The present disclosure relates generally to using Listen Before Talk (LBT) for transmissions.
New Radio (NR) in Unlicensed Spectrum (NR-U)
Allowing unlicensed networks, i.e., networks that operate in shared spectrum (or unlicensed spectrum) to effectively use the available spectrum is an attractive approach to increase system capacity. Although unlicensed spectrum does not match the qualities of the licensed regime, solutions that allow an efficient use of it as a complement to licensed deployments have the potential to bring great value to the Third Generation Partnership Project (3GPP) operators, and, ultimately, to the 3GPP industry as a whole. This type of solutions would enable operators and vendors to leverage the existing or planned investments in Long Term Evolution (LTE)/NR hardware in the radio and core network.
For a node to be allowed to transmit in unlicensed spectrum in lower frequency band, it typically needs to perform a Clear Channel Assessment (CCA) or Listen Before Talk (LBT). This procedure typically includes sensing the wireless medium to be unoccupied. Sensing the medium to be idle can be done in different ways, e.g., using energy detection, preamble detection or using virtual carrier sensing. Where the former implies that the node listens to the channel and measures the energy of the interference (plus noise) for a number of time intervals. If the energy is smaller than a certain threshold (often called Energy Detection (ED) threshold), it declares that the medium is idle. Otherwise, it declares that the medium is busy (or occupied).
After sensing the medium to be idle, the node is typically allowed to transmit for a certain duration, sometimes referred to as Transmission Opportunity (TXOP) or COT (Channel Occupancy Time). In some jurisdictions, the maximum duration of a COT depends on the type of CCA that has been performed. Typical ranges are 1 ms to ms. This limit is denoted Maximum Channel Occupancy Time (MCOT). During a COT a New Radio Base Station (gNB) is allowed to share its access to the wireless medium with uplink transmissions from User Equipments (UEs). Sometimes, this is referred to as shared COT. A major goal of introducing the shared COT concept is to minimize the need of UEs to perform a long LBT prior to transmissions in the uplink. In some jurisdictions, a scheduled UE is permitted performing a short LBT immediately following the downlink transmission.
NR-U Operation in High Frequency Spectrum
RP-193259, New SID: Study on supporting NR from 52.6 GHz to 71 GHz and RP-193229, New WID on Extending current NR operation to 71 GHz were approved in RAN #86 to study and extend NR support in the frequency range of 52.6 GHz to 71 GHz. One of the main objectives of this Study Item (SI) and Work Item (WI) is the study of channel access mechanism, considering potential interference to/from other nodes, assuming beam based operation, in order to comply with the regulatory requirements applicable to unlicensed spectrum for frequencies between 52.6 GHz and 71 GHz.
Regulatory Requirements
In Europe and European Conference of Postal and Telecommunications Administrations (CEPT), the new frequency bands and regulatory parameters for the 57-71 GHz band for Wideband Data Transmission Systems are defined in ERC/REC 70-03. Corresponding updates have also been made to the technical annex of EC Decision 2006/771/EC for short range devices (SRD) in 2019. ERC/REC 70-03 defines three sub-bands in the 57-71 GHz band as summarized in in Table 1.
CEPT mandates implementing adequate spectrum sharing mechanism for operation in 57-71 GHz. Those mechanisms can differ from one technology to another. Some exemplary mechanisms include: Automatic Transmit Power Control (ATPC) and Listen Before Talk (LBT). Hence, in principle LBT is not mandated by CEPT.
Among the spectrum allocations for U.S.A., frequency ranges 57 GHz to 71 GHz are available for mobile use as part of unlicensed spectrum regulated by Title 47 Part 15 of the FCC regulations. Spectrum access and mitigation requirements are not specified. Instead, only requirements on transmission power limits in terms of Effective Isotropically Radiated Power (EIRP) and/or maximum conducted output power are specified.
Similarly, countries in ITU region 2 and 3 only specify transmission power limits in terms of EIRP and/or maximum conducted power. LBT is not required in these countries either.
Energy Detection Threshold Adaptation for NR
Some disclosures discuss various methods for adapting the ED threshold. Some disclosures discuss various methods for fractional frequency reuse of resources with flexible energy detection where different resources in time, frequency, or space use different energy detection thresholds.
It should be noted that setting the ED threshold to a very high value (Infinity) is not equivalent to no LBT mode, because even if the ED threshold is very high, the transmitter still need to defer and sense the channel, thus additional overhead is added. Improved systems and methods for transmitting with or without LBT are needed.
Systems and methods for changing Listen Before Talk (LBT) for unlicensed networks are provided. In some embodiments, a method performed by a wireless device includes: receiving signaling from a base station that indicates when the wireless device uses LBT for transmissions; determining, based on the received signaling, whether or not to use LBT for transmissions; and transmitting based on the determination whether or not to use LBT for transmissions.
In some embodiments, a method of determining and signaling the LBT mode (LBT or no LBT) according to the network's status is considered, wherein: The New Radio Base Station (gNB)/User Equipment (UE) determines LBT mode statically or dynamically based on the long term or short term status of the network. The gNB uses or does not use LBT mode for downlink (DL) transmissions and/or signals to the UE(s) the LBT mode to be used for the next uplink (UL) transmissions or alternatively configures the UE with a set of rules based on which the UE can determine the LBT mode by itself.
Without loss of any generality, the method is described for New Radio Unlicensed Spectrum (NR-U) but can also be applied to other Radio Access Technologies (RATs).
There are, proposed herein, various embodiments which address one or more of the issues disclosed herein.
Certain embodiments may provide one or more of the following technical advantage(s). Some embodiments provide a low complexity (in term of signaling overhead and specification impact) approach of adaptively using LBT mechanism by defining two simple modes for LBT operation (LBT and No LBT modes).
The method reduces the probability of simultaneous transmissions that cause collisions, by using LBT mode, in environments and circumstances where network's performance suffers from collision and/or interferences. On the other hand, the method improves the spatial frequency reuse and reduces LBT overhead by using no LBT mode if it is allowed by relevant regional regulations or if devices experience less interference from simultaneous transmissions. Thus, the method improves the overall spectral efficiency by identifying and switching to the appropriate mode.
The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.
The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.
Radio Node: As used herein, a “radio node” is either a radio access node or a wireless communication device.
Radio Access Node: As used herein, a “radio access node” or “radio network node” or “radio access network node” is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), a relay node, a network node that implements part of the functionality of a base station (e.g., a network node that implements a gNB Central Unit (gNB-CU) or a network node that implements a gNB Distributed Unit (gNB-DU)) or a network node that implements part of the functionality of some other type of radio access node.
Core Network Node: As used herein, a “core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.
Communication Device: As used herein, a “communication device” is any type of device that has access to an access network. Some examples of a communication device include, but are not limited to: mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or Personal Computer (PC). The communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless or wireline connection.
Wireless Communication Device: One type of communication device is a wireless communication device, which may be any type of wireless device that has access to (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of a wireless communication device include, but are not limited to: a User Equipment device (UE) in a 3GPP network, a Machine Type Communication (MTC) device, and an Internet of Things (IoT) device. Such wireless communication devices may be, or may be integrated into, a mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or PC. The wireless communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless connection.
Network Node: As used herein, a “network node” is any node that is either part of the RAN or the core network of a cellular communications network/system.
Transmission/Reception Point (TRP): In some embodiments, a TRP may be a network node, a radio head, a spatial relation, or a Transmission Configuration Indicator (TCI) state. A TRP may be represented by a spatial relation or a TCI state in some embodiments. In some embodiments, a TRP may be using multiple TCI states.
Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.
Note that, in the description herein, reference may be made to the term “cell”; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.
The base stations 102 and the low power nodes 106 provide service to wireless communication devices 112-1 through 112-5 in the corresponding cells 104 and 108. The wireless communication devices 112-1 through 112-5 are generally referred to herein collectively as wireless communication devices 112 and individually as wireless communication device 112. In the following description, the wireless communication devices 112 are oftentimes UEs, but the present disclosure is not limited thereto.
Listen Before Talk (LBT) has been used as a medium access mechanism for unlicensed spectrum in lower frequency ranges, e.g., 2.4 and 5 GHz bands. However, since the millimeter wave frequency range is characterized by high radio propagation loss and directional transmission and reception from the usage of large antenna arrays, LBT is generally not beneficial. The intra and inter system interference condition in the 60 GHz band (or other higher frequency bands) is considerably different compared to lower frequency bands.
Firstly, the transmission power limitation imposed by different regulations and the attenuation characteristics around the 60 GHz range prohibits radio signal to cause strong interference to other nodes located tens of meters away. Secondly, highly directional signal transmission is less likely to interfere with other nodes even in the close vicinity, except for the nodes that lie directly in the transmission beam coverage. The probability of interference is further reduced for the nodes that employ directional reception. Thirdly, highly directional transmission also makes it very difficult for a transmitter to correctly detect the interference level at intended receiver, and hence the fundamental assumption in classical LBT for interference avoidance no longer holds.
LBT requirement is not mandatory in most regions and regulations. In many cases it negatively impacts on the system performance at 60 GHz due to the unnecessary back-off delay from LBT.
Even though this can be true in most cases, there can be cases in which these assumptions do not hold. For instance, not all equipment's are capable of transmitting with high directivity. Besides, cell edge UEs are more subject to interference than other UEs. Interference from neighboring cells can significantly impact the performance. Finally, as the number of nodes increase, the probability of being impacted by interference becomes higher. In such cases, using LBT to avoid collisions and interference from other nodes may have a positive impact on the performance.
Hence, it is beneficial for a wireless radio access network to statically or dynamically switch on or off LBT, based on the operation frequency bands, spectrum congestion level, system traffic level, devices capabilities, etc., to improve overall system performance.
Systems and methods for changing LBT for unlicensed networks are provided. In some embodiments, a method performed by a wireless device includes: receiving signaling from a base station that indicates when the wireless device uses LBT for transmissions; determining, based on the received signaling, whether or not to use LBT for transmissions; and transmitting based on the determination whether or not to use LBT for transmissions.
Some embodiments provide a low complexity (in term of signaling overhead and specification impact) approach of adaptively using LBT mechanism by defining two simple modes for LBT operation (LBT and No LBT modes).
The method reduces the probability of simultaneous transmissions that cause collisions, by using LBT mode, in environments and circumstances where network's performance suffers from collision and/or interferences. On the other hand, the method improves the spatial frequency reuse and reduces LBT overhead by using no LBT mode if it is allowed by relevant regional regulations or if devices experience less interference from simultaneous transmissions. Thus, the method improves the overall spectral efficiency by identifying and switching to the appropriate mode.
In some embodiments, a UE does not even have LBT implemented if certain hardware conditions are fulfilled.
In this embodiment, a method in which a device may operate without LBT is based the configuration of the systems, device hardware capabilities, or predefined rules, which is satisfied one or more of the following thresholds or conditions:
In this embodiment, the devices could transmit without performing LBT prior to the transmission based on:
Without loss of generality, the method is described for New Radio Unlicensed Spectrum (NR-U) but can also be applied to other RATs.
In a scenario where operating with LBT is mandatory, or if the gNB determines that operation with LBT is beneficial, and the UE does not support LBT, the gNB makes sure that the UE UL transmissions are part of the gNB's initiated COT.
In this embodiment, the switching of LBT modes is between a frame based equipment (FBE) mode and a load based equipment (LBE) mode. The modes could then also be configured with appropriate energy detection thresholds. For example, the energy detection threshold for FBE can be set very high so that there is effectively no LBT performed, except for a 9 microsecond delay prior to transmission since FBE only requires sensing in a single slot.
In this embodiment, the switching of LBT modes is between two LBE modes where one has random exponential backoff and one doesn't. For instance, in the LBE mode without any backoff, the gNB or UE always chooses a random counter between 0 and Contention Window (CW), where CW is fixed. In the LBE mode with backoff, this CW is increased (e.g., doubled) when a transmission is detected to not be successful, for instance through the reception of a negative acknowledgement. Again, as in the previous embodiment, the energy detection thresholds can be varied based on the level of reuse desired between resources in different cells.
In this embodiment, the LBT mode used is chosen based on the time, frequency or spatial resources being used for a particular transmission. Furthermore, the configuration of the resources can be coordinated between cells to enable LBT for UEs operating at the cell edge (both on the downlink and uplink) while disabling or modifying the mode significantly for UEs operating closer to the gNB. An exemplary example of this is shown in
In this embodiment, the LBT mode is configured as part of the bandwidth part configuration. UEs may be configured with more than one bandwidth part with each bandwidth part being configured with a different LBT mode. The gNB can control the LBT modes used by the choice of bandwidth part used for communication with the UE.
In this embodiment, the UE may be configured with different LBT modes for different DCI formats. For instance, the UE could be configured to receive PUSCH scheduling via DCI format 0_1 and 0_2 each of which has its own time domain resource allocation (TDRA) table. The UE could be configured with a different LBT mode for these DCI formats. For instance, the network could configure the UE to associate PUSCH allocations signaled via DCI format 0_1 to not use LBT while allocations signaled via DCI format 0_2 may use LBT. Any of the different LBT modes or associated parameters can be configured for each of these DCI formats.
It will be obvious to those skilled in the art that any of the previous embodiments can be used in combination with each other. For instance, the Time Domain Resource Allocation (TDRA) tables for DCI formats 0_1 and 0_2 could be configured to emulate the fractional frequency/time reuse schemes in the
As used herein, a “virtualized” radio access node is an implementation of the radio access node 300 in which at least a portion of the functionality of the radio access node 300 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node 300 may include the control system 302 and/or the one or more radio units 310, as described above. The control system 302 may be connected to the radio unit(s) 310 via, for example, an optical cable or the like. The radio access node 300 includes one or more processing nodes 400 coupled to or included as part of a network(s) 402. If present, the control system 302 or the radio unit(s) are connected to the processing node(s) 400 via the network 402. Each processing node 400 includes one or more processors 404 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 406, and a network interface 408.
In this example, functions 410 of the radio access node 300 described herein are implemented at the one or more processing nodes 400 or distributed across the one or more processing nodes 400 and the control system 302 and/or the radio unit(s) 310 in any desired manner. In some particular embodiments, some or all of the functions 410 of the radio access node 300 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 400. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 400 and the control system 302 is used in order to carry out at least some of the desired functions 410. Notably, in some embodiments, the control system 302 may not be included, in which case the radio unit(s) 310 communicate directly with the processing node(s) 400 via an appropriate network interface(s).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 300 or a node (e.g., a processing node 400) implementing one or more of the functions 410 of the radio access node 300 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the wireless communication device 600 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
With reference to
The telecommunication network 800 is itself connected to a host computer 816, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server, or as processing resources in a server farm. The host computer 816 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 818 and 820 between the telecommunication network 800 and the host computer 816 may extend directly from the core network 804 to the host computer 816 or may go via an optional intermediate network 822. The intermediate network 822 may be one of, or a combination of more than one of, a public, private, or hosted network; the intermediate network 822, if any, may be a backbone network or the Internet; in particular, the intermediate network 822 may comprise two or more sub-networks (not shown).
The communication system of
Example implementations, in accordance with an embodiment, of the UE, base station, and host computer discussed in the preceding paragraphs will now be described with reference to
The communication system 900 further includes a base station 918 provided in a telecommunication system and comprising hardware 920 enabling it to communicate with the host computer 902 and with the UE 914. The hardware 920 may include a communication interface 922 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 900, as well as a radio interface 924 for setting up and maintaining at least a wireless connection 926 with the UE 914 located in a coverage area (not shown in
The communication system 900 further includes the UE 914 already referred to. The UE's 914 hardware 934 may include a radio interface 936 configured to set up and maintain a wireless connection 926 with a base station serving a coverage area in which the UE 914 is currently located. The hardware 934 of the UE 914 further includes processing circuitry 938, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The UE 914 further comprises software 940, which is stored in or accessible by the UE 914 and executable by the processing circuitry 938. The software 940 includes a client application 942. The client application 942 may be operable to provide a service to a human or non-human user via the UE 914, with the support of the host computer 902. In the host computer 902, the executing host application 912 may communicate with the executing client application 942 via the OTT connection 916 terminating at the UE 914 and the host computer 902. In providing the service to the user, the client application 942 may receive request data from the host application 912 and provide user data in response to the request data. The OTT connection 916 may transfer both the request data and the user data. The client application 942 may interact with the user to generate the user data that it provides.
It is noted that the host computer 902, the base station 918, and the UE 914 illustrated in
In
The wireless connection 926 between the UE 914 and the base station 918 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 914 using the OTT connection 916, in which the wireless connection 926 forms the last segment. More precisely, the teachings of these embodiments may improve the e.g., data rate, latency, power consumption, etc. and thereby provide benefits such as e.g., reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc.
A measurement procedure may be provided for the purpose of monitoring data rate, latency, and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 916 between the host computer 902 and the UE 914, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 916 may be implemented in the software 910 and the hardware 904 of the host computer 902 or in the software 940 and the hardware 934 of the UE 914, or both. In some embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 916 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the software 910, 940 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 916 may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not affect the base station 918, and it may be unknown or imperceptible to the base station 918. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer 902's measurements of throughput, propagation times, latency, and the like. The measurements may be implemented in that the software 910 and 940 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 916 while it monitors propagation times, errors, etc.
Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.
While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).
Embodiment 1: A method performed by a wireless device, the method comprising one or more of: determining whether or not to use LBT for transmissions; transmitting based on the determination; determining whether or not a base station is using LBT for transmissions; and receiving transmission from the base station based on the determination.
Embodiment 2: The method of embodiment 1 wherein one or more of the determining steps is based on the configuration of the systems, device hardware capabilities, or predefined rules.
Embodiment 3: The method of any of embodiments 1-2 wherein one or more of the determining steps is based on satisfaction of one or more of the following thresholds or conditions: a. the number of antennas at the transmitter is larger than a certain threshold. The number of antennas to be considered could be the total equipped antennas or a sub-set of total antennas used for transmitting. b. the directivity of the transmissions from the transmitter is larger than a certain threshold; i. the directivity to be considered could include beamforming gain and antenna gain. ii. the beamforming gain to be considered could be long-term averaged or instantaneous; c. the transmit power or EIRP is smaller than a certain threshold. The transmit power and EIRP to be considered could be average or peak power. d. The transmit duration or duty cycle is smaller than a certain threshold. e. The scenario of network, e.g., controlled environment, or no coexistence with other networks, or no coexistence with other technologies. Input to this could be: i. Configured information in the gNB (configured through operation and maintenance means). ii. Information collected from Automatic Neighbor Relation (ANR) reports or similar reports from UEs about the presence of neighbor cells, gNBs, access points, networks, etc. in the area. iii. Information collected from centralized spectrum allocation entities.
Embodiment 4: The method of any of the previous embodiments wherein determining whether or not to use LBT for transmissions comprises transmitting without performing LBT prior to the transmission based on one or more of: a. receiving signaling from the base station, that indicates the wireless device may transmit without LBT (e.g., the indication can be based on RRC configuration or signaled via MAC-CE or DCI) E.g.: i. No LBT mode indication from base station via system information broadcasting. ii. No LBT mode activation from base station via dedicated RRC signaling (e.g., the wireless device will use no LBT mode until receiving another notification from base station or based on a timer). iii. No LBT mode activation from base station via MAC CE (e.g., the wireless device will use no LBT mode until receiving another notification from base station or based on a timer). iv. No LBT mode indication via the UL grant from base station, e.g., base station signal cat1 LBT in DCI for each transmission; b. receiving an indication regarding the conditions in which it is allowed to transmit without performing an LBT (e.g., the wireless device could operate without LBT or change from LBT to no LBT mode by itself if the above thresholds or conditions is satisfied. For instance, the wireless device is RRC configured with those thresholds or conditions. Embodiment 5: The method of any of embodiments 1-4 wherein one or more of the determining steps is based on the collision rates or unsuccessful transmission rate of the DL or/and UL transmissions observed over a certain period.
Embodiment 6: The method of embodiment 5 wherein, if the base station/wireless device counts the number of NACK over an observation period is larger than a certain threshold, it will change from no LBT to LBT mode.
Embodiment 7: The method of any of embodiments 1-6 wherein one or more of the determining steps comprises: measuring the ACK/NACK ratio over a period of time and trying to keep it at a particular target (e.g., 10%) using a control loop (e.g., if ACK/NACK ratio is larger than the target, LBT mode is used; Otherwise, no LBT mode is used).
Embodiment 8: The method of any of embodiments 1-7 wherein one or more of the determining steps comprises: determining based on the current or typical situation of aspects impacting interference between nodes and devices in the area, e.g., the number active wireless devices in the base station's cell (and neighbor cell), the traffic load measured by one or more metrics, e.g., the packet arrival rate, and so on).
Embodiment 9: The method of any of embodiments 1-8 wherein one or more of the determining steps comprises: determining based on the SINR of the uplinks for the wireless devices being served by the base station.
Embodiment 10: The method of any of embodiments 1-9 wherein one or more of the determining steps comprises: determining based on the SINR of the downlink from the base station (e.g., if the SINR is lower than a certain threshold, LBT mode is used).
Embodiment 11: The method of any of embodiments 1-10 wherein the modulation and coding rate (MCS) is jointly chosen together with the LBT mode.
Embodiment 12: The method of any of embodiments 1-11 wherein one or more of the determining steps comprises: taking into account the latency requirement of the data to be sent.
Embodiment 13: The method of any of embodiments 1-12 wherein one or more of the determining steps comprises: determining based at least in part on base station declaration of radio link failure.
Embodiment 14: The method of any of embodiments 1-13 wherein one or more of the determining steps comprises: determining based at least in part on its declaration of layer 1 control message failure (DCI and/or UCI).
Embodiment 15: The method of any of embodiments 1-14 wherein one or more of the determining steps comprises: determining based at least in part on the CSI measurement report from the wireless device.
Embodiment 16: The method of any of embodiments 1-15 wherein one or more of the determining steps comprises: determining based at least in part on wireless device declaration of radio link failure and subsequent RRC Connection Re-establishment attempts.
Embodiment 17: The method of any of embodiments 1-16 wherein one or more of the determining steps comprises: determining based on the average measured energy on the channel, i.e., the energy detected over a certain time duration where the time duration may be greater than the measurement slot sizes used in the LBT procedure.
Embodiment 18: The method of any of embodiments 1-17 wherein one or more of the determining steps comprises: determining based on the RSSI measurement on the operation channel during idle time (i.e., no active DL or UL transmission in the cell) within a certain time window (e.g., if the measured RSSI during idle time is below a certain threshold, no LBT could be used).
Embodiment 19: The method of any of embodiments 1-18 wherein one or more of the determining steps comprises: determining based on the one or a combination of more than one set of statistics from all or a subset of the active wireless devices.
Embodiment 20: The method of any of embodiments 1-19 wherein one or more of the determining steps comprises: determining based on the one or a combination of: a. a combination of more than one set of statistics; b. the receiver sensitivity measured by the received signal strength corresponding to the lowest successful MCS received from the wireless device/base station over an observation period; c. the type of transmission or signal; d. at least in part on information of how harmful interference (if any) the transmitter would cause for other devices in the area; e. information of how often the receiver fails to receive the transmission, or what SINR the receiver of the transmission experiences; f. statistics of the detected energy level; and g. performance metrics such as cell throughput, user throughput including mean and fifth percentile throughput, mean latency, fifth percentile latency etc.
Embodiment 21: The method of any of embodiments 1-20 wherein the different LBT mode could be selected for different signals.
Embodiment 22: The method of any of embodiments 1-21 wherein the LBT mode is signaled using L1 signaling.
Embodiment 23: The method of any of embodiments 1-22 wherein the base station makes sure that the wireless device UL transmissions are part of the base station's initiated COT.
Embodiment 24: The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host computer via the transmission to the base station.
Embodiment 25: A method performed by a base station, the method comprising one or more of: determining whether or not to use LBT for transmissions; transmitting based on the determination; determining whether or not a wireless device is using LBT for transmissions; and receiving transmission from the wireless device based on the determination.
Embodiment 26: The method of embodiment 25 wherein one or more of the determining steps is based on the configuration of the systems, device hardware capabilities, or predefined rules.
Embodiment 27: The method of any of embodiments 25-26 wherein one or more of the determining steps is based on satisfaction of one or more of the following thresholds or conditions: a. the number of antennas at the transmitter is larger than a certain threshold. The number of antennas to be considered could be the total equipped antennas or a sub-set of total antennas used for transmitting. b. the directivity of the transmissions from the transmitter is larger than a certain threshold; i. the directivity to be considered could include beamforming gain and antenna gain. ii. the beamforming gain to be considered could be long-term averaged or instantaneous; c. the transmit power or EIRP is smaller than a certain threshold. The transmit power and EIRP to be considered could be average or peak power. d. The transmit duration or duty cycle is smaller than a certain threshold. e. The scenario of network, e.g., controlled environment, or no coexistence with other networks, or no coexistence with other technologies. Input to this could be: i. Configured information in the gNB (configured through operation and maintenance means). ii. Information collected from Automatic Neighbor Relation (ANR) reports or similar reports from UEs about the presence of neighbor cells, gNBs, access points, networks, etc. in the area. iii. Information collected from centralized spectrum allocation entities.
Embodiment 28: The method of any of the previous embodiments wherein determining whether or not to use LBT for transmissions comprises transmitting without performing LBT prior to the transmission based on one or more of: a. receiving signaling from the base station, that indicates the wireless device may transmit without LBT (e.g., the indication can be based on RRC configuration or signaled via MAC-CE or DCI) E.g.: i. No LBT mode indication from base station via system information broadcasting. ii. No LBT mode activation from base station via dedicated RRC signaling (e.g., the wireless device will use no LBT mode until receiving another notification from base station or based on a timer). iii. No LBT mode activation from base station via MAC CE (e.g., the wireless device will use no LBT mode until receiving another notification from base station or based on a timer). iv. No LBT mode indication via the UL grant from base station, e.g., base station signal cat1 LBT in DCI for each transmission; b. receiving an indication regarding the conditions in which it is allowed to transmit without performing an LBT (e.g., the wireless device could operate without LBT or change from LBT to no LBT mode by itself if the above thresholds or conditions is satisfied. For instance, the wireless device is RRC configured with those thresholds or conditions.
Embodiment 29: The method of any of embodiments 25-28 wherein one or more of the determining steps is based on the collision rates or unsuccessful transmission rate of the DL or/and UL transmissions observed over a certain period.
Embodiment 30: The method of embodiment 29 wherein, if the base station/wireless device counts the number of NACK over an observation period is larger than a certain threshold, it will change from no LBT to LBT mode.
Embodiment 31: The method of any of embodiments 25-30 wherein one or more of the determining steps comprises: measuring the ACK/NACK ratio over a period of time and trying to keep it at a particular target (e.g., 10%) using a control loop (e.g., if ACK/NACK ratio is larger than the target, LBT mode is used; Otherwise, no LBT mode is used).
Embodiment 32: The method of any of embodiments 25-31 wherein one or more of the determining steps comprises: determining based on the current or typical situation of aspects impacting interference between nodes and devices in the area, e.g., the number active wireless devices in the base station's cell (and neighbor cell), the traffic load measured by one or more metrics, e.g., the packet arrival rate, and so on).
Embodiment 33: The method of any of embodiments 25-32 wherein one or more of the determining steps comprises: determining based on the SINR of the uplinks for the wireless devices being served by the base station.
Embodiment 34: The method of any of embodiments 25-33 wherein one or more of the determining steps comprises: determining based on the SINR of the downlink from the base station (e.g., if the SINR is lower than a certain threshold, LBT mode is used).
Embodiment 35: The method of any of embodiments 25-34 wherein the modulation and coding rate (MCS) is jointly chosen together with the LBT mode.
Embodiment 36: The method of any of embodiments 25-35 wherein one or more of the determining steps comprises: taking into account the latency requirement of the data to be sent.
Embodiment 37: The method of any of embodiments 25-36 wherein one or more of the determining steps comprises: determining based at least in part on base station declaration of radio link failure.
Embodiment 38: The method of any of embodiments 25-37 wherein one or more of the determining steps comprises: determining based at least in part on its declaration of layer 1 control message failure (DCI and/or UCI).
Embodiment 39: The method of any of embodiments 25-38 wherein one or more of the determining steps comprises: determining based at least in part on the CSI measurement report from the wireless device.
Embodiment 40: The method of any of embodiments 25-39 wherein one or more of the determining steps comprises: determining based at least in part on wireless device declaration of radio link failure and subsequent RRC Connection Re-establishment attempts.
Embodiment 41: The method of any of embodiments 25-40 wherein one or more of the determining steps comprises: determining based on the average measured energy on the channel, i.e., the energy detected over a certain time duration where the time duration may be greater than the measurement slot sizes used in the LBT procedure.
Embodiment 42: The method of any of embodiments 25-41 wherein one or more of the determining steps comprises: determining based on the RSSI measurement on the operation channel during idle time (i.e., no active DL or UL transmission in the cell) within a certain time window (e.g., if the measured RSSI during idle time is below a certain threshold, no LBT could be used).
Embodiment 43: The method of any of embodiments 25-42 wherein one or more of the determining steps comprises: determining based on the one or a combination of more than one set of statistics from all or a subset of the active wireless devices.
Embodiment 44: The method of any of embodiments 25-43 wherein one or more of the determining steps comprises: determining based on the one or a combination of: a. a combination of more than one set of statistics; b. the receiver sensitivity measured by the received signal strength corresponding to the lowest successful MCS received from the wireless device/base station over an observation period; c. the type of transmission or signal; d. at least in part on information of how harmful interference (if any) the transmitter would cause for other devices in the area; e. information of how often the receiver fails to receive the transmission, or what SINR the receiver of the transmission experiences; f. statistics of the detected energy level; and g. performance metrics such as cell throughput, user throughput including mean and fifth percentile throughput, mean latency, fifth percentile latency etc.
Embodiment 45: The method of any of embodiments 25-44 wherein the different LBT mode could be selected for different signals.
Embodiment 46: The method of any of embodiments 25-45 wherein the LBT mode is signaled using L1 signaling.
Embodiment 47: The method of any of embodiments 25-46 wherein the base station makes sure that the wireless device UL transmissions are part of the base station's initiated COT.
Embodiment 48: The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host computer or a wireless device.
Embodiment 49: A wireless device, the wireless device comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the wireless device.
Embodiment 50: A base station, the base station comprising: processing circuitry configured to perform any of the steps of any of the Group B embodiments; and power supply circuitry configured to supply power to the base station.
Embodiment 51: A User Equipment, UE, the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.
Embodiment 52: A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a User Equipment, UE; wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station's processing circuitry configured to perform any of the steps of any of the Group B embodiments.
Embodiment 53: The communication system of the previous embodiment further including the base station.
Embodiment 54: The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.
Embodiment 55: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application.
Embodiment 56: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs any of the steps of any of the Group B embodiments.
Embodiment 57: The method of the previous embodiment, further comprising, at the base station, transmitting the user data.
Embodiment 58: The method of the previous 2 embodiments, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application.
Embodiment 59: A User Equipment, UE, configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform the method of the previous 3 embodiments.
Embodiment 60: A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward user data to a cellular network for transmission to a User Equipment, UE; wherein the UE comprises a radio interface and processing circuitry, the UE's components configured to perform any of the steps of any of the Group A embodiments.
Embodiment 61: The communication system of the previous embodiment, wherein the cellular network further includes a base station configured to communicate with the UE.
Embodiment 62: The communication system of the previous 2 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE's processing circuitry is configured to execute a client application associated with the host application.
Embodiment 63: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the UE performs any of the steps of any of the Group A embodiments.
Embodiment 64: The method of the previous embodiment, further comprising at the UE, receiving the user data from the base station.
Embodiment 65: A communication system including a host computer comprising: communication interface configured to receive user data originating from a transmission from a User Equipment, UE, to a base station; wherein the UE comprises a radio interface and processing circuitry, the UE's processing circuitry configured to perform any of the steps of any of the Group A embodiments.
Embodiment 66: The communication system of the previous embodiment, further including the UE.
Embodiment 67: The communication system of the previous 2 embodiments, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station.
Embodiment 68: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE's processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.
Embodiment 69: The communication system of the previous 4 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and the UE's processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.
Embodiment 70: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, receiving user data transmitted to the base station from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.
Embodiment 71: The method of the previous embodiment, further comprising, at the UE, providing the user data to the base station.
Embodiment 72: The method of the previous 2 embodiments, further comprising: at the UE, executing a client application, thereby providing the user data to be transmitted; and at the host computer, executing a host application associated with the client application.
Embodiment 73: The method of the previous 3 embodiments, further comprising: at the UE, executing a client application; and at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application; wherein the user data to be transmitted is provided by the client application in response to the input data.
Embodiment 74: A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a User Equipment, UE, to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station's processing circuitry configured to perform any of the steps of any of the Group B embodiments.
Embodiment 75: The communication system of the previous embodiment further including the base station.
Embodiment 76: The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.
Embodiment 77: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.
Embodiment 78: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.
Embodiment 79: The method of the previous embodiment, further comprising at the base station, receiving the user data from the UE.
Embodiment 80: The method of the previous 2 embodiments, further comprising at the base station, initiating a transmission of the received user data to the host computer.
At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).
Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.
This application claims the benefit of provisional patent application Ser. No. 63/065,945, filed Aug. 14, 2020, the disclosure of which is hereby incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/072637 | 8/13/2021 | WO |
Number | Date | Country | |
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63065945 | Aug 2020 | US |