Patent Description:
The following abbreviations and acronyms are herewith defined, at least some of which are referred to within the following description.

Third Generation Partnership Project ("3GPP"), Channel Busy Ratio ("CBR"), Device-to-Device ("D2D"), further enhancement Device-to-Device ("feD2D"), Downlink Control Information ("DCI"), Downlink ("DL"), Evolved Node B ("eNB"), Frequency Division Duplex ("FDD"), Frequency-Division Multiplexing ("FDM"), Frequency Division Multiple Access ("FDMA"), Long Term Evolution ("LTE"), LTE Advanced ("LTE-A"), Modulation and Coding Scheme ("MCS"), Machine Type Communication ("MTC"), Physical Downlink Control Channel ("PDCCH"), Physical Downlink Shared Channel ("PDSCH"), ProSe Per Packet Priority ("PPPP"), Physical Sidelink Control Channel ("PSCCH"), Physical Sidelink Shared Channel ("PSSCH"), Physical Uplink Control Channel ("PUCCH"), Physical Uplink Shared Channel ("PUSCH"), Radio Network Temporary Identity ("RNTI"), Radio Resource Control ("RRC"), Reference Signal Receiving Power ("RSRP"), Receive Signal Strength Indicator ("RSSI"), Receive ("RX"), Scheduling Assignment ("SA"), Sidelink Control Information ("SCI"), Signal to Interference plus Noise Ratio ("SINR"), Sidelink ("SL"), Semi-Persistent Scheduling ("SPS"), Time Division Duplex ("TDD"), Time-Division Multiplexing ("TDM"), Transmission Time Interval ("TTI"), Transmit ("TX"), User Entity/Equipment (Mobile Terminal) ("UE"), Uplink ("UL"), Universal Mobile Telecommunications System ("UMTS"), Vehicle-to-Vehicle ("V2V") and Vehicle-to-Everything ("V2X"), Vehicle-to-Infrastructure/Network ("V2I/N"), Vehicle-to-Pedestrian ("V2P").

In Release <NUM> (Rel-<NUM>), it is expected to enhance the Cellular-based V2X services (V2V, V2I/N, and V2P) as identified in the 3GPP meetings.

One of the objectives for this study is the reduction of latency between the time when packets arrive at Layer <NUM>, which is also referred as physical layer herein, and the time when resource is selected for transmission, as regarding to UE using mode <NUM>. The requirements for the latency vary from <NUM> to <NUM> as defined in the 3GPP meetings. UEs using mode <NUM> and mode <NUM> are also referred as mode <NUM> UE(s) and mode <NUM> UE(s) respectively herein. Particularly, Radio resource for Mode <NUM> UE is scheduled by eNB, while radio resource for Mode <NUM> UE, which is out of an coverage of eNB or configured out of there, is autonomously selected from a resource set by itself, as defined in Release <NUM> (Rel-<NUM>).

In another aspect, The goal of reducing the latency not only need a support for latency requirements, but also a consideration for an enough percentage of the candidate resource in the resource set as well as good channel condition of the candidate resource for collision avoidance.

<NPL>, and discusses potential solutions for reducing the maximum time between packet arrival at Layer <NUM> and resource selected for V2X mode <NUM>.

<NPL>, and discusses discuss resource utilization across carriers and resource pools for improved resource allocation.

Claims <NUM> and <NUM> define respective apparatus, claims <NUM> and <NUM> define respective methods. In the following, any method and/or apparatus referred to as embodiments but nevertheless do not fall within the scope of the appended claims are to be understood as examples helpful in understanding the invention.

Enhancements to reduction of the latency between the time when packets arrive at Layer <NUM> and the time when resource is selected for transmission requires a tradeoff between the percentage of the candidate resource in the resource set and the channel quality such as SINR for the candidate resource. For example, in order to meet the latency requirements of <NUM> or less, a simple solution is to reduce time interval as resource (re)selection window. In that way, if the windows size is shorten to <NUM> or less, the percentage of the candidate resource in the resource set may not meet <NUM>%, i.e., the default percentage requirement. However, in another aspect, if the percentage is obsessively guaranteed by increasing allowed power of interference signal, the lower SINR may be resulted in for the candidate resource. From a perspective of the whole system, it may reduce the coverage of sidelink transmission and increase the collision probability for multiple UEs in V2X.

Method and apparatus for reduction of latency between the time when packets arrive at Layer <NUM> and the time when resource is selected for transmission are disclosed. One method of mode <NUM> UE for latency reduction includes excluding resource from a resource set for packets transmission on SL based on at least one of parameters which are determined according to a latency requirement for the packets, wherein, the parameters comprise a required percentage of the candidate resource in the resource set, maximum power threshold of interference signal, and maximum number of times for increasing power threshold of interference signal.

Further, in response to a percentage of the candidate resource in the resource set having not reached the required percentage, the power threshold of interference signal is increased until one of the required percentage of the candidate resource in the resource set, the maximum power threshold of interference signal and/or the maximum number of times for increasing power threshold of interference signal is reached.

Further, the parameters are further determined based on at least one of Channel Busy Ratio (CBR) and ProSe Per Packet Priority (PPPP).

The method and apparatus herein consider a tradeoff between the percentage of the candidate resource in the resource set and the channel quality such as SINR for the candidate resource, as regarding to the requirements for latency between the time when packets arrive at Layer <NUM> and the time when resource is selected for transmission. Further, the physical layer of mode <NUM> UE can report a used percentage of the candidate resource in the resource set, a used power threshold of interference signal, a used number of times for increasing power threshold of interference signal and/or an index corresponding to a set of the determined parameters to higher layer thereof, so that the higher layer can set transmission parameters based on wireless conditions.

Given that these drawings depict only some embodiments and are not therefore to be considered to limit scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:.

As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or a program product. Accordingly, embodiments may take the form of an all-hardware embodiment, an all-software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects.

Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred to hereafter as code".

The storage device may be, for example, but is not limited to being, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

A non-exhaustive list of more specific examples of the storage device may include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory ("RAM"), a read-only memory ("ROM"), an erasable programmable read-only memory ("EPROM" or Flash memory), a portable compact disc read-only memory ("CD-ROM"), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

The terms "including", "comprising", "having", and variations thereof mean "including but not limited to", unless expressly specified otherwise. The terms "a", "an", and "the" also refer to "one or more" unless expressly specified otherwise.

This code may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions - executed via the processor of the computer or other programmable data processing apparatus - create a means for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagrams.

The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other devices to produce a computer implemented process such that the code executed on the computer or other programmable apparatus provides processes for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagram.

One skilled in the relevant art will recognize, however, that the flowchart diagrams need not necessarily be practiced in the sequence shown in the Figures, and are able to be practiced without one or more of the specific steps, or with other steps not shown in the Figures.

For example, two blocks shown in succession may, in fact, be substantially executed in concurrence, or the blocks may sometimes be executed in reverse order, depending upon the functionality involved.

The goal of reducing the latency in eV2X should consider both event-triggered and periodic transmission traffic types. For example, two sets of platooning performances requirements are supported in the proposal for 3GPP Rel-<NUM>:.

That is, two Key Performance Indicators (KPI) are required in eV2X according to the above two sets: triggered and periodic transmission of small data packets (e.g. <NUM>-<NUM> bytes) should be supported; and end-to-end latency of <NUM> for message transfer among a group of UEs should be supported.

Thus, enhancements to reduction of the latency between the time when packets arrive at Layer <NUM> and the time when resource is selected for transmission should apply different latency requirement to different packets. Disclosed herein are methods, apparatuses, and systems that provide a technical solution of resource exclusion from a resource set for packets transmission on SL based on at least one of parameters which are determined according to a latency requirement for the packets. As described hereinafter, the parameters comprise a required percentage of the candidate resource in the resource set, maximum power threshold of interference signal, and maximum number of times for increasing power threshold of interference signal. Further, according to one embodiment, CBR and/or PPPP are also considered to determine the applied values of the parameters along with the latency requirement for the packets. It would be appreciated the disclosed enhancements is implemented on a mode <NUM> UE, although these parameters may be preconfigured from a base station such as eNB or a higher layer of the mode <NUM> UE.

<FIG> is a schematic diagram illustrating transmission in V2X. As shown in <FIG>, a mode <NUM> UE is in the coverage of an eNB, while mode <NUM> UEs are out of the coverage of an eNB or configured out of there. It is noted that mode <NUM> UEs may be in the coverage of another eNB which is not shown in <FIG>, but is non-RRC connection state for the shown eNB. The resource on SL for the mode <NUM> UE is scheduled by the eNB using DCI format 5A over PDCCH. For example, the eNB schedules a SL transmission resource with a SL SPS configuration index in the case that the resource allocation for SL transmission is based on SPS. The mode <NUM> UE performs SL transmission using the scheduled resource allocated by the eNB on PC5 interface. The mode <NUM> UEs autonomously select resource for SL transmission from a resource pool, and perform SL transmission with the selected resource on PC5 interface. Thereby, it is required for the mode <NUM> UEs to monitor the conditions of signal transmitted on SL in order to select candidate resources from a resource set by the physical layer (also referred as Layer <NUM>) thereof in an efficient way.

<FIG> is a schematic diagram illustrating signal sensing and resource (re)selection on a mode <NUM> UE. As shown in <FIG>, when requested by higher layers in subframe n for data transmission, the physical layer of mode <NUM> UE determines a resource for PSSCH transmission. Particularly, the UE assumes that any resource within (re)selection window of the time interval [n+T<NUM>,. , n+T<NUM>] may be the candidate resource, wherein the selections of T<NUM> and T<NUM> are up to UE implementations within T<NUM>≤<NUM> and <NUM>≤T<NUM>≤<NUM>. The selection of T<NUM> should meet the latency requirement. It would be noted that the duration of <NUM> subframe is <NUM>, thus the resource (re)selection window can be represented as subframes [n+T<NUM>,. , n+T<NUM>]. In order to select resource with an acceptable quality, the UE shall monitor a sensing window of subframes [n-<NUM>, n-<NUM>,. , n-<NUM>] (or time interval in milliseconds) except for those in which its transmissions occur. Further, the UE performs the procedure for resource selection based on the measured RSRP and/or S-RSSI for PSSCH as well as the decoding for PSCCH in these subframes, as described in <FIG>.

Additionally, the mode UE monitors subframes [n-<NUM>,. , n-<NUM>] (or time interval [n-<NUM>,. , n-<NUM>] in milliseconds) to learn CBR which reflects the extent of channel busy, as described hereinafter.

<FIG> is a call flow illustrating a selection of candidate resource according to the first embodiment. As shown in <FIG>, in S301, the mode <NUM> UE keeps sensing for <NUM> or <NUM> subframes. Particularly, the UE monitors the power and/or strength of signals in subframes [n-<NUM>, n-<NUM>,. , n-<NUM>] except for those in which its transmissions occur, that is because that the power and/or strength of signals in sensing window can reflect that of interference signal in the resource (re)selection window according to a predefined mapping relationship. For example, the possible power of the interference signal in the time interval/subframes [n+T<NUM>,. , n+T<NUM>] can be reflected by the measured RSRP for time interval/subframes [n-<NUM>, n-<NUM>,. , n-<NUM>].

In S302, the physical layer of the mode <NUM> UE receives a request for data transmission from the higher layer thereof.

In S303, the UE learns reserved resource for other UE(s) from a decoded SA, which has a collision with the resource set in the time interval [n+T<NUM>,. , n+T<NUM>]. The SL transmission from other UE(s) is regarded as an interference to the transmission of the mode <NUM> UE. However, the SL transmission in reserved resource from other UE(s) may have limited or fewer impacted on that of the mode <NUM> UE, for example, in the case of different transmission directions. The mode <NUM> UE thus deduces the power impact of the interference signal in the reserved resource from the PSSCH-RSRP for the associated resource in the time interval [n-<NUM>, n-<NUM>,. , n-<NUM>], according to the predefined mapping relationship between the sensing and resource (re)selection window. In the case that the PSSCH-RSRP for the associated resource is larger than a default power threshold such as <NUM> dB, the UE excludes the reserved resource for other UE(s) from the resource set in the (re)selection window, wherein the remained resource after the exclusion is also referred as candidate resource herein.

In S304, if the percentage of candidate resource in the resource set is less than a default percentage such as <NUM>% after the exclusion (Y in S304), the procedure continues to S305, wherein, the power threshold is increased by a preconfigured offset such as 3dB. Then, the procedure returns back to S303, wherein, the UE excludes the reserved resource for other UE(s) from the resource set in the (re)selection window in the case that the PSSCH-RSRP for the associated resource in the sensing window is larger than the increased power threshold. In S304, the UE decides again if the percentage of candidate resource in the resource set is less than the default percentage after the exclusion.

In response to the percentage of the candidate resource in the resource set having not reached the default percentage, the power threshold is increased until the default percentage is reached. When the default percentage is reached (N in S304), the procedure continues to S306, wherein, the mode <NUM> UE ranks the candidate resources in the resource set based on the measured strength of the signal in the associated resources in sensing window, such as a metric of RSSI.

In S307, the physical layer of mode <NUM> UE reports the candidate resource with the smallest metric to a higher layer. According to one embodiment, the mode <NUM> UE randomly selects the transmission resource from the reported candidate resource with the acceptable metric.

It is obvious that the percentage of the candidate resource in the resource set is a fix value in the first embodiment without consideration for different types of packets. In that way, it's possible that a lower SINR may be resulted in for the candidate resource. Disclosure herein provides a technical solution of applying different parameters according to the latency requirement for packets.

<FIG> is a call flow illustrating a selection of candidate resource according to the second embodiment. Steps of S401 and S402 are similar with steps of S301 and S302, respectively, therefore the description thereof are omitted for the purpose of brevity.

In S403, the mode <NUM> UE determines a parameter P, which is a required percentage of the candidate resource in the resource set, according to the latency requirement for the packets to be transmitted on SL. The longer the required latency is, the larger the parameter P is, that is because more candidate resource can be selected for a longer required latency. According to another embodiment, the required percentage of the candidate resource in the resource set is determined by a default percentage and a scaling factor for percentage corresponding to the latency requirement for the packets. For example, the required percentage is a product of the default percentage such as <NUM>% and the scaling factor for percentage which is referred as p. Table <NUM> is an example of the values for P and p for different values for the required latency.

As shown in Table <NUM>, the required percentage of the candidate resource in the resource set is <NUM>% for the latency requirement of <NUM>. Alternatively, the required percentage can be obtained by a product of the default percentage <NUM>% and a scaling factor <NUM>, which is <NUM>% (<NUM>%×<NUM>). It would be understood that the physical layer of mode <NUM> UE may receive these parameters from an eNB when it is in the coverage of the eNB, or from the higher layer thereof such as by manually input.

Other steps from S404 to S408 are similar with steps of S303 and S307, respectively, except that the default percentage <NUM>% is replaced by a dynamic percentage P according to the latency requirement for packets, therefore the description thereof are omitted for the purpose of brevity.

Additionally, in S408, the mode <NUM> UE may reports a used percentage of the candidate resource in the resource set to a higher layer thereof besides the candidate resource. And the higher layer of the mode <NUM> UE may set transmission parameters, such as MCS, transmission power and number of retransmissions based on the used percentage of the candidate resource in the resource set.

It would be understood that the percentage of the candidate resource in the resource set is determined according to the latency requirement for the packets to be transmitted on SL. In that way, the latency between the time when packets arrive at Layer <NUM> and the time when resource is selected can be reduced for packets with smaller size.

<FIG> is a call flow illustrating a selection of candidate resource according to the third embodiment. Steps of S501 and S502 are similar with steps of S301 and S302, respectively, therefore the description thereof are omitted for the purpose of brevity.

In S503, the mode <NUM> UE determines a parameter X, which is a maximum power threshold of interference signal, according to the latency requirement for the packets to be transmitted on SL. The longer the required latency is, the larger the parameter X is, that is because more candidate resource which is more tolerant to interference signal can be selected for a longer required latency. It would be understood that the physical layer of mode <NUM> UE may receive these parameters from an eNB when it is in the coverage the eNB, or from the higher layer thereof such as by manually input.

In S504, the mode <NUM> UE sets a power threshold to be an initial power threshold which may be preconfigured.

In S505, the UE learns reserved resource for other UE(s) from a decoded SA, which has a collision with the resource set in the time interval [n+T<NUM>,. , n+T<NUM>]. The mode <NUM> UE then deduces the power impact of the interference signal in the reserved resource from the PSSCH-RSRP for the associated resource in the time interval [n-<NUM>, n-<NUM>,. , n-<NUM>], according to the predefined mapping relationship between the sensing and resource (re)selection window. In the case that the PSSCH-RSRP for the associated resource is larger than the initial power threshold such as <NUM> dB, the UE excludes the reserved resource for other UE(s) from the resource set in the (re)selection window.

In S506, if the percentage of candidate resource in the resource set is less than a default percentage such as <NUM>% after the exclusion (Y in S506), the procedure continues to S507, wherein, the power threshold is increased by a preconfigured offset such as 3dB.

In S508, the mode <NUM> UE decides if the power threshold is larger than X. If Y is S508, which means the maximum power threshold of interference signal corresponding to the latency requirement for the packets is reached, the procedure continues to S509, wherein, the mode <NUM> UE ranks the candidate resources in the resource set based on the measured strength of the signal in the associated resources in sensing window, such as a metric of RSSI. S509 is followed by S510, wherein, the physical layer of mode <NUM> UE reports the candidate resource with the smallest metric to a higher layer.

If N is S508, the procedure returns back to S505, wherein, the UE excludes the reserved resource for other UE(s) from the resource set in the (re)selection window in the case that the PSSCH-RSRP for the associated resource in the sensing window is larger than the increased power threshold. In S506, the UE decides again if the percentage of candidate resource in the resource set is less than the default percentage after the exclusion.

In response to the percentage of the candidate resource in the resource set having not reached the default percentage, the power threshold is increased until the default percentage is reached. When the default percentage is reached (N in S506), the procedure continues to S509 and then S510, the description of which have been described above.

Additionally, in S510, the mode <NUM> UE may reports a finally used power threshold of interference signal to a higher layer thereof besides the candidate resource. For example, the finally used power threshold of interference signal is less than the maximum power threshold of interference signal in the case that the default percentage is reached earlier than the maximum power threshold of interference signal. The higher layer of the mode <NUM> UE may set transmission parameters, such as MCS, transmission power and number of retransmissions based on the finally used power threshold of interference signal.

It would be understood that, the mode <NUM> UE may stop excluding resource from the resource set for packets transmission on SL in response to one of the default percentage and the maximum power threshold of interference signal being reached. In that way, the resource which may be intolerant to the interference signal can be excluded from the resource set.

<FIG> is a call flow illustrating a selection of candidate resource according to the fourth embodiment. The implementation in <FIG> is similar with that in <FIG>, except that the maximum power threshold of interference signal is replaced by the maximum number of times for increasing power threshold of interference signal in <FIG>. Steps of S601 and S602 are similar with steps of S301 and S302, respectively, therefore the description thereof are omitted for the purpose of brevity.

In S603, the mode <NUM> UE determines a parameter N, which is a maximum number of times for increasing power threshold of interference signal, according to the latency requirement for the packets to be transmitted on SL. The longer the required latency is, the larger the parameter N is, that is because more candidate resource which is more tolerant for interference signal can be selected for a longer required latency. According to another embodiment, the maximum number of times for increasing power threshold of interference signal is determined by a default number of times and a scaling factor for number of times corresponding to the latency requirement for the packets. For example, the maximum number of times is a product of the default number of times such as <NUM> and the scaling factor for number of times which is referred as x. Table <NUM> is an example of the values for X and x for different values for the required latency.

As shown in Table <NUM>, the maximum number of times for increasing power threshold of interference signal is <NUM> for the latency requirement of <NUM>. Alternatively, the maximum number of times can be obtained by a product of the default number of times <NUM> and a scaling factor <NUM>, which is <NUM> (<NUM>×<NUM>). It would be understood that the physical layer of mode <NUM> UE may receive these parameters from an eNB when it is in the coverage of the eNB, or from the higher layer thereof such as by manually input.

Steps of S604 and S607 are similar with steps of S504 and S507, respectively, therefore the description thereof are omitted for the purpose of brevity.

In S608, the mode <NUM> UE counts a number of times for increasing the power threshold.

In S609, the mode <NUM> UE decides if the number of times for increasing the power threshold is larger than N. If Y is S609, which means the maximum number of times for increasing the power threshold corresponding to the latency requirement for the packets is reached, the procedure continues to S610, wherein, the mode <NUM> UE ranks the candidate resources in the resource set based on the measured strength of the signal in the associated resources in sensing window, such as a metric of RSSI. S610 is followed by S611, wherein, the physical layer of mode <NUM> UE reports the candidate resource with the smallest metric to a higher layer.

If N is S609, the procedure returns back to S605, wherein, the UE excludes the reserved resource for other UE(s) from the resource set in the (re)selection window in the case that the PSSCH-RSRP for the associated resource in the sensing window is larger than the increased power threshold. In S606, the UE decides again if the percentage of candidate resource in the resource set is less than the default percentage after the exclusion.

In response to the percentage of the candidate resource in the resource set having not reached the default percentage, the power threshold is increased until the default percentage is reached. When the default percentage is reached (N in S606), the procedure continues to S610 and then S611, the description of which have been described above.

Additionally, in S611, the mode <NUM> UE may reports a finally used number of times for increasing the power threshold to a higher layer thereof besides the candidate resource. For example, the finally used number of times for increasing the power threshold is less than the maximum number of times for increasing the power threshold in the case that the default percentage is reached earlier than the maximum number of times for increasing the power threshold. The higher layer of the mode <NUM> UE may set transmission parameters, such as MCS, transmission power and number of retransmissions based on the finally used number of times for increasing the power threshold.

It would be understood that, the mode <NUM> UE may stop excluding resource from the resource set for packets transmission on SL in response to one of the default percentage and the maximum number of times for increasing the power threshold being reached. In that way, the resource which may be intolerant to the interference signal can be excluded from the resource set.

<FIG> is a call flow illustrating a selection of candidate resource according to the fifth embodiment. The implementation in <FIG> supports the latency reduction by applying the combination of the required percentage of the candidate resource in the resource set, the maximum power threshold of interference signal, and the maximum number of times for increasing power threshold of interference signal. Further, the implementation in <FIG> considers CBR and/or PPPP for SL transmission of the mode <NUM> UE in the determination of the values for the parameters, along with the latency requirement for the packets to be transmitted on SL.

In S701, the mode <NUM> UE keeps sensing for <NUM> or <NUM> subframes.

In S702, the mode <NUM> UE monitors subframes [n-<NUM>,. , n-<NUM>] (or time interval [n-<NUM>,. , n-<NUM>] in milliseconds) to learn CBR which reflects the extent of channel busy. Take PSSCH as an example, the ratio of subframes, S-RSSI on which measured in the sub-channels for PSSCH exceeds a preconfigured threshold, against all of the subframes [n-<NUM>,. , n-<NUM>] is defined as the CBR of PSSCH. In the case that PSCCH is transmitted with the corresponding PSCCH in adjacent resource blocks, the CBR of PSCCH can be deduced from that of PSSCH. In the case that PSCCH is transmitted with the corresponding PSCCH in non-adjacent resource blocks, the CBR of PSCCH can be measured in a similar way with the measurement for CBR of PSSCH. That is, the ratio of subframes, S-RSSI on which measured in the sub-channels for PSCCH exceeds a preconfigured threshold, against all of the subframes [n-<NUM>,. , n-<NUM>] is defined as the CBR of PSCCH.

Additionally, the mode <NUM> UE determines PPPP for SL transmission thereof.

In S703, the physical layer of the mode <NUM> UE receives a request for data transmission from the higher layer thereof.

In S704, the mode <NUM> UE determines at least one of parameters P, X, N, which are defined as above, according to the latency requirement for the packets to be transmitted on SL as well as CBR and/or PPPP for SL transmission of the mode <NUM> UE. As described above, the longer the required latency is, the larger the parameters P, X, N are. Similar, according to another embodiment, the required percentage of the candidate resource in the resource set may be determined by a default percentage and a scaling factor for percentage corresponding to the latency requirement for the packets, and the maximum number of times for increasing power threshold of interference signal may be determined by a default number of times and a scaling factor for number of times corresponding to the latency requirement for the packets.

Table <NUM> is an example of the combinations of parameters vs. the combination of required latency, CBR and PPPP.

As shown in Table <NUM>, take the indices <NUM>-<NUM> as examples, in the case that the measured CBR is less than <NUM> and PPPP for SL transmission thereof is from <NUM> to <NUM> in decimal, i.e. in the case of index <NUM>, the required percentage of the candidate resource P in the resource set is <NUM>%, the maximum power threshold of interference signal X is <NUM> dB, and the maximum number of times for increasing power threshold of interference signal N is <NUM>. In another case that the measured CBR is less than <NUM> and PPPP for SL transmission thereof is from <NUM> to <NUM> in decimal, i.e. in the case of index <NUM>, the required percentage of the candidate resource P in the resource set is <NUM>%, the maximum power threshold of interference signal X is <NUM> dB, and the maximum number of times for increasing power threshold of interference signal N is <NUM>. It would be understood that the physical layer of mode <NUM> UE may receive these parameters from an eNB when it is in the coverage of the eNB, or from the higher layer thereof such as by manually input.

In S705, the mode <NUM> UE sets a power threshold to be an initial power threshold which may be preconfigured.

In S706, the UE learns reserved resource for other UE(s) from a decoded SA, which has a collision with the resource set in the time interval [n+T<NUM>,. , n+T<NUM>]. The mode <NUM> UE then deduces the power impact of the interference signal in the reserved resource from the PSSCH-RSRP for the associated resource in the time interval [n-<NUM>, n-<NUM>,. , n-<NUM>], according to the predefined mapping relationship between the sensing and resource (re)selection window. In the case that the PSSCH-RSRP for the associated resource is larger than the initial power threshold such as <NUM> dB, the UE excludes the reserved resource for other UE(s) from the resource set in the (re)selection window.

In S707, if the percentage of candidate resource in the resource set is less than the determined P after the exclusion (Y in S707), the procedure continues to S708, wherein, the power threshold is increased by a preconfigured offset such as 3dB.

In S709, the mode <NUM> UE counts a number of times for increasing the power threshold.

In S710, the mode <NUM> UE decides if the power threshold is larger than X. If Y is S710, which means the maximum power threshold of interference signal corresponding to the latency requirement for the packets is reached, the procedure continues to S712, wherein, the mode <NUM> UE ranks the candidate resources in the resource set based on the measured strength of the signal in the associated resources in sensing window, such as a metric of RSSI. S712 is followed by S713, wherein, the physical layer of mode <NUM> UE reports the candidate resource with the smallest metric to a higher layer.

If N is S710, the mode <NUM> UE decides if the number of times for increasing the power threshold is larger than N in S711. If Y is S711, which means the maximum number of times for increasing the power threshold corresponding to the latency requirement for the packets is reached, the procedure continues to S711 and then S712, the description of which have been described above.

If Y is S711, the procedure returns back to S706, wherein, the UE excludes the reserved resource for other UE(s) from the resource set in the (re)selection window in the case that the PSSCH-RSRP for the associated resource in the sensing window is larger than the increased power threshold. In S712, the UE decides again if the percentage of candidate resource in the resource set is less than the determined P after the exclusion.

In response to the percentage of the candidate resource in the resource set having not reached the determined P, the power threshold is increased until it is reached. When the determined P is reached (N in S707), the procedure continues to S712 and then S713, the description of which have been described above.

It would be noted that parameters P, X, N are optional and so are the corresponding decision steps. Particularly, the mode <NUM> UE may any combinations of the three parameters P, X, N to exclude resources from a resource set for packets transmission on SL. For example, the mode <NUM> UE can apply the parameters P, X to the exclusion of the resource using steps of S707 and S710. or the parameters P, N to the exclusion of the resource using steps of S707 and S711, or the parameters X, N to the exclusion of the resource using steps of S710 and S711 and a default percentage such as <NUM>%.

Additionally, it would be understood that the required percentage of the candidate resource in the resource set may be determined by a default percentage and a scaling factor for percentage corresponding to the latency requirement for the packets, and the maximum number of times for increasing power threshold of interference signal is determined by a default number of times and a scaling factor for number of times corresponding to the latency requirement for the packets, as described above.

Additionally, in S713, the mode <NUM> UE may reports at least one of a finally used percentage of the candidate resource in the resource set, a finally used power threshold of interference signal, a finally used number of times for increasing power threshold of interference signal and an index corresponding to a set of the determined parameters, to a higher layer thereof, besides the candidate resource. The higher layer of the mode <NUM> UE may set transmission parameters, such as MCS, transmission power and number of retransmissions based on at least one of the reported index, the used percentage of the candidate resource in the resource set, the used power threshold of interference signal and the used number of times for increasing power threshold of interference signal.

It would be understood that, the mode <NUM> UE may stop excluding resource from the resource set for packets transmission on SL in response to until one of the required percentage of the candidate resource in the resource set, the maximum power threshold of interference signal and/or the maximum number of times for increasing power threshold of interference signal is reached. In that way, the resource which may be intolerant to the interference signal can be excluded from the resource set. Meanwhile, the latency between the time when packets arrive at Layer <NUM> and the time when resource is selected can be reduced.

One skilled in the relevant art will recognize, however, that the process described from <FIG> and <FIG> need not necessarily be practiced in the sequence shown in the Figures, and are able to be practiced without one or more of the specific steps, or with other steps not shown in the Figures.

<FIG> is a schematic block diagram illustrating components of a mode <NUM> UE according to one embodiment.

Mode <NUM> UE <NUM> is an embodiment of Mode <NUM> UE described from <FIG>. Furthermore, Mode <NUM> UE <NUM> may include a processor <NUM>, a memory <NUM>, and a transceiver <NUM>. In some embodiments, Mode <NUM> UE <NUM> may include an input device <NUM> and/or a display <NUM>. In certain embodiments, the input device <NUM> and the display <NUM> may be combined into a single device, such as a touch screen.

The processor <NUM> is communicatively coupled to the memory <NUM>, the input device <NUM>, the display <NUM>, and the transceiver <NUM>.

In some embodiments, the processor <NUM> controls the transceiver <NUM> to receive DL signals from Network Equipment <NUM>. For example, the processor <NUM> may control the transceiver <NUM> to receive the parameters P, X, N in RRC signaling from an eNB when it is in its coverage, as described above.

In some embodiments, the memory <NUM> stores parameters relating to different requirements for packets to be transmitted on SL. In some embodiments, the memory <NUM> also stores program code and related data, such as an operating system or other controller algorithms operating on Mode <NUM> UE <NUM>.

Mode <NUM> UE <NUM> may optionally include an input device <NUM>. In some embodiments, the input device <NUM> may be integrated with the display <NUM>, for example, as a touch screen or similar touch-sensitive display. In some embodiments, the input device <NUM> includes a touch screen such that text may be input using a virtual keyboard displayed on the touch screen and/or by handwriting on the touch screen. In certain embodiments, the input device <NUM> may include one or more sensors for monitoring an environment of Mode <NUM> UE <NUM>.

Mode <NUM> UE <NUM> may optionally include a display <NUM>. For example, the display <NUM> may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or a similar display device capable of outputting images, text, or the like to a user.

In certain embodiments, the display <NUM> may include one or more speakers for producing sound. For example, the input device <NUM> and display <NUM> may form a touch screen or similar touch-sensitive display.

The transceiver <NUM>, in one embodiment, is configured to communicate wirelessly another Mode <NUM> UE. In certain embodiments, the transceiver <NUM> comprises a transmitter <NUM> and a receiver <NUM>. The transmitter <NUM> is used to transmit SL communication signals to another Mode <NUM> UE and the receiver <NUM> is used to receive SL communication signals from another Mode <NUM> UE. For example, the receiver <NUM> may receive SA information indicating the reserved resource.

The transmitter <NUM> and the receiver <NUM> may be any suitable types of transmitters and receivers. Although only one transmitter <NUM> and one receiver <NUM> are illustrated, the transceiver <NUM> may have any suitable number of transmitters <NUM> and receivers <NUM>. For example, in some embodiments, Mode <NUM> UE <NUM> includes a plurality of transmitter <NUM> and receiver <NUM> pairs for communicating on a plurality of wireless networks and/or radio frequency bands, each transmitter <NUM> and receiver <NUM> pair configured to communicate on a different wireless network and/or radio frequency band than the other transmitter <NUM> and receiver <NUM> pairs.

<FIG> is a schematic block diagram illustrating components of a network equipment according to one embodiment.

Network Equipment <NUM> includes one embodiment of eNB mentioned from <FIG>. Furthermore, Network Equipment <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, and a transceiver <NUM>. As may be appreciated, the processor <NUM>, the memory <NUM>, the input device <NUM>, and the display <NUM> may be substantially similar to the processor <NUM>, the memory <NUM>, the input device <NUM>, and the display <NUM> of Mode <NUM> UE <NUM>, respectively.

In some embodiments, the processor <NUM> controls the transceiver <NUM> to transmit DL signals to Mode <NUM> UE <NUM> when the Mode <NUM> UE <NUM> is in its coverage. For example, the processor <NUM> may control the transceiver <NUM> to transmit the parameters P, X, N in RRC signaling to Mode <NUM> UE <NUM> when the Mode <NUM> UE <NUM> is in its coverage, as described above.

Claim 1:
An apparatus (<NUM>) comprising:
a processor (<NUM>) arranged to,
exclude resources from a resource set for packets transmission on sidelink based at least on parameters determined according to a latency requirement for the packets, wherein the parameters comprise:
a required percentage of a candidate resource in the resource set;
a maximum power threshold of interference signal; and
a maximum number of times for increasing power threshold of interference signal;
wherein the required percentage of the candidate resource in the resource set is determined by a default percentage and a scaling factor for percentage corresponding to the latency requirement for the packets.