Patent Application
20230413320
The present disclosure relates to Channel Occupancy Time (COT) sharing in a cellular communications system.
Ultra-Reliable and Low Latency Communication (URLLC) is one of the main use cases of Third Generation Partnership Project (3GPP) Fifth Generation (5G) New Radio (NR). URLLC has strict requirements on transmission reliability and latency, i.e., 99.9999% reliability within 1 millisecond (ms) one-way latency. In NR Release 15, several new features and enhancements were introduced to support these requirements. In Release 16, standardization works are focused on further enhancing URLLC system performance as well as ensuring reliable and efficient coexistence of URLLC and other NR use cases. One example scenario is when both enhanced Mobile Broadband (eMBB) and URLLC User Equipments (UEs) co-exist in the same cell. Here, mainly two approaches have been identified to support multiplexing/prioritization.
In addition to operation in licensed bands, NR has been enhanced in 3GPP Release 16 (RP-190706, Revised WID on NR-based Access to Unlicensed Spectrum) to allow operation in unlicensed bands, i.e., NR-Unlicensed (NR-U). Allowing unlicensed networks, i.e., networks that operate in unlicensed or shared spectrum to effectively use the available spectrum is an attractive approach to increase system capacity. For convenience, the term “unlicensed spectrum” is used to refer to both unlicensed and shared spectrum.
Although it is more challenging to match the qualities of the licensed regime on unlicensed spectrum, solutions that allow an efficient use of it as a complement to licensed deployments have the potential to bring great value to the 3GPP operators, and, ultimately, to the 3GPP industry as a whole. Some features in NR need to be adapted to comply with the special characteristics of the unlicensed band as well as also different regulations. Further, if a UE intends to use unlicensed spectrum, it may employ Clear Channel Assessment (CCA) schemes to find out whether the channel is free or not over a certain period. One such technique is Listen Before Talk (LBT). There are many different flavors of LBT, depending on which channel access mode the device uses and which type of data it wants to transmit in the upcoming transmission opportunity, referred to as channel occupancy time (COT). Common for all flavors is that the sensing is done in a particular channel (corresponding to a defined carrier frequency) and over a predefined bandwidth. Further, two modes of access operations are defined—Frame-Based Equipment (FBE) and Load-Based Equipment (LBE). In FBE mode, the sensing period is simple, while the sensing scheme in LBE mode is more complex.
In FBE mode as defined in 3GPP Release 16 and illustrated in
In each FFP, DL/UL transmissions are only allowed within a subset of FFP time resource, where the remaining time at the end of the FFP is reserved so that other nodes also have the chance to sense and utilize the channel. The reserved time at the end of each FFP is referred to as an IDLE period.
This procedure can be repeated with a certain periodicity. Hence in FBE operation, the channel is sensed at specific intervals just before the FFP boundary. The FFP can be set to values between 1 and 10 milliseconds (ms) and can be changed after a minimum of 200 ms. The IDLE period is a regulatory requirement and is supposed to be at least TIDLE≥max(0.05*COT, 100 μμs). In 3GPP Technical Specification (TS) 37.213, this has been simplified to be T IDLE >max(0.05*FFP, 100 μs), i.e. the maximum channel occupancy time (MCOT) would be defined as TMCOT=min(0.95*FFP, FFP−0.1 ms). So for 10 ms FFP, the MCOT would be 9.5 ms, while for 1 ms FFP the MCOT would be 0.9 ms=0.9*FFP.
The FBE mode supported in Release 16 is referred to as “gNB-initiated COT” where a DL transmission at the beginning of an FFP determines that that FFP before the corresponding idle period can be used by gNB and UE for DL and UL transmissions, respectively. In this manner, gNB is “initiating” the COT, and UEs are “sharing” the COT that is initiated by gNB.
In Release 17, 3GPP supports “UE-initiated COT” in addition to gNB-initiated COT. The details of the procedure are under discussion while the same principle as gNB initiated COT is applicable. That implies that a UE would be associated with an FFB that might be the same or different from the gNB FFP. If the UE transmits a UL transmission at the beginning of FFP after successfully sensing the channel for 9 μs, the UE has initiated a COT in that FFP that can be shared with gNB.
The default LBT mechanism for LBE operation, LBT category 4, provides dynamic channel occupancy. More specifically, LBT category 4 is similar to existing Wi-Fi operation, where a node can sense the channel at any time and start transmitting if the channel is free after a deferral and backoff period. For specific cases, e.g. shared COT, other LBT categories allowing a very short sensing period are allowed.
In regard to LBT channels in wideband operation mode, there are different wideband operation modes. The nodes perform LBT on a certain bandwidth referred to as an “LBT channel”, which are up to 20 Megahertz (MHz). The transmission bandwidth is therefore also limited by the LBT bandwidth. The channels can however be aggregated in wideband operation modes using either carrier aggregation or using one wideband carrier which is divided into several so-called resource block sets, RB sets. An RB set is also referred to as an LBT bandwidth or LBT subband. In either mode, the LBT can be performed according to one of the following procedures: (1) independent category 4 (CAT4) LBT on each of the carriers, (2) CAT4 LBT on the primary carrier and sensing for a fixed CCA on the remaining carriers just before the end of the CAT4 LBT on the primary carrier.
Same as in NR, a UE in NR-U can be semi-statically scheduled for uplink transmission based on Type 1 or Type 2 configured grant (CG). There have been specific enhancements in configured grant related to time-domain resource allocation, configured grant Uplink Control Information (CG-UCI), and autonomous uplink (AUL) transmission.
In NR-U, a new timer is introduced named as CG re-transmission timer (CGRT). This timer can be used for AUL. There is also another timer configuredGrantTimer (CGT). CGT limits maximum AUL retransmission attempts for a Hybrid Automatic Repeat Request (HARQ) process. When the CGT expires, the UE should flush the HARQ buffer for this HARQ process and transmit new data associated to it. An example is illustrated in
As stated 3GPP TS 38.321 V16.0.0, Section 5.8.2, there are three types of transmission without dynamic grant:
HARQ Process ID=[floor(CURRENT_symbol/periodicity)]modulo nrofHARQ-Processes
HARQ Process ID=[floor(CURRENT_symbol/periodicity)]modulo nrofHARQ-Processes+harq-ProcID-Offset2
CG-UCI is included in every CG Physical Uplink Shared Channel (CG-PUSCH) transmission and includes the information listed in Table 1. CG-UCI is mapped as per Release 15 rules with CG-UCI having the highest priority. It is mapped on the symbols starting after first Demodulation Reference Signal (DMRS) symbol. To determine the number of Resource Elements (REs) used for CG-UCI, the mechanism of beta-offset in Release 15 NR for HARQ Acknowledgment (HARQ-ACK) on CG-PUSCH is reused. Nonetheless, a new Radio Resource Control (RRC) configured beta-offset for CG-UCI is defined.
If CG-PUSCH resources overlap with Physical Uplink Control Channel (PUCCH) carrying Channel State Information (CSI)-part 1 and/or CSI-part 2, the later can be sent on CG-PUSCH. RRC configuration can be provided to the UE indicating whether to multiplex CG-UCI and HARQ-ACK. If configured, in the case of PUCCH overlapping with CG-PUSCH(s) within a PUCCH group, the CG-UCI and HARQ-ACK are jointly encoded as one UCI type. Otherwise, configured grant PUSCH is skipped if CG-PUSCH overlaps with PUCCH that carries HARQ ACK feedback.
To reduce the signaling overhead corresponding to explicit feedback transmission, NR-U supports an enhanced Downlink Control Information (DCI) format 0_1 for indicating downlink feedback information (“CG-DFI”) that carries a HARQ-ACK bitmap for all UL HARQ processes from the same UE. Additionally, the gNB may trigger an adaptive retransmission using a dynamic grant.
In Section 6.1 in specification 38.214 V 16.1.0, it is stated that
In regard to DL preemption in NR, once DL URLLC data appears in a buffer, a base station should choose the earliest moment of time when resources can be normally allocated without colliding with the resources allocated for an already ongoing downlink transmission for the corresponding UE. This may be either in the beginning of the slot or a mini-slot where the mini-slot can start at any Orthogonal Frequency Division Multiplexing (OFDM) symbol. Hence, downlink pre-emption may happen when long term allocation(s) (e.g., slot based) occupy resources (particularly wideband resources) and there is no room for URLLC data transmission, typically supported using a mini-slot. In this case, a scheduler can send DCI to the UE for which the URLLC data is intended and thereby inform the UE that an override (pre-emption) has been triggered for the ongoing transmission in downlink When an eMBB DL transmission is pre-empted, the pre-empted part of the original message pollutes the soft buffer (only noise/interference is received). It is therefore important (though not required by the standard) to flush the affected bits from the soft buffer to increase the decodability of the eMBB data at the UE. If not, the pre-empted bits may negatively impact decoding in retransmissions, which will likely happen. Release 15 allows DCI based indication of the DL pre-emption by explicit signaling, which is carried either:
Option 1 gives an indication as a 14-bit bitmap, which addresses reference downlink resource domains in between two pre-emption indication (PI) messages. The reference resource is configured by RRC, where the highest resolution of this signaling in time is 1 OFDM symbol and in frequency is half of the BWP (Bandwidth Part), but not at the same time. The longer the periodicity of messages, the coarser the resolution. The group common DCI format 2_1 indicates which part of the configured reference resource is preempted. Since this is a group common signaling, all UEs within the BWP may read it.
Option 2 is a user specific way of signaling. The HARQ retransmission DCI, which contains a set of CB/CBGs, may have a special bit to indicate that the UE must overwrite existing bits in the soft buffer (do not combine) by retransmitted CB/CBGs soft bits. In this case, the gNB is responsible for determination of a subset of CB/CBGs which needs to be flushed before the soft-combining process. This option is not considered further in the present disclosure.
In Release 16, two methods are adopted to enable inter-UE UL cancellation (aka, pre-emption) in NR.
The first method is based on power control to increase the power of the URLLC to make it more resilient to interference from the eMBB user(s). Additional power control for Release 16 UEs are specified in 3GPP TS 38.213, Section 7.1.1. The main advantage with this option is that it does not require any changes in the behavior of the eMBB UE; hence it works with Release 15 UEs. One disadvantage is that to guarantee the performance of the URLLC UE while being interfered by eMBB traffic, the transmit power spectral density (PSD) may have to be increased significantly which can cause interference to other cells. Also, UEs not in the close vicinity of the gNB may not have the power budget to do this increase and will therefore experience much lower Signal to Interference and Noise Ratio (SINR) than the required.
The second method is based on a cancellation indicator being transmitted from the gNB to the interfering eMBB UEs. When a URLLC UE is scheduled on time/frequency resources that are already scheduled to a lower priority eMBB UE, the gNB can transmit a cancellation indicator to the eMBB UE. Upon reception of this indicator, the eMBB UE will avoid transmitting on a set of indicated resources. The details of the cancellation indicator and the UE behavior upon reception of this signal is specified in 3GPP TS 38.213.
The mechanism for UL cancellation indication (CI) includes a reference time-frequency region that is configured for the UE by RRC signaling, and a DCI that indicates parts of the configured resources within which the transmission should be cancelled. The reference time-frequency region is also referred to as “reference resource”, RR. The size of the cancellation indication DCI as well as the time domain granularity are configurable. The frequency domain granularity can then be determined from the total bit field size and the time domain granularity.
A typical use case for this is when eMBB traffic is scheduled in a whole slot and all Physical Resource Blocks (PRBs) and time sensitive URLLC needs to be transmitted. Here, time sensitive means that it requires instant access to the channel and waiting until the next slot before transmission will introduce too much delay. In NR, URLLC traffic may be scheduled on one or a few OFDM symbols and with a significantly shorter time from the uplink grant to when the uplink transmission takes place. This means that eMBB users may already have been scheduled on all available time/frequency resources. With the cancellation indicator the gNB can choose to cancel the eMBB traffic and hence reduce the interference to the URLLC UE.
Systems and methods are disclosed that relate to transmission by a radio node having an opportunity to use any of multiple Channel Occupancy Times (COTs). In one embodiment, a method performed by a radio node comprises determining, for a particular transmission, that the radio node has an opportunity to use either of two COTs consisting of a base station initiated COT and a wireless device initiated COT. The method further comprises, responsive to determining that the radio node has an opportunity to use either of the two COTs, selecting) a particular COT from among the two COTs to be used for the particular transmission. The method further comprises determining that an idle period associated to the particular COT is a valid idle period in which no transmissions to or from the radio node are to occur. In this manner, non-deterministic behavior when the radio node has the opportunity to transmit on multiple COTs is avoided.
In one embodiment, selecting the particular COT from among the two COTs comprises selecting the particular COT from among the two COTs based on one or more predefined rules. In one embodiment, the one or more predefined rules comprise a rule that is based on priority of the two COTs relative to one another.
In one embodiment, the radio node is a wireless communication device, and the method further comprises receiving information from a base station that indicates the priority of the base station initiated COT relative to that of the wireless device initiated COT. In one embodiment, receiving the information comprises receiving the information via: downlink control information (DCI), downlink (DL) semi-persistent scheduling (SPS) activation or release DCI, radio resource control (RRC) configuration, a new DCI signaling to indicate changes in COT priority, physical downlink shared channel (PDSCH), or system information block (SIB) signaling. In one embodiment, the rule that is based on the priority of the two COTs relative to one other is a rule that a highest priority COT of the two COTs is to be considered by the radio node first when the radio node has an opportunity to use either of the two COTs. In one embodiment, the rule is further that a lowest priority COT of the two COTs is to be considered by the radio node only if the idle period associated to the highest priority COT occurs during the particular transmission.
In one embodiment, the radio node is a wireless communication device, the particular transmission is an uplink transmission, and the one or more rules comprise a rule that if the uplink transmission starts at a beginning of an Fixed Frame Period (FFP) associated to the wireless communication device and ends before an idle period associated to the FFP, the wireless device initiated COT is to be selected or considered first for the particular transmission.
In one embodiment, the radio node is a wireless communication device, the particular transmission is an uplink transmission, and the one or more rules comprise a rule that if the uplink transmission starts at a beginning of a FFP associated to a base station associated to the base station initiated COT and ends before an idle period associated to the FFP and the wireless communication device has already determined that the base station initiated COT is initiated, the base station initiated COT is to be selected or considered first for the particular transmission.
In one embodiment, the radio node is a wireless communication device, the particular transmission is a downlink transmission, and the one or more rules comprise a rule that if the downlink transmission starts within a FFP associated to a base station associated to the base station initiated COT and ends before an idle period associated to the FFP, the base station initiated COT is to be selected or considered first for the particular transmission.
In one embodiment, the radio node is a wireless communication device, the particular transmission is a second uplink transmission that is subsequent to a first uplink transmission associated to the wireless device initiated COT in a Fixed FFP, and the one or more rules comprise a rule that the second uplink transmission is also associated to the wireless device initiated COT if the second uplink transmission ends before an idle period of the FFP.
In one embodiment, the radio node is a wireless communication device, the particular transmission is a second uplink transmission that is subsequent to a first uplink transmission associated to the base station initiated COT in a FFP, and the one or more rules comprise a rule that the second uplink transmission is also associated to the base station initiated COT if the second uplink transmission ends before an idle period of the FFP.
In one embodiment, the radio node is a wireless communication device, the particular transmission is an uplink transmission, and selecting the particular COT from among the two COTs comprises selecting the particular COT from among the two COTs autonomously. In one embodiment, the method further comprises sending, to a base station associated to the base station initiated COT, information that indicates a priority of the two COTs relative to one another.
In one embodiment, the radio node is a wireless communication device, and the method further comprises choosing the priority of the two COTs relative to one another. In one embodiment, choosing the priority of the two COTs relative to one another comprises choosing the priority of the two COTs relative to one another based on a rule. In one embodiment, choosing the priority of the two COTs relative to one another comprises choosing the priority of the two COTs relative to one another based on durations of respective idle periods for the two COTs.
In one embodiment, the radio node is a wireless communication device, and the wireless communication device is configured with two or more FFPs. In one embodiment, idle periods from one or more FFPs of a base station and idle periods of the two or more FFPs of the wireless communication device are excluded from a downlink preemption resource and/or an uplink cancellation reference resource. In one embodiment, idle periods from the two or more FFPs of the wireless communication device are included in a downlink preemption resource and/or an uplink cancellation reference resource. In one embodiment, idle periods from one or more FFPs of a base station, but not idle periods of the two or more FFPs of the wireless communication device, are excluded from a downlink preemption resource and/or an uplink cancellation reference resource.
In one embodiment, the radio node is a wireless communication device, the particular transmission is an uplink transmission, and selecting the particular COT comprises selecting the particular COT from among the two COTs to be used for the uplink transmission based on an uplink transmission type of the UL transmission.
In one embodiment, the radio node is a wireless communication device, the particular transmission is an uplink transmission, and selecting the particular COT comprises selecting the particular COT from among the two COTs to be used for the uplink transmission based on one or more time-domain characteristics of the uplink transmission.
In one embodiment, the radio node is a wireless communication device, the particular transmission is an uplink transmission, and selecting the particular COT comprises selecting the particular COT from among the two COTs to be used for the uplink transmission based on an importance of the uplink transmission.
In one embodiment, the method further comprises transmitting or receiving the particular transmission in the particular COT.
In one embodiment, the radio node is a wireless communication device.
In one embodiment, the radio node is a base station.
Corresponding embodiments of a wireless communication device are also disclosed. In one embodiment, a wireless communication device comprises one or more transmitters, one or more receivers, and processing circuitry associated with the one or more transmitters and the one or more receivers. The processing circuitry is configured to cause the wireless communication device to determine, for a particular transmission, that the radio node has an opportunity to use either of two COTs consisting of a base station initiated COT and a wireless device initiated COT. The processing circuitry is further configured to cause the wireless communication device to, responsive to determining that the radio node has an opportunity to use either of the two COTs, select a particular COT from among the two COTs to be used for the particular transmission. The processing circuitry is further configured to cause the wireless communication device to determine that an idle period associated to the particular COT is a valid idle period in which no transmissions to or from the radio node are to occur.
Corresponding embodiments of a base station are also disclosed. In one embodiment, a base station comprises processing circuitry configured to cause the base station to determine, for a particular transmission, that the radio node has an opportunity to use either of two COTs consisting of a base station initiated COT and a wireless device initiated COT. The processing circuitry is further configured to cause the base station to, responsive to determining that the radio node has an opportunity to use either of the two COTs, select a particular COT from among the two COTs to be used for the particular transmission. The processing circuitry is further configured to cause the base station to determine that an idle period associated to the particular COT is a valid idle period in which no transmissions to or from the radio node are to occur.
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.
Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.
Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will be apparent from the following description.
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.
There currently exist certain challenge(s). In 3GPP Release 16, a UE transmits in a gNB initiated Channel Occupancy Time (COT). 3GPP has agreed to add another possibility with UE-initiated COT in Release 17. When these COTs are available, the UE and the gNB each has the possibility to transmit in either COT, either by initiating a COT or sharing an initiated COT. Each COT is associated to a Fixed Frame Period (FFP) including an idle period. Based on the following 3GPP agreement, if a UE or gNB initiates or shares a COT for a transmission, the UE or gNB is not allowed to transmit in the idle period of the FFP associated to that COT.
When there are overlapping FFPs, a downlink (DL) or uplink (UL) transmission can occur in a gNB initiated COT or a UE initiated COT or both. In case the DL or UL transmission occurs in either a gNB initiated COT or a UE initiated COT, there would be a valid idle period following up the transmission based on the agreement above where the idle period would not include any DL or UL transmission, respectively. In case the DL or UL transmission occurs in both gNB initiated COT and UE initiated COT, there would be two idle periods following up the transmission based on the agreement above, while only one of the idle periods should be considered the valid idle period where the valid idle period would not include any DL or UL transmission, respectively.
Therefore, multiple candidates for a valid idle period can lead to non-deterministic behavior unless a rule is devised for a transmission in a COT when a UE has the possibility to transmit in multiple COTs.
Another problem is ambiguity in puncturing/cancellation/preemption when a UE has multiple COTs at its disposal. The UE can be configured with UL cancellation and DL preemption reference regions for the puncturing/cancellation/preemption where a previously scheduled lower-priority transmission of a UE is preempted/cancelled/punctured by some other higher-priority transmission of different UE. Therefore, to support preemption, the reference region must exclude the invalid symbols, e.g., for UL reference region, it must exclude DL symbols or some reference signaling resources, and vice-versa for DL reference region [Section 11.2, 11.2A, 3GPP TS 38.213, see below, the quoted text]. Furthermore, if a UE has only one FFP/COT available, then the idle period is excluded from the reference region (for both UL and DL preemption). However, when multiple FFPs/COTs are available, then some idle periods cannot be deemed invalid, and thus require new treatment for the idle periods which are valid in defining reference region for UL/DL preemption.
Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. For a UL or DL transmission, a UE or gNB may respectively have the opportunity to transmit in either of a gNB-initiated COT and a UE-initiated COT. In the description below, rules are provided based on which the UE or gNB selects a COT for its UL or DL transmission, respectively. When a UE-initiated COT or a gNB initiated COT is selected, the idle period ending the FFP associated to that COT is considered as the valid idle period.
Certain embodiments may provide one or more of the following technical advantage(s). When multiple COTs are available to a node, the transmission in COT based on some rule helps to eliminate non-deterministic behavior.
The base stations 402 and the low power nodes 406 provide service to wireless communication devices 412-1 through 412-5 in the corresponding cells 404 and 408. The wireless communication devices 412-1 through 412-5 are generally referred to herein collectively as wireless communication devices 412 and individually as wireless communication device 412. In the following description, the wireless communication devices 412 are oftentimes UEs, but the present disclosure is not limited thereto.
Now, a description of embodiments of the present disclosure will be provided. For this description, the base stations 402 are gNBs and, as such, are sometimes referred to as gNBs 402. Similarly, the wireless communication devices 412 are UEs and, as such, are sometimes referred to as UEs 412.
For a UL or DL transmission, a UE 412 or gNB 402 may respectively have the opportunity to transmit in either of a gNB-initiated COT and a UE-initiated COT. In the description below, rules are provided based on which the UE 412 or gNB 402 selects a COT for its UL or DL transmission, respectively. When a UE-initiated COT or a gNB-initiated COT is selected, the idle period ending the FFP associated to that COT is considered as the valid idle period.
In one option, if the UE 412 has the opportunity to transmit in both a gNB-initiated COT and a UE-initiated COT, the UE 412 always considers first to transmit in the UE-initiated COT. If the UE-initiated COT has an idle period during its intended UL transmission, the UE 412 then considers the gNB-initiated COT in case the COT period is valid (i.e., no idle period in gNB-initiated COT). In other words, the UE-initiated COT is always prioritized over the gNB-initiated COT for UL transmission, unless the intended UL transmission is not possible in the UE-initiated COT.
In one option, if the UE 412 has the opportunity to transmit in both a gNB-initiated COT and a UE-initiated COT, the UE 412 always considers first to transmit in the gNB-initiated COT. If the gNB-initiated COT has an idle period during its intended UL transmission, the UE 412 then considers the UE-initiated COT in case the COT period is valid (i.e., no idle period in UE-initiated COT). In other words, the gNB-initiated COT is always prioritized over the UE-initiated COT for UL transmission, unless the intended UL transmission is not possible in the gNB-initiated COT.
In one option, the gNB 402 communicates the priority of the COT (between gNB-initiated COT and UE-initiated COT) for an UL transmission or DL transmission in case the UE 412 has the opportunity to transmit in both a gNB-initiated COT and a UE-initiated COT. The gNB 412 can communicate this priority using any of following non-limiting options:
For example, if the gNB 402 communicates to the UE 412 an indication that a UE-initiated COT is prioritized in a DCI, then the UE 412 always considers first to transmit in a UE-initiated COT. If the idle period corresponding to the UE-initiated COT occurs during the intended UL transmission, the UE 412 then considers the gNB-initiated COT in case the UL transmission during the COT is valid and not occurring during the corresponding idle period in the gNB-initiated COT. In other words, the UE-initiated COT is always prioritized over gNB-initiated COT for UL transmission.
In one option, the gNB 412 indicates by DCI for a scheduled UL transmission or a DL transmission whether gNB-initiated COT or UE-initiated COT is applicable.
In one option, if a UL transmission with or without scheduling DCI starts at the beginning of an FFP associated to the UE 412 and ends before the idle period corresponding to that FFP, the UE 412 assumes UE-initiated COT for the UL transmission and does not transmit any UL transmission in the corresponding idle period. In another example, if a UL transmission with or without scheduling DCI starts within an FFP associated to the gNB 402 and ends before the idle period corresponding to that FFP and the UE 412 has already determined that the gNB initiated COT is initiated, the UE 412 assume gNB-initiated COT for the UL transmission and does not transmit any UL transmission or expect to receive any DL transmission in the corresponding idle period.
In one option, if a DL transmission with or without scheduling DCI starts within an FFP associated to the gNB 412 and ends before the idle period corresponding to that FFP, the UE 412 assumes gNB-initiated COT for the DL transmission and is not expecting any DL transmission in the corresponding idle period.
In one option, if a first UL transmission is associated to the UE initiated COT in an FFP, a second UL transmission ending before the idle period of that FFP is also associated to the UE initiated COT, and the UE 412 does not transmit any UL in the corresponding idle period. In another example, if a first UL transmission is associated to the gNB initiated COT in an FFP, a second UL transmission ending before the idle period of that FFP is also associated to the gNB initiated COT, and the UE 412 does not transmit any UL transmission or expect to receive any DL transmission in the corresponding idle period.
In one option, if a first UL transmission is associated to the UE initiated COT in an FFP, a second UL transmission starting in that FFP scheduled by a DCI can be indicated with gNB initiated COT for the second UL transmission, and the UE 412 does not transmit any UL transmission or expect to receive any DL transmission in the corresponding idle period. In another example, if a first UL transmission is associated to the gNB initiated COT in an FFP, a second UL transmission starting in that FFP scheduled by a DCI can be indicated by the DCI indicating UE initiated COT for the second UL transmission, and the UE 412 does not transmit any UL transmission in the corresponding idle period.
In one option, the UE 412 chooses the COT priority autonomously (between gNB-initiated COT and UE-initiated COT) for an UL transmission.
In another option, if the UE 412 chooses the COT priority autonomously (between gNB-initiated COT and UE-initiated COT) for an UL transmission, the UE 412 indicates the priority to the gNB 402 (e.g., in an Uplink Control Information (UCI), e.g., CG-UCI).
In one option, the UE 412 chooses the COT priority between gNB-initiated COT and UE-initiated for an UL transmission based on some implicit rule (in agreement with gNB 402). For example, the UE 412 always prefer to transmit in the COT having a lesser amount idle period (i.e., a smaller idle period) when both COTs are available for transmission.
In one option, if a COT is prioritized, the prioritization would uphold for a certain time period/counter. After that time expires, the UE 412 is provided a new update with the priority among the COTs (between gNB-initiated COT and UE-initiated COT).
In one option, the UE 412 can send a request (e.g., via UCI) for COT priority from gNB 402. The request (e.g., UCI including the request) can be sent on Physical Uplink Control Channel (PUCCH) or multiplexed with PUSCH.
In one option, the UE 412 can be configured/allocated with multiple FFPs (UE-FFPs), and therefore different priorities can be configured or set for among all FFPs (multiple UE-FFPs and gNB-FFP). All the above options (UE is allocated with one UE-FFP) can be reproduced here.
In one option, both idle periods (from gNB-FFP and UE-FFP) are excluded from DL preemption reference resource, and UL cancellation reference resource. This is in extension to a known solution, where only one FFP (gNB-FFP) is considered.
In one option, if both FFPs are configured for the UE 412, then both idle periods (from gNB-FFP and UE-FFP) are included in DL preemption reference resource, and UL cancellation reference resource. This is because the gNB 402 may not know at a point of time where the UE 412 is utilizing gNB-FFP or UE-FFP.
In one option, if both FFPs are configured for the UE 412, then the idle period of gNB-FFP only is deemed invalid and thus excluded from DL preemption reference resource and UL cancellation reference resource. This is because the gNB 402 has greater control over gNB-FFP than UE-FFP (as it's initiated by the UE 412), and thus the gNB 412 perhaps interested in not sending DL preemption indicator or UL cancellation indication in the idle period of its FFP, i.e., gNB-FFP.
In another embodiment, the option of following gNB-initiated COT or UE-initiated COT depends on the UL transmission type. The UL transmission type may include: dynamically scheduled PUSCH, UL CG PUSCH, Physical Random Access Channel (PRACH), Msg3 in four-step Random Access Channel (RACH), MsgB in two-step RACH, PUCCH, or Sounding Reference Signal (SRS).
In another embodiment, the option of following gNB-initiated COT or UE-initiated COT can depend on the time-domain characteristics of the intended UL transmission.
In another embodiment, the option of following gNB-initiated COT or UE-initiated COT can depend on the urgency or importance of the UL transmission.
As discussed above, for a particular transmission (i.e., a particular UL transmission or a particular DL transmission), the radio node determines that the radio node has an opportunity to transmit or receive in either of two COTs, namely, a gNB-initiated COT and a UE-initiated COT (step 504). For example, if the radio node is the UE 412 and the particular transmission is a particular UL transmission, the UE 412 determines that the UE 412 has an opportunity to transmit the particular UL transmission in either a gNB-initiated COT or a UE-initiated COT. In other words, both a gNB-initiated COT and a UE-initiated COT are available for use.
Responsive to the determination made in step 504, the radio node selects a particular COT from among the gNB-initiated COT and the UE-initiated COT to be used for the particular transmission (step 506). The radio node then transmits or receives the particular transmission in the selected COT (step 508). The radio node also determines that an idle period associated to the selected COT is a valid idle period, as discussed above (step 510). Note that the details provided above about how the radio node selects which of the COTs to use and selects the valid idle period are equally applicable here to step 506 and 510.
In this example, functions 710 of the network node 600 described herein (e.g., one or more functions of the gNB 402 as described herein) are implemented at the one or more processing nodes 700 or distributed across the one or more processing nodes 700 and the control system 602 and/or the radio unit(s) 610 in any desired manner In some particular embodiments, some or all of the functions 710 of the network node 600 described herein (e.g., one or more functions of the gNB 402 as 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) 700. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 700 and the control system 602 may be used in order to carry out at least some of the desired functions 710. Notably, in some embodiments, the control system 602 may not be included, in which case the radio unit(s) 610 communicate directly with the processing node(s) 700 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 the network node 600 or a node (e.g., a processing node 700) implementing one or more of the functions 710 of the network node 600 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 900 according to any of the embodiments described herein (e.g., one or more functions of the UE 412 as 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 1100 is itself connected to a host computer 1116, 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 1116 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 1118 and 1120 between the telecommunication network 1100 and the host computer 1116 may extend directly from the core network 1104 to the host computer 1116 or may go via an optional intermediate network 1122. The intermediate network 1122 may be one of, or a combination of more than one of, a public, private, or hosted network; the intermediate network 1122, if any, may be a backbone network or the Internet; in particular, the intermediate network 1122 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 1200 further includes a base station 1218 provided in a telecommunication system and comprising hardware 1220 enabling it to communicate with the host computer 1202 and with the UE 1214. The hardware 1220 may include a communication interface 1222 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 1200, as well as a radio interface 1224 for setting up and maintaining at least a wireless connection 1226 with the UE 1214 located in a coverage area (not shown in
The communication system 1200 further includes the UE 1214 already referred to. The UE's 1214 hardware 1234 may include a radio interface 1236 configured to set up and maintain a wireless connection 1226 with a base station serving a coverage area in which the UE 1214 is currently located. The hardware 1234 of the UE 1214 further includes processing circuitry 1238, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The UE 1214 further comprises software 1240, which is stored in or accessible by the UE 1214 and executable by the processing circuitry 1238. The software 1240 includes a client application 1242. The client application 1242 may be operable to provide a service to a human or non-human user via the UE 1214, with the support of the host computer 1202. In the host computer 1202, the executing host application 1212 may communicate with the executing client application 1242 via the OTT connection 1216 terminating at the UE 1214 and the host computer 1202. In providing the service to the user, the client application 1242 may receive request data from the host application 1212 and provide user data in response to the request data. The OTT connection 1216 may transfer both the request data and the user data. The client application 1242 may interact with the user to generate the user data that it provides.
It is noted that the host computer 1202, the base station 1218, and the UE 1214 illustrated in
In
The wireless connection 1226 between the UE 1214 and the base station 1218 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 1214 using the OTT connection 1216, in which the wireless connection 1226 forms the last segment.
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 1216 between the host computer 1202 and the UE 1214, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1216 may be implemented in the software 1210 and the hardware 1204 of the host computer 1202 or in the software 1240 and the hardware 1234 of the UE 1214, or both. In some embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 1216 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 1210, 1240 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1216 may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not affect the base station 1218, and it may be unknown or imperceptible to the base station 1218. 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 1202's measurements of throughput, propagation times, latency, and the like. The measurements may be implemented in that the software 1210 and 1240 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1216 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.).
Some example embodiments of the present disclosure are as follows:
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. 63/093,251, filed Oct. 18, 2020, the disclosure of which is hereby incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/059586 | 10/18/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63093251 | Oct 2020 | US |
