Patent Application
20220150968
For data transmission a physical resource grid may be used. The physical resource grid may comprise a set of resource elements to which various physical channels and physical signals are mapped. For example, the physical channels may include the physical downlink, uplink and sidelink shared channels (PDSCH, PUSCH, PSSCH) carrying user specific data, also referred to as downlink, uplink and sidelink payload data, the physical broadcast channel (PBCH) carrying for example a master information block (MIB) and a system information block (SIB), the physical downlink, uplink and sidelink control channels (PDCCH, PUCCH, PSSCH) carrying for example the downlink control information (DCI), the uplink control information (UCI) and the sidelink control information (SCI). For the uplink, the physical channels may further include the physical random access channel (PRACH or RACH) used by UEs for accessing the network once a UE synchronized and obtained the MIB and SIB. The physical signals may comprise reference signals or symbols (RS), synchronization signals and the like. The resource grid may comprise a frame or radio frame having a certain duration in the time domain and having a given bandwidth in the frequency domain. The frame may have a certain number of subframes of a predefined length, e.g. 1 ms. Each subframe may include one or more slots of 12 or 14 OFDM symbols depending on the cyclic prefix (CP) length. A frame may also consist of a smaller number of OFDM symbols, e.g. when utilizing shortened transmission time intervals (sTTI) or a mini-slot/non-slot-based frame structure comprising just a few OFDM symbols.
The wireless communication system may be any single-tone or multicarrier system using frequency-division multiplexing, like the orthogonal frequency-division multiplexing (OFDM) system, the orthogonal frequency-division multiple access (OFDMA) system, or any other IFFT-based signal with or without CP, e.g. DFT-s-OFDM. Other waveforms, like non-orthogonal waveforms for multiple access, e.g. filter-bank multicarrier (FBMC), generalized frequency division multiplexing (GFDM) or universal filtered multi carrier (UFMC), may be used. The wireless communication system may operate, e.g., in accordance with the LTE-Advanced pro standard, or the 5G or NR, New Radio, standard, or the NU-U, New Radio Unlicensed, standard.
The wireless network or communication system depicted in
In addition to the above described terrestrial wireless network also non-terrestrial wireless communication networks exist including spaceborne transceivers, like satellites, and/or airborne transceivers, like unmanned aircraft systems. The non-terrestrial wireless communication network or system may operate in a similar way as the terrestrial system described above with reference to
It is noted that the information in the above section is only for enhancing the understanding of the background of the invention and therefore it may contain information that does not form conventional technology that is already known to a person of ordinary skill in the art.
Starting from conventional technology as described above, there may be a need for improvements in the wireless communication among entities of a wireless communication network, in case the communication employs configured grants, CGs, like an NR-U operation using one or more subbands, in which some or all of the used subbands are in the unlicensed spectrum.
An embodiment may have a user device, UE, for a wireless communication system,
wherein the UE is served by a base station and is to use one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT,
wherein the UE is configured, e.g., using an RRC signaling, with
Another embodiment may have a base station, BS, for a wireless communication system,
wherein the BS is to serve one or more UEs and is to use one or more frequency bands for a communication with the one or more UEs in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT,
wherein the BS is to configure, e.g., using an RRC signaling, the one or more UEs with
Yet another embodiment may have one or more UEs and one or more BSs, wherein the one or more UEs include a user device, UE, for a wireless communication system,
the one or more BSs include an inventive BS.
According to another embodiment, a method for operating a wireless communication system may have the steps of:
serving a UE by a base station so as to one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT, and
configuring the UE, e.g., using an RRC signaling, with
According to yet another embodiment, a non-transitory digital storage medium may have a computer program stored thereon to perform the inventive method, when said computer program is run by a computer.
Embodiments of the present invention will be detailed subsequently referring to the appended drawings, in which:
Embodiments of the present invention are now described in more detail with reference to the accompanying drawings in which the same or similar elements have the same reference signs assigned.
In mobile communication systems or networks, like those described above with reference to
When using a single frequency band, the communication may be referred to as a single-band operation, e.g., a UE transmits/receives radio signals to/from another network entity on frequencies being within the 20 MHz band.
When using a two or more frequency bands, the communication may be referred to as a multi-band operation or as a wideband operation or as a carrier aggregation operation. The frequency bands may have different bandwidths or the same bandwidth, like 20 MHz. For example, in case of frequency bands having the same bandwidths a UE may transmit/receive radio signals to/from another network entity on frequencies being within two or more of the 20 MHz bands so that the frequency range for the radio communication may be a multiple of 20 MHz. The two or more frequency bands may be continuous/adjacent frequency bands or some or all for the frequency bands may be separated in the frequency domain.
The multi-band operation may include frequency bands in the licensed spectrum, or frequency bands in the unlicensed spectrum, or frequency bands both in the licensed spectrum and in the unlicensed spectrum.
Carrier aggregation, CA, is an example using two or more frequency bands in the licensed spectrum and/or in the unlicensed spectrum.
5G New Radio (NR) may support an operation in the unlicensed spectrum so that a multi-band operation may include frequency bands in the unlicensed spectrum bands. This may be referred to as NR-based access to unlicensed spectrum, NR-U, and the frequency bands may be referred to as subbands. The unlicensed spectrum may include bands with a potential IEEE 802.11 coexistence, such as the 5 GHz and the 6 GHz bands. NR-U may support bandwidths that are an integer multiple of 20 MHz, for example due to regulatory requirements. The splitting into the subbands is performed so as to minimize interference with coexisting systems, like IEE 802.11 systems, which may operate in one or more of the same bands with the same nominal bandwidth channels, like 20 MHz channels. Other examples of coexisting systems may use subbands having subband sizes and nominal frequencies different from the above-described IEEE 802.11 systems. For example, the unlicensed spectrum may include the 5 GHz band, the 6 GHz band, the 24 GHz band or the 60 GHz band. Examples of such unlicensed bands include the industrial, scientific and medical, ISM, radio bands reserved internationally for the use of radio frequency energy for industrial, scientific and medical purposes other than telecommunications.
During an operation using unlicensed subbands a channel access procedure is to be performed separately per subband, e.g., Listen-before-talk, LBT, or a request to send/clear to send mechanism, RTS/CTS mechanism. This may lead to a situation in which one or more of the subbands are busy or occupied due to an interference, for example, from other communication systems coexisting on the same band, like other public land mobile networks, PLMNs or systems operating in accordance with the IEEE 802.11 specification. In such a situation, the transmitter, either the transmitting gNB or the transmitting UE, is only allowed to transmit on the subbands which are detected to be not busy, also referred to as subbands being free or non-occupied, as is determined by the LBT algorithm. For example for a transmission spanning more than 20 MHz in the 5 GHz operational unlicensed band, the transmitter, like the gNB or the UE, performs Listen-Before-Talk, LBT, separately on each subband. Once the LBT results are available for each subband, the devices, for example, the gNB in the downlink, DL, or the UE in the uplink, UL, are allowed to transmit on those subbands which are determined to be free or unoccupied, i.e., to transmit on the won subband(s). No transmission is allowed on the occupied, busy or non-won subbands. In such a case, the receiver, e.g., a UE, may waste energy by blind decoding not only over all the free or non-occupied subbands, which may also be referred to as won subbands, but also over the busy or occupied subbands.
Also the spectral efficiency may decrease, since the channel occupancy during the LBT of the transmitter, like the gNB, may only be of short duration. For example, there may be a short WiFi transmission at the time the gNB performs the LBT which only occupies a part of the transmission time allocated for this transmission, like only a portion of a frame, so that the major part of the frame is unused thereby reducing the spectral efficiency.
As an example, a situation is now considered in which a subset of the subbands is busy or occupied due to interference by systems operating according to the IEEE 802.11 specification.
[1] https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Mobility/emob41dg/emob41dg-wrapper/ch5 QoS.html#wp1021972,
[2] https://www.tu-ilmenau.de/fileadmin/public/iks/f iles/lehre/mobicom/AN-10-IEEE 802 11.pdf
As is shown in
The three interframe spaces comprise the short interframe space, SIFS, having a duration of typically 10 μs, the point coordination function, PCF, interframe space, PIFS, which is composed of the SCIFS plus 1× slot time which amounts typically to 30 μs, and the DCF interframe space, DIFS, which is composed of the SCIFS plus 2× the slot time of 10 μs so that it amounts typically to 50 μs. The interframe spaces SCIFS, PIFS and DIFS are provided to control which traffic gets first access to the channel after carrier sensing declares the channel to be free, wherein management frames and those frames not expecting contention, like a frame that is part of a sequence of frames, uses SIFS, while data frames use DIFS. In
Reference [3] (https://www.etsi.org/deliver/etsi en/301800 301899/301893/01.07.01 60/en 301893v010701p.pdf) describes a high performance wireless access system including radio local area network equipment which is used in wireless local area networks. Such networks provide high speed data communications in between devices connected to the wireless infrastructure, and ad-hoc networking is described to allow the devices to communicate directly with each other. In such systems load based equipment may implement an LBT based spectrum sharing mechanism based on the clear channel assessment, CAA, mode using energy detect as described in IEEE 802.11.
For example, the 5G New Radio (NR) technology supports operation in unlicensed bands through a technology referred to as NR-based access to unlicensed spectrum (NR-U). The unlicensed spectrum may include bands, e.g., with potential IEEE 802.11 coexistence, such as the 5 GHz and the 6 GHz bands. NR-U may support bandwidths that are an integer multiple of 20 MHz, for example due to regulatory requirements. Each of the 20 MHz bandwidth channels is designed as a subband, and the splitting into the subbands is performed so as to minimize interference with coexisting systems, like IEE 802.11 systems, which may operate in one or more of the same bands with the same nominal bandwidth channels, like 20 MHz channels. Other examples, of coexisting systems may use subbands having subband sizes and nominal frequencies different from the above-described IEEE 802.11 systems. For example, unlicensed subbands may be used, for example, the 24 GHz band or the 60 GHz band. Examples of such unlicensed subbands include the industrial, scientific and medical, ISM, radio bands reserved internationally for the use of radio frequency energy for industrial, scientific and medical purposes other than telecommunications.
In general, during a wideband operation using unlicensed subbands, for example a transmission spanning more than 20 MHz in the 5 GHz operational unlicensed band, the transmitter, like the gNB or the UE perform LBT separately on each subband, and once the LBT results are available for each subband, the devices, for example, the gNB in the downlink, DL, or the UE in the uplink, UL, are allowed to only transmit on those subbands which are determined to be free or unoccupied, i.e., to transmit on the won subband. For example, in the 5 GHz unlicensed band, the number of 20 MHz subbands used for a wideband operation may be four, so that the overall bandwidth is 80 MHz, however, the number of actually used subbands may differ.
FIG. 4 schematically illustrates a wideband operation for NR-U as described above. For such a wideband operation a certain wideband configuration may be employed which specifies the overall bandwidth for the wideband operation, the number of subbands, the respective bandwidths of the subbands, the duration, like the number of symbols, of the wideband operation over time, also referred to as the channel occupancy time, COT. In the system one or more such wideband configurations may exist. In cases there are multiple wideband configurations the transmitter may select the wideband configuration to be used from the plurality of available wideband configurations.
As is described, for example, in RP-150271, “Status Report to TSG: Study on Licensed-Assisted Access to Unlicensed Spectrum,” 3GPP RAN #67, March 2015), the LBT schemes in 3GPP RAN may be classified into four different categories:
In
User devices for the above described wireless communication networks may be configured with configured grants, CGs, thereby providing resources that may be randomly utilized by the user devices whenever there is data to be transmitted. CGs avoid the package transmission delay for a scheduling request procedure and may increase the utilization ratio of allocated periodic radio resources. Different configured grant time domain resource allocation mechanisms exist in NR, referred to as type 1 CG and type 2 CG. A UE may be configured with CG(s) by RRC signaling at some time and the CG(s) may be periodically used by the UE. However, using CGs, for example due to their periodic nature, may lead to drawbacks in wideband operations using bands, some of which may be in the unlicensed spectrums and, therefore, only allow for a communication during the above-described channel occupancy time, COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
For example, when considering the regulations for the unlicensed 5 GHz band, and when considering a so-called frame-based equipment, FBE, device, there may be some problems when employing CGs. FBE is a channel access mechanism defined in EN 301.893 for allowing periodic access to a channel.
However, even for other devices, for example for a load based equipment, LBE device sharing the COT may be a problem. An LBE device may access the channel at any time after performing the CCA with random back-off and it is allowed to share its COT on the current operating channel without any condition regarding the time. Thus, initially it may appear that sharing the COT with a CG UE is not a problem, however, it has been found that even in such situations problems may occur because the CG opportunities within a COT may lead to the so-called hidden node issue to be avoided. More specifically, in case the CG falls into the uplink, UL, region of the gNB COT, the UE may not hear the transmitting other UEs during an LBT and transmit without noticing an ongoing transmission to the gNB which may result in additional interference.
Further, any device sharing a COT, in case of a CG transmission opportunity, TO, inside the COT, may be allowed to use the configured TO only if the transmission is granted by an activation or triggering signal by the device that initiated the COT. Thus, in case the COT initiator device is not sending an explicit or implicit grant/activation/triggering for the sharing device, the sharing device may not use the configured grants, i.e., the transmission opportunities for the configured grants are skipped within the COT.
A further issue with using CGs in the unlicensed bands may be that due to the channel access procedures for the communicating devices, for example the random back-off, even a periodic transmission, such as a CG, may collide with gNB transmissions from time to time. Under certain circumstances, the COT duration may extend up to 20 ms which may have a significant impact on the CG of a UE since the UE has to wait for 20 ms to obtain an empty time slot where it may transmit using its CG. However, since the starting point of a gNB COT may vary, an original CG configuration provided as a default may not be simply applied to a current COT structure.
The present invention provides improvements and enhancements in the wireless communication system addressing the above described problems. The wireless communication system may use one or more subbands, also referred to as channels or frequency bands of a NR carrier, wherein a frequency band includes a start frequency, an end frequency and all intermediate frequencies between the start and end frequencies. A subband may have a predefined bandwidth, like 20 MHz. When using a plurality of subbands, the operation is also referred to as a wideband operation.
Embodiments of the present invention may be implemented in a wireless communication system as depicted in
User Device
The present invention provides (see for example claim 1) a user device, UE, for a wireless communication system, wherein the UE is served by a base station and is to use one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure e.g. Listen-Before-Talk, LBT,
wherein the UE is configured, e.g., using an RRC signaling, with one or more configured grant, CG, configurations so as to allow the UE to perform one or more CG transmissions, and
wherein responsive to detecting a COT and a potential collision of a CG transmission with the COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system, the UE is to deactivate or back off the CG transmission.
In accordance with embodiments (see for example claim 2), the UE is to scan the information from the BS regarding one or more unlicensed frequency bands used by the BS and the COT length so as to derive a potential collision of a CG transmission with the COT.
In accordance with embodiments (see for example claim 3), one or more CG configurations include one or multiple CG opportunities, and wherein, responsive to detecting a COT, the UE is to automatically deactivate all CG opportunities colliding with the COT, and to perform the channel access procedure only for CG opportunities which are outside the COT, if any.
In accordance with embodiments (see for example claim 4), one or more CG configurations include one or more CG opportunities, and wherein, responsive to detecting a COT, the UE is to assume all channel access procedure observation slots colliding with the COT being busy, and to perform a channel access procedure back off procedure accordingly.
In accordance with embodiments (see for example claim 5), one or more CG configurations include one or more CG opportunities, and wherein, responsive to detecting a COT, the UE is to automatically deactivate all CG opportunities except a subset of CG opportunities which are indicated to be used within the COT.
In accordance with embodiments (see for example claim 6), one or more CG configurations include one or more CG opportunities, and wherein, responsive to detecting a COT, the UE is to automatically deactivate all CG opportunities, at least for the time of the COT, and switch to one or more different CG configurations or in-COT CG configurations for use within the COT.
In accordance with embodiments (see for example claim 7), one or more CG configurations include one or multiple CG opportunities, and in the case the CG opportunities fully or partly apply to a COT, the UE is to
In accordance with embodiments (see for example claim 8), responsive to deactivating the whole CG configuration, the UE is to change to a configured or preconfigured within-COT CG procedure, the pre-configured within-COT CG procedure specifying for example certain resources within the COT to be used for a CG transmission.
In accordance with embodiments (see for example claim 9), the UE is to read information provided from the BS which indicates whether the current COT is a frame-based equipment, FBE, COT or a load-based equipment, LBE, COT, and to deactivate the CG transmission only if the current COT is a FBE COT.
In accordance with embodiments (see for example claim 10), responsive to deactivating the CG transmission, the UE is to change to a configured or preconfigured within-FBE-COT CG procedure, the pre-configured within-FBE-COT CG procedure specifying for example certain resources within the FBE-COT to be used for a CG transmission and/or involving an explicit CG activation signaling within the COT.
In accordance with embodiments (see for example claim 11), the UE is configured with one or more additional CG resources across one or more of the plurality of frequency bands, and wherein, responsive to detecting a COT and a potential collision of a CG transmission with the COT, the UE is to perform the CG transmission using one or more of the additional CG resources within one or more failed frequency bands, or outside a COT, e.g. on a different frequency band, or within a licensed band.
In accordance with embodiments (see for example claim 12), is to perform a CG transmission within the COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system, only in response to receiving an activation signaling or grant from a certain entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
The present invention provides (see for example claim 13) a user device, UE, for a wireless communication system,
wherein the UE is served by a base station and is to use one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure e.g. Listen-Before-Talk, LBT,
wherein the UE is configured, e.g., using an RRC signaling, with one or more configured grant, CG, configurations so as to allow the UE to perform one or more CG transmissions,
wherein the UE is to perform a CG transmission within the COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system, only in response to receiving an activation signaling or grant from a certain entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
In accordance with embodiments (see for example claim 14), the UE is to receive the activation signaling as part of control information, e.g., DCI, SCI, transmitted in a control region, e.g., PDCCH or PSCCH of one or more of the frequency bands, e.g. using a certain RNTI or an explicit field in the DCI for indicating an activation of a specific CG configuration, a group of CG configurations or CG configurations within a certain time/frequency.
In accordance with embodiments (see for example claim 15), the activation signaling has one or more of the following functionalities:
In accordance with embodiments (see for example claim 16), the activation signaling is a group signaling indicating a pre-configured subset or all CG configurations for a plurality of UEs or for a group of UEs, and wherein the UE is to receive the group signaling as part of group control information transmitted in a control region, e.g., GC-PDCCH or GC-PSCCH, of one or more of the frequency bands.
In accordance with embodiments (see for example claim 17), the group signaling has one or more of the following functionalities:
In accordance with embodiments (see for example claim 18), the activation signaling is an in-COT CG-activation that operates for both type-1 CG and type-2 CG configurations, wherein
The present invention provides (see for example claim 19) a user device, UE, for a wireless communication system,
wherein the UE is served by a base station and is to use one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT,
wherein the UE is configured, e.g., using an RRC signaling, with
In accordance with embodiments (see for example claim 20), the UE is to be semi-statically or dynamically configured within a radio frame with the in-COT CG configurations, wherein the in-COT CG configurations may be stretched over time or over frequency or code domains.
In accordance with embodiments (see for example claim 21), the UE is configured using a semi-static signaling, e.g., an RRC signaling, and wherein an in-COT CG configuration includes one or more of the following parameters:
In accordance with embodiments (see for example claim 22), the UE is configured using a dynamic signaling using control information, e.g., DCI, SCI, transmitted in a control region, e.g., PDCCH or PSCCH, of one or more of the frequency bands, and wherein
In accordance with embodiments (see for example claim 23), the UE is to use a CAT-2 LBT and/or interleaved-OFDMA in order to perform an interlaced transmission within the COT.
In accordance with embodiments (see for example claim 24), the UE is to apply an in-COT CG configuration only in response to receiving an activation signaling or grant from a certain entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
Base Station
The present invention provides (see for example claim 25) a base station, BS, for a wireless communication system,
wherein the BS is to serve one or more UEs and is to use one or more frequency bands for a communication with the one or more UEs in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT,
wherein the BS is to configure, e.g., using an RRC signaling, the one or more UEs with one or more configured grant, CG, configurations so as to allow the UEs to perform one or more CG transmissions, and
wherein the BS is to signal to the one or more UEs one or more unlicensed frequency bands used by the BS and the COT length so as to allow the UEs to deactivate or back off the CG transmission responsive to detecting a potential collision of a CG transmission with the COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
The present invention provides (see for example claim 26) a base station, BS, for a wireless communication system,
wherein the BS is to serve one or more UEs and is to use one or more frequency bands for a communication with the one or more entities in the wireless communication system,
wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT,
wherein BS is to configure, e.g., using an RRC signaling, the one or more UEs with one or more configured grant, CG, configurations so as to allow the UEs to perform one or more CG transmissions,
wherein the BS is to send to the one or more UEs an activation signaling or grant enabling a UE to perform a CG transmission within a COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
The present invention provides (see for example claim 27) a base station, BS, for a wireless communication system,
wherein the BS is to serve one or more UEs and is to use one or more frequency bands for a communication with the one or more UEs in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT,
wherein the BS is to configure, e.g., using an RRC signaling, the one or more UEs with
System
The present invention provides (see for example claim 28) a wireless communication system, comprising one or more UEs and one or more BSs, wherein the one or more UEs comprise a UE in accordance with the present invention and/or the one or more BSs comprise a BS in accordance with the present invention.
In accordance with embodiments (see for example claim 29),
the UE comprises one or more of a mobile terminal, or stationary terminal, or cellular IoT-UE, or vehicular UE, or vehicular group leader (GL) UE, an IoT or narrowband IoT, NB-IoT, device, or a ground based vehicle, or an aerial vehicle, or a drone, or a moving base station, or road side unit, or a building, or any other item or device provided with network connectivity enabling the item/device to communicate using the wireless communication network, e.g., a sensor or actuator, and/or
the BS comprises one or more of a macro cell 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 road side unit, or a UE, or a group leader (GL), or a relay, or a remote radio head, or an AMF, or an SMF, or a core network entity, or mobile edge computing entity, or a network slice as in the NR or 5G core context, or any transmission/reception point, TRP, enabling an item or a device to communicate using the wireless communication network, the item or device being provided with network connectivity to communicate using the wireless communication network.
Method
The present invention provides (see for example claim 30) a method for operating a wireless communication system, the method comprising:
serving a UE a base station so as to use one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure e.g. Listen-Before-Talk, LBT, wherein the UE is configured, e.g., using an RRC signaling, with one or more configured grant, CG, configurations so as to allow the UE to perform one or more CG transmissions, and
responsive to detecting a COT and a potential collision of a CG transmission with the COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system, the UE, deactivating or backing off the CG transmission.
The present invention provides (see for example claim 31) a method for operating a wireless communication system, the method comprising:
serving a UE by a base station so as to use one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure e.g. Listen-Before-Talk, LBT, wherein the UE is configured, e.g., using an RRC signaling, with one or more configured grant, CG, configurations so as to allow the UE to perform one or more CG transmissions,
performing, by the UE, a CG transmission within the COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system, only in response to an activation signaling or a grant from a certain entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
The present invention provides (see for example claim 32) a method for operating a wireless communication system, the method comprising:
serving a UE by a base station so as to one or more frequency bands for a communication with one or more entities, e.g., other UE(s) or other gNB(s), in the wireless communication system, wherein some or all of the plurality of frequency bands are unlicensed frequency bands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g., Listen-Before-Talk, LBT, and
configuring the UE, e.g., using an RRC signaling, with
Computer Program Product
The present invention provides a computer program product comprising instructions which, when the program is executed by a computer, causes the computer to carry out one or more methods in accordance with the present invention.
Aspect 1
In accordance with embodiments of a first aspect of the present invention, an explicit grant or activation signal for the configured grant, CG, is provided.
In accordance with embodiments, a UE specific activation is employed and the UE performs a CG transmission only in response to receiving an activation signaling or grant from the gNB or another network entity like another UE in case of a sidelink, SL, communication, a roadside unit, RSU, a drone, a WIFI device, a relay device or the like. The activation signaling refers to a certain CG configuration and, upon receipt, allows the UE to perform the CG transmission. Thus, the above mentioned problems associated with, e.g., FBE, LBE of other devices are addressed in that, in accordance with embodiments of the first aspect, the UE is receiving the grant that may be given to perform a transmission, for example during the COT, e.g. the COT of another entity, e.g., other UE(s) or other gNB(s), in the wireless communication system.
The signaling may be transmitted using a DCI in the PDCCH or, in case of a SL communication, with a SCI in the PSCCH. For example, a certain RNTI may be used for indicating the activation of a specific CG configuration. The activation signaling may have one or more of the following functionalities:
In accordance with other embodiments of the first aspect of the present invention, the explicit grant or activation signaling for performing a CG may be obtained via a group activation. For example, a group signaling, like a group common-PDCCH, GC-PDCCH, or a group cast on a group common side link control channel, SCI, may be transmitted in order to activate a pre-configured subset or all CG configurations for some or all UEs of a group. The activation signaling may have one or more of the following functionalities:
The activation signaling, in accordance with embodiments, operates for type 1 CGs and type 2 CGs. In case of a type-1 CG, the RRC signaling configures the transmission period, the transmission offset and the other CG information. Later, once a UE, or a group of UEs, that has been considered with type-1 configured grants, and a transmission opportunity, TO, occurs within a gNB COT, the UE needs or expects the activation signal before the TO inside the COT. The in-COT CG-activation may be configured in the information element used during RRC signaling, for example, it may be indicated that the in-COT CG-activation is active or inactive, for example by setting a corresponding field in the NR rrc_configuredGrantCon figuration IE to be true or false. In case the in-COT CG-activation is set to be active or true via the RRC signaling, the UE may receive the in-COT activation via a DCI or a SCI.
In case of type-2 CG, the RRC configuration may configure the periodicity of the TOs while the time offset and the activation signaling may be configured via DCI or SCI signaling. Then, the in-COT CG-activation may be configured as described above, for example to be active or inactive by setting a field within the configuration information element to be true or false, and in case the activation signaling is set, i.e., it is configured to be true, the UE has to wait for the in-COT CG-activation before transmitting on the TO within the COT. In accordance with examples, in type-2 CG, the in-COT activation to be sent via the DCI or the SCI may reuse the CG type-2 activation signaling also for the in-COT activation, and in other examples the CG type-2 activation signaling may only be used for setting the time offset and the frequency resources while a separate in-COT activation signaling may be used for activating the TO within the COT.
Thus, embodiments of the first aspect of the present invention avoid the problems described above that CGs may not be employed when sharing COT as, in accordance with the present invention, for performing the CG transmission within a COT the UE receives an explicit activation signal allowing the CG transmission.
Aspect 2
In accordance with embodiments of a second aspect of the present invention, different CG configurations are provided to be used within an outside a COT, like a gNB COT. More specifically, in accordance with embodiments a UE may be configured with two different configurations, explicitly or implicitly, one of which is to be used within the gNB COT or the COT of another entity, e.g., other UE(s), and the other one is to be used outside the gNB COT.
To address the above described issues with conventional-technology approaches, e.g., that an initial CG configuration may not be applied to a current COT structure, in accordance with embodiments of the second aspect, different configurations for CGs to be performed within and outside a gNB COT are provided or indicated to the UE. In other words, in addition to the default CG configuration, an additional configuration is provided to be used inside the COT. For example, the additional configuration may indicate dedicated CG resources within a COT to be used for the CG TOs.
It is noted that the invention is not limited to embodiments in which a UE shares a COT of a gNB as illustrated in
The additional configuration, which may be referred to as an in-COT configuration, may be semi-statically or dynamically configured within a radio frame and may be stretched over time and/or over frequency and/or over code domains. In case of a semi-static configuration, the UE may be provided with the additional configuration using RRC signaling so as to configure the CG transmission within a COT, for example a gNB COT. This configuration may include one or more of the following parameters:
In case of a dynamic configuration, the additional configuration may be provided using dynamic signaling, such as a DCI in the PDCCH. The DCI may either explicitly reference a certain CG configuration or may implicitly refer to a certain CG configuration. When implicitly referring to the CG configuration, the UE may match certain parameters from the DCI with respective parameters of the CG configurations so as to find the CG configuration matching the parameters indicated in the DCI, like a transmission size, CG configuration ID, timing, HARQ process ID and the like. In case a dynamic grant is received, which matches a certain CG configuration, LBT is performed only for the dynamic grant, and the actually default CG occasion is skipped.
In accordance with yet further embodiments, CGs may be interlaced with the gNB COT. For example, outside a gNB COT, a UE may perform a CAT-4 LBT with a random back-off so as to initiate a CG. The CG may span the entire transmission bandwidth and multiplexing between different CG UEs may be possible in a TDM manner. Within a gNB COT, interlaced transmissions offer high multiplexing capabilities using CAT-2 LBT. Therefore, in accordance with embodiments of the second aspect, a CAT-2 LBT is used in order to perform an interlaced transmission with the gNB COT.
In accordance with further embodiments, interleaving may be achieved using (block)-interleaved-OFDMA (IFDMA). Moreover, CAT-2 LBT UEs may use certain CDMA codes when transmitting within the gNB COT.
The above described embodiments of the second aspect of the present invention may be combined with the embodiments of the first aspect of the present invention so that the additional CG configuration to be used within the COT may be employed only upon an activating, for example upon receiving an activation signaling as described above with regard to the first aspect.
Aspect 3
In accordance with embodiments of a third aspect of the present invention, an automatic partial or full deactivation of a CG is employed, for example responsive to detecting a COT. For example, in response to detecting a gNB COT (FBE or LBE), the UE may deactivate or back off its CG transmission in case a potential collision with the gNB COT is detected. The UE may scan information from the gNB regarding the operating channel and the COT length, and from this information the UE may derive a potential collision of a CG transmission to be performed by the UE with the gNB COT.
In accordance with further embodiments of the third aspect of the present invention, a CG configuration may include multiple CG opportunities, and responsive to detecting a gNB COT, the UE may automatically deactivate all CG opportunities that are expected to collide with the gNB COT and to perform only CCA for those CG opportunities which are outside the gNB COT, if any. In case the CG opportunities partly or fully apply to the gNB COT, the UE may apply different behaviors which are described below.
In accordance with embodiments, the UE may deactivate the entire or whole CG opportunities if at least one opportunity is within the gNB COT.
In accordance with further embodiments, the UE may deactivate the entire or whole CG opportunities according to previously mentioned criteria except those which are flagged to support in-COT operation. The gNB may provide this flag via semi static configuration, such as RRC, or it may be implicitly derived. For example, one or more CG opportunities lying first in time may be supporting in-COT operation by default. Hence, the UE automatically deactivates only the other CG opportunities responsive to detecting a collision with a gNB COT.
In a further embodiment, only a subset of CG opportunities of the CG configuration which are flagged implicitly, e.g. order in time, or explicitly, e.g. RRC signaling, as in-COT CG opportunities are used in a gNB COT. For example, all CG opportunities except the first one in time are deactivated responsive to detecting a collision with a gNB COT. Hence, the gNB knows where it may expect a CG transmission within its COT structure.
In accordance with another embodiment, the functionality may be that within the COT, also referred to as in-COT, a different configuration is applied, at least for the time of the COT. For example, responsive to detecting a COT, the UE may to automatically deactivate all CG opportunities, at least for the time of the COT, and switch to one or more different CG configurations or in-COT CG configurations for use within the COT.
In accordance with further embodiments, responsive to deactivating a CG configuration, the UE may change to a within-COT procedure. For example, the UE may be configured with additional CG configurations to be used within the COT that are illustrated in
In accordance with other embodiments, the entire CG configuration may be deactivated in case a certain number of CG opportunities, like k, K=1,2,3, . . . , opportunities, are within the COT.
In accordance with yet further embodiments, the whole or entire CG configuration may be deactivated in case all opportunities are within the gNB COT as is illustrated in
In accordance with further embodiments of the third aspect of the present invention, the UE may decide about the activation/deactivation of multiple CG opportunities dependent on a channel access mechanism of the gNB. For example, the UE may read information provided by the gNB which indicates whether the current COT is an FBE COT or an LBE COT. The UE deactivates its CG configuration only in case it detects an FBE COT.
In the embodiments described above, the respective opportunities opp-1 to opp-3 of the CG configurations are configured to be arranged across time; however, in accordance with further embodiments, the multiple CG opportunities may also be provided across frequency. More specifically, in addition to the multiple CG opportunities provided across time, the UE may also be configured, for example, by the network, with additional CG resources across frequency, for example, across LBT subbands. For example, responsive to detecting a COT and a potential collision of a CG transmission with the COT, the UE may perform the CG transmission using one or more of the additional CG resources within one or more failed frequency bands, or outside a COT, e.g. on a different frequency band, or within a licensed band.
In accordance with further embodiments, the UE uses CG opportunities which do not collide with a gNB COT as is illustrated in
With regard to the above described embodiments, it is noted that some of them have been described in detail with regard to a gNB COT; however, the embodiments are not limited to the gNB COT, rather, the mentioned COT may also be a UE COT communicating with a gNB over the Uu interface or with other UEs over a sidelink interface.
General
Embodiments of the present invention have been described in detail above, and the respective embodiments and aspects may be implemented individually or two or more of the embodiments or aspects may be implemented in combination.
Further, the embodiments described herein may be employed when communicating via a single subband that may be an unlicensed subband. However, the inventive approach is not limited to a communication over a single subband, rather, the communication may be over a plurality of subbands for a communication with one or more entities, like other UE(s) or other gNB(s), in the wireless communication system, and some or all of the plurality of subbands may be unlicensed subbands on which a communication is allowed for a certain transmission time (COT) responsive to a successful channel access procedure, e.g. Listen-Before-Talk, LBT, or a request to send/clear to send mechanism, RTS/CTS mechanism, that may be used for higher frequencies.
With regard to the above-described embodiments of the various aspects of the present invention, it is noted that they have been described in an environment in which a communication is between a transmitter, like a gNB or a UE, and a receiver, like a UE and a gNB. However, the invention is not limited to such a communication, rather, the above-described principles may equally be applied for a device-to-device communication, like a D2D, V2V, V2X communication. In such scenarios, the communication is over a sidelink between the respective devices. The transmitter is a first UE and the receiver is a second UE communicating using the sidelink resources.
In accordance with embodiments, the wireless communication system may include a terrestrial network, or a non-terrestrial network, or networks or segments of networks using as a receiver an airborne vehicle or a spaceborne vehicle, or a combination thereof.
In accordance with embodiments, a receiver may comprise one or more of a mobile or stationary terminal, an IoT device, a ground-based vehicle, an aerial vehicle, a drone, a building, or any other item or device provided with network connectivity enabling the item/device to communicate using the wireless communication system, like a sensor or actuator. In accordance with embodiments, a transmitter may comprise one or more of a macro cell base station, or a small cell base station, or a spaceborne vehicle, like a satellite or a space, or an airborne vehicle, like a unmanned aircraft system (UAS), e.g., a tethered UAS, a lighter than air UAS (LTA), a heavier than air UAS (HTA) and a high altitude UAS platforms (HAPs), or any transmission/reception point (TRP) enabling an item or a device provided with network connectivity to communicate using the wireless communication system.
Although some aspects of the described concept have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or a device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.
Various elements and features of the present invention may be implemented in hardware using analog and/or digital circuits, in software, through the execution of instructions by one or more general purpose or special-purpose processors, or as a combination of hardware and software. For example, embodiments of the present invention may be implemented in the environment of a computer system or another processing system.
The terms “computer program medium” and “computer readable medium” are used to generally refer to tangible storage media such as removable storage units or a hard disk installed in a hard disk drive. These computer program products are means for providing software to the computer system 500. The computer programs, also referred to as computer control logic, are stored in main memory 506 and/or secondary memory 508. Computer programs may also be received via the communications interface 510. The computer program, when executed, enables the computer system 500 to implement the present invention. In particular, the computer program, when executed, enables processor 502 to implement the processes of the present invention, such as any of the methods described herein. Accordingly, such a computer program may represent a controller of the computer system 500. Where the disclosure is implemented using software, the software may be stored in a computer program product and loaded into computer system 500 using a removable storage drive, an interface, like communications interface 510.
The implementation in hardware or in software may be performed using a digital storage medium, for example cloud storage, a floppy disk, a DVD, a Blue-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable.
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.
Generally, embodiments of the present invention may 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.
Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier. 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.
A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet. A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.
In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are advantageously performed by any hardware apparatus.
While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and compositions of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations and equivalents as fall within the true spirit and scope of the present invention.
BS Base Station
CBR Channel Busy Ratio
D2D Device-to-Device
EN Emergency Notification
eNB Evolved Node B (base station)
FDM Frequency Division Multiplexing
LTE Long-Term Evolution
PC5 Interface using the Sidelink Channel for D2D communication
PPPP ProSe per packet priority
PRB Physical Resource Block
ProSe Proximity Services
RA Resource Allocation
SCI Sidelink Control Information
SL sidelink
sTTI Short Transmission Time Interval
TDM Time Division Multiplexing
TDMA Time Division Multiple Access
TPC Transmit power control/transmit power command
UE User Entity (User Terminal)
URLLC Ultra-Reliable Low-Latency Communication
V2V Vehicle-to-vehicle
V2I Vehicle-to-infrastructure
V2P Vehicle-to-pedestrian
V2N Vehicle-to-network
V2X Vehicle-to-everything, i.e., V2V, V2I, V2P, V2N
| Number | Date | Country | Kind |
|---|---|---|---|
| 19188276.0 | Jul 2019 | EP | regional |
This application is a continuation of copending International Application No. PCT/EP2020/070483, filed Jul. 20, 2020, which is incorporated herein by reference in its entirety, and additionally claims priority from European Application No. EP 19188276.0, filed Jul. 25, 2019, which is incorporated herein by reference in its entirety. The present application relates to the field of wireless communication systems or networks, more specifically to enhancements in the communication among network entities of the communication network when performing a communication over one or more subbands, some or all of which include unlicensed bands. Embodiments of the present invention concern enhancements in an NR-U operation employing configured grants, CGs.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2020/070483 | Jul 2020 | US |
| Child | 17581672 | US |
