Contention- and priority-based channel access in wireless communication networks

Abstract

The present disclosure relates to contention-based channel access to wireless channels in a shared spectrum. A method and system for incorporating priority as a factor into a contention-based channel access process is disclosed. Priority is incorporated so that a service with a higher priority can be provided with a higher probability of successfully contending for a channel in a shared spectrum via a contention-based channel access process.

Description

Technical Field

[0001] The present disclosure is directed to contention and priority-based channel access of a shared channel in a wireless communication network. Background Art

[0002] Wireless communication resources may be provided in a wireless access communication network for uplink and downlink transmission of data and control information. Such wireless communication resources may be organized as wireless channels comprising radio frequency resources and time slots. Such wireless channels may be shared by a plurality of wireless network devices and the communication services therein. Each of these wireless network devices may compete with each other for the shared channel for the transmission of data and control information corresponding to various communication services. These communication services may be associated with different levels of service priority. Summary of the invention

[0003] The present disclosure relates to methods, systems, and devices for contention and priority-based channel access of a shared channel in a wireless communication network.

[0004] In some exemplary embodiments, a method for wireless channel access is disclosed. The method may include: determining a channel access priority class for a channel; obtaining a priority indication for the channel; and performing a channel access procedure for one or more transmissions including the channel based on the channel access priority class and the priority indication.

[0005] In some other embodiments, another method for wireless channel access is disclosed. The method includes: determining a channel access priority class for a channel; obtaining a priority indication for the channel; determining a set of allowed contention window sizes between a minimum contention window size and a maximum contention window size; and adjusting the contention window size to one of the set of allowed contention window sizes based on the priority indication for use in a channel access process for one or more transmissions comprising the channel.

[0006] In some other embodiments, a network device is disclosed, which mainly includes one or more processors and one or more memories, wherein the one or more processors are configured to read computer codes from the one or more memories to implement any one of the above methods.

[0007] In some other embodiments, a computer program product is disclosed. The computer program product may include a non-transitory computer-readable program medium having computer code stored thereon, which, when executed by one or more processors, causes the one or more processors to implement any of the above methods.

[0008] Further aspects and alternatives of the above-described embodiments and their implementation are explained in more detail below in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A radio access network with exemplary uplink, downlink and control channel configurations is shown.

[0010] Figure 2 An exemplary mechanism for channel access of a shared spectrum uplink channel in a wireless access network is shown.

[0011] Figure 3 A logic flow of an exemplary contention-based channel access procedure for a shared spectrum uplink channel in a wireless access network is shown.

[0012] Figure 4 A logic flow of an exemplary contention window adjustment process for contention-based channel access of a shared spectrum uplink channel in a wireless access network is shown. DETAILED DESCRIPTION

[0013] A wireless communication network may include a radio access network for providing network access to wireless terminal devices, and a core network for routing data between access networks or between a wireless network and other types of data networks. In a radio access network, radio resources are provided for allocation and used to transmit data and control information. Figure 1 An exemplary wireless access network 100 is shown, which includes a wireless access network node or wireless base station 102 (referred to herein as a wireless base station or base station) and a wireless terminal device or user equipment (UE) 104 (referred to herein as a user equipment or UE), which communicate with each other via over-the-air (OTA) wireless communication resources 106. The wireless access network 100 can be implemented as, for example, a 2G, 3G, 4G / LTE or 5G cellular wireless access network. Accordingly, the base station 102 can be implemented as a 2G base station, a 3G node B, an LTE eNB or a 5G new wireless (NR) gNB. The user equipment 104 can be implemented as a mobile or fixed communication device equipped with a mobile identity module for accessing the base station 102. The user equipment 104 may include, but is not limited to, a mobile phone, a laptop computer, a tablet computer, a personal digital assistant, a wearable device, a distributed remote sensor device, and a desktop computer. Alternatively, the wireless access network 100 can be implemented as other types of wireless access networks such as Wi-Fi, Bluetooth, ZigBee and WiMax networks.

[0014] The wireless communication resources 106 may include a licensed portion of a wireless frequency band, an unlicensed portion of a wireless frequency band, or a mixed portion of both the licensed and unlicensed wireless frequency bands. The wireless communication resources 106 that can be used to carry wireless communication signals between the base station 102 and the user equipment 104 can be further divided into a physical downlink channel 110 for sending wireless signals from the base station 102 to the user equipment 104 and a physical uplink channel 120 for sending wireless signals from the user equipment 104 to the base station 102. The physical downlink channel 110 can also include a physical downlink control channel (physical downlink control channel, PDCCH) 112 and a physical downlink shared channel (physical downlink shared channel, PDSCH) 114. Similarly, the physical uplink channel 120 can also include a physical uplink control channel (PUCCH) 122 and a physical uplink shared channel (physical uplink shared channel, PUSCH) 124. For simplicity, other types of downlink and uplink channels are not described in detail. Figure 1 102, but are within the scope of the present disclosure. Control channels PDCCH 112 and PUCCH 122 may be used to carry control information in the form of control messages 116 and 126. Shared channels (shared between data and control information) PDSCH 114 and PUSCH 124 may be allocated and used to transmit downlink data transmissions 118 and uplink data transmissions 128 between base station 102 and user equipment 104.

[0015] In communications involving shared spectrum (e.g., unlicensed frequency bands), various devices (e.g., different UEs) and various communication services within each device may compete or contend for wireless channels within the shared spectrum for the transmission of data or control information according to a predefined contention-based channel access process. The following various embodiments of the present disclosure provide a priority-based contention mechanism for wireless channel access in a shared spectrum. For example, this mechanism may be applied to networks including, but not limited to, 4G LTE or 5G cellular networks to provide channel access to a shared spectrum in the context of licensed assisted access (LAA).

[0016] This competition mechanism increases the probability that a communication service with a higher priority obtains channel access to the shared spectrum during the channel access competition process. Although the following embodiments are mainly described in the context of contention-based access to uplink channels, the basic principles are not limited thereto, but are applicable to contention-based access to downlink channels. This competition mechanism is applicable to both control channels for the transmission of control information and data channels for the transmission of data. The word "shared" in the term "shared spectrum" is used to refer to the sharing of the same wireless resources by different wireless devices or services via access competition, while the word "shared" in the term "shared channel" is used to refer to channels for the transmission of data information. Thus, channels in the shared spectrum can be contended by various wireless devices or communication services to be used as control channels or data channels for each of the competing wireless devices or services.

[0017] Figure 2 An exemplary contention-based channel access mechanism 200 for uplink channel access in a shared spectrum in a wireless access network is shown. Figure 2 As shown, uplink control channels such as PUCCH 122 and / or uplink shared channels such as PUSCH 124 may be contended by various user devices 104 supporting various communication services. Channel access for each of these services may be associated with a channel access priority class (CAPC) 202 and a priority indication 204. Channel access in the contention-based channel access mechanism 200 may be controlled by the interaction between the CAPC 202 and the priority indication 204 for underlying communication services that require access to a channel 122 or 124 in a shared spectrum.

[0018] The contention-based channel access mechanism described herein for communication service descriptions may be performed at the data flow level within a specific communication service. Such data flows within a communication service may be characterized by different transmission quality of service (QoS) requirements, as described in further detail below. Although the description herein may relate to channel access through a specific communication service, the underlying principles apply to channel access at the data flow level. Thus, the term "communication service" may be replaced by "communication service or data flow".

[0019] continue Figure 2, the CAPC 202 for a particular communication service may be determined based on various factors for channel access purposes. For example, the CAPC 202 may include one of a predetermined number of priority categories, which may be associated with quality of service (QoS) requirements for the communication service. In some embodiments, as described above, a communication service may be provided via multiple data streams, each of which is associated with a set of QoS requirements. Such data streams within a communication service may be referred to as QoS streams. In some exemplary embodiments, the QoS requirements for each of the QoS streams may be associated with one of a predetermined number of QoS profiles. Each of these QoS profiles may be identified by a QoS profile identifier (QoS profile identifier, QFI). The QFI may be associated with a QoS class identifier (QoS class identifier, QCI). The QCI may be specified by an upper layer. Thus, the CAPC 202 for a communication service or data stream may be derived based on the QCI information and the correlation between the QCI and the CAPC category. Alternatively, the CAPC 202 may be indicated by downlink control signaling, such as in a downlink control information (DCI) message from a base station.

[0020] Determining the CAPC 202 among a predetermined number of priority categories may additionally be based on other factors. For example, in some embodiments, access to a channel (e.g., PUCCH) that is a control channel in a shared spectrum may always be assigned a specific (e.g., CAPC=1) highest CAPC priority level, regardless of the nature of the underlying communication service or data flow. Thus, the CAPC 202 for a communication service or data flow may be assigned to represent the QoS requirements of the communication service or data flow, as well as a mix of other channel access and data characteristics.

[0021] The priority indication 204 for a specific communication service or data stream can be used to indicate the nature of the communication service in terms of its priority. For example, the communication service may belong to an ultra-reliable low latency communication (URLLC) service, an enhanced mobile broadband (eMBB) service, or the like. In some embodiments, the priority indication 204 may be designated as a high priority or a low priority. For example, a URLLC service may be assigned a high priority priority indication, while a service including an eMBB service in addition to the URLLC service may be assigned a low priority priority indication. In other alternative embodiments, more than one priority may be specified. The priority indication 204 for a specific communication service or data stream may be specified in a DCI message from a base station and used together with the CAPC 202 to control contention-based channel access for a specific communication service or data stream.

[0022] As shown in further detail below, Figure 2 The combination of CAPC202 and priority indication 204 for controlling channel access contention can enable a communication service or data stream with a higher priority (such as a priority indication indication) in a service or data stream with the same CAPC to increase the probability of successfully competing for a channel. For example, PUCCH access for all communication services or data streams (including URLLC and eMBB services / data streams) can be assigned the same highest CAPC, and it may be expected to provide a better probability of channel access success than eMBB services / data streams during the PUCCH competition process for URLLC services / data streams. Similarly, PUSCH access for URLLC services / data streams can be assigned the same CAPC as eMBB services, and it may be expected to provide a better probability of channel access success than eMBB services / data streams during the PUSCH competition process for URLLC services / data streams. Making the channel contention process dependent on an additional priority indication, such as giving a URLLC service / data stream a high priority state and giving an eMBB service / data stream a low priority state, will give the URLLC service / data stream a better chance relative to the eMBB service / data stream during the channel access contention process.

[0023] CAPC may include a predetermined number of categories. By way of example only, CAPC categories are predefined as four categories, which are represented in descending order of channel access priority starting from p=1, 2, 3, and 4. As described above, the p value for channel access for a communication service or data stream may be assigned / determined according to rules involving the QCI and other channel access characteristics corresponding to the communication service or data stream. For example, access to PUCCH may always be assigned p=1 (the highest channel access priority category). For another example in a 5G wireless communication system, a PUSCH channel access for a communication service / data stream having a first group of QCIs (e.g., QCIs of 1, 3, 5, 65-67, 69, 70, 79, 80, and 82 to 85) may be assigned with p=1, while a PUSCH channel access for a communication service / data stream having a second group of QCIs (e.g., QCIs of 2 and 7) may be assigned with p=2, and a PUSCH channel access for a communication service / data stream having a third group of QCIs (e.g., QCIs of 4, 6, 8, and 9) may be assigned with p=3. For another example, a PUSCH channel access for a URLLC service / data stream may be more likely to be assigned with p=1, while a PUSCH channel access for an eMBB service / data stream may be assigned with p=1, 2, 3, or 4.

[0024] Figure 2 It is also shown that the contention-based channel access mechanism 200 may include a contention-based channel access process 210, which is performed by a user equipment when competing for channel access for a communication service or data stream. The channel contention process for a specific communication service or data stream may be performed according to a set of predefined channel access contention parameters, which correspond to a CAPC (p value) for channel access for a communication service or data stream modified or adjusted according to a priority indication of the communication service / data stream.

[0025] Table 1 below shows an exemplary set of basic channel access contention parameters for each of the exemplary CAPC category groups. For each CAPC p value, these channel access contention parameters may include, but are not limited to, CW p , CW min,p , CW max,p and m p .CW p Indicates from CW min,p (minimum contention window of CAPC with p-value) and CW max,p The contention window is selected from a set of predefined contention window values ​​between (maximum contention window of CAPC with p value). For each p value CW min,p , C.W. max,pAn exemplary set of allowed contention window values ​​between p In some embodiments, the allowed CWs of higher channel access priority categories (lower p values) are p The size may not be larger than the allowed CW for lower channel access priority classes (higher p values). p Size, as shown in Table 1. Delay parameter m p Can be used to determine the length of the time delay that a communication service or data flow may be allowed to gain channel access for transmission.

[0026] Table 1

[0027] CAPC(p) <![CDATA[m p ]]> <![CDATA[CW min，p ]]> <![CDATA[CW max，p ]]> <![CDATA[Allowed CW p Size]]> 1 2 3 7 {3,7} 2 2 7 15 {7,15} 3 3 15 1023 {15,31,63,127,255,511,1023} 4 7 15 1023 {15,31,63,127,255,511,1023}

[0028] An exemplary principle of the contention-based channel access process 210 is described as follows. Essentially, a UE that begins contending for access to an uplink channel (PUCCH or PUSCH in a shared spectrum) for a communication service or data stream having a channel access priority class p may not be able to gain access. Instead, depending on the channel state (e.g., idle or busy), the UE may be forced to go through a period of N length until it can be granted access and can transmit. The number N may be set to 0 and CW p A random number between (it can be CW min,p and CW max,p A set of allowed CW p size), which will be determined in conjunction with the following Figure 4 Described in more detail. Since the CW of the communication service or data flow with a lower p value (higher priority class) p Communication services or data flows with higher p values ​​(lower priority classes) may not be greater than those with higher p values, and thus communication services or data flows with higher CAPC classes may be provided with a higher probability of having a lower N number, and therefore a higher probability of successfully competing and obtaining earlier channel access.

[0029] In addition, the contention-based channel access process 210 incorporates the priority of the communication service or data flow (as reflected in the priority indication) so that within competing communication services or data flows having the same CAPC category p value, a communication service or data flow having a higher priority will have a higher probability of successful contention and earlier access to the shared channel for transmission.

[0030] Additionally, the contention-based channel access mechanism 200 may include a contention window adjustment process 220 so that the UE 104 can adjust the allowed CW for each of the CAPC categories (p values). p Timely determine and adjust the competition window CWp As about Figure 4 As described in more detail, the contention window adjustment process 220 may be dependent on the priority indication for each CAPC class. Thus, the contention window adjustment process 220 may be designed so that it generates an adjusted CW in a manner that favors channel access contention for communication services or data flows that have a higher priority in a particular CAPC class (as indicated by its priority indication). p .

[0031] from Figure 2 continue, Figure 3 shows the communication service or data flow Figure 2 2 is an exemplary logic flow of a contention-based channel access process 210 for a communication service or data flow having a CAPC value of p and a priority indication of high priority or low priority. The priority indication may be indicated by a base station via a DCI. For example, in a 5G wireless communication system, an indication of giving high priority to PUSCH access may be provided by a base station via a DCI format 0_1 / 0_2, and an indication of giving high priority to PDSCH / PUCCH access may be provided by a base station via a DCI format 1_1 / 1_2.

[0032] exist Figure 2 In the contention-based channel access process 210, the counter N is initialized to 0 and the contention window CW p A random number between , and is iteratively counted down after the UE determines that the channel is idle for a certain duration in each iteration. After the counter N counts down to 0, the UE can obtain access to the channel for transmission. Various alternatives for incorporating priority information into the contention-based channel access process 210 (such as shown in steps 301, 302, 308, 310 and 314) can facilitate channel access contention for communication services or data streams with higher priorities indicated by the priority indication.

[0033] like Figure 3 As shown in step 301, before step 302, the UE may first sense the channel until the channel is idle for a period of time. The length of the time period and the sensing of the channel state may be configured in any manner (such as the manner described below with respect to step 314). As shown in step 302, the UE sets the counter N to N. init , where N init is set to 0 and the contention window CW p A random number between . CW p The allowed CWs in base table 1 for CAPC category p can be p Choose from size. CW p The larger the size, the more random initThe probability of being a larger number is higher and is less beneficial to the communication service or data flow during the channel contention process.

[0034] In some implementations of step 301, the CW may be performed according to the priority indication. p Select. For example, CW in base table 1 min,p or CW max,p The value can be adjusted based on the priority indication. Specifically, the CW for higher priority within the same p-category min,p can be adjusted to a smaller value. Additionally or alternatively, the CW for lower priority within the same p category min,p can be adjusted to a larger value, as shown in Tables 2 and 3 below. Additionally or alternatively, a CW for a higher priority within the same p category max,p can be adjusted to a smaller value. Additionally or alternatively, a CW for a lower priority within the same p category max,p can be adjusted to a larger value, as shown in Tables 4 and 5 below. The allowable CW in Tables 2 to 5 p Size can be based on CW min,p and / or CW max,p The changes made to the CW for higher priority are modified accordingly. min,p and / or CW max,p Downward modification and / or for lower priority CW min,p and / or CW max,p The upward modification of may promote the contention for channel access by services or data flows with higher priority, because the random N generated in step 302 and under these modifications init Services or data flows with higher priority may have a higher probability of being a smaller number.

[0035] In Tables 2 to 5, the priority consideration applies only to CAPC, where p = 1 as an example. However, CW min,p and CW max,p The basic principle of adjusting a parameter away from its base value to depend on the priority indication can be extended to other p-categories. Further, the priority indication is not necessarily limited to a binary value (high level priority or low level priority). The priority can contain more than two levels, and the CW of each of the more than two priority levels within a CAPC category can be modified accordingly. min,p and CW max,p value to achieve a lower N for a higher priority init .

[0036] Table 2

[0037]

[0038] Table 3

[0039]

[0040] Table 4

[0041]

[0042] Table 5

[0043]

[0044] At step 304, the UE determines whether the counter N is 0. If the UE determines that the counter N is 0, the contention-based channel access process 210 for the communication service / data flow stops, and the UE is allowed to transmit on the channel, as shown in step 306. Otherwise, the UE decrements the counter N by 1, or alternatively decrements the counter N by one counting step according to the priority indication, as shown in 308. For example, as indicated by the priority indication, the decrement step size of the counter N can be set to a larger value for a higher priority, and the decrement step size of the counter N can be set to a smaller value for a lower priority. In a specific example, the decrement step size can be set to 1 for a lower priority indication priority, and the decrement step size can be set to 2 for a higher priority indication priority. Other decrement steps of the counter N can be used. By setting the decrement step of counter N according to the priority indication, in the contention-based channel access process 210, counter N can reach 0 in fewer iterations, and thus the UE has a higher probability to obtain earlier channel access for higher priority communication services or data flows.

[0045] exist Figure 3 After step 308, the UE performs an additional sensing time slot for a duration of T sl The channel state is sensed within the time slot to determine whether the channel is idle, as shown in step 310. The sensing time slot duration T sl can be predefined to be any suitable length of time. For example, T sl Can be predefined as 9μs. The sensing time slot duration T sl During this period, the UE measures the time-varying energy level in the channel and compares the measurement result with the predetermined energy threshold E t A comparison is made to determine whether the channel is considered idle during the sensing time slot duration. In some embodiments, a time period T within the sensing time slot duration may be predefined. le If the measured energy level is at least sl Duration period T le Below E t, the UE can determine that the channel is idle during the sensing time slot duration. Otherwise, the UE can determine that the channel is idle during the sensing time slot duration T sl Alternatively, the UE may compare the time average of the energy level measured during the sensing time slot duration with E t Compare, and when the time average is less than or equal to E t The channel is determined to be idle when the time average value is higher than E t The channel is determined to be busy.

[0046] like Figure 3 As further shown in step 310 of , priority information can be incorporated into step 310 to promote more favorable channel access contention for communication services or data flows with higher priority. For example, when the priority indication indicates a high priority, the channel detection energy threshold E t can be set to a higher value, and when the priority indication indicates a low priority, E t This embodiment helps to improve the probability of a UE with a high-priority communication service or data stream competing for channel access to detect an idle channel compared to another UE with a low-priority communication service or data stream competing for channel access.

[0047] exist Figure 3 In step 312, if the UE detects that the channel is idle during the sensing time slot duration in step 310, the UE iterates back to step 304. Otherwise, the UE proceeds to step 314 to perform additional channel state detection. Figure 3 As shown in step 314 in the above, the UE may also perform the delay for a duration of T d The state of the channel can be sensed within the sensing time slot duration T described in step 308. sl Similarly, at T d Each sensing time slot duration T sl During this period, the UE measures the time-varying energy level in the channel and compares the measurement result with the predetermined energy threshold E t The comparison is done to determine the channel duration T during the sensing time slot. sl For example, if the measured energy level is lower than a predetermined energy threshold E r The cumulative time is at least the time period T le , the UE may determine that the channel is idle. Otherwise, the UE may determine that the channel is busy during the sensing time slot duration Tsl. Alternatively, the UE may compare the time average of the energy level measured during the sensing time slot duration with E t Compare, and when the time average is less than or equal to E tThe channel is determined to be idle when the time average value is higher than E t The channel is determined to be busy when the delay time T d It can usually be determined as T d =T f +m p *T sl , where T f It can be a predetermined time length (e.g., 16 μs), and the base m p It can be predefined according to the CAPC p category value, for example, by Table I. Thus, the delay duration T d In exemplary step 314, the UE senses the channel until (1) a busy sensing slot duration of the channel is detected, or (2) for T d The channel is detected as idle for all sensing slot durations within .

[0048] like Figure 3 As further shown in step 314 of the present invention, the priority information can be incorporated into step 314 to promote more favorable channel access contention for communication services or data flows with higher priority in at least two different ways. In a first manner similar to the manner described in step 310 above, when the priority indication indicates a high priority, the channel detection energy threshold E t can be set to a higher value, and when the priority indication indicates a low priority, E t This embodiment is advantageous in that a UE with a high-priority communication service or data stream competing for channel access will be delayed for the duration T compared to another UE with a low-priority communication service or data stream competing for channel access. d The probability of detecting an idle channel during the duration of all sensing time slots during the period is increased.

[0049] In the second method, the cardinality m in Table 1 p The delay duration T of the channel access contention for the communication service or data flow with a higher priority can be adjusted based on the priority indication. d The delay duration T of the communication service or data flow with lower priority d The channel access parameters (particularly m) are shorter (including a smaller number of sensing time slot durations), thereby promoting channel access contention for communication services or data flows with higher priority. Tables 6 and 7 below show effective channel access parameters (particularly m) to achieve this effect. p ). The examples of valid tables in Tables 6 and 7 are based on base table 1, where the cardinality m p The parameters are modified depending on the priority indication. In particular, in exemplary Table 6, for low priority, p=1, m pThe value remains at the base value 2 (Table 1), while for high priority, p = 1 m p The value is adjusted downward from the base value of 2 to 1. In the exemplary table 7, for high priority, m with p=1 p The value remains at the base value 2 (Table 1), while for low priority, p = 1 m p The value is adjusted upward from the base value of 2 to 3. In Tables 6 and 7, the priority consideration only applies to the CAPC with p = 1 as an example. p The basic principle of adjusting a parameter away from its base value to depend on the priority indication can be extended to other p categories. Furthermore, the priority indication is not necessarily limited to a binary value (high or low service priority). Priority can contain more than two levels, and the m of each of the more than two priority levels within a CAPC category can be adjusted accordingly. p value to achieve a lower m for a higher priority p .

[0050] Table 6

[0051]

[0052] Table 7

[0053]

[0054] continue Figure 3 And in step 316, if the UE d If the UE detects that the channel is idle during all sensing time slots during the period, it completes the current iteration of decrementing the counter N and returns to step 304 for the next iteration. However, if the UE detects that the channel is busy for the sensing time slot duration in step 314, the UE delays for another additional delay period T. d Repeat step 314 until T d All sensing slot durations during this time period are idle for the channel.

[0055] Steering Figure 2 The contention window adjustment process 220 and as described above with respect to Figure 3 As described in step 302, the contention window CW p plays a key role in the contention-based channel access process 210 because CW p Basically used by UE to convert the above N init The value is specified as 0 and CW p A random number between . Parameter CW p Can be CW min,p and CW max,p The allowed CW between pAny of the sizes, such as shown in Basic Channel Access Contention Parameters Table 1. For example, CW p It can be implemented as a single parameter maintained by the UE and used for the channel access contention process for all communication services or data flows from UEs with the same p category. In other words, Figure 2 Each of the UEs 104 in the CAPC class may maintain a single CW for each of the CAPC classes. p .CW p is the time-dependent contention window size that can be used Figure 2 The contention window adjustment process 220 is used to adjust.

[0056] For each CAPC category p, CW p Can be initialized to the allowed CW of base table 1 p The minimum value of the size, which can be, for example, the minimum contention window CW min,p . Adjust CW p The purpose is to prevent channel contention and deadlock based on retransmission and retransmission confirmation information, especially by extending the CW p To lead to a larger N init , and thus for each contention-based channel access procedure ( Figure 3 ) results in longer channel contention time. Figure 2 The contention window adjustment process 220 in may incorporate priority information so that during the contention-based channel access process 210, channel access contention by communication services or data flows having a higher priority (as indicated by their priority indications) may be advantageous.

[0057] Figure 4 Shows Figure 2 In step 402, the contention window of each CAPC category p is set to CW min,p In step 404, the UE determines that since the previous CW p Whether there has been any retransmission feedback for the communication service or data flow for the CAPC category since the update. If there has been any retransmission feedback since the previous CW pIf one or more retransmission acknowledgments have been received since the update, then in step 408, the UE determines whether there are enough acknowledgments (referred to as ACKs) for successful retransmissions. For example, the UE may determine whether the acknowledgments for successful retransmissions exceed a predefined ACK threshold. In some exemplary embodiments, the UE may determine whether the ACK exceeds the ACK threshold by determining whether an ACK is received for one or more PUSCHs with transmissions based on transport blocks (TBs), or determining that at least 10% (as an exemplary percentage only) of the HARQ (hybrid automatic repeat request) feedback is an ACK for one or more PUSCHs with transmissions based on code block groups (CBGs). If the received ACK exceeds the ACK threshold, the UE maintains CWp at CWp. min,p , as indicated by branch arrow 409. Otherwise, the UE proceeds to step 412.

[0058] If, as determined in step 404, since the previous CW p The UE determines in step 406 that the reason for not receiving the retransmission ACK is because the retransmission ACK has been received since the previous CW p No retransmission has been performed since the update, or there has been a retransmission but there was not enough time to receive any feedback. If the UE determines and confirms either of these two reasons, it maintains the current CW p size, as shown by 410 and branch arrow 407. Otherwise, when retransmission has been performed and sufficient time has passed since retransmission and feedback were expected, but there has been no feedback, the UE will CW p Added to the allowed CW in Base Table 1 for CAPC categories p The next higher value in magnitude is indicated by 414 and branching arrow 413 .

[0059] After the UE determines that the previous CW p After the update has received the retransmission feedback (step 404) and the amount of received ACKs does not exceed the ACK threshold (step 408), the UE can determine the priority of the current communication service or data flow of CAPC category p participating in the channel contention, as shown in step 412. If the UE determines that the current priority indication indicates a low priority, it will CW p Add to the allowed CW in base table 1 p The next higher size among the sizes is selected, as shown by 414 and branch arrow 431. However, if the UE determines that the current priority indication has a high priority, the UE may be provided with a method for adjusting the CW. p In the first option, as shown by the branch arrow 432, the UE canp Resize to CW min,p In the second option, as shown by branching arrows 430 and 410, the UE may maintain the current CW p In the third option, as shown by branching arrows 434 and 416, 410 and 418, if CW p Already in CW min,p , then the UE can use CW p Maintain CW min,p , or CW p Reduce to the allowable CW in Base Table 1 p The next smaller value in size.

[0060] thus, Figure 4 The contention window adjustment process 220 in the embodiment of the present invention helps to adjust the CW during the channel access contention by the communication services or data flows with higher priority (as indicated by their SPI) when the channel access is congested, such as to cause contention deadlock. p Adjust to the allowed CW p A smaller size within a size.

[0061] As mentioned above about Figures 2 to 4 As described above, a priority indication is introduced in the downlink control signaling. In addition, the contention-based channel access process and the contention window adjustment process combine various exemplary alternatives that take into account the priority indication of the competing communication services or data streams so that higher priority services or data streams are provided with a relatively higher probability of successfully obtaining earlier access to the competing channels. Any number of these options can be incorporated into the above-described procedures and can be combined in any manner.

[0062] Finally, back to the above Figure 3 and Tables 2 to 5, step 302 of the contention-based channel access process 210 is implemented by explicitly introducing priority levels into a set of CAPC categories. Alternatively, such a step may be implemented by implicitly incorporating priority designations for services or data flows by modifying the number of CAPC categories of base Table 1 and their channel access contention parameters and / or the allocation of CAPC categories.

[0063] For example, when assigning CAPC categories, the highest CAPC category of p=1 can be specifically assigned to channel access (PUSCH or PUCCH) for services / data flows with high priority. URLLC services can then generally be associated with high priority and, thus, will be assigned p=1. Channel access (including PUCCH and PUSCH channel access) for services that do not have a high priority designation, such as eMBB services, can be assigned to lower CAPC categories. In this way, URLLC services will gain an advantage during channel access contention.

[0064] In some embodiments, CAPC categories may be extended to more than 4. For example, CAPC categories may be extended to include p={1, 2, 3, 4, 5}, where p=1 is reserved for high priority. Within channel access for services or data streams that do not have a high priority designation, for example, PUCCH access may be associated with p=2 (the highest CAPC category is not assigned to high priority). Likewise, CAPC categories may be extended to more than 5, with the highest category being reserved for high priority services and data streams.

[0065] In some other embodiments, a mapping may be provided between CAPC categories (extended or unextended) and priorities. In an exemplary CAPC set of p={1, 2, 3, 4}, a subset of p may be mapped to high priority, while another subset of p may be mapped to low priority. For example, {1} may be mapped to high priority, while {3, 4} may be mapped to low priority (in which case {2} will be assigned to a service or data stream that has no priority designation). For another example, {1, 2} may be mapped to high priority, while {4} may be mapped to low priority (in which case {3} will be assigned to a service or data stream that has no priority designation). Any other combination of CAPC mappings to high priority and low priority may be used. In some exemplary mappings, the union of a subset of high priority CAPC categories and a subset of low priority CAPC categories may encompass the entire CAPC category set. For example, {1} may be mapped to high priority, while {2, 3, 4} may be mapped to low priority. For another example, {1, 2} may be mapped to high priority, while {2, 3, 4} may be mapped to low priority. In other words, the subsets may overlap.

[0066] The above description and accompanying drawings provide specific example embodiments and implementations. However, the described subject matter may be embodied in a variety of different forms, and therefore, the subject matter covered or claimed is intended to be interpreted as not being limited to any example embodiment set forth herein. A reasonably broad scope of the subject matter claimed or covered is contemplated. Among them, for example, the subject matter may be embodied as a method, device, component, system, or non-transitory computer-readable medium for storing computer code. Therefore, the embodiments may, for example, take the form of hardware, software, firmware, storage media, or any combination thereof. For example, the above method embodiments may be implemented by a component, device, or system including a memory and a processor by executing a computer code stored in a memory.

[0067] Throughout the specification and claims, in addition to the explicitly stated meanings, terms may have suggested or implied subtle meanings in the context. Likewise, the phrase "in one embodiment / implementation" as used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment / implementation" as used herein does not necessarily refer to a different embodiment. For example, the claimed subject matter is intended to include combinations of the example embodiments in whole or in part.

[0068] In general, terms can be understood at least in part from usage in context. For example, terms such as "and", "or" or "and / or" as used herein can include multiple meanings, which can depend at least in part on the context in which these terms are used. Typically, "or" if used in an association list (such as A, B or C) is intended to represent A, B and C (used in an inclusive sense here), and A, B or C (used in an exclusive sense here). In addition, the term "one or more" as used herein (depending at least in part on the context) can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. Similarly, terms such as "one", "an" or "the" can be understood to convey singular usage or to convey plural usage, which depends at least in part on the context. In addition, the term "based on" can be understood as not necessarily intended to convey a set of factors that are exclusive, and can alternatively allow the presence of additional factors that are not necessarily explicitly described, which also depends at least in part on the context.

[0069] References throughout this specification to features, advantages, or similar language do not imply that all features and advantages that may be implemented using the present solution should or are included in any single embodiment of the present solution. Rather, language referencing features and advantages is understood to mean that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, throughout this specification, discussion of features and advantages and similar language may, but do not necessarily, refer to the same embodiment.

[0070] Additionally, in one or more embodiments, the features, advantages, and characteristics of the present solution may be combined in any suitable manner. In view of the description herein, one of ordinary skill in the relevant art will recognize that the present solution may be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present solution.

Claims

1. A method for wireless channel access of a communication node, comprising: determining a channel access priority class for the channel; obtaining a priority indication for the channel; as well as Based on the channel access priority class and the priority indication, performing a channel access procedure for one or more transmissions comprising the channel, wherein performing the channel access procedure comprises: determining a set of channel access contention parameters based on the channel access priority category and the priority indication; and performing the channel access procedure based on the set of channel access contention parameters, wherein performing the channel access procedure based on the channel access priority class and the priority indication comprises iteratively counting down a counter with a count-down step size until the counter reaches zero, each iteration during the iterative count-down of the counter in the channel access procedure comprises detecting an idle state of the channel within a contention time iteration duration, and wherein Detecting the idle state of the channel during the contention time iteration duration is based on an energy threshold of energy detected in the channel, and for the same channel access priority category, the energy threshold when the priority indication indicates a high priority is greater than the energy threshold when the priority indication indicates a low priority, and If the channel is not detected to be idle for the contention time iteration duration, the channel state continues to be idle for the delay duration T d is sensed and the measurement result is measured for the duration of the delay T d Each sensing time slot duration T sl The energy threshold is compared with the energy threshold to determine the channel duration T in the sensing time slot. sl Is the period idle? The duration of the delay is T d Represented as T d =T f +m p *T sl , T f is the scheduled time length, base m p The adjustment is based on the priority indication, and for the same channel access priority category, the T corresponding to the priority indication with a higher priority d T than the priority indication with lower priority d Shorter.

2. The method according to claim 1, wherein: The set of channel access contention parameters includes a maximum contention window size and a minimum contention window size; as well as Determining the set of channel access contention parameters includes, in addition to determining the channel access priority category, determining at least one of the maximum contention window size and the minimum contention window size based on the priority indication.

3. The method of claim 2, wherein determining the maximum contention window size further comprises determining the maximum contention window size based on the priority indication, such that the determined maximum contention window size is no larger than another maximum contention window size, wherein the other maximum contention window size is determined for the same channel access priority category, but has a priority level lower than the priority level indicated by the priority indication.

4. The method of claim 2, wherein determining the minimum contention window size further comprises determining the minimum contention window size based on the priority indication, such that the determined minimum contention window size is no larger than another minimum contention window size, wherein the other minimum contention window size is determined for the same channel access priority category, but has a priority level lower than the priority level indicated by the priority indication.

5. The method according to claim 2, wherein: Execution of the channel access procedure depends on a contention window size; and The contention window size is selected from a set of allowed contention window sizes between the minimum contention window size and the maximum contention window size.

6. The method according to claim 1, wherein: The set of channel access contention parameters includes a channel access contention time factor; as well as Determining the set of channel access contention parameters includes, in addition to determining the channel access priority category, determining the channel access contention time factor based on the priority indication.

7. The method according to claim 6, wherein determining the channel access contention time factor further comprises determining the channel access contention time factor according to the priority indication, so that the determined channel access contention time factor is not greater than another channel access contention time factor, and the other channel access contention time factor is determined for the same channel access priority category, but the priority level is lower than the priority level indicated by the priority indication.

8. The method according to claim 7, wherein the channel access contention time factor controls the time length of the channel contention process in the channel access process.

9. The method according to claim 1, wherein: The set of channel access contention parameters includes an energy threshold, the energy threshold being used to determine whether the channel is active or idle at a particular time; as well as Determining the set of channel access contention parameters includes determining the energy threshold based on the priority indication in addition to determining a channel access priority category.

10. The method according to claim 1, wherein: The down-counting step size when the priority indication indicates a high priority is greater than the down-counting step size when the priority indication indicates a low priority.

11. A method for wireless channel access, comprising: determining a channel access priority class for the channel; obtaining a priority indication for the channel; For each channel access priority class, determining a set of allowed contention window sizes between a minimum contention window size and a maximum contention window size; as well as adjusting, for the same channel access priority class, a contention window size to one of a set of allowed contention window sizes based on the priority indication for use in a channel access procedure for one or more transmissions comprising the channel, wherein performing the channel access procedure based on the channel access priority class and the priority indication comprises iteratively counting down a counter with a count-down step size until the counter reaches zero, each iteration during the iterative count-down of the counter in the channel access procedure comprises detecting an idle state of the channel within a contention time iteration duration, and wherein Detecting the idle state of the channel during the contention time iteration duration is based on an energy threshold of energy detected in the channel, and for the same channel access priority category, the energy threshold when the priority indication indicates a high priority is greater than the energy threshold when the priority indication indicates a low priority, and If the channel is not detected to be idle for the contention time iteration duration, the channel state continues to be idle for the delay duration T d is sensed and the measurement result is measured for the duration of the delay T d Each sensing time slot duration T sl The energy threshold is compared with the energy threshold to determine the channel duration T in the sensing time slot. sl Is the period idle? The duration of the delay is T d Represented as T d =T f +m p *T sl , T f is the scheduled time length, base m p The adjustment is based on the priority indication, and for the same channel access priority category, the T corresponding to the priority indication with a higher priority d T than the priority indication with lower priority d Shorter.

12. The method of claim 11, wherein adjusting the contention window size comprises: The previous contention window size is maintained, the previous contention window size is reset to the minimum contention window size, or the contention window size is modified from the previous contention window size to an adjacent contention window size among the set of allowed contention window sizes.

13. The method of claim 12, wherein modifying the contention window size comprises reducing the previous contention window size to the adjacent contention window size among the set of allowed contention window sizes when the priority indication indicates a high priority.

14. The method of claim 11, wherein adjusting the contention window size to one of a set of allowed contention window sizes based on the priority indication comprises at least one of: When the priority indication indicates a high priority, and retransmission feedback received since the previous adjustment of the contention window size indicates that confirmation of successful retransmissions is below a predetermined confirmation threshold, maintaining the previous contention window size, resetting to or continuing to use the minimum contention window size, or decreasing from the previous contention window size; or When the priority indication indicates a low priority and retransmission feedback received since a previous adjustment of the contention window size indicates that acknowledgments of successful retransmissions are below the predetermined acknowledgment threshold, increasing from the previous contention window size.

15. A wireless network device, comprising one or more processors and a memory for storing computer instructions, wherein the one or more processors are configured to cause the wireless network device to implement the method according to any one of claims 1 to 14 when executing the computer instructions.

16. A computer program product comprising a non-transitory computer readable program medium having computer code stored thereon, which, when executed by one or more processors, causes the one or more processors to implement the method according to any one of claims 1 to 14.

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