Patent Publication Number: US-11647502-B2

Title: Apparatus, method for a radio communications network and use thereof

Description:
BACKGROUND OF THE INVENTION 
     The description provides advantageous examples for operating an apparatus of a radio communications network. 
     Connected mobility is gaining focus in different communication standards, e.g., the IEEE 802.11p/bd and 3GPP LTE/NR V2X. The latter is being developed further together with a cellular coverage. In case of 3GPP LTE/NR V2X, two situations are considered, the in coverage and the out of coverage. Additionally, part of the UEs who are connected together may be in-coverage, while other may be out of the network coverage. This case is called partial out of coverage as in  FIG.  1   . When the vehicle use-equipment (UE) is in coverage, the network and its terminal (e.g., base-station (BS), evolved-Node Base-station (eNB), or 5G-NR-Node Base-station (gNB)), the UE can be configured to perform sidelink (direct) communication inter-UEs. Resources allocation, data control, and communication procedure in this case is controlled by the UE. However, if the UE is the out-of-coverage of EUTRA or 5G-NR cells, the UE is pre-configured with the mandatory configuration for autonomous communication over the sidelink frequencies. In this case, the UE is also pre-configured with the out-of-coverage frequencies, which includes the intelligent transport system (ITS) frequencies. 
     SUMMARY OF THE INVENTION 
     A first aspect of the description is directed to an apparatus comprising at least one processor, at least one memory including computer program code, and at least one communication module, the at least one memory and computer program code configured, with the at least one processor, and the at least one communication module, to cause the apparatus at least to: receive a plurality of radio signals; determine at least one resource conflict indicator in dependence on the received radio signals, wherein the at least one resource conflict indicator indicates at least one radio resource that has a potential risk of a resource conflict; and transmit the resource conflict indicator. 
     The resource conflict indicator provides information about potentially conflicting resources in the network. For example, receiving entities, which transmit data via distributed scheduling mechanisms benefit. In addition, entities, which are not able to do sensing or only do partial sensing, will benefit. Sensing operations of other entities can even be reduced, resulting in a network-wide energy consumption. 
     According to an advantageous example, the apparatus is further configured to: determine the at least one resource conflict indicator at a point in time; and transmit and/or re-transmit the resource conflict indicator if a validity period is running since the determined point in time; and/or transmit a validity indicator associated with the determined at least one resource conflict indicator. 
     Advantageously, the validity of the resource conflict indicator is pre-determined and the transmission event is randomized in order to increase equality between entities transmitting resource conflict indicators on the same channel. 
     According to an advantageous example, the apparatus is further configured to: determine at least one communication parameter in dependence on at least one of the monitored radio signals; and determine the at least one validity period in dependence on the determined at least one communication parameter. 
     Advantageously, the validity period adapts to the channel state. Distributed Scheduling benefits due to a managed penetration of the network by conflict indicators, which assist other UEs to reserve and use potentially non-conflicting radio resources. 
     According to an advantageous example, the apparatus is further configured to: determine at least one communication parameter in dependence on at least one of the monitored radio signals; map the determined at least one communication parameter to at least one transmission parameter for the resource conflict indicator; and determine and/or transmit the resource conflict indicator in dependence on the transmission parameter. 
     Advantageously, the transmission of the resource conflict indicator depends on the determined communication parameters indicating the probably conflicting communication. 
     According to an advantageous example, the transmission parameter is a priority, and wherein the apparatus is further configured to: determine a plurality of resource conflict indicators associated with a respective priority as the at least one transmission parameter; and select one of the plurality of resource conflict indicators in dependence on the associated priorities; and transmit the selected one of resource conflict indicators. 
     Advantageously, the resource conflict indicators are put into a priority queue. Therefore, a priority scheduling of the resource conflict indicators is provided. 
     According to an advantageous example, the apparatus is further configured to: receive at least a part of the mapping between the at least one communication parameter and the at least one transmission property. 
     Advantageously, the network is able to configure the apparatus with the mapping in order to adapt the penetration of the network with the resource conflict indicators. 
     According to an advantageous example, the apparatus is configured to: draw a randomized value; and determine and/or transmit the resource conflict indicator when the determined randomized value exceeds a probability threshold. 
     The randomized penetration of the radio communications network has several advantages. For example, other communication can override the resource conflict indicator and a distributed penetration of the network can be established. 
     According to an advantageous example, the apparatus is configured to: determine at least one communication parameter in dependence on at least one of the monitored radio signals; and determine the probability threshold in dependence on the determined at least one communication parameter. 
     Advantageously, the probability of the transmission of the resource conflict indicator is adapted to the present radio situation. 
     According to a second aspect of the description a method to operate an apparatus is provided, the method comprising: receiving a plurality of radio signals; determining at least one resource conflict indicator in dependence on the received radio signals, wherein the at least one resource conflict indicator indicates at least one radio resource that has a potential risk of a resource conflict; and transmitting the resource conflict indicator. 
     According to a third aspect of the description an apparatus is provided, the apparatus comprising at least one processor, at least one memory including computer program code, and at least one communication module, the at least one memory and computer program code configured, with the at least one processor, and the at least one communication module, to cause the apparatus at least to: receive at least one resource conflict indicator, wherein the at least one resource conflict indicator indicates at least one radio resource that has a potential risk of a resource conflict; determine data for a transmission; determine a radio resource for the transmission of the data in dependence on the received at least one resource conflict indicator; and transmit the determined data via the determined radio resource. 
     Advantageously, the apparatus is able to suppress the use of potentially conflicting radio resources. In particular distributed scheduling benefits as the apparatus is of knowledge of potential conflicts detected by a remote apparatus. 
     According to an advantageous example, the apparatus is further configured to: receive a validity indicator associated with the at least one conflict indicator; and refrain from using at least one radio resource, which is indicated by the at least one resource conflict indicator as long as the received validity indicator indicates that the received at least one resource conflict indicator is valid. 
     Advantageously, the apparatus is able to forget past conflict situations. On the other hand, if conflict situations persist, the apparatus is able to maintain the blocking of the indicated radio resource. 
     According to an advantageous example, the apparatus is configured to: determine a set of candidate radio resources in dependence on the received at least one resource conflict indicator; and determine the radio resource for the transmission of the data from the determined set of candidate radio resources. 
     Advantageously, the indicated potentially conflicting radio resources are avoided to be used. 
     According to an advantageous example, the apparatus is configured to: draw a randomized value; determine the set of candidate radio resources in dependence on the received resource conflict indicator when the randomized value exceeds a probability threshold. 
     Advantageously, the probability threshold determines a probability for an entry of the at least one potentially conflicting resource into the set of candidate resources. If the randomized value does not exceed the probability threshold, the received resource conflict indicator is ignored. In other words, the use of the radio resources indicated by the resource conflict indicator is suppressed with a probability. 
     According to an advantageous example, the apparatus is configured to: determine that at least an overlap between the at least one radio resource indicated via the resource conflict indicator and at least one radio resource, which has been used by the apparatus for a transmission in the past, has occurred; determine, if the overlap is determined, at least one communication parameter in dependence on the at least one radio resource, which has been used by the apparatus for a transmission in the past; and determine the probability threshold in dependence on the at least one determined communication parameter. 
     Advantageously, the probability threshold adapts to the communication that occurred on the observed radio channel. 
     A fourth aspect of the description relates to a method to operate an apparatus, the method comprising: receiving at least one resource conflict indicator, wherein the at least one resource conflict indicator indicates at least one radio resource that has a potential risk of a resource conflict; determining data for a transmission; determining a radio resource for the transmission of the data in dependence on the received at least one resource conflict indicator; and transmitting the determined data via the determined radio resource. 
     A fifth aspect is related to a radio terminal comprising the apparatus according to one of the preceding aspects. 
     A sixth aspect of the description is directed to a road vehicle comprising the apparatus according to one of the aspects and/or a radio terminal according to the previous aspect. 
     A seventh aspect of the description relates to a use of the apparatus according to one of the aspects and/or of a radio terminal according to the fifth aspect and/or of a method according to one of the respective aspects. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1  to  3    depict schematical sequence diagrams; 
         FIG.  4    depicts a schematical flow chart; and 
         FIG.  5    depicts schematically a traffic situation. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    depicts a schematical sequence diagram with three apparatuses UE 0 , UE 1 , and UE 2 . For example, UE 0  and UE 2  are not able to directly communicate with each other but with UE 1 . Throughout the description, the term UE is used for User Equipment and apparatus interchangeably and identifies furthermore the entities in the figures. 
     The first apparatus UE 1  comprises receiving means  100  to receive a plurality of radio signals s 0 , s 2  from the apparatus UE 0  and UE 2 . Determining means  104  are configured to determine at least one resource conflict indicator RCI in dependence on the received radio signals s 0 , s 2 , wherein the at least one resource conflict indicator RCI indicates at least one radio resource rr 1  that has a potential risk of a resource conflict on a radio channel being used by a plurality of apparatuses UE 0 , UE 1 , UE 2 . Once, the potential risk of a resource conflict is identified and RCI is determined, a message for RCI is initialized in a communication layer, e.g., L1-physical layer or L2-MAC layer. Transmitting means  106  are configured to transmit the resource conflict indicator RCI. 
     The second apparatus UE 2  comprises receiving means  206  to receive the at least one resource conflict indicator RCI from the first apparatus UE 1 . Determining means  208  are configured to determine data d for a transmission. Determining means  210  are configured to determine a radio resource rr 2  for the transmission of the data d in dependence on the received at least one resource conflict indicator RCI. Transmitting means  212  are configured to transmit the determined data d via the determined radio resource rr 2 . 
     The at least one resource conflict indicator RCI is determined by UE 1  if a potential conflict is determined. The potential conflict is determined, for example, when least two apparatuses UE 0  and UE 2  transmit on one or more overlapping radio resources. In another example, a detected transmission by at least two apparatuses UE 0  and UE 2 , for example within the same group, on one or more overlapping time resources i.e., frequency resources may be non-overlapping; also known as half-duplex problem, or partially overlapping will lead to the determination of the resource conflict indicator RCI. 
     In Sidelink communication, the overlapping transmission, either in time or in both, time and frequency, are computed for apparatuses UE 0 , UE 2  within a certain communication range or belonging to the same communication group. According to another example of sidelink communication, the received signal strength RSSI or RSRP of the identified overlapping transmission results in a determination of a potential conflict, if exceeding a certain threshold. RSSI stands for Received Signal Strength Indicator, RSRP stands for Reference Signal Received Power. 
     According to an example, the received signal and overlapping identification is determined by the determination means  104  comprising at least one of the following: 1 based on SCI, Sidelink Control Information, decoding, overlapping reservations in an SCI transmitted before the determination instant, RSRP can be computed from the reservation transmission if possible; overlapping transmission identified by two or more decoded SCI containing associated reservations of the same time slot and frequency resources, where the latter can be fully overlapping, partially overlapping, or non-overlapping note: here time resources are always overlapping; 2 based on DMRS decoding: Overlapping transmissions overlapping time/frequency resources are identified by decoding the associated DMRS resources of two or more overlapping transmissions. This is also valid if apparatus UE 1  cannot decode the SCI contained in a PSCCH. Hence, an RSSI can be computed; A group may have an identified DMRS, hence, apparatus UE 1  decides whether the collision or potential collision belongs to a certain group from the decoded DMRS; Based on RSSI: overlapping transmission overlapping time/frequency resources are identified if the SCI in PSCCH, Physical Sidelink Shared Channel or DMRS, Demodulation Reference Signal, cannot be decoded by apparatus UE 1  but the RSSI, of non-decodable transmission/collision, is still above a threshold. If a collision arises between the group members, where the group members uses the same DMRS, hence, DMRS cannot be used to resolve the potential conflict but rather RSSI threshold if RSI is identified, e.g., if SCI is not decodable. 
     If the apparatus UE 1  is able to decode the SCI transmission at least contained in one or more PSCCH transmission, the apparatus UE 1  computes the RSRP. If the apparatus UE 1  is not able to decode the SCI transmission of one or more overlapping resources, the UE computes the RSSI instead of RSRP. According to an example, for both RSSI and RSSP there may be different threshold declared to identify the potential conflict. 
     The at least one resource conflict indicator RCI comprises or is accompanied by at least one of the following: a priority field of the assisting information, a time/frequency resources of possible colliding packets i.e., full, partial, no-frequency overlapping, a number of colliding transmitters on different resources, a time validity of the RCI, a periodicity of the occurrence of the RCI, a periodicity of the indicated radio resources, a time offset of the potential resource conflict indicated from the point of time of the reporting of RCI, a periodicity P of RCI, frequency positions of overlapping resources, Resource Pools/BWPs index indices of the potential resource conflict, the validity period p 1 . The validity period can be evaluated such that, the longer the potential conflict exist, the higher validity timer p 1  is sent. 
     The measurements of the signals s 1 , s 2  according to the determining means  104  are conducting via at least one of the following: sensing, RSSI detection, RSRP detection, etc. . . . . Therefore, the RSSI comprises information about possible transmission overlapping or transmission collision between UE 0  and UE 2 , or between other apparatuses transmitting and resulting in radio interference in the radio communications network. 
     For example, the RCI is carried on a higher layer signaling e.g., a MAC control element or on lower layer control signaling, i.e., 1st stage SCI and/or 2nd stage SCI. 
     The transmission of the RCI via transmitting means  106  is done by group communication, for example with connection establishment even using unicast PC5 RRC, radio resource control, signaling. The configuration of the RCI and its capability is transmitted using, e.g., PC5 RRC signaling. 
     According to another example, the RCI is transmitted in connection-less group communication with or without PC5 RRC signaling. The configuration of the RCI is done by a base-station or is pre-configured. 
     In an exemplary radio communications system with three UEs, the assisting apparatus UE 1  conducts measurements and/or data decoding and evaluation of the situation according to determining means  104 . The determining means  104  performs at least one of the following: channel sensing, RSSI measurement, RSRP measurement, and CBR constant bit rate measurement. 
     For example, the apparatus UE 1  decodes control data received from at least one other apparatus UE 0 . The apparatus UE 1  identifies the L1/L2 source identity and/or destination identity, TX transmits power of other UEs, Casting type of other UE, priority of communication. 
     For example, the assisting apparatus UE 1  decodes DMRS signals of the said other apparatuses UE 0 , UE 2 , if other UEs have different DM-RS patterns or if the DM-RS patterns have logical meaning regarding reservation, channel utilization, groupcast configuration etc. 
     For example, the assisting apparatus UE 1  evaluates the TX positions and/or communication ranges based either on a zone identity or the RSRP of the other apparatuses UE 0 , UE 2 . 
     In yet another example, the apparatus UE 1  identifies transmission radio resources and/or retransmission radio resources reserved by other apparatuses UE 0 , UE 2 . 
     Radio resources include time/frequency resource locations and/or a periodicity and/or time/frequency resources patterns. 
     According to an example, the RCI comprises a time-index, which indicates where the resource conflict exists, with respect to UE 1  time-line or the network time-line, i.e., from a reference point. This reference can refer, e.g., to the instance where UE 1  reported information, i.e., instance 0, or the network sub-frame number SFN or a time-stamp computed from the GNSS or any other synchronization reference point. In one example, the reporting time slot is the zero instance t=0 and time offset is in negative time position; i.e., based on detected resource conflict at UE 1 , which may be detected when the collision happens. In another example, the reporting time slot is, again, the zero instance t=0 and time offset is in positive time position, i.e., if the resource conflict is identified for a future slot when SCI reservations are decodable. L bits can be pre-configured to address a position of one or more potential conflicts. Additionally, one more bit b_i may be needed to consider to indicate either position e.g., b_i=0 or negative e.g., b_i=1. Hence, L+1 bits are needed to encode one or more Time-offset positions of the resource conflict from the reporting instance t=0. Assuming the reporting time slot is 0 and time offsets is indicated in negative time position i.e., b_i=1. Time offset is from −T to −Delta_T represented by code points, where Delta_T is a processing time. E.g., if the time-offset has 7 bits, i.e., up to 128 units can be encoded, Delta_T=−1 unit to −T=−127 units assuming b_i=1. If more than one conflict time-offsets are to be reported in the negative time positions, the first code points, say X bits, encode the first instant −T 1  e.g., Delta_T=−1 unit to −T=−127, the next Y bits encode the second instance −T 2  e.g., −T 1 +1 unit to −T=−127, and so on until the number of encoded positions are satisfied, i.e., if more than one or two positions. The referenced time-offset, for the potential resource conflict, in the previous example can be considered similarly for a positive time between Dela_T to T; however, assuming b_i=0. Hence, the first instance T 1  is from Delta_T=1 to T=127 encoding N-bits, e.g., if L=7 bits. If we have more position, then T 2  is encoded from T 1 +1 to T, and so on. The lower bound for reported offset position Dela_T is a function of the processing time of the layer associated with the reporting of RCI. Hence, the RCI transmission minimum reporting position for a Processing time T_Proc_L1 is for layer 1, where Delta_T&gt;=T_Proc_L1, Processing time T_Proc_L2 is for layer 2, where Delta_T&gt;=T_Proc_L2. 
     In another example, the position in time and frequency of a potential resource conflict could be encoded in a single value if the value provides enough code points. 
     In another example, the position in time may be referenced to a global unique slot SFN, time-stamp number computed from the network, UE 1  reference node, or GNSS. 
     A periodicity P indicates the periodicity where RCI is repeated. In this case, if UE 2  detected the resource conflict, UE 1  may include the periodicity P in the RCI. In this case, if P=0, this means that UE 1  does not detect or does not require to indicate periodic existence of the resource conflict. However, periodicity P can be a non-zero value which indicates the periodicity in either: Certain Periodicity steps either configured or pre-configured with few amount of bits, e.g., R bits, E.g., if it is 4 bits, then 16 values need to be configured; or in absolute value, i.e., quantized in R bits. 
     In a further example, the frequency offset as part of the RCI indicates the overlapping resources. In one example, only if overlapping of frequency resources exists on the encoded time positions, e.g., 1 bit for each indicated time offset. Thus, e.g., 0 means no overlap in this case half-duplex or 1 means overlap exits, either partially or fully. 
     In another example, if overlap exists partially, fully, or no overlap. E.g., with 2 bits, the frequency offset as part of the RCI is encoded as follows: 00=no overlap half-duplex; 01 which means overlapping between 25% to 50% of the frequency resource partial overlap; 10 which means overlapping between 50% to 75% of the frequency resource partial overlap; 11 which means overlapping between 75% to 100% of the frequency resource almost full frequency overlap. A receiving apparatus like UE 2  may use this information of the frequency offset to learn about the traffic and severity of the resource conflict. 
     In another example, if exact overlapping resources are required to be feedback, F-bits of RCI encode the starting position of overlapping frequency resources where F is a function of Log 2number-of-frequency resources, and S-bits of RCI encode the length of the length of overlapping resources, where S-bits is Log 2number-of-frequency resources. 
     In another example, time and frequency resources, as well as the number of overlapping frequency resources quantity may be encoded in a single code-point in RCI. 
     In an example, send the time information and/or the frequency information of all over lapping resources, or the time information plus the frequency information of all overlapping resources, or the time information plus the frequency information plus the length of all overlapping resources in the assisting information. 
     In another example, if the potential resource conflict is periodic, send the periodicity along with the overlapping resources time/frequency as in a previous example. 
     If the frequency position or frequency overlapping information is absent, e.g., in the pre-configured RCI or the received RCI element, all receiving UEs assume that the frequency overlapping is on the whole BWP or the configured resources pool at the identified time-offset/positions. 
     In an embodiment, the UE 2  may also identify the Resource pool index/BWP index, which includes the potential resource conflict. The UE 1  identifies one resource pool index per reported RCI. In this case, the UE 2  that receives the RCI identifies this indicated resource pool index and all other overlapping resources pools if resource pools/BWPs are configured or pre-configured to be overlapping. BWP is an abbreviation for Bandwidth Part. 
     If the RCI is initiated/established and formed in a higher layer e.g., Layer 2, e.g., MAC layer, the RCI could be carried on a higher layer signaling e.g., a MAC control element MAC-CE, e.g., like CSI reporting. 
     According to an example, the RCI if found in Layer 2 as stated here can be carried on a unique MAC control element CE, e.g., namely RCI MAC-CE. This RCI MAC-CE may include information about the affected radio resources with the potential conflict, i.e., either periodic or aperiodic, including information stated in a previous embodiment, e.g., time-offset, frequency resources, periodicity, etc. For configured periodic resources a reference to the periodic resources, e.g., configured resource ID e.g., SPS ID, Semi-Persistent Scheduling Identifier if known to UE 1 , may be signaled. 
     In another example, the RCI is transmitted based on an extending MAC CE report, e.g., CSI report MAC-CE. In this case, UE 1  may send an extended MAC-CE, e.g., CSI report, including: CQI values or other quantified values indicating the existence of the potential conflict. Those values need to be pre-configured to quantify the potential resource conflict in, e.g., a certain resource pool, on certain frequency resources and/or a certain time instance. For example, those quantified values may be: The amount of interference power as stated above, i.e., quantizing the RSSI or RSRP measured values where the resource conflict exists, where the scale of the new Quantized values for the RSSI or RSRP need to be encoded with a certain number of bits. 
     According to an example, a layer-3 filter is designed to be able to track the severity of the potential resource conflict over elapsed time. The amount of interferers sensed, i.e., the number of colliding interferers, can be quantified. In this case, UE 1  may send a single value indicating the amount of interference sources: E.g., using two bits: 00 for one interference, 01 for two interferences, 10 for two/three interferences, 11 for 3 or more interferences. More bits can be used with a mapping. This layer-3 filter may be used to compress the reported information. Hence, filtering is done over time, frequency, and/or space. In our case, the filter may include: The whole resource pool frequency resources filtered as a single value; A set of contiguous sidelink frequency subchannels resulting in a set of filter values with the same length; A set of contiguous sidelink frequency Resource Blocks or Resource Block groups resulting in a set of filter output with the same length. Where these values are reported per each time instance, where the time instance reported may be encoded to be tracked at the receiving UEs, i.e., to track the determined potential resource conflict over time. An example of Layer-3 filter is represented by the following equation: Fn=1−a*Fn−1+a*Mn, where Fn=This is used for measurement reporting and represent updated filtered measurement result, Fn−1 represent the old filtered measurement result; Mn represents the latest received measurement result from physical layer. a=14 and Mn is filter co-efficient for corresponding measurement quantity received by the quantity configuration parameter. 
     According to a layer 1 example, the RCI can be sent over Layer 1 control signaling, e.g., sidelink control information SCI, i.e., either on a 1st stage SCI and/or 2nd stage SCI. Additionally, it is also possible that part of the RCI can be carried in lower layer control information, i.e., 1st stage SCI and or 2nd stage SCI. If only part of the RCI is sent on Layer 1 signaling, other information may be conveyed via upper layer signaling higher than Layer 1. However, a receiving UE e.g., UE 1  or UE 2  can first decode the Layer1 signaling known it is an RCI message. Thereafter, the UE extracts detail reports from Layer 2 signaling. If the receiver UE is not configured to receive RCI, the UE may discarded the packet. A lower layer 1 signaling RCI comprises the 1st stage and the second stage. 1st stage may include Flip one of the reserved bits to 1 making it an assisting report i.e., 0 means a normal data or another Physical sidelink feedback channel. 1st stage may include: If no reservation, then assisting information is to be transmitted for one time. 1st stage may include: If there is reservation then it&#39;s the repetition of the assisting information. 1st stage may include: Priority field is mapped to the priority values of the assisting information. 2nd stage may include the destination IDs of the UEs source interference. 2nd stage may include the destination IDs of the UEs which may utilize the suggested resource, e.g., a victim UE, or a UE in a group whether it is in the UE-X group or not. 2nd stage may include information about the allocated MAC control element, e.g., number of repetition, time to live, time offset in DFN, SFN. 
     If an upper layer e.g., Layer 2 is used additionally, e.g., MAC CE it may include at least one of the following: the CSI extend report as described above, containing interference level and number of interferes; affected configurations or SPS or configured resources, e.g., offset, time/freq resources, period, etc., where interference or the resource conflict exists. This may include a mapping with multiple configured resources/multiple SPS with, e.g., one to one, mapping linking configured resource to Layer 2 ID, i.e., identifying affecting or affected UEs; no linking to Layer 2 IDs, i.e., without identifying affecting or affected UEs. 
     After sensing and information collection about the potential conflict via determining means  210 , the apparatus UE 1  indicates the source of the potential conflict via the RCI, for example: a one shot transmission; a semi-persistent scheduling SPS i.e., periodic transmission; or a pseudo random time/frequency resource pattern TFRP if TFRP transmission patterns are pre-configured to other UEs. Hence, apparatus UE 1  reports possible existing collision or half-duplex problem or possible quantified interference to some concerned UEs or the apparatus UE 2 . The concerned UEs are the overlapping/colliding UEs. 
     For example, the apparatus UE 2  resolves the potential conflict by identifying a set of one or more specific UEs involved in the potential conflict, e.g., if UE 2  is able to decode the associated SCI and/or MAC headers/frames. Apparatus UE 2  identifies the other UEs e.g. by Physical layer ID L1 ID resolution, Layer-2 ID L2 ID resolution. For example, UE 2  transmits a unicast transmission to one or more of the involved UEs in the identified potential resource conflict. Moreover, UE 2  may decide to send a group cast information regarding the potential resource conflict to the group of identified UEs. 
     For example, the apparatus UE 2  defines a communication range to which UEs within the communication range the RCI should be transmitted, e.g., using group-cast. The communication range for resolution-2 is pre-/configured by an upper layer. Apparatus UE 2  may execute this range resolution from the beginning or when the resolution of the last paragraph. 
     According to yet another example, the apparatus UE 2  transmits the RCI in a broadcast message. Hence, all nearby UEs should be able to decode the RCI, which is sent either standalone or piggy-packed in a previous message. UE 2  executes this resolution from the beginning or when Resolution 1 or 2 according to the last two paragraphs fails. 
     In an example, the RCI receiving UEs are signaled with the appropriate RCI messages, either Layer 1 or Layer 2 signaling. Those UEs are within a group with UE 1  belonging to a group, where the UE group members belonged to the UE 1 , where the receiving UEs receive a message via groupcast/unicast communication, and/or belonging to a group, where all UE group members belonged to the UE 1 , where the receiving UEs receive a message via broadcast if unicast or group cast is not configured or not feasible. 
     In another example, within a group without UE 1  belonging to a group, where the UE 1  does not belong to this group, where the receiving UEs receive the RCI message via groupcast/unicast/broadcast communication. 
     However, if UE 1  is configured/pre-configured to determine RCI and UE 1  declares the RCI, where UE 1  cannot identified one or more of the colliding/overlapping UEs, UE-X may send RCI. 
     An another example, a range of UEs is in the vicinity of UE 1  such that the receiving UEs can relate RCI to its past transmitted resources or to future reserved resources, where the RCI is sent using groupcast with a communication range or broadcast. The colliding UEs may assume that the report include their transmission if the time offset refers to one or more of their previously transmitted frames. 
     The receiving UE 1  may suppress existing or continuing transmission e.g., periodic transmission. Additionally the UE 1  may decide to suppress future transmission if expected based on the assisting information to have the potential conflict indicated via RCI. Additionally, receiving UEs may consider one or more of the following: RCI for re-evaluation of selected but not previously reserved resources; RCI for pre-empting selected and already reserved resources; RCI to trigger reselection procedure again from scratch. 
     In another example, the receiving UE 2  receive the RCI from other UE 1  concerning the identified collision location of resource conflict in future resources or previously used resources and continuing to future resources may decide to send or not to send further transmission on the identified resources with the resource conflict if periodic or aperiodic, if the UE 2  is configured to suppress transmission with a probability P_suppress, where P_suppress is configured per resource pool per CBR/CR per transmission priority per communication range. In this case, if the receiving UE 2  receives from the assisting UE 1  an RCI, the receiving UE 2  will decide to generate a random variable, e.g., transmitProbabilty_A_Info. If the transmitProbabilty_A_Info&lt;P_suppress, the receiving UE 2  will suppress future possible transmission producing the resource conflict. However, if the opposite happens, i.e., transmitProbabilty_A_Info&gt;P_suppress the UE 2  decides to discard the RCI. Additionally, the UE 2  may decide to increase the P_suppress by X %, where X is configured per resource pool, per CBR, per transmission priority per communication range. A mapping function can be for a single resource pool and comprises, for example, several entries for: P_suppress, CBR, CR, priority, communication range. 
       FIG.  2    illustrates a radio situation in a schematic sequence diagram. UE 0  transmits signals to UE 1 , but UE 2  is out of reach. UE 0  is out of reach for UE 2 . Signals s 0  and s 2  on radio resource rr 1  # 0  collide and indicate a resource conflict situation, which is determined via determining means  104 . After receiving the RCI, UE 2  determines the radio resource rr 1  # 2  to omit. To the contrary, UE 2  determines rr 2  different from rr 1  # 2  in order to transmit data d. The periodicity of the radio resources rr 1  # 0  to rr # 3  is transmitted via the RCI in order to refrain from using rr 1  # 2  for the transmission of data d. 
       FIG.  3    depicts a schematic sequence diagram. Reference is made to  FIG.  1   . Receiving means  118  are configured to receive at least a part of a mapping mp 1  between the at least one communication parameter cp and the at least one transmission property tp. For example, the mapping mp 1  defines a mapping function to different, e.g., QoS and or CBR ranges. The mapping mp 1  may be defined or pre-configured per Resource Pool or BWP. The network configures the UE 1  by means of the mapping mp 1 . 
     Determining means  110  are configure to determine at least one communication parameter cp in dependence on at least one of the monitored radio signals s 0 , s 1 . Determining means  112  are configured to determine the at least one validity period p 1  in dependence on the determined at least one communication parameter cp. 
     The at least one validity period p 1  determines how many times the potential conflict happens before or how long the potential conflict exists. Therefore, the validity period p 1  is an indicator in order to evaluate how severe the potential conflict is. One example comprises that the determined RCI is repeated periodically with a periodicity and remains valid before the validity period p 1  lapses. Hence, the apparatus UE 2  may indicate the periodicity where RCI is repeated. Another example comprise that the RCI is repeated and stays valid for multiple slots between at least two apparatuses before the lapse of the validity period p 1 . In this case, the apparatus UE 2  may send a repetition value, which indicates how many times or how many slots the RCI is repeated. Few bits can quantize the repetition value, e.g., 00: first time, 01: 2 times before, 10: 5 times before, 11: more than 5 times before. 
     For example, the validity period p 1  is a function of one or multiple communication parameters cp, including at least one of the following: CBR, transmission range, QoS, communication group size, priority. 
     In one example, if p 1  is function of CBR, it may be designed such that too many UEs report RCI indicating the same conflict is avoided. Thus, p 1  is set to a large value if CBR is low and vice versa. 
     In another example, if T p 1  is function of QoS, it may be designed such that the apparatus UE 1  may extend p 1  for high QoS transmissions. 
     In yet another example, if a potential conflict appears within a certain communication range, or if a certain communication group as in group-cast communication, or if the potential conflict appears in Sidelink communication and the measured/evaluated RSSI and/or RSRP exceeds the pre-configured or determined or mapped RSSI/RSRP thresholds, etc., the apparatus UE 1  sends one or more transmissions including the RCI either standalone message or piggy-packed to other messages. 
     According to an example, the validity period p 1  is determined such that, the longer the potential conflict exists the higher the validity period p 1  is set. Consequently, the apparatus UE 1  remains transmitting the RCI corresponding to the existing/persisting potential conflict. 
     According to an example, in order to determine the validity period p 1 , apparatus UE 1  monitors a set of radio resources, e.g., on one or more resource pools or at least one BWP where RCI is pre-configured. In order to declare the potential conflict for any of these identified resources, the apparatus UE 2  is configured to monitor the radio resources within a monitoring window of a certain size of slots, measured in time units used for transmission, e.g., slots/ms. The monitoring window size may be pre-configured per resource pool or per BWP. Monitoring window size may be equal to a sensing window or shorter. The monitoring window may contain one or more potential resource conflicts. The apparatus UE 1  may decide to determine and send a RCI if the conflict appears in the last T-max ms before a transmission opportunity. The identified potential conflict relative to UE 1  transmission time-line may: a appear at least one time within the T-max before the transmission opportunity and not any time before monitoring window, e.g., validity time is 00; b appear at least one time within the T-max before transmission opportunity and another time before in monitoring window, e.g., validity time&gt;=01; c appear in one or more periods before the RCI transmission opportunity, e.g., validity time&gt;=01+the Periodicity P of the transmission of the RCI. 
     In another example, if the RCI procedure determines a transmission indicator for a determined RCI, and if the CBR is high enough, i.e., exceeding a certain CBR threshold, the apparatus UE 1  may postpone the transmission of the RCI to the next possible selected, reselected or reserved radio resources by UE 21  as far as the postponing time does not exceed allowed history time-factor or validity period p 1 . 
     Determining means  110  are configured to determine the at least one communication parameter cp in dependence on at least one of the monitored radio signals s 0 , s 1 . For example, Channel Busy Ratio CBR is defined as the proportion of channel time where the energy measured on the channel is above the Clear Channel Assessment CCA threshold. Mapping means  114  map the determined at least one communication parameter cp to at least one transmission parameter tp for the resource conflict indicator RCI. Determining means  104  determine and/or transmitting means transmit  106  the resource conflict indicator RCI in dependence on the transmission parameter tp. 
     The resource conflict indicator RCI is determined and/or transmitted based on some triggering parameters. For example, the trigger is based on at least one of the following communication parameters of the monitored signals: CBR, CR, communication range, priority, survival-time, periodicity, or severity of the determined conflict e.g., how many times the collision appeared in the past. 
     The transmission parameter tp comprises at least one of the following: e.g., time validity, validity period p 1 , RSSI/RSRP threshold/Communication Priority/Communication group size. The at least one transmission parameter tp may be limited to/or Pre-configured to certain resource pools or a Bandwidth Part BWP. In one example, the Resource Pool Configuration/Pre-Configuration or the BWP pre-configuration for sidelink communication may define/enumerate/list those transmission parameter tp. In another example, the pre-configuration of apparatus UE 2  for sidelink communication may define/enumerate/list the aforementioned transmission parameters. 
     In another example, based on the determined CBR for a given resource pool or a given BWP, UE 1  may prioritize the assisting information of only the more severe potential conflicts e.g., based on RSSI, RSRP/Priority/QoS if SCI is decoded. Hence, a mapping between the CBR from one side and RCI priority based on priority field in the control information of the affected transmission and/or severity based on RSSI/RSRP, communication range, communication group, etc. is done. In this case, the RCI reporting may be limited only to a smaller number of sources of potential conflicts. The mapping function determines pre-configured ranges, where apparatus UE 2  transmits the RCI. The mapping function comprises for example: CBR, RSSI_Threshold, RSRP_Threshold, Priority, and Communication Range. 
     In the previous examples, UE 1  may evaluate the available/remaining size of a possibly reserved RCI and/or the possible channel occupancy ratio, CR that allows for future transmission. Accordingly, and based on the pre-configured mapping function defined above, UE 1  may select/prioritize the RCIs associated with sever potential conflicts e.g., based on RSSI, RSRP/Priority/QoS if SCI is decoded. The selected prioritized RCIs can be transmitted first if possible. If the UE 1  does not have further resources for further remaining RCIs to report, UE 1  may drop all the remaining RCIs if they cannot be accommodated. 
     The determination of the resource conflict indicator RCI comprises at least one of the following or a combination of: sensing a dedicated radio channel that comprises the radio signals; measuring RSSI, Received Signal Strength Indicator, of the radio signals; measuring RSRP, Reference Signal Received Power, of the radio signals; measuring CBR, Channel Business Ratio, of the radio signals. 
     Determining means  122  determine the probability threshold th in dependence on the determined at least one communication parameter cp. 
     Determining means  120  draw a randomized value rv, for example a pseudo-random number according to a configured distribution. Determining means determine and/or transmitting means  106  transmit the resource conflict indicator RCI when the determined randomized value rv exceeds a probability threshold th. 
     Based on at least one communication parameter cp, the apparatus UE 1  transmits the resource collision indicator RCI based on a random probability, which is configured as a range or a single value like the probability threshold th. For example, the apparatus UE 1  will set the threshold th to a high value when measured/evaluated CBR is low and will set the probability threshold th to a small value when measured/evaluated CBR is high. 
     In another example, based on the computed CBR and/or CR, the UE 1  may transmit RCI based on the random probability. Probability will be high when measured/evaluated CBR is small. After RCI is determined, UE 1  may generate the random value rv with a distribution PDF-X e.g., uniform and compare it to the mapped value for the RCI transmission. If rv&lt;=probability threshold th, the RCI is transmitted. Else if rv&gt;th, then the RCI is backed-off to another transmission opportunity within the validity period p 1  or, otherwise, the RCI is dropped. A mapping between the measured/evaluated CBR and evaluated CR from one side to the Probability of RCI TX P_i comprises, for example: CBR, CR, probability threshold th. The random process may be generated once after the potential conflict is identified and between identification moment t 1  zero, 0 and a lapse of the validity period since the identification moment t 1 . Additionally, the random process may be generated one or more extra time after the first generation, i.e., for one potential conflict, and until a timer T expires. 
     In another example, the probability of transmitting RCI may be a function of configured transmission parameters: Priority of transmission, RSSI/RSRP Thresholds, communication range, etc. . . . . Hence, a mapping can be represented differently as where P_i is the probability of sending RCI: probability threshold th, RSSI_Threshold, RSRP_Threshold, Priority, and Communication Range. 
     In yet another example, the probability of sending RCI may be a function or mapping between the measured/evaluated CBR and/or CR and transmission parameters e.g., Priority of transmission, RSSI/RSRP Thresholds, communication range, etc. 
     According to an example, the apparatus UE 1  determines the at least one resource conflict indicator RCI at a point t 1  in time; and transmits and/or re-transmits the resource conflict indicator RCI if a validity period p 1  is running since the determined point t 1  in time. Therefore, the apparatus UE 1  may transmit a further determined RCI and not the older ones, i.e. elder than p 1  ms. 
     According to another example, the apparatus UE 1  transmits a validity indicator, for example indicating the validity period p 1 , associated with the determined at least one resource conflict indicator RCI. 
     The validity period p 1  is configured or pre-configured, where the apparatus UE 1  evaluates and considers the determined resource conflict indicator within the last p 1  ms/slots/time units. For example, p 1  is function of at least one of the following: CBR, RSPR, RSSI, communication range, and transmission priority. 
     For example, the validity period p 1  is selected to allow apparatus UE 1  to transmit RCI not elder than p 1 -ms/p 1 -slots/p 1 -time-Unit. Therefore, the validity period ca also be referred to as a forgetting factor of older RCIs. the validity period p 1  itself is a function of at least one of the following: Channel Busy Ratio CBR, e.g., is for busy channel high CBR p 1  is shorter as CBR occurred earlier, RCI is reported by other devices and vice versa when the CBR is low; a communication priority of the potentially conflicting communication; a communication range of the potentially conflicting communication; a communication group size associated with the potentially conflicting communication; communication survival time of the potentially conflicting communication. Upon the target apparatus UE 2  receives the RCI, target apparatus UE 2  starts after a short processing time re-evaluation of selected resources or directly trigger resource reselection. 
     Determining means  104  determine a plurality of resource conflict indicators RCI associated with a respective priority as the at least one transmission parameter tp. Selecting means  116  select one of the plurality of resource conflict indicators RCI in dependence on the associated priorities. Transmitting means  106  transmit the selected one of resource conflict indicators RCI prior to the remaining resource conflict indicators. 
     According to an example, the apparatus UE 1  is further configured to determine an origin indicator, for example an identity or position or distance, of at least one further apparatus, for example UE 0 , which is involved in said resource conflict, in dependence on at least one of the monitored radio signals. For example, if the origin indicator indicates that the transmitting entity of the received radio signal is far away, then the resource conflict indicator is not determined or not transmitted. Therefore, if the origin indicator indicates that a distance to the transmitting entity of one of the plurality of received signals is above a distance threshold, then the determination or transmission of an associated resource conflict indicator is omitted. The resource conflict indicator RCI comprises the determined origin indicator. Advantageously, other apparatuses get aware of the identity and/or position of the conflicting entity and can react. 
     In an example, in group communication with possible connection establishment even when using unicast PC5 RRC signaling, configuration and capability of RCI can be transmitted using, e.g., PC5 RRC signaling, e.g., included in the UE capability information. Hence, the assisting UE 1  may send an RRC message with a logical sidelink control channel SCCH containing the UE capability, e.g., UECapabilityInformationSidelink include: AssistingInformationCapability: set to true. Additionally, another UE may send a request for RCI or enquiry whether UE 1  supports assisting information transmission, e.g., via UECapabilityEnquirySidelink. Additionally, size of the RCI can be set within the group using RRC establishment protocol. The specific configuration of the MAC control element CE containing the said RCI can be set or selected or configured via the RRC message establishment. In the configuration message, information about the RCI periodicity, time/frequency information, validity, etc., can be configured within the group. Hence, in an example a kind of synchronous RCI transmission between the group may be considered. For example, if the feedback is for RSRP, the RRC configures: filterCoefficientRSRPAssistingInformation. 
     In another example, in case of connection-less group communication, i.e., with no PC5 RRC signaling establishment, configuration of RCI is done by a base-station or is pre-configured and RCI establishment handshaking between UE pairs can be omitted. 
     Determining means  240  of UE 2  determine that at least an overlap o between the at least one radio resource indicated via the resource conflict indicator RCI and at least one radio resource, which has been used by the apparatus UE 2  for a transmission in the past, has occurred. Determining means  242  determine, if the overlap o is determined, at least one communication parameter cp 2  in dependence on the at least one radio resource, which has been used by the apparatus UE 2  for a transmission in the past. Determining means  244  determine the probability threshold th 2  in dependence on the at least one determined communication parameter cp 2 . 
     The second UE 2  receives via receiving means  206  the validity indicator associated with the at least one resource conflict indicator RCI. Determining means  210  refrain from using at least one radio resource, which is indicated by the at least one resource conflict indicator RCI as long as the received validity indicator indicates that the received at least one resource conflict indicator RCI is valid. 
     Determining means  230  determine a set of candidate radio resources crr in dependence on the received at least one resource conflict indicator RCI. Determining means  210  determine the radio resource rr 2  for the transmission of the data d from the determined set of candidate radio resources crr. 
     The determination means  210  is configured to determine the set of candidate radio resources crr by omitting the indicated at least one radio resource that has the potential risk of the resource conflict. Therefore, the set of candidate resources is determined by excluding the at least one radio resource indicated by the resource conflict indicator from the candidate resources. By omitting the indicated at least one potentially conflicting radio resource, the set of candidate radio resources does not comprise the potentially conflicting radio resource. 
     Determining means  232  draw a randomized value rv 2 . Determining means  230  determine the set of candidate radio resources crr in dependence on the received resource conflict indicator RCI when the randomized value rv 2  exceeds a probability threshold th 2 . According to an example, the suppressing probability is incremented by reducing the threshold th 2  when it is triggered or when the set of candidate resources crr is determined. 
       FIG.  4    depicts a schematical block diagram of the determining means  104  for the at least one resource conflict indicator. According to determining means  402  The determining means  402  determines, whether overlapping reservations of a plurality of further apparatuses can be decoded. If affirmative, RSRP for an overlapping transmission is determined as the at least one resource conflict indicator via determining means  404 . SCIs are decoded before the overlapping resources i.e., as reservation or during the time instance of overlapping resources. According to determining means  406 , there is determined, whether RSRP is greater than an associated threshold or whether communication is within a group or within a range or with a certain priority range. If affirmative, the potential conflict is determined via determining means  408 . 
     If the result of determining means  402  is not affirmative, determining means  412  determines whether overlapping DMRS are decodable. DMRSs can be distinguishably decoded for one or more of the overlapping UEs. If the result of determining means  412  is affirmative, determining means  414  determines the resource conflict indicator in form of RSSI for the overlapping transmission based on DMRS. According to determining means  416 , there is determined whether our society is greater than and associated threshold or whether the observed communication is associated with a group. If the result of the determining means  416  is affirmative, the determining means  408  determines the potential conflict. 
     If the result of the determining means  412  is not affirmative, determining means  422  determines whether overlapping SCI and DMR as are not decodable. If the result of the determining means  422  is affirmative, determining means  424  determines the at least one resource conflict indicator in form of RSSI for the overlapping transmission, for example based on an energy level detected. RSSI can be computed based on energy detected on the DMRS locations configured for the resource pool. According to determining means  426 , there is determined if RSI is greater than and associated threshold. If the result of the determining means  426  is affirmative, determining means  408  determines the potential conflict on at least one radio resource. 
       FIG.  5    shows a schematic perspective view of an exemplary traffic situation. UE 0  transmits signals to UE 1 , but UE 2  is out of reach as indicated by the coverage areas cov 0 , cov 1 . Therefore, direct radio channels D 2 D # 1 , D 2 D # 2  are used to communicate between UE 0  and UE 1 , UE 1 , UE 2 , respectively. Each vehicle V 0 , V 1 , V 2  comprises radio terminal in form of the apparatus UE 0 , UE 1 , UE 2 , which together form a radio communication network. Each of the apparatuses UE 0 , UE 1 , UE 2  comprises a data bus B 0 , B 1 , B 2  connecting at least one processor P 0 , P 1 , P 2 , a memory M 0 , M 1 , M 2  and a radio module C 0 , C 1 , C 2 . At least one antenna A 0 , A 1 , A 2  is connected to the radio module C 0 , C 1 , C 2 . The respective radio module C 0 , C 1 , C 2  is configured to transmit and receive radio signals via the antenna A 0 , A 1 , A 2 . A computer program in the sense of a computer program product is stored in the memory M 0 , M 1 , M 2 . The computer program is designed to execute the method steps set out in this description, in particular with the aid of the at least one processor P 0 , P 1 , P 2 , the at least one memory M 0 , M 1 , M 2  and the at least one radio module C 0 , C 1 , C 2 , and to communicate with further terminals via the at least one antenna A 0 , A 1 , A 2 . Alternatively or additionally, the processors P 0 , P 1 , P 2  are implemented as ASICs in order to execute the described method steps.