Downlink (DL) power control

Abstract

A method performed by a network node. In one embodiment, the method includes scheduling a downlink (DL) transmission to a second user equipment (UE). The method also includes selecting a transmit (Tx) power for the transmission to the second UE using a first reference signal (RS) transmission transmitted by a first UE. The method also includes performing the DL transmission using the selected Tx power.

Description

[0001] DOWNLINK (DL) POWER CONTROL

[0002] TECHNICAL FIELD

[0003] Disclosed are embodiments related to uplink (DL) power control.

[0004] BACKGROUND

[0005] Setting output power levels of transmitters (e.g., base stations in downlink (DL) and user equipments (UEs) in uplink (UL)) in mobile systems is commonly referred to as power control (PC). Objectives of PC include improved capacity, coverage, and system robustness, as well as reduced power consumption.

[0006] Network traffic may comprise a mix of packets, such as high priority packets and low priority packets. A high priority packet may have a strict requirement on latency and / or reliability, whereas a low priority packet may not have such strict requirements. The varying requirements are due to varying priority among the users, and due to requirements being different for different services (mobile broadband (MBB) vs Ultra-Reliable Low Latency Communication (URLLC) for example).

[0007] SUMMARY

[0008] Certain challenges presently exist. For instance, meeting a strict requirement on latency and / or reliability for a high priority packet is a challenging task. One of the challenges is that one typically would like to allow the transmission of the high priority packet occur in parallel with a transmission of a packet with lower priority, but this may cause the higher priority transmission to be interfered with by interference generated from the lower priority transmission.

[0009] Accordingly, in one aspect there is provided a method performed by a network node. In one embodiment, the method includes scheduling a downlink (DL) transmission to a second user equipment (UE). The method also includes selecting a transmit (Tx) power for the transmission to the second UE using a first reference signal (RS) transmission transmitted by a first UE. The method also includes performing the DL transmission using the selected Tx power. In another embodiment, the method includes deciding to schedule a downlink, DL, transmission to a first UE. The method also includes scheduling the DL transmission. The method also includes, as a result of scheduling or deciding to schedule the DL transmission, triggering the first UE to perform a first RS transmission using a first RS resource, wherein the network node does not use the first RS transmission to select a Tx power for the DL transmission. The method also includes performing the scheduled DL transmission.

[0010] In another embodiment, the method includes scheduling a downlink, DL, transmission to a UE. The method also includes, based on a classification of the DL transmission, selecting a Tx power setting mode from a set of two or more Tx power setting modes, the set of two or more Tx power setting modes comprises a first Tx power setting mode and a second Tx power setting mode. The method also includes selecting a Tx power for the DL transmission to the UE using the selected Tx power setting mode. The method also includes performing the DL transmission using the selected Tx power. If the first Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a first set of zero or more reference signal, RS, resource measurements, and if the second Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a second set of one or more RS resource measurements, wherein the second set of RS resource measurements includes at least one RS resource measurement that is not included in the first set of RS resource measurements.

[0011] In another aspect there is provided a computer program comprising instructions which when executed by processing circuitry of a network node causes the network node to perform any of the network node methods disclosed herein. In one embodiment, there is provided a carrier containing the computer program wherein the carrier is one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium. In another aspect there is provided a network node that is configured to perform the network node methods disclosed herein. The network node may include memory and processing circuitry coupled to the memory.

[0012] In another aspect there is provided a method in a communication system that includes a first network node serving a first UE and a second network node serving a second UE. The method includes the first network node deciding to schedule a DL transmission to the first UE. The method also includes the first network node scheduling the DL transmission to the first UE. The method also includes, as a result of scheduling or deciding to schedule the DL transmission to the first UE, the first network node triggering the first UE to perform a first RS transmission using a first RS resource. The method also includes the second network node scheduling a DL transmission to the second UE. The method also includes the second network node selecting a transmit, Tx, power for the DL transmission to the second UE based on a measurement of the first RS resource. The method also includes the second network node performing the DL transmission using the selected Tx power.

[0013] An advantage of the embodiments disclosed herein is that they enable a network node (e.g., a gNB) to cause another network node to use less power when transmitting a non- high priority packet so that the transmission of the non-high priority packet will interfere less with the transmission of a high priority packet.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments.

[0016] FIG. 1 illustrates a system according to an embodiment.

[0017] FIG. 2 is a message flow diagram illustrating a message flow according to an embodiment.

[0018] FIGs. 3A, 3B, 3C, 3D show results illustrating the advantage of the embodiments.

[0019] FIG. 4 is a flowchart illustrating a process according to an embodiment.

[0020] FIG. 5 is a flowchart illustrating a process according to an embodiment.

[0021] FIG. 6 is a flowchart illustrating a process according to an embodiment.

[0022] FIG. 7 is a flowchart illustrating a process according to an embodiment.

[0023] FIG. 8 is a block diagram of a network node according to an embodiment. DETAILED DESCRIPTION

[0024] FIG. 1 illustrates a system 100 according to an embodiment. System 100 includes a first UE 101 (a.k.a., “UE A”) being served by a network node 104 (a.k.a., “gNBl”) and a second UE 102 (a.k.a., “UE B”) being served by another network node 106 (a.k.a., “gNB2”).

[0025] In the example shown, gNBl performs a high priority PDSCH transmission denoted PDSCHHRLLC, where HRLLC implies “high reliability low latency communication” (i.e., gNBl transmit a high priority packet over PDSCH), which is received by UE A. gNB2, however, performs a non-high priority transmission, denoted PDSCHMBB, which is received by UE B. In the embodiments described herein, the transmit power selected by gNB2 for the non-high priority transmission will depend on an UL reference signal (RS) transmitted by UE A on a certain RS resource (denoted “qd,l”) and an UL RS transmitted by UE B on another RS resource (denoted “qd,101”), whereas the transmit power selected by gNBl for the high priority transmission will not depend on RS(qd,l) (e.g., the transmit power selected by gNBl for the high priority transmission will depend an UL RS transmitted by UE A on another RS resource (denoted “qd,2”)). More specifically, as a result of scheduling the high priority PDSCH transmission to UE A, gNBl triggers UE A to transmit RS(qd,l) to cause gNB to potentially reduce its transmit power.

[0026] FIG. 2 is a message flow diagram (a.k.a., signaling diagram) illustrating an embodiment.

[0027] Configure RS parameters

[0028] In a first step, parameters related the UL transmissions RS(qa,2) and / or RS(qa,i) and / or RS(qa,ioi) from UE A and UE B are configured. These UL transmissions may, for example, be sounding reference signal (SRS) or demodulation reference signal (DMRS) or any physical UL shared channel (PUSCH) transmission. In some embodiments, only on RS(qa,i) is configured, whereas in other embodiments RS(qa,2) and / or RS(qa,ioi) are also configured.

[0029] In case that the UL transmissions are SRSs, this may be configured in a periodic, semi-static or aperiodic fashion. It may also be so that one of the UL transmissions, e.g. RS(qa,i), is configured to be aperiodic whereas one of the other transmissions, e.g. RS(qa,2), is configured to be periodic.

[0030] While the example above in FIG. 1 illustrates one UE (UE A) transmitting RS(qa,i) there may be multiple UEs, from multiple cells, configured to transmit an RS using RS resource qd,l (i.e., same time and frequency resource). As an example, multiple UEs may be configured to transmit aperiodic SRSs on the same time and frequency resource (e.g., resource qd,l).

[0031] Select power control (PC) mode

[0032] In one embodiment, each gNB has multiple modes for how to determine its DL power when performing a transmission (e.g., a PDSCH transmission) and which mode to use will depend on the traffic type of the transmission. In one embodiment, there are two modes: one mode is used for a first traffic type (e.g., high priority packets (e.g. HRLLC)) and the other mode is used for a second traffic type (e.g., non-high priority packet (e.g. MBB). These modes are referred to herein as the “high priority (HP) mode” and the “low priority (LP) mode.”

[0033] The gNB selects which mode to use based on the traffic type of the transmission. That is, when the gNB schedules the first type of transmission (e.g., a HP transmission), then the gNB will use the HP mode to select the Tx power for the transmission, otherwise the gNB uses the LP mode to select the Tx power.

[0034] LP Mode

[0035] In the LP mode, the gNB uses an estimate related to the received signal RS(qa,i) when determining the transmit power used. This may imply that a function is used to derive the power and this function depends on a measurement (e.g., reference signal received power (RSRP) measurement) of the received signal RS(qa,i) (e.g., the function depends at least on the measurement). The characteristics of the function is such that an increase of the received signal power at RS(qa,i) may decrease the PDSCH output power (in order to decrease any interference that may be caused by the transmission) and vice versa. This mechanism will hence protect the reception of PDSCHHRLLC at UA A from interference caused by the transmission of PDSCHMBB from gNB2. Using FIG. 1 as an example, in some embodiments the determination of PDSCH output power for the PDSCHMBB transmission by gNB2 will also depend on a measurement of the received power of RS(qa,ioi). Also here the characteristics of the function is such that an increase of the received signal power at RS(qa,ioi) may decrease the PDSCH output power from gNB2 and vice versa.

[0036] Examples

[0037] Three examples of how gNB2 may select the transmit power for the PDSCHMBB transmission to UE B are provided below. PDSCH,gNB2 = min{PMAx> PA + PL qd,i))} [dBm] (Example 1) (Example 2) (Example 3) where

[0038] EPDSCH,gNB2 is the PDSCH transmit power for the PDSCHMBB transmission to UE B,

[0039] PMAX is the maximal output power (this is configurable),

[0040] PAis a parameter relating to desired received power at UE A,

[0041] PL qd,i) is an estimated path loss between gNB2 and UE A based on a measurement of RS(qa,i).

[0042] PBis a parameter relating to desired received power at UE B,

[0043] PL (Qd,ioi) is an estimated path loss between gNB2 and UE B based on a measurement of RS(qa,ioi); and x is configurable threshold.

[0044] HP Mode

[0045] When a gNB uses the HP mode, the gNB will not use an estimate related to the received signal RS(qa,i) when determining the Tx power (i.e., RS(qa,i) is effectively ignored). This consequently implies that an increase (or decrease) of the received signal power at RS(qa,i) will not impact the Tx power. In some embodiments the determination of PDSCH output power of gNB2 will depend on an estimate related to the received signal RS(qa,ioi). Here the characteristics of the function is such that an increase of the received signal power at RS(qa,ioi) may decrease the PDSCH output power from gNB2 and vice versa.

[0046] Using FIG. 1 as an example, in some embodiments the determination of PDSCH output power for the PDSCHHRLLC transmission by gNBl will also depend on a measurement of RS(qa,2). Also here the characteristics of the function is such that an increase of the received signal power at RS(qa,i) may decrease the PDSCH output power from gNBl and vice versa.

[0047] Examples

[0048] Two examples of how gNBl may select the transmit power for the PDSCHHRLLC transmission to UE A are provided below.

[0049] ^PDSCH, gNBl = PMAX [dBm] (Example 1) (Example 2).

[0050] Trigger UL transmissions, derive DL power and perform PDSCH transmission

[0051] Because the Tx power of gNBs running in LP mode will be impacted from the transmission of RS(qa,i) this implies that a given gNB (e.g., gNBl) can impact the output power of some neighboring gNBs (e.g., gNB2) by triggering an UL transmission on RS(qa,i) from one or more UEs served by the given gNB. The given gNB may therefore chose to trigger an UL transmission on RS(qa,i) when a high priority packet is about to be transmitted / scheduled on PDSCH since that may increase the SINR at the UE for the received high priority packet. This is elaborated on using the examples below.

[0052] No HP Transmission Scheduled

[0053] When gNBl does not have a HP transmission for any UEs that it is serving (e.g., UE A), gNBl does not trigger UE A to transmit on RS(qa,i); UE A is instead muted with respect to RS(qa,i). gNBl may also schedule a non HRLLC packet (e.g. MBB) transmission on PDSCH to UE A, since there is no HRLLC to transmit, and will then operate in LP mode for PDSCH power. This implies that if any other UE is transmitting on RS(qa,i) this will impact the derivation of Consequently, this may result in a power backoff, when performing PDSCH transmission, if the measured signal level on RS(qa,i) is high enough.

[0054] Likewise, when gNB2 does not have a HP transmission for any UEs that it is serving (e.g., UE B), gNB2 does not trigger UE B to transmit on RS(qa,i); LE B is instead muted with respect to RS(qa,i). gNB2 may also schedule a non HRLLC packet (e.g. MBB) transmission on PDSCH to LE B and will then operate in LP mode for PDSCH power. Also this will imply that if any other UE is transmitting on RS(qa,i) this may impact the derivation °f ^PDSCH,^NB2 •

[0055] LE A and LE B may or may not be triggered to transmit on RS(qa,2) and / or RS(qa,ioi) respectively (in line with previous embodiments).

[0056] HP Transmission is Scheduled

[0057] When gNBl has an HP transmission for a LE that it is serving (e.g., LE A in the example shown in the figures) (e.g., gNBl schedules a high priority packet on PDSCH to LE A), gNBl selects to operate in the above described HP mode for determining the Tx power of the HP transmission to LE A. Consequently, even if other UEs are transmitting on RS(qa,i) this will not result in a power backoff, when gNB 1 performs the HP PDSCH transmission to LE A. gNBl also triggers LE A to transmit on RS(qa,i), as illustrated in FIG. 2, and this implies that other gNBs operating in LP mode may perform a power backoff.

[0058] In this example, gNB2 does not have a high priority packet and does therefore not trigger LE B to transmit on RS(qa,i); LE B is muted with respect to RS(qa,i). gNB2 may also schedule a non HRLLC packet (e.g. MBB) transmission on PDSCH to LE B and will then operate in LP mode for PDSCH power. This may hence imply a power backoff of PDSCH power PpDscH,^NB2 since LE A is transmitting on RS(qa,i).

[0059] LE A and LE B may or may not be triggered to transmit on RS(qa,2) and / or RS(qa,ioi) respectively (in line with previous embodiments).

[0060] Advantages / Results

[0061] FIGs. 3 A-3D illustrate the advantages of the embodiments. The pathloss formula from TR. 38.901 (LOS propagation UMa at 3.5 GHz) is used to translate distance to pathloss. Also, it is assumed that P / =43dBm and that PPDSCH,gNB2= m^n{PMAx> PA + PL ,qd,i) (PB + PL ( d,ioi))} [dBm] in LP mode

[0062] PL ( d, ioi))} [dBm] in HP mode. Furthermore, PBand PAhave been chosen to target a received signal to interference ratio (SIR) of lOdB for a high priority packet.

[0063] FIGs. 3 A and 3B illustrate the transmit power of gNB2. More specifically, FIG. 3 A we have gNB2’s transmit power when it is in HP mode. As can be seen, the transmit power will only relate to distance to UE B which means that the interference generated towards UE A will not impact the transmit power. In FIG. 3B it is assumed that UE A is transmitting on RS(qa,i) and that gNB2 operates in LP mode. As can be seen the transmit power will be limited when UE A is close to gNB2 which in turn will limit the interference generated towards UE A. For the perspective of the link between UE B and gNB2 there will be a cost of this in some cases since the received signal at UE B will become weaker than in FIG. 3A.

[0064] If the received SIR at UE A is studied, as done FIGs. 3C and 3D, the benefit of the embodiments can be seen. It is assumed here that distance between UE A and gNBl is large enough so that gNB 1 would need to transmit with a high power to reach UE A (it may e.g. be located on cell edge). In FIG. 3C, UE A’s SIR when the embodiments are not employed can be seen; as can be seen the interference generated from gNB2 substantially limits the UE A SIR in some cases. In FIG. 3D, the embodiments are used and as can be seen the UE A’s SIR is high also when the distance between UE B and gNB2 is small since gNB2 will limit its output power. This will consequently benefit the transmission of the HRLLC packet from gNBl to UE A.

[0065] FIG. 4 is a flow chart illustrating a process 400 according to an embodiment. Process 400 is performed by a network node and may begin in step s402.

[0066] Step s402 comprises scheduling a DL transmission to a second UE.

[0067] Step s404 comprises selecting a Tx power for the transmission to the second UE using a first RS transmission transmitted by a first UE.

[0068] Step s406 comprises performing the DL transmission using the selected Tx power.

[0069] In some embodiments, the network node selects the transmit power for the transmission to the second UE using the first RS transmission transmitted by a first UE as a result of scheduling the transmission to the second UE and the transmission being classified as a non-high priority transmission.

[0070] In some embodiments, the first UE is served by another network node.

[0071] In some embodiments, selecting the transmit power for the DL transmission to the second UE comprises: measuring power of the first RS transmission transmitted by the first UE to produce a first RS measurement value and selecting the Tx power using the first RS measurement value and a maximum Tx power value.

[0072] In some embodiments, selecting the Tx power using the first RS measurement value and the maximum Tx power value comprises using the first RS measurement value to produce a first Tx power value and selecting a Tx power value from a set of Tx power values, wherein the set of Tx power values comprises the first Tx power value and the maximum Tx power value.

[0073] In some embodiments, selecting a Tx power value from the set of Tx power values comprises selecting the first Tx power value if Txl < Tmax, otherwise selecting the maximum Tx power value, where Txl is the first Tx power value and Tmax is the maximum Tx power value.

[0074] In some embodiments, selecting the transmit power for the DL transmission to the second UE comprises: measuring power of the first RS transmission transmitted by the first UE to produce a first RS measurement value; measuring power of a second RS transmission transmitted by the second UE to produce a second RS measurement value; and selecting the Tx power using the first RS measurement value, the second RS measurement value, and a maximum Tx power value.

[0075] In some embodiments, selecting the Tx power using the first RS measurement value, the second RS measurement value, and the maximum Tx power value comprises: using the first RS measurement value to produce a first Tx power value; using the second RS measurement value to produce a second Tx power value; and selecting a Tx power value from a set of Tx power values, wherein the set of Tx power values comprises the first Tx power value, the second Tx power value, and the maximum Tx power value. In some embodiments, selecting a Tx power value from the set of Tx power values comprises: selecting the first Tx power value if Txl < Tx2 and Txl < Tmax, where Txl is the first Tx power value, Tx2 is the second Tx power value and Tmax is the maximum Tx power value, selecting the second Tx power value if Tx2 < Txl and Tx2 < Tmax, or selecting the maximum Tx power value if Tmax < Txl and Tmax < Tx2.

[0076] In some embodiments, the scheduled DL transmission is performed using the selected transmit power value.

[0077] FIG. 5 is a flow chart illustrating a process 500 according to an embodiment. Process 500 is performed by a network node and may begin in step s502.

[0078] Step s502 comprises deciding to schedule a DL transmission to a first UE.

[0079] Step s504 comprises scheduling the DL transmission.

[0080] Step s506 comprises, as a result of scheduling or deciding to schedule the DL transmission, triggering the first UE to perform a first RS transmission using a first RS resource, wherein the network node does not use the first RS transmission to select a Tx power for the DL transmission.

[0081] Step s508 comprises performing the scheduled DL transmission.

[0082] In some embodiments, the first UE is configured to perform a second RS transmission using a second RS resource, and the method further comprise using the second RS transmission to select the Tx power.

[0083] In some embodiments, the DL transmission is classified as a high priority transmission.

[0084] FIG. 6 is a flow chart illustrating a process 600 according to an embodiment. Process 600 is performed by a network node and may begin in step s602.

[0085] Step s602 comprises scheduling a DL transmission to a UE.

[0086] Step s604 comprises, based on a classification of the DL transmission, selecting a Tx power setting mode from a set of two or more Tx power setting modes, the set of two or more Tx power setting modes comprises a first Tx power setting mode and a second Tx power setting mode. Step s606 comprises selecting a Tx power for the DL transmission to the UE using the selected Tx power setting mode.

[0087] Step s608 comprises performing the DL transmission using the selected Tx power.

[0088] If the first Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a first set of zero or more reference signal, RS, resource measurements, but if the second Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a second set of one or more RS resource measurements, wherein the second set of RS resource measurements includes at least one RS resource measurement that is not included in the first set of RS resource measurements.

[0089] In some embodiments process 600 also includes classifying the DL transmission as a non-high priority transmission, wherein the second set of RS resource measurements comprises a first RS measurement, selecting the Tx power setting mode comprises selecting the second Tx power setting mode as a result of classifying the DL transmission as a non- high priority transmission, and selecting the Tx power for the DL transmission to the UE using the second Tx power setting mode comprises selecting the Tx power using the first RS measurement and the maximum Tx power value.

[0090] In some embodiments the second set of RS resource measurements further comprises a second RS measurement, and selecting the Tx power for the DL transmission to the UE using the second Tx power setting mode comprises selecting the Tx power using the first RS measurement, the second RS measurements, and the maximum Tx power value.

[0091] In some embodiments process 600 also includes classifying the DL transmission as a high priority transmission, wherein selecting the Tx power setting mode comprises selecting the first Tx power setting mode as a result of classifying the DL transmission as a high priority transmission, and selecting the Tx power for the DL transmission to the UE using the first Tx power setting mode comprises selecting the Tx power using the maximum Tx power value.

[0092] In some embodiments, the first set of RS resource measurements comprises a first RS measurement, and selecting the Tx power for the DL transmission to the UE using the first Tx power setting mode comprises selecting the Tx power using the maximum Tx power value and the first RS measurement.

[0093] FIG. 7 is a flow chart illustrating a process 700, according to an embodiment. The process is performed in a communication system comprising a first network node (e.g,. gNB 104) serving a first UE (e.g., UE 101) and a second network node (e.g., gNB 106) serving a second UE (e.g, UE 102). Process 700 may begin in step s702.

[0094] Step s702 comprises the first network node deciding to schedule a DL transmission to the first UE.

[0095] Step s704 comprises the first network node scheduling the DL transmission to the first UE.

[0096] Step s706 comprises, as a result of scheduling or deciding to schedule the DL transmission to the first UE, the first network node triggering the first UE to perform a first RS transmission using a first RS resource.

[0097] Step s708 comprises the second network node scheduling a DL transmission to the second UE.

[0098] Step s710 comprises the second network node selecting a Tx power for the DL transmission to the second UE based on a measurement of the first RS resource.

[0099] Step s712 comprises the second network node performing the DL transmission using the selected Tx power.

[0100] In some embodiments, selecting the transmit power for the DL transmission to the second UE comprises using the measurement of the first RS resource to produce a first transmission, Tx, power value and selecting a Tx power value from a set of Tx power values, wherein the set of Tx power values comprises the first Tx power value and a maximum Tx power value. In some embodiments, selecting a Tx power value from the set of Tx power values comprises selecting the first Tx power value if Txl < Tmax, otherwise selecting the maximum Tx power value, where Txl is the first Tx power value and Tmax is the maximum Tx power value.

[0101] In some embodiments process 700 also includes measuring power of an RS transmission transmitted by the second UE to produce a second RS measurement and using the second RS measurement to produce a second Tx power value, wherein the set of Tx power values further comprises the second Tx power value. In some embodiments, selecting a Tx power value from the set of Tx power values comprises: selecting the first Tx power value if Txl < Tx2 and Txl < Tmax, where Txl is the first Tx power value, Tx2 is the second Tx power value and Tmax is the maximum Tx power value, selecting the second Tx power value if Tx2 < Txl and Txl < Tmax, or selecting the maximum Tx power value if Tmax < Txl and Tmax < Tx2.

[0102] FIG. 8 is a block diagram of a network node 800 (e.g., network node 104 or network node 106), according to some embodiments for performing the methods disclosed herein. As shown in FIG. 8, network node 800 may comprise: processing circuitry (PC) 802, which may include one or more processors (P) 855 (e.g., a general purpose microprocessor and / or one or more other processors, such as an application specific integrated circuit (ASIC), field-programmable gate arrays (FPGAs), and the like), which processors may be co-located in a single housing or in a single data center or may be geographically distributed (i.e., the network node 800 may be a distributed computing apparatus); a network interface 868 comprising a transmitter (Tx) 865 and a receiver (Rx) 867 for enabling network node 800 to transmit data to and receive data from other nodes connected to a network 110 (e.g., an Internet Protocol (IP) network) to which network interface 868 is connected; communication circuitry 848 (e.g., radio transceiver circuitry comprising an Rx 847 and a Tx 845) coupled to an antenna system 849 for wireless communication with UEs or other nodes; and a storage unit (a.k.a., “data storage system”) 808, which may include one or more nonvolatile storage devices and / or one or more volatile storage devices. In embodiments where PC 802 includes a programmable processor, a computer readable storage medium (CRSM) 842 may be provided. CRSM 842 may store a computer program (CP) 843 comprising computer readable instructions (CRI) 844. CRSM 842 may be a non-transitory computer readable medium, such as, magnetic media (e.g., a hard disk), optical media, memory devices (e.g., random access memory, flash memory), and the like. In some embodiments, the CRI 844 of computer program 843 is configured such that when executed by PC 802, the CRI causes network node 800 to perform steps described herein (e.g., steps described herein with reference to one or more flow charts). In other embodiments, network node 800 may be configured to perform steps described herein without the need for code. That is, for example, PC 802 may consist merely of one or more ASICs. Hence, the features of the embodiments described herein may be implemented in hardware and / or software.

[0103] Conclusion

[0104] As the above demonstrates, a network node may serve a set of UEs with different traffic types (e.g. MBB and HRLLC). At least one of the traffic types has a higher priority (“HRLLC”) than another traffic type (“MBB”). The network node operates in different modes for deriving PDSCH power (e.g., a first mode (LP mode) and a second mode (HP mode). For at least the first mode, the PDSCH power is derived based on a measurement of a UL reference signal (e.g., reference signal received power measurement) whereas for the second mode the PDSCH power is not derived based on a measurement of the UL reference signal. When the network node schedules a higher priority packet to a UE, the network node selects to use the HP mode and the network node triggers the UE to transmit a signal, corresponding to the said UL reference signal. But when the network node schedules a LP transmission to a UE the network node uses the LP mode to determine the Tx power for the LP transmission and the network node does not trigger the UE to transmit a signal corresponding to the said UL reference signal. The network node may also trigger transmissions of additional UL reference signals used by the network node for PDSCH power control regardless of traffic type.

[0105] While various embodiments are described herein, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of this disclosure should not be limited by any of the above-described exemplary embodiments. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

[0106] As used herein transmitting a message “to” or “toward” an intended recipient encompasses transmitting the message directly to the intended recipient or transmitting the message indirectly to the intended recipient (i.e., one or more other nodes are used to relay the message from the source node to the intended recipient). Likewise, as used herein receiving a message “from” a sender encompasses receiving the message directly from the sender or indirectly from the sender (i.e., one or more nodes are used to relay the message from the sender to the receiving node). Further, as used herein “a” means “at least one” or “one or more.”

[0107] Additionally, while the processes described above and illustrated in the drawings are shown as a sequence of steps, this was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be re-arranged, and some steps may be performed in parallel.

Claims

CLAIMS1. A method (400) performed by a network node (106), the method comprising: scheduling (s402) a downlink, DL, transmission to a second user equipment, UE, (102); selecting (s404) a transmit, Tx, power for the transmission to the second UE using a first reference signal, RS, transmission transmitted by a first UE (101); and performing (s406) the DL transmission using the selected Tx power.

2. The method of claim 1, wherein the network node selects the transmit power for the transmission to the second UE using the first RS transmission transmitted by a first UE as a result of scheduling the transmission to the second UE and the transmission being classified as a non-high priority transmission.

3. The method of claim 1 or 2, wherein the first UE is served by another network node (104).

4. The method of any one of claims 1-3, wherein selecting the transmit power for the DL transmission to the second UE comprises: measuring power of the first RS transmission transmitted by the first UE to produce a first RS measurement value; and selecting the Tx power using the first RS measurement value and a maximum Tx power value.

5. The method of claim 4, wherein selecting the Tx power using the first RS measurement value and the maximum Tx power value comprises: using the first RS measurement value to produce a first Tx power value; and selecting a Tx power value from a set of Tx power values, wherein the set of Tx power values comprises the first Tx power value and the maximum Tx power value.

6. The method of claim 5, wherein selecting a Tx power value from the set of Tx power values comprises selecting the first Tx power value if Txl < Tmax, otherwise selecting themaximum Tx power value, where Txl is the first Tx power value and Tmax is the maximum Tx power value.

7. The method of any one of claims 1-3, wherein selecting the transmit power for the DL transmission to the second UE comprises: measuring power of the first RS transmission transmitted by the first UE to produce a first RS measurement value; measuring power of a second RS transmission transmitted by the second UE to produce a second RS measurement value; and selecting the Tx power using the first RS measurement value, the second RS measurement value, and a maximum Tx power value.

8. The method of claim 7, wherein selecting the Tx power using the first RS measurement value, the second RS measurement value, and the maximum Tx power value comprises: using the first RS measurement value to produce a first Tx power value; using the second RS measurement value to produce a second Tx power value; and selecting a Tx power value from a set of Tx power values, wherein the set of Tx power values comprises the first Tx power value, the second Tx power value, and the maximum Tx power value.

9. The method of claim 6, wherein selecting a Tx power value from the set of Tx power values comprises: selecting the first Tx power value if Txl < Tx2 and Txl < Tmax, where Txl is the first Tx power value, Tx2 is the second Tx power value and Tmax is the maximum Tx power value, selecting the second Tx power value if Tx2 < Txl and Tx2 < Tmax, or selecting the maximum Tx power value if Tmax < Txl and Tmax < Tx2.

10. The method of any one of claims 4-9, wherein the scheduled DL transmission is performed using the selected transmit power value.

11. A method (500) performed by a network node (104), the method comprising: deciding (s501) to schedule a downlink, DL, transmission to a first user equipment, UE,(ioi); scheduling (s502) the DL transmission; as a result of scheduling or deciding to schedule the DL transmission, triggering (s504) the first UE to perform a first reference signal, RS, transmission using a first RS resource, wherein the network node does not use the first RS transmission to select a transmit, Tx, power for the DL transmission; and performing (s506) the scheduled DL transmission.

12. The method of claim 11, wherein the first UE is configured to perform a second RS transmission using a second RS resource, and the method further comprise using the second RS transmission to select the Tx power.

13. The method of claim 11 or 12, wherein the DL transmission is classified as a high priority transmission.

14. A method (600) performed by a network node (104, 106), the method comprising: scheduling (s602) a downlink, DL, transmission to a user equipment, UE, (101, 102); based on a classification of the DL transmission, selecting (s604) a transmit, Tx, power setting mode from a set of two or more Tx power setting modes, the set of two or more Tx power setting modes comprises a first Tx power setting mode and a second Tx power setting mode; selecting a Tx power for the DL transmission to the UE using the selected Tx power setting mode; and performing (s606) the DL transmission using the selected Tx power, wherein if the first Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a first set of zero or more reference signal, RS, resource measurements, and if the second Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a second set of one or more RS resource measurements,wherein the second set of RS resource measurements includes at least one RS resource measurement that is not included in the first set of RS resource measurements.

15. The method of claim 14, further comprising classifying the DL transmission as a non- high priority transmission, wherein the second set of RS resource measurements comprises a first RS measurement, selecting the Tx power setting mode comprises selecting the second Tx power setting mode as a result of classifying the DL transmission as a non-high priority transmission, and selecting the Tx power for the DL transmission to the UE using the second Tx power setting mode comprises selecting the Tx power using the first RS measurement and the maximum Tx power value.

16. The method of claim 15, wherein the second set of RS resource measurements further comprises a second RS measurement, and selecting the Tx power for the DL transmission to the UE using the second Tx power setting mode comprises selecting the Tx power using the first RS measurement, the second RS measurements, and the maximum Tx power value.

17. The method of claim 14, further comprising classifying the DL transmission as a high priority transmission, wherein selecting the Tx power setting mode comprises selecting the first Tx power setting mode as a result of classifying the DL transmission as a high priority transmission, and selecting the Tx power for the DL transmission to the UE using the first Tx power setting mode comprises selecting the Tx power using the maximum Tx power value.

18. The method of claim 17, wherein the first set of RS resource measurements comprises a first RS measurement, and selecting the Tx power for the DL transmission to the UE using the first Tx power setting mode comprises selecting the Tx power using the maximum Tx power value and the first RS measurement.

19. A computer program (843) comprising instructions (844) which when executed by processing circuitry (802) of a network node causes the network node to perform the method of any one of claims 1-18.

20. A carrier containing the computer program of claim 19, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium (842).

21. A method (700) in a communication system comprising a first network node (104) serving a first user equipment, UE (101), and a second network node (106) serving a second UE (102), the method comprising: the first network node deciding (s702) to schedule a downlink, DL, transmission to the first UE; the first network node scheduling (s704) the DL transmission to the first UE; as a result of scheduling or deciding to schedule the DL transmission to the first UE, the first network node triggering (s706) the first UE to perform a first reference signal, RS, transmission using a first RS resource; the second network node scheduling (s708) a DL transmission to the second UE; the second network node selecting (s710) a transmit, Tx, power for the DL transmission to the second UE based on a measurement of the first RS resource; and the second network node performing (s712) the DL transmission using the selected Tx power.

22. The method of claim 21, wherein selecting the transmit power for the DL transmission to the second UE comprises: using the measurement of the first RS resource to produce a first transmission, Tx, power value; and selecting a Tx power value from a set of Tx power values, wherein the set of Tx power values comprises the first Tx power value and a maximum Tx power value.

23. The method of claim 22, wherein selecting a Tx power value from the set of Tx power values comprises selecting the first Tx power value if Txl < Tmax, otherwise selecting the maximum Tx power value, where Txl is the first Tx power value and Tmax is the maximum Tx power value.

24. The method of claim 22, further comprising: measuring power of an RS transmission transmitted by the second UE to produce a second RS measurement; and using the second RS measurement to produce a second Tx power value, wherein the set of Tx power values further comprises the second Tx power value.

25. The method of claim 24, wherein selecting a Tx power value from the set of Tx power values comprises: selecting the first Tx power value if Txl < Tx2 and Txl < Tmax, where Txl is the first Tx power value, Tx2 is the second Tx power value and Tmax is the maximum Tx power value, selecting the second Tx power value if Tx2 < Txl and Txl < Tmax, or selecting the maximum Tx power value if Tmax < Txl and Tmax < Tx2.

26. A network node (106, 800), the network node being configured to perform a method comprising: scheduling (s402) a downlink, DL, transmission to a second user equipment, UE, (102); selecting (s404) a transmit, Tx, power for the transmission to the second UE using a first reference signal, RS, transmission transmitted by a first UE (101); and performing (s406) the DL transmission using the selected Tx power.

27. The network node of claim 26, wherein the network node is further configured to perform the method of any one of claims 1-10.

28. A network node (104, 800), the network node being configured to perform a method comprising:deciding (s501) to schedule a downlink, DL, transmission to a first user equipment, UE,(101); scheduling (s502) the DL transmission; as a result of scheduling or deciding to schedule the DL transmission, triggering (s504) the first UE to perform a first reference signal, RS, transmission using a first RS resource, wherein the network node does not use the first RS transmission to select a transmit, Tx, power for the DL transmission; and performing (s506) the scheduled DL transmission.

29. The network node of claim 28, wherein the network node is further configured to perform the method of any one of claims 12-13.

30. A network node (104, 106, 800), the network node being configured to perform a method comprising: scheduling (s602) a downlink, DL, transmission to a user equipment, UE, (101, 102); based on a classification of the DL transmission, selecting (s604) a transmit, Tx, power setting mode from a set of two or more Tx power setting modes, the set of two or more Tx power setting modes comprises a first Tx power setting mode and a second Tx power setting mode; selecting a Tx power for the DL transmission to the UE using the selected Tx power setting mode; and performing (s606) the DL transmission using the selected Tx power, wherein if the first Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a first set of zero or more reference signal, RS, resource measurements, and if the second Tx power setting mode is selected, then the selected Tx power will be based on a maximum Tx power value and a second set of one or more RS resource measurements, wherein the second set of RS resource measurements includes at least one RS resource measurement that is not included in the first set of RS resource measurements.

31. The network node of claim 30, wherein the network node is further configured to perform the method of any one of claims 15-18.

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