the RLF and continues after the RLF.

9. The wireless communication system according to claim 1, wherein: The allocated resources are resources for a configured grant, wherein the configured grant includes: an RRC configured grant without any L1 signaling, RRC type 1; or an RRC configured grant with L1 signaling for activation or deactivation, RRC type 2.

10. The wireless communication system according to claim 9, wherein: The configured authorization includes one or more of the following: a grant for the configuration of a TX resource pool for a specific UE, Commonly configured authorized resources used by group UEs, configured via group common signaling, a commonly configured authorized resource used by all UEs, or The configured authorized resources are configured via RRC and / or DCI signaling to operate in the following: Anomaly pool for use during radio failures and other radio abnormal conditions, UL resources, if the UE is allowed to perform SL communication via the Uu configured resources, X / Flexible / S resources or time slots, if the UE is allowed to perform SL communication via the Uu configured resources, DL resources, if the UE is allowed to perform SL communication via the resources configured by Uu, The LTE device configures the SPS configuration for the UE.

11. A user equipment UE for a wireless communication system, the UE comprising an antenna and a transceiver, the wireless communication system comprising one or more base stations and one or more user equipment UE, in, The UE will use the allocated resources to communicate with the base station and / or another UE, The UE is controlled by a serving base station using Uu, and the UE is configured to communicate with the serving base station using a Uu interface, or to communicate with one or more other UEs using a side link interface, The UE will receive resource allocation from the serving base station for the UE to use for communication, wherein, in the event that the UE is out of coverage of its serving base station, the UE will maintain or reserve at least some of the allocated resources of the serving base station within a predefined time interval T, thereby avoiding the UE from dumping the allocated resources and allowing the UE to continue communicating via a side link or to reuse the allocated resources immediately after the UE returns to coverage of the serving base station, The UE monitors a radio link between the UE and the serving base station to determine whether the UE is out of coverage. In response to determining that the coverage is exceeded, the UE will start a timer for the allocated resources, wherein the timer indicates the predefined time interval T as a specific time period or a specific number of subframes, and wherein the timer is defined based on one or more of the following: - Single fixed value configured via signaling or preconfigured in the UE or preconfigured by the network - More than one value configured via signaling or preconfigured in the UE or preconfigured by the network - One or more values ​​configured via upper layer signaling, wherein the values ​​convey one or more Quality of Service (QoS) indicators - One or more values ​​measured by the UE, wherein the UE is requested to perform timing measurements, wherein the timing measurements imply different criteria, such as speed, routing direction, location, packet priority, QoS.

12. A method for operating a wireless communication system, the wireless communication system comprising: one or more base stations; and one or more user equipments UE, configured to communicate with a base station and / or another UE using the allocated resources, the method comprising: The serving base station (300) performs Uu control on the UE (3021), configuring the UE to communicate with the serving base station using a Uu interface or to communicate with one or more other UEs using a sidelink interface, Allocating resources by the serving base station for the UE to use for communication, In case the UE is out of the coverage of the serving base station, at least some of the allocated resources of the serving base station are maintained or reserved for a predefined time interval T, thereby avoiding the UE (3021) from dumping the allocated resources and allowing the UE (3021) to continue communicating via a side link or to reuse the allocated resources immediately after the UE (3021) returns to the coverage of the serving base station (300), monitoring a radio link between the UE and the serving base station to determine that the UE is out of coverage, and In response to determining the out of coverage, starting a timer for the allocated resources, wherein the timer indicates the predefined time interval T as a specific time period or a specific number of subframes, and wherein the timer is defined based on one or more of the following: - A single fixed value configured via signaling or preconfigured in the UE (3021) or preconfigured by the network - More than one value configured via signaling or preconfigured in the UE (3021) or preconfigured by the network - One or more values ​​configured via upper layer signaling, wherein the values ​​convey one or more Quality of Service (QoS) indicators - one or more values ​​measured by the UE (3021), wherein the UE (3021) is requested to perform timing measurements, wherein the timing measurements imply different criteria, such as speed, routing direction, location, packet priority, QoS.

13. A method for operating a user equipment UE of a wireless communication system, the wireless communication system comprising: one or more base stations; and one or more user equipments UE, wherein the UE will communicate with a base station and / or another UE using the allocated resources, and wherein the UE is Uu controlled by a serving base station, and the UE is configured to communicate with the serving base station using a Uu interface, or to communicate with one or more other UEs using a sidelink interface, the method comprising: receiving, by the UE, a resource allocation for the UE to use for communication, In the case where the UE is out of the coverage of its serving base station, at least some of the allocated resources of the serving base station are maintained or reserved by the UE for a predefined time interval T, thereby avoiding the UE from dumping the allocated resources and allowing the UE to continue communicating via a side link or to reuse the allocated resources immediately after the UE returns to the coverage of the serving base station, monitoring, by the UE, a radio link between the UE and the serving base station to determine out-of-coverage of the UE, and In response to determining the out of coverage, starting a timer for the allocated resources by the UE, wherein the timer indicates the predefined time interval T as a specific time period or a specific number of subframes, and wherein the timer is defined based on one or more of the following: - Single fixed value configured via signaling or preconfigured in the UE or preconfigured by the network - More than one value configured via signaling or preconfigured in the UE or preconfigured by the network - One or more values ​​configured via upper layer signaling, wherein the values ​​convey one or more Quality of Service (QoS) indicators - One or more values ​​measured by the UE, wherein the UE is requested to perform timing measurements, wherein the timing measurements imply different criteria, such as speed, routing direction, location, packet priority, QoS.

14. A computer readable medium storing instructions, which, when executed on a computer, perform the method according to claim 12 or 13.

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