WO2021098052A1

WO2021098052A1 - Methods for control channel monitoring

Info

Publication number: WO2021098052A1
Application number: PCT/CN2020/075355
Authority: WO
Inventors: Qiujin GUO; Mengzhu CHEN; Jun Xu; Xiaoying Ma; Xuan MA; Focai Peng
Original assignee: Zte Corporation
Priority date: 2020-02-14
Filing date: 2020-02-14
Publication date: 2021-05-27
Also published as: CN115066933A

Abstract

This disclosure relates to wireless communication methods that reduce power usage in a mobile station cause by monitoring Physical Downlink Control Channel (PDCCH). The mobile station can switch between different PDCCH monitoring behaviors associated with different PDCCH monitoring parameter sets or a PDCCH skipping parameter set.

Description

METHODS FOR CONTROL CHANNEL MONITORING

TECHNICAL FIELD

This disclosure is directed generally to methods for monitoring a control channel by a mobile station.

BACKGROUND

With the development of wireless communication technology, the transmission rate, delay, throughput, reliability and other performance indices of wireless communication system have been greatly improved through the use of high frequency bands, large bandwidths, multi-antenna arrangements, and other technologies. On the other hand, in order to achieve high-performance wireless transmission, terminals, such a mobile stations, need to carry out more complex processing to meet performance requirements, such as monitoring larger control channel bandwidths, and encoding and decoding processing for more complex control information and data information. The power consumption of the mobile stations affects user experience. Therefore, there is a desire to provide power savings solutions for mobile stations within a wireless communication system.

SUMMARY

In one embodiment, a method of communicating between a wireless access node and a mobile station includes the mobile station operating according to a first Physical Downlink Control Channel (PDCCH) monitoring behavior associated with a first PDCCH monitoring parameter set. The method also includes the mobile station switching from operating according to the first PDCCH monitoring behavior to operating according to a second PDCCH monitoring behavior associated with a second PDCCH monitoring parameter set. Each of the first PDCCH monitoring parameter set and the second PDCCH monitoring parameter set may define a unique pattern defining one or more monitoring slots within a monitoring period wherein the mobile station monitors a PDCCH for a Downlink Control Information (DCI) message.

In another embodiment, another method of communicating between a wireless access node and a mobile station includes the mobile station operating according to a first PDCCH monitoring behavior associated with a first PDCCH monitoring parameter set. The method also includes the mobile station switching between operating according to the first PDCCH monitoring behavior and operating according to a second PDCCH monitoring behavior associated with a PDCCH skipping parameter set. The first PDCCH monitoring parameter set may define a unique pattern defining one or more monitoring slots within a monitoring period wherein the wireless access node monitors a PDCCH for a DCI message. The skipping parameter set may define at least a skipping period during which the mobile station does not monitor the PDCCH for the DCI message.

The above embodiments and other aspects and alternatives of their implementations are described in greater detail in the drawings, the descriptions, and the claims below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example system diagram including a mobile station and a wireless access node according to various embodiments.

FIG. 2 shows an example timing diagram illustrating an example PDCCH monitoring behavior without DRX configuration according to various embodiments.

FIG. 3 shows another example timing diagram illustrating an example PDCCH monitoring behavior with DRX configuration according to various embodiments.

FIG. 4 provides an example flow diagram illustrating a method of communicating between a wireless access node and a mobile station according to various embodiments.

FIG. 5 shows another example timing diagram illustrating various aspects of a PDCCH skipping behavior according to various embodiments.

FIG. 6 provides an example flow diagram illustrating another method of communicating between a wireless access node and a mobile station according to various embodiments.

DETAILED DESCRIPTION

A wireless access network provides network connectivity between mobile stations and an information or data network (such as a voice communication network or the Internet) . An example wireless access network may be based on cellular technologies, which may further be based on, for example, 4G, Long Term Evolution (LTE) , 5G, New Radio (NR) , and/or New Radio Unlicensed (NR-U) technologies and/or formats.

FIG. 1 shows an example system diagram including a mobile station 102 and a wireless access node 104 according to various embodiments. The mobile station 102 may comprise a user equipment (UE) (and may be referred to as such herein) , which may further include but is not limited to a mobile phone, smart phone, tablet, laptop computer, or other mobile devices that are capable of communicating wirelessly over a network. The mobile station 102 may include transceiver circuitry 106 coupled to an antenna 108 to effect wireless communication with the wireless access node 104. The transceiver circuitry 106 may also be coupled to a processor 110, which may also be coupled to a memory 112 or other storage device. The memory 112 may store therein instructions or code that, when read and executed by the processor 110, cause the processor 110 to implement various ones of the methods described herein.

Similarly, the wireless access node 104 may comprise a base station or other wireless network access points capable of communicating wirelessly over a network with one or many mobile stations. For example, the wireless access node 104 may comprise a 4G LTE base station, a 5G NR base station, a 5G central-unit base station, a 5G distributed-unit base station, or a next generation Node B (gNB) , an enhanced Node B (eNB) , or other base station, in various embodiments. The wireless access node 104 may include transceiver circuitry 114 coupled to an antenna 116, which may include an antenna tower 118 in various approaches, to effect wireless communication with the mobile station 102. The transceiver circuitry 114 may also be coupled to one or more processors 120, which may also be coupled to a memory 122 or other storage device. The memory 122 may store therein instructions or code that, when read and executed by the processor 120, cause the processor 120 to implement various ones of the methods described herein.

The wireless access network may provide or employ various transmission formats and protocols for wireless message transmission between the mobile station 102 and the wireless access node 104. In the existing long term evolution (LTE) and 5G new radio (NR) access technology communication systems, the mobile station 102 (e.g., user equipment (UE) ) needs to know the uplink scheduling grant information for sending physical uplink shared channel (PUSCH) and downlink scheduling allocation information for receiving physical downlink shared channel (PDSCH) . The information is included in the downlink control information (DCI) and is sent by the wireless access node (e.g., base station or gNB) to the mobile station (e.g., UE) on the physical downlink control channel (PDCCH) in different DCI formats. Therefore, the mobile station should first monitor the PDCCH.

The UE needs to keep monitoring PDCCH in PDCCH monitoring occasions to avoid missing any data scheduling information. The PDCCH monitoring occasions are determined by parameters of periodicity ks, a duration Ts in a periodicity, and an offset Os associated with the start position of a periodicity. These parameters may be configured in SearchSpace information element (IE) in the radio resource control (RRC) signaling. FIG. 2 shows a timing diagram illustrating an example PDCCH monitoring behavior (without DRX configuration) having ks = 2 slots, Ts = 1 slot, and Os = 0. The PDCCH monitoring occasions 202 are shown interspaced with slots where no monitoring occurs, according to the example PDCCH monitoring behavior.

The UE may monitor for the PDCCH on the control resource set (CORESET) in PDCCH monitoring occasions defined by a search space set. The relevant monitoring parameters of the PDCCH may be included in the SearchSpace field of the radio resource control (RRC) signaling, where the searchSpaceId and the controlResourceSetId information elements (IE) may indicate the search space set index and CORESET applicable for this SearchSpace for PDCCH monitoring. The searchSpaceType IE in the SearchSpace field indicates the search space type of the DCI formats carried by PDCCH that the UE should monitor. In various approaches, the common search space (CSS) /UE-Specific search space (USS) corresponds to different DCI formats to be detected, and the UE-Specific search space may contain less DCI formats, wherein the DCI format 0_0 or 1_0 also belongs to CSS.

In various approaches, a duration IE of the RRC signaling is a duration of Ts < ks, indicating the number of slots that the UE monitors PDCCH in search space set s. The monitoringSlotPeriodicityAndOffset IE indicates a PDCCH monitoring periodicity of ks slots and a PDCCH monitoring offset of Os slots. The monitoringSymbolsWithinSlot IE indicates the symbol (s) of the CORESET within a slot for PDCCH monitoring. The specific PDCCH monitoring occasion (s) can be obtained as follows. For a search space set s, the UE determines that a PDCCH monitoring occasion (s) exists in a slot with number

in a frame with number n _f if

The UE monitors PDCCH in the search space set s for Ts consecutive slots, starting from slot

and does not monitor PDCCH in the search space set s for the next ks –Ts consecutive slots. In this disclosure, the PDCCH monitoring frequency means the ratio of PDCCH monitoring duration Ts and PDCCH monitoring periodicity ks, specifically, Ts /ks.

In various examples, as is also shown in FIG. 3, the mobile station may implement a Discontinuous Reception (DRX) mode to implement power savings. The basic mechanism of DRX is to configure a DRX cycle for mobile station. A drx-ondurationTimer begins at the starting position of a DRX cycle, during which the mobile station is in the DRX Active Time and continues monitoring the PDCCH. If the mobile station successfully decodes a PDCCH during the DRX Active Time, the mobile station stays awake in the Active Time and starts an inactivity timer configured by the parameter of drx-inactivityTimer. The mobile station can go back to sleep during the period outside Active Time. In the period outside Active Time the mobile station does not monitor PDCCH, and therefore reduces power consumption. However, according to previous solutions, during DRX Active Time, the mobile station continues monitoring PDCCH, which does not save power. The PDCCH monitoring behavior of the mobile station still consumes much unnecessary power during Active Time. In a sparse traffic model, for example, particularly for a longer Active Time of the DRX configuration, more power for monitoring PDCCH is wasted.

Other power saving solutions have been proposed. For example, during Active Time, the mobile station can be configured with at least one minimum applicable scheduling offset (i.e., K0min and/or K2min) , and a DCI can indicate an index of the configured value. If the indicated value of K0min and/or K2min is greater than 0, the power consumption of PDCCH monitoring can be reduced by relaxing the PDCCH processing time and additional power saving gain can be realized by the mobile station. Similarly, the indication of dormancy-like behavior transition on Scell (s) can trigger the UE to perform dormancy behavior on some Scells of the Scell group. However, there are many PDCCH-only monitoring behaviors that consume unnecessary power during the Active Time.

The methods provided in the current disclosure describe a power saving method in which the mobile station 102 reduces a PDCCH periodicity monitoring behavior (e.g., a frequency of PDCCH monitoring) by switching PDCCH monitoring parameters. These exemplary power saving techniques can reduce the UE power consumption compared with the legacy PDCCH monitoring methods.

Switching PDCCH monitoring behavior between at least two PDCCH monitoring parameter sets.

In various embodiments, the mobile station 102 (e.g., UE 102) can switch a PDCCH monitoring behavior between two or more PDCCH monitoring parameter sets. FIG. 4 provides an example flow diagram illustrating a method 400 of communicating between a wireless access node 104 and a mobile station 102 to achieve such PDCCH monitoring behavior switching functionality, according to various embodiments. At step 402, the mobile station operates according to a first PDCCH monitoring behavior associated with a first PDCCH monitoring parameter set. At step 404, the mobile station 102 switches from operating according to the first PDCCH monitoring behavior to a second PDCCH monitoring behavior associated with a second PDCCH monitoring parameter set. In this embodiment, each of the first PDCCH monitoring parameter set and the second PDCCH monitoring parameter set defines a unique pattern defining one or more monitoring occasions within a monitoring period (e.g., ks) wherein the mobile station 102 monitors a PDCCH for a DCI message.

In various embodiments, the mobile station 102 receives from the wireless access node 104 an indication to switch to the second PDCCH monitoring behavior, and then switches to the second PDCCH monitoring behavior in response to receiving the indication to switch to the second PDCCH monitoring behavior. In various embodiments, receiving the indication to switch to the second PDCCH monitoring behavior includes the mobile station 102 receiving from the wireless access node 104 a DCI message including a message part indicating the mobile station 102 is to use the second PDCCH monitoring behavior. In various embodiments, the message part indicating the mobile station is to use the second PDCCH monitoring behavior includes at least a portion of an existing message field of the DCI under some specific state that is reinterpreted. In one example, the message field of the DCI format 0_1 or 1_1 that is reinterpreted or repurposed from another purpose is minimum applicable scheduling offset message field or a resource assignment message field. The specific state may be that some existing fields of DCI format 0_1 or 1_1 are set to all “0” or all “1” . In various embodiments, the existing fields may include at least “Frequency domain resource assignment” and/or “Time domain resource assignment” fields in DCI format 0_1 or 1_1, “Modulation and coding scheme, ” “New data indicator, ” “Redundancy version” and/or “HARQ process number” fields in DCI format 0_1 or 1_1, “Modulation and coding scheme, ” “New data indicator, ” “Redundancy version” and/or “HARQ process number’ ” fields for transport block 2 in DCI format 1_1 if high-layer parameter maxNrofCodeWordsScheduledByDCI equals 2. For example, if the “Time domain resource assignment” field is set to all “1, ” “HARQ process number” fields are set to all “0, ” and the fields for transport block 2, including “Modulation and coding scheme” field is set to all “1” and the “Redundancy version” field is set to all “0” in DCI format 1_1, the minimum applicable scheduling offset field may be reinterpreted into the indication of the PDCCH monitoring behavior switching function. Where the maxNrofCodeWordsScheduledByDCI parameter equals to 2. If high-layer parameter configures UE being able to switch the PDCCH monitoring behavior, then the UE switches to the first PDCCH monitoring behavior if the field is set to “0, ” otherwise, the UE switches to the second PDCCH monitoring behavior. If the high-layer parameter does not configure UE being able to switch the PDCCH monitoring behavior, the field is set to 0 bit or the UE will ignore the indication of the field, or the UE expects the field is not to be reinterpreted.

In certain embodiments, each of the first PDCCH monitoring behavior and the second PDCCH monitoring behavior defines the associated unique pattern according to a monitoring periodicity (ks) , a monitoring duration (Ts) , and a monitoring offset (Os) . The monitoring periodicity (ks) defines a duration of a monitoring cycle as ks slots, the monitoring duration (Ts) defines a duration of Ts consecutive slots during which monitoring occurs, wherein Ts ≤ ks, the monitoring offset (Os) defines a beginning of the monitoring cycle, and the remaining slots of the monitoring cycle that are not within the Ts consecutive slots (e.g., ks –Ts slots) define slots where monitoring does not occur.

In some implementations, the mobile station 1020 may receive from the wireless access node a definition of the first PDCCH monitoring behavior and the second PDCCH monitoring behavior via Radio Resource Control (RRC) signaling. In some examples, a UE can be configured to have N search space sets, which may be configured by high-layer signaling such as radio resource control (RRC) signaling. N may be an integer that is not larger than 10 and not smaller than 2 in some examples, and not smaller than 1 in other examples. The search space sets may be separated into M groups, where M is an integer that is not smaller than 2 in one example, and not smaller than 1 in another example. Note that, all search space sets in a group may correspond to a PDCCH monitoring parameter set. One search space set may be included in at least 2 groups, or one search space set may be included in only one of the M search space set groups.

In some implementations, the lowest PDCCH monitoring frequency (e.g., Ts /ks) corresponding to all search space sets in a search space group is not smaller than a minimum threshold. In some implementation, the minimum threshold is not smaller than 1/T _{drx-onDurationTimer}. In some implementations, the lowest PDCCH monitoring frequency corresponding to at least two search space set groups are different. In some examples, the search space set group with a smaller group index includes a search space set configuration corresponding to a smaller PDCCH monitoring frequency. Accordingly, in one example, the first PDCCH monitoring behavior has a pattern with a lower frequency of monitoring slots than the second PDCCH monitoring behavior. In some implementations, the lowest PDCCH monitoring frequency corresponding to all search space sets in a group is not larger than a maximum threshold. In some examples, the maximum threshold is not larger than 1. The largest PDCCH monitoring frequency corresponding to at least two search space set groups may be different. The search space set group with a larger group index may include a search space set configuration corresponding to a larger PDCCH monitoring frequency.

For example, the lowest PDCCH monitoring frequency may be 1/4 among PDCCH monitoring parameter sets corresponding to all search space sets in the first search space set group, while the lowest PDCCH monitoring frequency may be 1/2 among PDCCH monitoring parameter sets corresponding to all search space sets in the second search space sets. In another example, the largest PDCCH monitoring frequency may be 1/2 among PDCCH monitoring parameter sets corresponding to all search space sets in the first search space set group, while the largest PDCCH monitoring frequency may be 1 among PDCCH monitoring parameter sets corresponding to all search space sets in the second search space set group. Many other examples are possible.

In various embodiments, the mobile station 102 may switch a PDCCH monitoring behavior to a default PDCCH monitoring parameter set. As such, one of the first PDCCH monitoring behavior or the second PDCCH monitoring behavior may be a default PDCCH monitoring behavior for the mobile station 102, and in a particular example, the first PDCCH monitoring behavior may be the default for the mobile station 102. In various examples, the mobile station 102 may receive from the wireless access node 104 a definition of the one of the first PDCCH monitoring behavior or the second PDCCH monitoring behavior as the default PDCCH monitoring behavior via Radio Resource Control (RRC) signaling or another high-layer signaling.

In some implementations, the UE is configured with a default search space set group by a high-layer parameter. The default search space set group may contain at least one search space set. The PDCCH monitoring frequency among the PDCCH monitoring parameter sets corresponding to all search space sets in the default search space set group may have a minimum threshold (e.g., not smaller than 1/T _{drx-onDurationTimer}) . Conversely, in some implementations, the PDCCH monitoring frequency among the PDCCH monitoring parameter sets corresponding to all search space sets in the default search space set group may have a maximum threshold (e.g., not larger than 1, or the PDCCH monitoring frequency corresponding to the current search space set configuration) . In some implementations, the UE determines to monitor PDCCH in the PDCCH monitoring occasions determined by the default search space set when a timer is expired and no PDCCH has been monitored by the UE. In some implementations, the UE determines to monitor PDCCH in the PDCCH monitoring occasions determined by the default search space set when a timer is expired and no PDCCH has been monitored by the UE if the duration parameter of the default search space set is not equal to 0. In some implementations, the UE determines to monitor PDCCH in the PDCCH monitoring occasions determined by the default search space set indicated by a specific DCI format or a high-layer parameter.

In other embodiments, the UE can switch a PDCCH monitoring behavior by selecting a search space set from all of the search space sets in an active BWP, and then monitoring PDCCH in PDCCH monitoring occasions determined by the selected search space set. In some implementation, a UE can be configured with N search space sets by RRC signaling. In some implementation, N is an integer that is not larger than 10 and not smaller than 1, for example.

The following includes description of various examples of indications that can be provided to the mobile station 102 (e.g., UE) to indicate which PDCCH monitoring behavior to utilize. Such indications can be explicit indications (e.g., such as express indications provided within signaling to inform the UE of the PDCCH monitoring behavior to utilize) or can be implicit indications (e.g., such as timers) . In some embodiments, the timer is started or restarted by receiving a PDCCH with data scheduling. In some embodiments, the timer is started or restarted by receiving a PDCCH without data scheduling. In some embodiments, the timer is started or restarted by receiving a PDCCH in USS.

In some embodiments, the UE is configured with a search space set group switching function by high-layer parameter. In some implementations, the UE may report its available PDCCH monitoring behavior (s) to the wireless access node 104. In some embodiments, the search space set group switching function may be indicated by a DCI message. For example, the search space set group switching function may be indicated by a DCI format with data scheduling. For example, the search space set group switching function may be indicated by DCI format 0_1 or DCI format 1_1 with data scheduling. In another example, the search space set group switching function is indicated by DCI format 0_1 or DCI format 1_1 with scheduling a new transmission. In other examples, the search space set group function is indicated by an additional field of DCI message with a DCI format 0_1 or DCI format 1_1. The additional field of DCI format 0_1 or DCI format 1_1 hay have at most, for example, a 2 bit width. In some embodiments, the search space set group function is indicated by reinterpreting or repurposing one or more existing field of a DCI message with a DCI format 0_1 or DCI format 1_1. For example, the reinterpreted or repurposed field may be a field indicating a minimum applicable scheduling offset (e.g., K0min or K2min) . In some implementations, the search space set group switching function is indicated by DCI message with a DCI format without data scheduling. For example, the search space set group switching function may be indicated by DCI format 0_1 or DCI format 1_1 without data scheduling. In some implementation, the search space set group function is indicated by reinterpreting or repurposing some existing fields of the DCI message with DCI format 0_1 or DCI format 1_1. In some examples, the reinterpreted or repurposed field of DCI format 0_1 or DCI format 1_1 is a field indicating time domain resource assignment. In some implementation, the reinterpreted or repurposed field is a field indicating minimum applicable scheduling offset. In some implementation, the reinterpreted or repurposed field is a field indicating time domain resource assignment.

In some embodiments, the field indicating minimum applicable scheduling offset in DCI format 0_1 or DCI format 1_1 is reinterpreted or repurposed as the search space set group switching function configured by a specific high-layer parameter. In some examples, the field indicating minimum applicable scheduling offset in DCI format 0_1 or DCI format 1_1 is reinterpreted or repurposed as the search space set group switching function if the high-layer parameter indicating minimum applicable scheduling offset (e.g., the minimum value of K0 or K2) is not configured for the UE and some existing fields are set to specific states. In some implementation, the field indicating minimum applicable scheduling offset in DCI format 0_1 or DCI format 1_1 is reinterpreted or repurposed as the search space set group switching function if the high-layer parameter indicating a specific timer associated with search space set group switching is configured for the UE.

In some embodiments, a field indicating time domain resource assignment in DCI format 0_1 or DCI format 1_1 is reinterpreted or repurposed as the search space set group switching function configured by a specific high-layer parameter. In some examples, this field is reinterpreted as the search space set group switching function if the high-layer parameter indicating time domain resource assignment is not configured for the UE. In some implementation, this field is reinterpreted as the search space set group switching function if the high-layer parameter indicating a specific timer associated with search space set group switching is configured for the UE.

In some implementation, the field is reinterpreted as the PDCCH monitoring parameter switching function when some predefined fields is set to a predefined state.

In some embodiments, the mobile station 102 (e.g., UE) may utilize implicit indications, such as a timer, to perform PDCCH monitoring behavior switching. In various embodiments, the UE starts or restarts a timer, the value of which is indicated by a high-layer parameter. The UE then monitors PDCCH with the search space set group with a larger group index (e.g., a higher monitoring frequency) after a predefined Q slots or symbols after a slot that a specific type of DCI format is monitored or received by the UE. The predefined Q slots may depend on the reported UE capability. The predefined Q slots may be determined by the application delay of the minimum applicable scheduling offset if the UE is configured with the minimum applicable scheduling offset as “1. ” In some examples, the predefined Q slots associated with the indication “1” of the minimum applicable scheduling offset indicator is noted as Q1 and the predefined Q slots associated with the indication “0” of the minimum applicable scheduling offset indicator is noted as Q2. In some implementation, Q1 is larger than Q2.

In some implementation, the UE starts or restarts a timer which is indicated by a high-layer parameter and monitors PDCCH in the search space set group with smaller group index (e.g., a lower monitoring frequency) after a predefined Q slots or symbols after a slot during which the timer expired and no PDCCH has been monitored by the UE. The predefined Q slots may depend on the reported UE capability. The predefined Q slots may be determined by the application delay of the minimum applicable scheduling offset if the UE is configured with the minimum applicable scheduling offset as “1. ” The predefined Q slots associated with the indication “1” of the minimum applicable scheduling offset indicator may be noted as Q1 and the predefined Q slots associated with the indication “0” of the minimum applicable scheduling offset indicator may be noted as Q2. In some implementation, Q1 is not smaller than Q2.

In accordance with these disclosures, the method discussed above may be further defined. In various embodiments, the mobile station 102 may, in response to receiving a DCI signal intended for the mobile station, start or restart a timer, and switch to operating according to the second PDCCH monitoring behavior for a duration of the timer. In a particular example, the first PDCCH monitoring behavior has a pattern with a lower frequency of monitoring slots (e.g., a lower monitoring frequency) than the second PDCCH monitoring behavior. In certain approaches, after expiration of the timer, the mobile station 102 may switch back to operating according to the first PDCCH monitoring behavior. In certain approaches, the first PDCCH monitoring behavior is a default PDCCH monitoring behavior for the mobile station, while in other approaches the second PDCCH monitoring behavior is a default PDCCH monitoring behavior for the mobile station.

In another example, the mobile station 102 may start or restart a timer and allow the timer to expire. The mobile station 102 may determine that no DCI signal intended for the mobile station 102 was received during the duration of the timer. In response, the mobile station 102 may restart the timer and switch to operating according to the second PDCCH monitoring behavior for a next duration of the timer. The mobile station 102 may repeat this process for up to a maximum number of cycles as long as the mobile station 102 does not receive a DCI signal. In various examples, the first PDCCH monitoring behavior has a pattern with a higher frequency of monitoring slots than the second PDCCH monitoring behavior.

In some implementations, the UE monitors DCI format 0_1 or 1_1 in one of the search space set groups. In some embodiments, the UE does not expect to monitor PDCCH carrying DCI format scrambled by at least one of the P-RNTI, RA-RNTI, TC-RNTI, SI-RNTI, PS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, and TPC-SRS-RNTI. In some embodiments, the UE expects to monitor PDCCH carrying a DCI format with UE-specific search space type. In some embodiments, the search space set group switching function is only used to trigger the UE to monitor the PDCCH carrying DCI format 0_1 or 1_1 scrambled by at least one of C-RNTI, MCS-C-RNTI, CS-RNTI. In some examples, the UE does not expect to monitor PDCCH in PDCCH monitoring occasions determined by a switched search space set group when the UE is performing at least one of a physical random access channel (PRACH) procedure, a radio link monitoring (RLM) procedure, or a beam failure detection (BFD) procedure.

In various embodiments, for cross carrier scheduling, the UE may monitor PDCCH in search space set (s) , wherein the search space set (s) may include search space sets in both the search space set group in Pcell or PScell, and the search space set group in the cross carrier with data scheduling. For cross-carrier scheduling, the UE may perform search space set group switching in both Pcell or PScell and the cross carrier with data scheduling. In some implementation, a default search space set is configured per each bandwidth part (BWP) .

In some examples, a supported maximum number of search space sets in each search space set group is equal amongst the groups. In some implementation, the supported maximum number of search space sets in each search space set group is smaller than the maximum number of search space sets in an active BWP.

The number of search space sets in each search space set group may be different, and/or a maximum number of search space sets in each search space set group may be different. In some examples, the maximum number of search space sets in a search space set group with lower index is smaller than that of a search space set group with a larger index. In some examples, the supported maximum number of CORESET (s) associated with the search space sets in each search space set group is not larger than the maximum number of CORESET (s) in an active BWP. In some examples, the maximum number of CORESET (s) associated with the search space set in each search space set group may be different. In some examples, the maximum number of CORESET (s) associated with the search space set (s) in a search space set group with a lower index is smaller than that of the search space sets in a search space set group with a larger index. In some examples, the search space sets in any search space set group are not the recovery search space set or the search space set with ID=0. In some examples, the CORESET associated with the search space sets in any search space set group are not the CORESET with CORESET ID=0.

PDCCH Monitoring parameter adaptation

In various embodiments, PDCCH monitoring behavior may be changed by altering one or more of the individual parameters of the PDCCH monitoring parameter set. For example, the wireless access node 104 may manipulate one or more of the PDCCH monitoring parameters to cause a mobile station 102 to switch from operating according to a first PDCCH monitoring behavior to a second PDCCH monitoring behavior. In some embodiments, a scaling factor is utilized to alter one or more of the PDCCH monitoring parameters. As such, the method disclosed above can be further defined. In accordance with various embodiments, the mobile station 102 may receive from the wireless access node 104 a scaling factor for at least one parameter of an associated pattern of the first PDCCH monitoring behavior. The switching from the first PDCCH monitoring behavior to the second PDCCH monitoring behavior then includes applying the scaling factor to the at least one parameter of the associated pattern of the first PDCCH monitoring behavior to create the second PDCCH monitoring behavior. The at least one parameter of the associated pattern of the first PDCCH monitoring behavior may include a monitoring periodicity (ks) , a monitoring duration (Ts) , and/or a monitoring offset (Os) .

In some embodiments, the UE is configured with a set of scaling factors used for PDCCH monitoring periodicity (ks) by a specific DCI format or a high layer signaling. The set of scaling factors may include at least one offset value.

In some implementations, the scaling factor includes at least one of the values of 1/2, 1/3, 1/4, or 1/5, for example. Other scaling factors are possible. In some embodiments, the UE switches the PDCCH monitoring periodicity by multiplying it by the scaling factor indicated by the specific DCI format message. In some embodiments, the UE switches the PDCCH monitoring periodicity by multiplying it by the scaling factor indicated by the specific DCI format message and a high-layer parameter. In some implementations, the UE switches PDCCH monitoring periodicity by dividing it by the scaling factor indicated by the specific DCI format message and the high-layer parameter. In some implementation, the UE receives the PDCCH monitoring periodicity switching indicated by the specific DCI format when the high-layer parameter or signaling indicates that PDCCH monitoring periodicity switching is configured for the UE. In some examples, the scaling factor is configured per each BWP. In some implementations, the indication of the scaling factor is a reinterpreted or repurposed existing field of the specific DCI format message. The specific DCI format may be a DCI format with data scheduling, and may be a DCI format 0_1 or a DCI format 1_1.

In various embodiments, a scaling factor set includes at least one scaling factor. The scaling factor in a scaling factor set may be not smaller than 1 in some examples, and may be not larger than 1 in other examples. The scaling factor set may be configured by a high-layer parameter. In some implementations, the scaling factor value is indicated by a specific DCI format or a Medium Access Control (MAC) Control Element (CE) . The specific DCI format may be a DCI format 0_1 or a DCI format 1_1. In some approaches, the scaling factors in the scaling factor set is not larger than a maximum threshold, wherein the maximum threshold may be not smaller than the DRX onDuration timer. In some examples, the UE switches the PDCCH monitoring periodicity by subtracting the scaling factor indicated by the specific DCI format message. In some examples, the UE switches the PDCCH monitoring periodicity by multiplying it by the scaling factor indicated by the specific DCI format message and the high-layer parameter. In some implementations, the UE receives the PDCCH monitoring periodicity switching as indicated by the specific DCI format message when the high-layer parameter or signaling indicating the PDCCH monitoring periodicity switching is configured for the UE. The PDCCH monitoring scaling factor may be configured per BWP. The indication of the scaling factor used for PDCCH monitoring periodicity may be a reinterpreted or repurposed existing field of the specific DCI format. In certain embodiments, the specific DCI format is a DCI format with data scheduling.

In various embodiments, the UE is configured with a set of scaling factors used for monitoring duration (Ts) parameters in a search space set by a specific DCI format or a high layer signaling. The set of scaling factor may include at least one offset value.

In some examples, the scaling factor includes at least one of the values of 1/2, 1/3, 1/4, or 1/5. Other scaling factors are possible. In some embodiments, the UE switches PDCCH monitoring duration by multiplying it by the scaling factor indicated by the specific DCI format message. In some embodiments, the UE switches the PDCCH monitoring duration by multiplying it by the scaling factor indicated by the specific DCI format message and the high-layer parameter. In some examples, the UE switches the PDCCH monitoring duration by dividing it by the scaling factor indicated by the specific DCI format message and the high-layer parameter. In some examples, the UE receives the PDCCH monitoring duration switching indicated by the specific DCI format when the high-layer parameter or signaling indicates that PDCCH monitoring duration switching is configured for the UE. In some implementations, the scaling factor used for duration is configured per each BWP. In some examples, the indication of the scaling factor used for duration is a reinterpreted or repurposed existing field of the specific DCI format message. The specific DCI format may be a DCI format with data scheduling, and may be a DCI format 0_1 or a DCI format 1_1.

In various embodiments, a scaling factor set includes at least one scaling factor. The scaling factor in a scaling factor set may be not smaller than 1 in some examples, and may be not larger than 1 in other examples. The scaling factor set may be configured by a high-layer parameter. In some implementations, the scaling factor value is indicated by a specific DCI format or a Medium Access Control (MAC) Control Element (CE) . The specific DCI format may be a DCI format 0_1 or a DCI format 1_1. In some approaches, the scaling factors in the scaling factor set is not larger than a maximum threshold, wherein the maximum threshold may be not smaller than the DRX onDuration timer. In some examples, the UE switches PDCCH monitoring duration by subtracting the periodicity offset indicated by the specific DCI format. In some implementations, the UE switches PDCCH monitoring duration by multiplying it by the scaling factor indicated by the specific DCI format message and the high-layer parameter. In some implementation, the UE receives the PDCCH monitoring duration switching as indicated by the specific DCI format message when the high-layer parameter or signaling indicating the PDCCH monitoring duration switching is configured for the UE. The scaling factor used for PDCCH monitoring duration may be configured per each BWP. In some implementations, the indication of the scaling factor used for PDCCH monitoring duration is a reinterpreted or repurposed existing field of the specific DCI format. In certain embodiments, the specific DCI format is a DCI format with data scheduling.

In various embodiments, the UE is configured with a set of offsets used for the offset parameter Os in search space set IE by a specific DCI format or a high layer signaling. In some implementation, the set of offsets used for Os includes at least one offset value.

In accordance with various examples, the offset value is an integer and the unit is slots or ms. The UE may switch the Os parameter by adding or subtracting the offset value used for Os as indicated by the specific DCI format message. The UE may also switch the Os by adding or subtracting the offset indicated by the specific DCI format message and the high-layer parameter. An offset set may include at least one offset value. The offset value in an offset set is not smaller than 1 in some examples, and is not larger than the value of the PDCCH monitoring periodicity (ks) in other examples. The offset set may be configured by high-layer parameter. The offset value may be indicated by a specific DCI format message or MAC CE. The specific DCI format may be a DCI format 0_1 or a DCI format 1_1. In some examples, the offset values in an offset set is not larger than a maximum threshold. In various implementations, the maximum threshold is not smaller than the DRX onDuration timer, or is not smaller than the value of the PDCCH monitoring periodicity (ks) . In some examples, the UE receives the Os parameter switching indicated by the specific DCI format message when the high-layer parameter or signaling indicating that the Os parameter switching is configured for the UE. The offset used for Os may be configured per BWP. In some examples, the indication of the offset used for Os is a reinterpreted or repurposed existing field of the specific DCI format. In some examples, the specific DCI format is a DCI format with data scheduling.

In some embodiments, the PDCCH monitoring parameter switching indication, e.g. PDCCH monitoring periodicity ks, duration Ts, and the PDCCH monitoring offset Os, are configured by high-layer parameters. The UE may determine the specific offset value according to the index indicated by a level 1 (L1) signaling and the set of scaling factor or offset value associated with the corresponding parameter switching behavior configured by high-layer parameter.

Bundling PDCCH monitoring behavior with other power saving functions

In some embodiments, the PDCCH monitoring behavior may be bundled with a wake-up indication. For example, the UE may switch the PDCCH monitoring behavior by selecting a search space set 1 or a new search space set group 1 when DCI format 2_6 triggers the UE to monitor PDCCH in the next “DRX On” duration (Active Time) . Similarly, the UE may switch PDCCH monitoring behavior by selecting a search space set 2 or a new search space set group 2 when a DCI format 2_6 triggers UE not to monitor PDCCH in the next “DRX On” duration. In some embodiments, if the wake-up signal is not received by the UE for a DRX cycle because of missed detection of the DCI format 2-6, the UE may perform the PDCCH monitoring behavior according to the default configuration of the wake-up indication. In some embodiments, if the wake-up signal is not detected by the UE for a DRX cycle, the UE shall perform the PDCCH monitoring behavior by selecting a search space set 2 or search space set group 2. In some embodiments, if the wake-up signal is not detected by the UE for a DRX cycle, the UE shall perform the current PDCCH monitoring behavior.

In some embodiments, the PDCCH monitoring behavior switching function is indicated by DCI format 2-6 for a UE. In some embodiments, the field of the PDCCH monitoring behavior switching function in DCI format 2-6 is behind the field of the dormancy-like behavior transitioning function on Scells for a UE. In some embodiments, the field of the PDCCH monitoring behavior switching function in DCI format 2-6 is behind the field of the wake-up function for a UE.

In some examples, the search space set 1 is a default search space set, and may have a lower PDCCH monitoring frequency among that of all the search space sets in the active BWP. This PDCCH monitoring frequency may be smaller than a minimum monitoring threshold. In various approaches, the minimum monitoring threshold is not smaller than 1/the maximum value of ks and/or is not larger than 1/2. In specific examples, the minimum threshold is not larger than 1/T _{drx-onDurationTimer}. In other examples, the search space set 1 may have a higher or a highest PDCCH monitoring frequency among that of all the search space sets in the active BWP.

In some examples, the search space set 2 is a default search space set, and may have a larger PDCCH monitoring frequency among that of all the search space sets in the active BWP. The PDCCH monitoring frequency may be larger than a maximum monitoring threshold. In various approaches, the maximum monitoring threshold is not larger than 1 and/or is not smaller than 1/2. In specific examples, the minimum threshold is not smaller than 1/T _{drx-onDurationTimer}. In other examples, the search space set 2 may have a lower or a lowest PDCCH monitoring frequency among that of all the search space sets in the active BWP.

The search space set 1 and search space set 2 may be different search space sets with different indices for one UE for an active BWP. In another approach, the search space set 1 and search space set 2 are the same search space set, but with modified PDCCH monitoring parameters, for example, Duration, monitoringSlotPeriodicityAndOffset, or monitoringSymbolsWithinSlot, for an active BWP.

In certain embodiments, the search space set group 1 is a default search space set group, and may include a search space set with a lower PDCCH monitoring frequency among that of all the search space sets in the active BWP. This PDCCH monitoring frequency may be smaller than a minimum monitoring threshold. In various approaches, the minimum monitoring threshold is not smaller than 1/the maximum value of ks and/or is not larger than 1/2. In specific examples, the minimum threshold is not larger than 1/T _{drx-onDurationTimer}. In other examples, the search space set group 1 may include a search space set with a higher or a highest PDCCH monitoring frequency among that of all the search space sets in the active BWP.

In certain embodiments, the search space set group 2 is a default search space set group, and may include a search space set with a larger PDCCH monitoring frequency among that of all the search space sets in the active BWP. This PDCCH monitoring frequency may be larger than a maximum monitoring threshold. In various approaches, the maximum monitoring threshold is not larger than 1 and/or is not smaller than 1/2. In specific examples, the minimum threshold is not smaller than 1/T _{drx-onDurationTimer}. In other examples, the search space set group 2 may include a search space set with a lower or a lowest PDCCH monitoring frequency among that of all the search space sets in the active BWP.

The search space set group 1 and search space set group 2 may be different search space sets with different indices for one UE for an active BWP. In another approach, the search space set group 1 and search space set group 2 include the same search space set, wherein, for example, the same search space set is not smaller than the search space set with a lowest PDCCH monitoring frequency in the search space set group 1 and/or the same search space set is not larger than the search space set with highest PDCCH monitoring frequency in the search space set group 2.

Accordingly, the method disclosed above can be further defined. In accordance with various embodiments, the mobile station 102 (e.g., UE) receives the indication to switch to the second PDCCH monitoring behavior, which includes the mobile station 102 receiving a wake-up indication for a discontinuous reception (DRX) mode cycle instructing the mobile station to wake-up for a next DRX cycle. In various approaches, the first PDCCH monitoring behavior has a pattern with a higher frequency of monitoring slots (e.g., higher monitoring frequency) than the second PDCCH monitoring behavior (or vice versa) .

In some embodiments, the PDCCH monitoring behavior may be bundled with cross-slot scheduling. For example, the UE may switch PDCCH monitoring behavior to a search space set 1 or a search space set group 1 when the minimum applicable scheduling offset (e.g., K0min or K2min) is indicated as a value larger than 0 by a DCI format 1_1 or DCI format 0_1. The UE may also switch the PDCCH monitoring behavior to a search space set 2 or a search space set group 2 when the minimum applicable scheduling offset is indicated as a value equal to 0 by a DCI format 1_1 or DCI format 0_1.

In some embodiments, the UE may perform PDCCH monitoring switching behavior when the minimum applicable scheduling offset is indicated as a value larger than 0 by a DCI format 1_1 or DCI format 0_1. In some embodiments, the UE may switch the PDCCH monitoring behavior to a search space set 1 or a search space set group 1 when the minimum applicable scheduling offset, e.g. K0min is larger than a minimum threshold 1. Similarly, in some embodiments, the UE may switch the PDCCH monitoring behavior to a search space set 2 or a search space set group 2 when the minimum applicable scheduling offset K0min is smaller than a minimum threshold 2. In some embodiments, the minimum threshold 1 may be larger than the minimum threshold 2, and the minimum threshold 2 may be not smaller than 0. In some embodiments, the minimum applicable scheduling offset K0min is configured by high-layer parameter.

In accordance with the above, the methods disclosed above can be further defined. In accordance with various embodiments, the mobile station 102 (e.g., UE) receives the indication to switch to the second PDCCH monitoring behavior, which may include receiving a change of a value of a Physical Downlink Shared Channel (PDSCH) minimum applicable scheduling offset (K0) between reception of a message on the PDCCH and a scheduling slot on the PDSCH. Similarly, this may include receiving a change of a value of a Physical Uplink Shared Channel (PUSCH) minimum applicable scheduling offset (K2) between reception of the message on the PDCCH and a scheduling slot on the PUSCH. In certain approaches, receiving the change of the value of the K0 or the K2 comprises receiving an increase in the value of the at least one of the K0 or the K2 above a minimum applicable scheduling offset threshold. In various approaches, the second PDCCH monitoring behavior has a pattern with a lower frequency of monitoring slots (e.g., lower monitoring frequency) than the first PDCCH monitoring behavior. Similarly, receiving the change of the value of the K0 or the K2 may comprise receiving a decrease in the value of the K0 or the K2 below a minimum applicable scheduling offset threshold. In various approaches, the second PDCCH monitoring behavior has a pattern with a higher frequency of monitoring slots (e.g., a higher monitoring frequency) than the first PDCCH monitoring behavior.

In some embodiments, the PDCCH monitoring behavior may be bundled with dormancy-like behavior transition on Scell. For example, the UE may switch PDCCH monitoring behavior to a search space set 1 or a search space set group 1 when the number of Scells with dormancy-like behavior indicated by DCI format 2_6, DCI format 1_0, or DCI format 1_1 is larger than a threshold Nd. In some examples, the UE switches the PDCCH monitoring behavior to a search space set 2 or a search space set group 2 when the number of Scells with non-dormancy-like behavior indicated by DCI format 2_6, DCI format 1_0, or DCI format 1_1 is larger than a threshold Nd. In some examples, Nd is not smaller than 1 and not larger than the total number of Scells in the scheduling Scell group.

Switching PDCCH monitoring behavior between PDCCH search space set switching behavior and PDCCH skipping behavior

In some embodiments, the mobile station 102 (e.g., UE) can perform a PDCCH skipping behavior for a skipping duration. FIG. 5 shows an example timing diagram illustrating various aspects of a PDCCH skipping behavior in accordance with various embodiments. A series of units, such as slots or times, are shown. After the occurrence of a skip triggering event (e.g., reception of a DCI message that indicates to the UE to use a PDCCH skipping behavior) , the UE may perform a PDCCH skipping for a skipping period of a duration of units (e.g., slots, time, etc. ) . Optionally, an application delay may be applied after the skip triggering event (e.g., after receipt of the DCI) and prior to performing the PDCCH skipping for the skipping period, during which the mobile station 102 continues to monitor PDCCH. The PDCCH skipping behavior may be associated with a PDCCH skipping parameter set, which may include one or more parameters that dictate the PDCCH skipping behavior. One such parameter is the PDCCH skipping period, which may be a number of units (or time) in which the mobile station 102 does not monitor PDCCH. It may be an integer greater than or equal to 0 (e.g., 1) . A unit may comprise slots, PDCCH monitoring occasions, PDCCH monitoring periodicity, or (sub-) frames, or milliseconds, or PDCCH monitoring durations.

In some embodiments, the mobile station 102 (e.g., UE) can switch the PDCCH monitoring behavior for the mobile station 102 between the PDCCH search space set switching behavior (described in detail above) and a PDCCH skipping behavior. Thus, in accordance with the above embodiments, the PDCCH monitoring behavior contains at least one of the following behaviors: a search space set switching behavior; a search space set selection behavior; a search space set group switching behavior; a PDCCH monitoring parameter switching behavior; a PDCCH monitoring parameter modification behavior; and a PDCCH skipping behavior.

In some embodiments, high-layer parameters (e.g., included within the RRC) configures the PDCCH monitoring behavior of the UE to switch between a PDCCH search space set/group switching behavior and a PDCCH skipping behavior.

In other embodiments, the UE switches or performs a particular PDCCH monitoring behavior according to an indication in layer 1 (L1) signaling, such as an indication with a DCI message.

In other embodiments, the UE switches or performs a particular PDCCH monitoring behavior according to a parameter indicated in L1 signaling (e.g., DCI) that corresponds to a PDCCH monitoring behavior configured by high-layer signaling (e.g., RRC) . For example, in some embodiments, the UE performs PDCCH skipping behavior for a predefined skipping duration indicated by the DCI format 0_1 or 1_1 message when the high-layer parameter configures a PDCCH skipping behavior for the UE. In some approaches, the UE also performs search space set or search space set group switching behavior as indicated by the DCI format 0_1 or 1_1 message when the high-layer parameter configures a PDCCH skipping behavior for the UE.

In some implementation, a set of the PDCCH skipping parameter is configured by the high-layer parameter and the UE determines the value of the PDCCH skipping parameters according to an index indicated by L1 signaling (e.g., a DCI) . In some examples, the bit width of the index of the PDCCH skipping parameter set indicated by L1 signaling (e.g., DCI) is not larger than 2. In some examples, the L1 signaling is DCI format 0_1 or 1_1 with data scheduling. In some examples, the L1 signaling is DCI format 0_1 or 1_1 without data scheduling and with the predefined field (s) set to be all “0” or all “1. ” In some examples, the predefined field is the field of frequency domain resource allocation, the field of time domain resource allocation, the field of MCS index, and/or the field of HARQ process number.

The indication for performing or switching PDCCH skipping behavior, which can be provided in the DCI, may be the same or similar to the indication discussed above for PDCCH search space switching behavior, in various embodiments. Further, in the above embodiments, the methods discussed above for PDCCH monitoring switching may also be suitable for switching to or switching the parameters of the PDCCH skipping behavior.

In some embodiments, the UE can report its features associated with the PDCCH monitoring behavior for power saving. The UE can report or transmit a preferred PDCCH monitoring behavior to the wireless access node 104. The UE can then perform PDCCH monitoring with the parameters indicated by L1 signaling (e.g., DCI) corresponding to the reported feature of PDCCH monitoring behavior.

In some embodiments, the parameters of the PDCCH skipping behavior include an offset used to determine the start position (e.g., offset) of the skipping period and/or a skipping period duration used to trigger the UE not to monitor PDCCH in the duration of the skipping period.

In some embodiments, for example, where the PDCCH skipping parameters do not include a predefined offset, the UE may start to skip PDCCH monitoring from a slot n. The slot n may be the slot after Sk slots or ms from a next slot in which the DCI is received by the UE. The Sk may be the application delay, in which the unit are defined as slots or ms. The Sk may be a UE capability reported by the UE to the wireless access node 104. In some approaches, the Sk is not smaller than the application delay of the minimum applicable scheduling offset if the cross-slot scheduling and PDCCH skipping behavior are both indicated in a same DCI.

In some embodiments, the parameters of PDCCH skipping behavior may include the same parameters as the search space set IE. For example, the parameters may include the PDCCH monitoring duration Ts, offset Os, and periodicity ks. In some implementation, the duration (Ts) for PDCCH skipping behavior is set to 0. In some embodiments, the UE performs PDCCH monitoring behavior only continuing a PDCCH periodicity (ks) , if the duration (Ts) of the corresponding monitoring parameters set is equal to 0. In some embodiments, the UE can fall back to perform the last recent PDCCH monitoring behavior after a whole PDCCH monitoring periodicity (ks) if the PDCCH monitoring duration (Ts) of the monitoring parameters set corresponding to the triggered PDCCH monitoring behavior is equal to 0.

In some examples, the PDCCH skipping period duration is an integer that is not larger than the “DRX On” duration timer configured by the high-layer parameter. In other examples, the PDCCH skipping period duration is an integer that is not larger than the DRX Inactivity timer configured by the high-layer parameter. In some implementation, the units of the PDCCH skipping period duration are slot or milliseconds (ms) .

In accordance with the above, the methods disclosed above can be further defined. FIG. 6 provides an example flow diagram illustrating a method 600 of communicating between a wireless access node 104 and a mobile station 102 to achieve such PDCCH monitoring behavior switching functionality (e.g., between space set switching and PDCCH monitoring skipping) , according to various embodiments. At step 602, the mobile station 102 operates according to a first PDCCH monitoring behavior associated with a first PDCCH monitoring parameter set. At step 604, the mobile station 102 switches from operating according to the first PDCCH monitoring behavior to a second PDCCH monitoring behavior associated with a PDCCH skipping parameter set. In this embodiment, the first PDCCH monitoring parameter set defines a unique pattern defining one or more monitoring slots or occasions within a monitoring period (e.g., ks) wherein the mobile station 102 monitors a PDCCH for a DCI message. However, the skipping parameter set defines at least a skipping period during which the mobile station does not monitor the PDCCH for the DCI message.

In some embodiments, the mobile station 102 performs the switching in response to receiving a DCI message including an indication to operate according to the second PDCCH monitoring behavior. In another embodiment, the mobile station 102 may receive high-layer signaling (e.g., RRC) configuring at least the PDCCH skipping parameter set of the second PDCCH monitoring behavior. In this embodiment, the mobile station 102 performs the switching in response to receiving a DCI message including an indication to operate according to the second PDCCH monitoring behavior, which may include an index indicating the PDCCH skipping parameter set of the second PDCCH monitoring behavior. The skipping parameter set of the second PDCCH monitoring behavior may also comprises at least one of a duration of the skipping period of an offset dictating a start position of the skipping period.

In another embodiment, the mobile station 102 transmits to the wireless access node 104 an indication of a preferred PDCCH monitoring behavior comprising at least the second PDCCH monitoring behavior (e.g., a PDCCH skipping behavior) . The mobile station 102 then switches from operating according to the first PDCCH monitoring behavior to the second PDCCH monitoring behavior in response to receiving a DCI message including an indication corresponding to the preferred PDCCH monitoring behavior (being the second PDCCH monitoring behavior) .

In some embodiments, for the case where the specific field is reinterpreted to be the indication of PDCCH monitoring parameter or behavior switching function for the UE, some existing fields or the predefined fields can be set to some specific states as presented in this disclosure. In some embodiments, these existing fields may include at least “Frequency domain resource assignment” and/or “Time domain resource assignment” fields in DCI format 0_1 or 1_1, “Modulation and coding scheme, ” “New data indicator, ” “Redundancy version” and/or “HARQ process number” fields in DCI format 0_1 or 1_1, “Modulation and coding scheme, ” “New data indicator, ” “Redundancy version” and/or “HARQ process number” fields for transport block 2 in DCI format 1_1 if high-layer parameter maxNrofCodeWordsScheduledByDCI equals 2. For example, if the “Time domain resource assignment” field is set to all “1, ” “HARQ process number” fields are set to all “0, ” and the fields for transport block 2, including “Modulation and coding scheme” field is set to all “1” and the “Redundancy version” field is set to all “0” in DCI format 1_1, the minimum applicable scheduling offset field may be reinterpreted into the indication of the PDCCH monitoring behavior switching function. Where the maxNrofCodeWordsScheduledByDCI parameter equals to 2. If high-layer parameter configures UE being able to switch the PDCCH monitoring behavior, then the UE switches to the first PDCCH monitoring behavior if the field is set to “0, ” otherwise, the UE switches to the second PDCCH monitoring behavior. If the high-layer parameter does not configure UE being able to switch the PDCCH monitoring behavior, the field is set to 0 bit or the UE will ignore the indication of the field, or the UE expects the field is not to be reinterpreted.

In some embodiments, the application delay of the PDCCH monitoring parameters or behaviors switching function is not smaller than that of the functions indicated by a same L1 signaling or performed by the UE at the same time. In some embodiments, the functions include the cross-slot scheduling, namely, the minimum value of K0 or K2 is larger than 0. In some embodiments, the functions include the BWP switching function. In some embodiments, the functions include the dormancy-like behavior transitioning function on Scell (s) .

Reporting UE capability of PDCCH monitoring behavior

In some embodiments, the UE reinterprets a specific field of a DCI format based on a reported parameter or a signaling. As mentioned above, the UE may report a preferred PDCCH monitoring behavior configuration according to a specific UE capability. In some examples, the UE reports a supported PDCCH monitoring behavior according to a specific UE capability. In other examples, the UE reports whether the UE supports the PDCCH monitoring parameter switching function according to a specific UE capability. In other examples, the UE reports whether the UE supports search space set switching function according to a specific UE capability. In other examples, the UE reports whether the UE supports search space set group switching function according to a specific UE capability. In other examples, the UE reports whether the UE supports PDCCH skipping behavior according to a specific UE capability. In some examples, the UE feature corresponding to at least one of the aforementioned UE capabilities or high-layer parameters is supported by the UE supporting release 16. In some implementation, the UE feature corresponding to the aforementioned UE capability or high-layer parameter is supported by the UE supporting release 17 and the updated release.

In accordance with the above, the methods disclosed above can be further defined. In accordance with various embodiments, the mobile station 102 (e.g., UE) transmits to the wireless access node 104 at least one of a preferred or supported mode of operating comprising at least one of the first PDCCH monitoring behavior and the second PDCCH monitoring behavior. The mobile station 102 may then receive from the wireless access node 104 a definition of the first PDCCH monitoring behavior and the second PDCCH monitoring behavior in accordance with the preferred or supported mode of operating.

In various embodiments, as illustrated in FIG. 1, the mobile station 102 includes a processor 110 and a memory 112, wherein the processor 110 is configured to read computer code from the memory 112 to implement any of the methods and embodiments disclosed above relating to operations of the mobile station 102. Similarly, the wireless access node 104 includes a processor 120 and a memory 122, wherein the processor 120 is configured to read computer code from the memory 122 to implement any of the methods and embodiments disclosed above relating to operations of the wireless access node 104. Also, in various embodiments, a computer program product includes a non-transitory computer-readable program medium (e.g., memory 112 or 122) with computer code stored thereupon. The computer code, when executed by a processor (e.g., processor 110 or 120) , causes the processor to implement a method corresponding to any of the embodiments disclosed above.

Various embodiments and solutions are disclosed above. These solutions may include one or more of the following:

1. The UE monitors PDCCH in PDCCH monitoring occasions determined by search space set (s) of a search space set group. Wherein the number of search space set group are not smaller than 1.

2. The search space set group is indicated by a DCI format with data scheduling. Wherein the indication of search space set group is reinterpreted by an existing field of minimum applicable scheduling offset indicator in DCI format 0_1 or 1_1 if the minimum applicable scheduling offset is not configured by RRC signaling.

3. The search space set group is indicated by a DCI format without data scheduling. Wherein the indication of search space set group is reinterpreted by an existing field of time domain resource assignment or minimum applicable scheduling offset indicator in DCI format 0_1 or 1_1.

4. The search space set group switching function is indicated by DCI format of UE-specific search space type.

5. in some approaches, the search space set group switching function may not be used for PDCCH monitoring with at least one of the following events:

1) DCI format scrambled by at least one of the RNTIs including P-RNTI, RA-RNTI, TC-RNTI, SI-RNTI, PS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, and TPC-SRS-RNTI;

2) performing at least one of the PRACH, RLM, or BFD procedures;

3) DCI format 0_0 or 1_0;

4) Minimum applicable scheduling offset indicator is set to “0” indicated by DCI format 0_1 or 1_1.

6. The maximum number of search space set in each search space set group may be different. The maximum number of search space set in a search space set group with lower index may be smaller than that in a search space set group with larger index.

7. The maximum number of CORESET associated with search space set in each search space set group may be different. The maximum number of CORESET associated with search space set in a search space set group with lower index may be smaller than that in a search space set group with larger index.

In other embodiments, the UE switches or performs a particular PDCCH monitoring behavior according to a timer.

In other embodiments, an indication of a PDCCH search space set/group switching behavior and an indication of PDCCH skipping behavior are jointly encoded.

In other embodiments, UE is only allowed to perform PDCCH skipping behavior when UE switches to a plurality of PDCCH search space sets/groups.

In other embodiments, UE is not allowed to perform PDCCH skipping behavior when UE switches to a plurality of PDCCH search space sets/groups.

In other embodiments, the UE switches or performs a particular PDCCH monitoring behavior according at least one of the following:

DRX cycle type, DRX group, OndurationTimer, DRXInactivityTimer.

In an example, the DRX cycle type includes short DRX cycle and/or long DRX cycle. In some examples, whether UE is allowed to perform PDCCH search space set/group switching behavior or PDCCH skipping behavior depends on the short DRX cycle or long DRX cycle is used.

In an example, the DRX group includes a first DRX group and/or a second DRX group. In some examples, whether UE is allowed to perform PDCCH search space set/group switching behavior or PDCCH skipping behavior depends on whether first DRX group or second DRX group is used. Wherein the first and second DRX group have same parameters except for OndurationTimer and/or DRXInactivityTimer.

In accordance with the various methods and embodiments disclosed above, various technical advantages are realized. Primarily, additional power savings are achieved by reducing the amount of time the mobile station 102 is required to monitor the PDCCH.

The description and accompanying drawings above provide specific example embodiments and implementations. The described subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any example embodiments set forth herein. A reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, subject matter may be embodied as methods, devices, components, systems, or non-transitory computer-readable media for storing computer codes. Accordingly, embodiments may, for example, take the form of hardware, software, firmware, storage media or any combination thereof. For example, the method embodiments described above may be implemented by components, devices, or systems including memory and processors by executing computer codes stored in the memory.

Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. 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. It is intended, for example, that claimed subject matter includes combinations of example embodiments in whole or in part.

In general, terminology may be understood at least in part from usage in context. For example, terms, such as “and” , “or” , or “and/or, ” as used herein may include a variety of meanings that may depend at least in part on the context in which such terms are used. Typically, “or” if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a, ” “an, ” or “the, ” may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present solution should be or are included in any single implementation thereof. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, discussions of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment.

Furthermore, the described features, advantages and characteristics of the present solution may be combined in any suitable manner in one or more embodiments. One of ordinary skill in the relevant art will recognize, in light of the description herein, that the present solution can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present solution.

Claims

A method of communicating between a wireless access node and a mobile station, the method comprising:

operating, by the mobile station, according to a first Physical Downlink Control Channel (PDCCH) monitoring behavior associated with a first PDCCH monitoring parameter set; and

switching, by the mobile station, from operating according to the first PDCCH monitoring behavior to a second PDCCH monitoring behavior associated with a second PDCCH monitoring parameter set.
The method according to claim 1,

wherein each of the first PDCCH monitoring parameter set and the second PDCCH monitoring parameter set defines a unique pattern defining at least one monitoring slot within a monitoring period wherein the mobile station monitors a PDCCH for a Downlink Control Information (DCI) .
The method according to claim 1, further comprising:

receiving, by the mobile station from the wireless access node, an indication to switch to the second PDCCH monitoring behavior;

wherein the switching to the second PDCCH monitoring behavior occurs in response to receiving the indication to switch to the second PDCCH monitoring behavior.
The method according to claim 3,

wherein receiving the indication comprises receiving, by the mobile station from the wireless access node, a DCI including a message part indicating the mobile station is to use the second PDCCH monitoring behavior.
The method according to claim 4,

wherein the message part indicating the mobile station is to use the second PDCCH monitoring behavior comprises at least a portion of a message field repurposed from another purpose.
The method according to claim 5,

wherein the message field repurposed from another purpose comprises at least one of a minimum applicable scheduling offset message field, a resource assignment message field or HARQ process number or the fields for a transport block including Modulation and coding scheme and Redundancy version fields.
The method according to claim 1,

wherein the first PDCCH monitoring behavior has a pattern with a lower frequency of monitoring slots than the second PDCCH monitoring behavior.
The method according to claim 1, further comprising:

receiving, by the mobile station from the wireless access node, a definition of the first PDCCH monitoring behavior and the second PDCCH monitoring behavior via Radio Resource Control (RRC) signaling.
The method according to claim 1:

wherein each of the first PDCCH monitoring behavior and the second PDCCH monitoring behavior defines the associated unique pattern according to a monitoring periodicity (ks) , a monitoring duration (Ts) , and a monitoring offset (Os) ,

wherein the monitoring periodicity (ks) defines a duration of a monitoring cycle as ks slots,

wherein the monitoring duration (Ts) defines a duration of Ts consecutive slots during which monitoring occurs, wherein Ts ≤ ks,

wherein the monitoring offset (Os) defines a beginning of the monitoring cycle, and

wherein the remaining slots of the monitoring cycle that are not within the Ts consecutive slots define slots where monitoring does not occur.
The method according to claim 9,

wherein each of the parameters configured by high-layer parameter has a unit of millisecond.
The method according to claim 1,

wherein one of the first PDCCH monitoring behavior or the second PDCCH monitoring behavior is a default PDCCH monitoring behavior for the mobile station.
The method according to claim 1,

wherein the first PDCCH monitoring behavior is a default PDCCH monitoring behavior for the mobile station.
The method according to any of claims 11 to 12, further comprising:

receiving, by the mobile station from the wireless access node, a definition of the one of the first PDCCH monitoring behavior or the second PDCCH monitoring behavior as the default PDCCH monitoring behavior via Radio Resource Control (RRC) signaling.
The method according to claim 1, further comprising:

in response to receiving a DCI signal intended for the mobile station:

starting or restarting a timer; and

switching to operating according to the second PDCCH monitoring behavior for a duration of the timer.
The method according to claim 14,

wherein the first PDCCH monitoring behavior has a pattern with a lower frequency of monitoring slots than the second PDCCH monitoring behavior.
The method according to any of claims 14 to 15, further comprising:

after expiration of the timer, switching back to operating according to the first PDCCH monitoring behavior.
The method according to any of claims 14 to 15, further comprising:

after a monitoring cycle, switching back to operating according to the first PDCCH monitoring behavior if the monitoring duration of the second PDCCH monitoring behavior is equal to 0.
The method according to any of claims 12 to 17,

wherein the first PDCCH monitoring behavior is a default PDCCH monitoring behavior for the mobile station.
The method according to claim 1, further comprising:

starting a timer;

allowing the timer to expire;

in response to determining that no DCI signal intended for the mobile station was received during a duration of the timer:

restarting the timer; and

switching to operating according to the second PDCCH monitoring behavior for a next duration of the timer.
The method according to claim 1, further comprising:

starting a timer;

allowing the timer to expire;

in response to determining that a DCI signal indicates the mobile station to perform another PDCCH monitoring behavior during a duration of the timer:

restarting the timer; and

switching to operating according to the PDCCH monitoring behavior for a next duration of the timer.
The method according to any of claims 19 to 20,

wherein the first PDCCH monitoring behavior has a pattern with a higher frequency of monitoring slots than the second PDCCH monitoring behavior.
The method according to claim 1, further comprising:

receiving, by the mobile station from the wireless access node, a scaling factor for at least one parameter of an associated pattern of the first PDCCH monitoring behavior;

wherein the switching from the first PDCCH monitoring behavior to the second PDCCH monitoring behavior comprises:

applying the scaling factor to the at least one parameter of the associated pattern of the first PDCCH monitoring behavior to obtain the second PDCCH monitoring behavior.
The method according to claim 22,

wherein the at least one parameter of the associated pattern of the first PDCCH monitoring behavior comprises at least one of a monitoring periodicity (ks) , a monitoring duration (Ts) , or a monitoring offset (Os) .
The method according to claim 23,

wherein the monitoring periodicity (ks) defines a duration of a monitoring cycle as ks slots,

wherein the monitoring duration (Ts) defines a duration of Ts consecutive slots during which monitoring occurs, wherein Ts ≤ ks,

wherein the monitoring offset (Os) defines a beginning of the monitoring cycle,

wherein the remaining slots of the monitoring cycle that are not within the Ts consecutive slots define slots where monitoring does not occur.
The method according to claim 3,

wherein receiving the indication to switch to the second PDCCH monitoring behavior comprises receiving a wake-up indication for a discontinuous reception (DRX) mode cycle instructing the mobile station to wake-up for a next DRX cycle.
The method according to claim 25,

wherein the first PDCCH monitoring behavior has a pattern with a higher frequency of monitoring slots than the second PDCCH monitoring behavior.
The method according to claim 25, further comprising:

switching, by the mobile station, to the second PDCCH monitoring behavior if there is no DCI format 2-6 received by the mobile station.
The method according to claim 3,

wherein receiving the indication to switch to the second PDCCH monitoring behavior comprises receiving a change of a value of a Physical Downlink Shared Channel (PDSCH) minimum applicable scheduling offset (K0) between reception of a message on the PDCCH and a scheduling slot on the PDSCH.
The method according to claim 3,

wherein receiving the indication to switch to the second PDCCH monitoring behavior comprises receiving a change of a value of a Physical Uplink Shared Channel (PUSCH) minimum applicable scheduling offset (K2) between reception of the message on the PDCCH and a scheduling slot on the PUSCH.
The method according to any of claims 28 to 29,

wherein receiving the change of the value of at least one of the K0 or the K2 comprises receiving an increase in the value of the at least one of the K0 or the K2 above a minimum applicable scheduling offset threshold, and

wherein the second PDCCH monitoring behavior has a pattern with a lower frequency of monitoring slots than the first PDCCH monitoring behavior.
The method according to any of claims 28 to 29,

wherein receiving the change of the value of at least one of the K0 or the K2 comprises receiving a decrease in the value of the at least one of the K0 or the K2 below a minimum applicable scheduling offset threshold, and

wherein the second PDCCH monitoring behavior has a pattern with a higher frequency of monitoring slots than the first PDCCH monitoring behavior.
The method according to any of claims 30 to 31,

wherein a minimum applicable scheduling offset threshold is not smaller than 0.
The method according to claim 1,

wherein the second PDCCH monitoring behavior associated with the second PDCCH monitoring parameters set is used to monitor the DCI format of USS for the mobile station.
The method according to claim 1, further comprising:

transmitting, by the mobile station to the wireless access node, at least one of a preferred or supported mode of operating comprising at least the first PDCCH monitoring behavior and the second PDCCH monitoring behavior; and

receiving, by the mobile station from the wireless access node, a definition of the first PDCCH monitoring behavior and the second PDCCH monitoring behavior.
A method of communicating between a wireless access node and a mobile station, the method comprising:

operating, by the mobile station, according to a first Physical Downlink Control Channel (PDCCH) monitoring behavior associated with a first PDCCH monitoring parameter set; and

switching, by the mobile station, from operating according to the first PDCCH monitoring behavior to a second PDCCH monitoring behavior associated with a PDCCH skipping parameter set;

wherein the first PDCCH monitoring parameter set defines a unique pattern defining one or more monitoring slots within a monitoring period wherein the wireless access node monitors a PDCCH for a Downlink Control Information (DCI) , and

wherein the PDCCH skipping parameter set defines at least a skipping period during which the mobile station does not monitor the PDCCH for the DCI.
The method according to claim 35,

wherein switching from operating according to the first PDCCH monitoring behavior to the second PDCCH monitoring behavior comprises switching in response to receiving a DCI message including an indication to operate according to the second PDCCH monitoring behavior.
The method according to claim 35, further comprising:

receiving high-layer signaling configuring at least the PDCCH skipping parameter set of the second PDCCH monitoring behavior;

wherein switching from operating according to the first PDCCH monitoring behavior to the second PDCCH monitoring behavior comprises switching in response to receiving a DCI message including an indication to operate according to the second PDCCH monitoring behavior.
The method according to claim 37,

wherein the DCI message including the indication to operate according to the second PDCCH monitoring behavior includes an index indicating the PDCCH skipping parameter set of the second PDCCH monitoring behavior.
The method according to claim 37,

wherein the PDCCH skipping parameter set of the second PDCCH monitoring behavior also comprises at least one of a duration of the skipping period of an offset dictating a start position of the skipping period.
The method according to claim 35, further comprising:

transmitting, by the mobile station to the wireless access node, an indication of a preferred PDCCH monitoring behavior comprising the second PDCCH monitoring behavior;

wherein switching from operating according to the first PDCCH monitoring behavior to the second PDCCH monitoring behavior comprises switching in response to receiving a DCI message including an indication corresponding to the preferred PDCCH monitoring behavior.
A mobile station comprising a processor and a memory, wherein the processor is configured to read computer code from the memory to implement a method in any one of claims 1 to 40.
A computer program product comprising a non-transitory computer-readable program medium with computer code stored thereupon, the computer code, when executed by a processor, causing the processor to implement a method of any one of claims 1 to 40.