WO2023174565A1

WO2023174565A1 - Transmission power boost for packet with high priority

Info

Publication number: WO2023174565A1
Application number: PCT/EP2022/064077
Authority: WO
Inventors: Karl Werner; Rikke APELFRÖJD; Niklas WERNERSSON; Christos VRANAS
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-03-18
Filing date: 2022-05-24
Publication date: 2023-09-21

Abstract

Systems and methods for transmission power boost for packets with high priority are disclosed. In some embodiments, a method performed by a Radio Access Network (RAN) node configured to communicate with a User Equipment (UE) comprises determining whether to use an increased transmission power based on a priority of a packet. The increased transmission power is a transmission power that is higher than a nominal transmission power for transmitting non-prioritized packets. Responsive to determining to use the increased transmission power, the method further comprises transmitting, to the UE, the packet with the increased transmission power.

Description

TRANSMISSION POWER BOOST FOR PACKET WITH HIGH PRIORITY

Technical Field

The present disclosure is related to solutions for increasing probability of packets with high priority to be correctly received by telecommunication entities like network nodes or wireless communication devices.

Background

With Orthogonal Frequency-Division Multiplexing (OFDM), data is transmitted in parallel on many subcarriers. In practice, this is often implemented taking symbols in the frequency domain and generating a time domain sequence through an Inverse Fast Fourier Transform (IFFT). An advantage of OFDM is its robustness to multipath propagation, but a disadvantage is a relatively high Peak-to-Average Power Ratio (PAPR).

In Figure 1, the solid line ("OUTPUT POWER OF POWER AMPLIFIER (PA)") illustrates a typical input-to-output power relationship of a Power Amplifier (PA). Typically, the input signal will be scaled to ensure that the input signal is below a certain threshold ("TH RESHOLD"). Further, Figure 1 illustrates the power distribution of two different signals, one with low Peak to Average Power Ratio (PAPR) signal ("DISTRIBUTION OF LOW PAPR SIGNAL") and one with high PAPR signal ("DISTRIBUTION OF HIGH PAPR SIGNAL") where both signals have been scaled to ensure that the peak power is below the threshold with a certain probability. Due to the input-to-output relationship of the PA, signals with high PAPR are often transmitted at lower output power than signals with low PAPR because the peak power of the signal fed into the PA should ideally be below a certain threshold which marks the region where the output power is approximately linear to the input power, with a certain probability (e.g., with a probability of 99.99%).

As the PAPR of OFDM signals is relatively high, in practical implementations, so- called Crest Factor Reduction (CFR) of PAPR is used to reduce the peaks of the input signal. By reducing the peaks, the average power of the signal can be increased for same PA. Thus, the received Signal-to-Noise-Ratio (SNR) will be higher. Effectively, the amplitude range where the PA needs to be linear is then reduced. Basic techniques for CFR include iterative clip-and-filtering and peak cancellation. The cost for using CFR is that distortions are introduced. The distortions will typically remain, at least for conventional techniques operating independently, on the signal to each antenna. The distortions due to clipping lead to inter-carrier interference, and will hence also affect carriers with no data mapped.

There is a trade-off between the distortion created by the CFR and the efficiency of the PA. When a high level of distortion can be tolerated, then the signal power distribution can be brought closer to the efficient region of the amplifier.

For the present disclosure, it is assumed that CFR is used to limit the signal peak power to a certain value so that a linear region of the PA is used. By the linear region, we mean the ratio of input power where the output power can be approximated as a linear function of the input power. It is noted that there is a dependency between the level of distortion and the output power. Distortions are commonly quantified in terms of Error Vector Magnitude (EVM) in percent. Even though there are also other imperfections in the radio signal path, such as phase noise, the CFR may often be the dominating source of the distortions. As a side note, a non-linear PA would also introduce distortions not only within the frequencies occupied by the desired signal but also at frequencies next to it. To avoid generating this kind of interference to signals using other frequencies, the signal can be pre-distorted to compensate for distortion that would be generated otherwise. However, this does not impact the basic assumption that there is dependency between the output power and the level of distortions.

In Fourth Generation (4G) and Fifth Generation (5G) systems using OFDM, the available channel bandwidth needs to be shared between multiple users. This can be done by multiplexing users in time and frequency utilizing different time slots and subcarriers. The smallest addressable unit is one subcarrier in one OFDM symbol, and this is referred to as a Resource Element (RE). A set of resource elements over twelve adjacent subcarriers is referred to as Physical Resource Block (PRB). Multiplexing in time is done using time slots, where each time slot has room for up to 14 adjacent OFDM symbols.

Dynamic scheduling and link adaptation are used to take instantaneous traffic demands and channel conditions into account with an update rate equal to a slot level (less than or equal to 1 millisecond (ms)). This means that users with high Signal-to- Interference-and-Noise-Ratio (SINR) can use several Multiple-Input-Multiple-Output (MIMO) layers and modulation and coding schemes with high modulation orders (like 256 Quadrature amplitude modulation (QAM)) and high code rates (up to 0.95), whereas users with low SINR can use a single layer with Quadrature Phase Shift Keying (QPSK) and low code rate (like 0.1).

In the absence of distortions caused by non-linearities, sources of interference include downlink transmissions by neighboring base stations (inter-cell interference) or even from the serving base station in the case of Multi-User MIMO (MU-MIMO) (intracell interference).

The distortions introduced by non-linear operations, e.g., CFR, also contribute to the interference. To be able to offer high peak data rates at least in the cell center and/or at low network load when there is little intercell interference, it is required that the distortions are kept adequately low, around 3.5%. However, since the non-linear distortions increase with the transmission power, it is required that they are kept adequately low, around 3.5%, for corresponding maximum average power. This, in turn, drives a requirement for a relatively high PAPR, for example, around 7.5 decibels (dB). Due to regulations, it may be required that this low level of distortions can be met when the radio is continuously transmitting its nominal power.

For the sake of the present disclosure, the followings are noted. First, distortion level depends on the output power used, i.e., it is higher if output power is high. Second, link adaptation is used to set transport format to match the requirements on decoding success rate of a packet. The transport format includes parameters such as modulation order (QPSK, 16QAM, etc.), code rate of the channel code, and also bandwidth of each transmission. Link adaptation needs to adjust the transport format so that it matches the varying channel quality (e.g., due to fading and varying interference levels). If the transport format is chosen to be too robust (i.e., too low code rate, modulation order or MIMO rank), spectral efficiency is lost, whereas a high block error rate may result if transport format is not robust enough (i.e., too high code rate, modulation order, MIMO rank). Thus, a fading margin needs to be added depending on reliability requirements. Third, traffic may comprise a mix of packets with different priority. Some packets have very strict requirements on latency/reliability. The varying requirements is due to varying priority among the users, and due to requirements being different for different services (Mobile BroadBand (MBB) vs Ultra Reliability Low-Latency Communication (URLLC), for example). Fourth, the successful decoding of a packet depends on the noise level (thermal noise, noise figure), interference level (instantaneous), fast fading state, transport format and other factors.

Systems and methods for transmission power boost for packets with high priority are disclosed. In one embodiment, a method performed by a Radio Access Network (RAN) node configured to communicate with a User Equipment (UE) comprises determining whether to use an increased transmission power based on a priority of a packet. The increased transmission power is a transmission power that is higher than a nominal transmission power for transmitting non-prioritized packets. Responsive to determining to use the increased transmission power, the method further comprises transmitting, to the UE, the packet with the increased transmission power. By this way, increasing the power on the high priority packets will increase their probability of successful decoding in a noise limited scenario.

In one embodiment, the method comprises determining whether a transport format of the packet supports the increased transmission power. The step of transmitting, to the UE, the packet with the increased transmission power further comprises transmitting, to the UE, the packet with the increased transmission power, responsive to determining whether a transport format of the packet supports the increased transmission power.

In one embodiment, the step of determining whether to use an increased transmission power based on a priority of a packet comprises determining the priority of the packet.

In one embodiment, the step of determining whether to use an increased transmission power based on a priority of a packet comprises determining whether a full bandwidth or close to the full bandwidth is needed to meet a requirement to transmit the packet.

In one embodiment, the requirement to transmit the packet to the UE comprises a latency requirement and/or a reliability requirement.

In one embodiment, the latency requirement is used in the step of determining whether to use an increased transmission power based on a priority of a packet.

In one embodiment, the reliability requirement is due to a service or is determined based on a UE identifier. In one embodiment, the method further comprises determining whether transport format of the packet does not support the increased transmission power; and responsive to determining that the transport format of the packet does not support the increased transmission power, determining a new transport format of the packet at least based on the increased transmission power. The step of transmitting the packet with the increased transmission power comprises transmitting the packet, in the new transport format, with the increased transmission power.

In one embodiment, the step of determining whether the transport format of the packet supports the increased transmission power for transmitting the packet comprises determining whether the transport format of the packet supports the increased transmission power for transmitting the packet based on a level of Error Vector Magnitude (EVM) tolerated by the transport format.

In one embodiment, the step of determining a priority of a packet comprises determining the priority of the packet based on a higher layer application transmitting or receiving the packet.

In one embodiment, the step of determining a priority of a packet comprises determining the priority of the packet based on a service level of a terminal, a subscription of the terminal, a service type, or a type of terminal.

In one embodiment, the step of determining a priority of a packet comprises determining the priority of the packet based on a delay tolerance of a service.

In one embodiment, the step of determining a priority of a packet comprises determining the priority of the packet based on a maximum number of transmission attempts of the packet.

In one embodiment, the step of determining a priority of a packet comprises determining the priority of the packet based on deep packet inspection.

In one embodiment, the step of determining a priority of a packet comprises determining the priority of the packet by determining whether a packet belongs to a control channel.

In one embodiment, the step of determining a priority of a packet comprises determining a priority of the packet so that a fraction of total packets receives an elevated priority.

In one embodiment, the power to transmit the fraction of total packets is measured over a time interval. In one embodiment, the step of determining whether a full bandwidth or close to the full bandwidth is needed to meet a requirement to transmit the packet comprises estimating a block error probability for a size of the packet.

In one embodiment, the step of determining whether a transport format of the packet supports an increased transmission power comprises determining whether the transport format of the packet supports the increased transmission power by using a table that includes correspondences between different transport formats and transmission power offsets.

In one embodiment, the increased transmission power is measured on an interface inside the RAN node or an antenna port of the RAN node.

In one embodiment, the increased transmission power is determined by optimizing a Signal-to-Interference-and-Noise Ratio (SINR) of a link between the RAN node and the UE.

In one embodiment, the SINR includes an Error Vector Magnitude (EVM).

In one embodiment, the packet is a New Radio (NR) transport block. Corresponding embodiments of a RAN node are also disclosed.

A RAN node configured to communicate with a UE is adapted to determine whether to use an increased transmission power based on a priority of a packet. The increased transmission power is a transmission power that is higher than a nominal transmission power for transmitting non-prioritized packets. Responsive to determine to use the increased transmission power, the RAN node is also adapted to transmit, to the UE, the packet with the increased transmission power.

A RAN node comprising processing circuitry configured to cause the RAN node to determine whether to use an increased transmission power based on a priority of a packet. The increased transmission power is a transmission power that is higher than a nominal transmission power for transmitting non-prioritized packets. Responsive to determine to use the increased transmission power, the RAN node is to transmit, to the UE, the packet with the increased transmission power.

Brief of the

The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure. Optional features are marked with dashed lines.

Figure 1 illustrates input-output power relationship of a Power Amplifier (PA) and examples of signal distributions.

Figure 2 illustrates one example of a cellular communications system according to some embodiments of the present disclosure.

Figures 3A, 3B, and 3C illustrate three scenarios in accordance with the present disclosure.

Figure 4 illustrates a flow chart of a Radio Access Network (RAN) node in accordance with some embodiments in the present disclosure.

Figure 5 illustrates an example of mapping between 'high/normal packets' and 'modulation orders/transmission power offsets.'

Figure 6 is a schematic block diagram of a radio access node according to some embodiments of the present disclosure.

Figure 7 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node of Figure 6 according to some embodiments of the present disclosure.

Figure 8 is a schematic block diagram of the radio access node of Figure 6 according to some other embodiments of the present disclosure.

Figure 9 is a schematic block diagram of a User Equipment (UE) according to some embodiments of the present disclosure.

Figure 10 is a schematic block diagram of the UE of Figure 9 according to some other embodiments of the present disclosure.

Detailed Description

The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure. Radio Node: As used herein, a "radio node" is either a radio access node or a wireless communication device.

Radio Access Node: As used herein, a "radio access node" or "radio network node" or "radio access network node" is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), a relay node, a network node that implements part of the functionality of a base station or a network node that implements a gNB Distributed Unit (gNB-DU)) or a network node that implements part of the functionality of some other type of radio access node.

Core Network Node: As used herein, a "core network node" is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing an Access and Mobility Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.

Communication Device: As used herein, a "communication device" is any type of device that has access to an access network. Some examples of a communication device include, but are not limited to: mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or Personal Computer (PC). The communication device may be a portable, hand-held, computer-comprised, or vehiclemounted mobile device, enabled to communicate voice and/or data via a wireless or wireline connection. Wireless Communication Device: One type of communication device is a wireless communication device, which may be any type of wireless device that has access to (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of a wireless communication device include, but are not limited to: a User Equipment device (UE) in a 3GPP network, a Machine Type Communication (MTC) device, Ultra Reliability Low-Latency Communication (URLLC), Higher Reliability Low- Latency Communication (HRLLC), and an Internet of Things (loT) device. Such wireless communication devices may be, or may be integrated into, a mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or PC. The wireless communication device may be a portable, hand-held, computer-comprised, or vehiclemounted mobile device, enabled to communicate voice and/or data via a wireless connection.

Network Node: As used herein, a "network node" is any node that is either part of the RAN or the core network of a cellular communications network/system.

Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.

Note that, in the description herein, reference may be made to the term "cell"; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.

Existing solutions for increasing the probability of certain (high priority) packets to be correctly received (within the latency budget) are discussed below.

First, coordination among base stations to avoid interference is one existing solution. This approach is efficient but poses significant implementation challenges and may require expensive/complicated deployments. It can be exceptionally challenging to use if the latency requirements are strict since coordination between base stations is often associated with delay (often in the order of tenths of ms).

Second, reserving resources to avoid interference (for example a full carrier or a part of a carrier) is another existing solution. This approach is inherently not spectrally efficient due to resources used for the high priority packets being often left blank (lost trunking gain).

Third, increasing bandwidth and lowering the transmission format of the high priority packets (higher fading margin) is yet another existing solution. This approach can only be used until the entire bandwidth is consumed (considering a fixed packet size).

Fourth, increasing system capacity (through denser deployments, larger bandwidths, etc.) is yet another existing solution. This will reduce system load and hence the probability of interference. This of course is expensive and may lead to overdimensioning of the system.

Another approach for increasing system capacity is to increase power output from the Power Amplifier (PA), at the expense of distortion, for all transmissions. This will increase performance to a point where the added distortions create a "noise floor" for the system as a whole, for neighboring carriers, and for "own carrier." There are also limits on the Error Vector Magnitude (EVM) allowed under regulations. In practice the average output power is set to balance performance and the issues mentioned here. Note also that increasing output power in general (even if no extra distortion was added) may make the system interference limited, after which further increase does not give benefit.

Typically, the output power, as measured by Power Spectral Density (PSD), is constant for downlink. In some cases, the output power is modulation dependent.

Systems and methods are disclosed herein that address issues associated to the existing solutions described above and/or other challenges. In one embodiment, a method of operation of a RAN node (e.g., a gNB) comprises the following steps. The RAN node determines a priority of a packet being sent. The RAN node determines a bandwidth required to meet requirements such as latency requirement and/or reliability requirement. If needed and applicable for a transport format being used, the RAN node boosts the power of the transmission (in terms of PSD) of the packet above a nominal power used for typical (e.g., non-prioritized) packets and transmits the packet with the boosted power.

In one embodiment, high priority packets are, when applicable for the given transport format, transmitted with higher PSD compared to typical packets, at least if the typical packets occupy the full bandwidth. The higher PSD may be such that the PA works in a non-linear region, and it may hence come at the expense of increased Error Vector Magnitude (EVM). The transport formats that are considered applicable, for a higher PSD transmission, can, however, tolerate an increased EVM. Consequently, the higher EVM is tolerable for the high priority traffic when the higher PSD transmission is applied, but not for the general (majority) of the traffic. The increased PSD will also come at the cost of increased noise level due to the extra distortion (also out of band). While this would not be tolerable if applied to the bulk of the packets, the relatively low frequency of prioritized packets may limit this issue.

Embodiments of the present disclosure may provide a number of advantages over the existing solutions. In general, high priority packets are uncommon and/or small and, therefore, constitute only a limited part of the total traffic. The advantages of embodiments of the present disclosure rely on the following observations. First, due to the reliability/latency requirements, high priority packets are often transmitted with lower order modulation and low code-rates - i.e., they have some margin in order to manage, e.g., fading. They are hence not as susceptible to high EVM (from serving cell) as lower priority packets. Second, due to the lower proportion of the high priority traffic, increasing the EVM in slots with high priority packets will not significantly increase average distortion/EVM/interference in the system (as would be the case if all packets use the increased power). Third, increasing the power on the high priority packets will increase their probability of successful decoding in a noise limited scenario, or in a low geometry scenario if interferers are using the nominal/non-raised power, which is likely given the assumption above. Fourth, even if all interferers use the increased power (in the unlikely case of all packets simultaneously being high priority), the probability of successful decoding will not decrease when embodiments of the present disclosure are used. In a worst case, the probability of successful decoding is the same; thus, the probability of successful decoding is saved for the added distortion. Fifth, raising power on some packets will increase the interference level in the system. Hence it will indeed come at a system performance cost for the lower priority traffic. Due to the opportunistic nature of the power boosting proposed, the cost will however be lower than the cost of reserving resources. Sixth, the embodiments of the present disclosure do not require any communication between transmission points (gNBs). This is a significant advantage compared to the existing solution of dynamically blanking resources to manage interference. Further, as high priority packets are rare, the decoding performance of those can be increased with only a slight increment in average output power. This may be beneficial in scenarios where regulations limit average output power.

Figure 2 illustrates one example of a cellular communications system 200 in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communications system 200 is a 5G system (5GS) including a Next Generation RAN (NG-RAN) and a 5G Core (5GC) or an Evolved Packet System (EPS) including an Evolved Universal Terrestrial RAN (E-UTRAN) and an Evolved Packet Core (EPC). In this example, the RAN includes RAN nodes 202-1, 202-2, 202-3, which in the 5GS are NR base stations (gNBs). The RAN nodes 202-1, 202-2, 202-3 are generally referred to herein collectively as RAN nodes 202 and individually as RAN node 202.

As one example, the RAN node 202-1 provides service to a wireless communication device 212, thus the RAN node 202-1 is referred to herein as a "serving radio access node" or "serving RAN node" of the wireless communication device 212. The other RAN nodes 202-2 and 202-3 are sources of inter-cell interference with respect to the wireless communication device 212 and, as such, are referred to as "interfering radio access nodes" or "interfering RAN nodes."

One aspect of the embodiments in the present disclosure is to selectively increase the output power of a PA in a transmit chain of a RAN node 202-1, in terms of PSD, from a nominal transmit power (Pnom) (e.g., to transmit non-prioritized packets) to a boosted transmit power (Pboost) in slots where high priority packets are transmitted. In one embodiment, this power boosting is done only if the high priority packets are transmitted on a maximum bandwidth. The increased output power in slots with high priority packets is higher than the output power would be if only typical packets (i.e., those with normal or lower priority) were transmitted. The RAN node 202-1 may need to determine the priority of a packet and set the output power depending on the priority of the packet.

Figures 3A, 3B, and 3C illustrate three different scenarios, respectively. In Figures 3A, the serving RAN node 202-1 has a high priority packet, and the interfering RAN nodes 202-2, 202-3 transmit low priority packets. In this case, Signal-to- Interference-and-Noise-Ratio (SINR) for the serving RAN node 202-1 is improved by transmitting the high priority packet with the increased, or boosted, transmit power, Pboost, both if noise at the receiver (<J²) dominates and if interference, P_nomPL + PnomP^, dominates in the denominator of the SINR expression). Hence the serving RAN node 202-1 will benefit (get lower error probability or may operate with less margin in link adaptation) by transmitting the high priority packet with the increased, or boosted, transmit power, Pboost.

In Figure 3B, the serving RAN node 202-1 has a high priority packet but so do the interfering RAN nodes 202-2, 202-3. If <J² dominates, there is still a performance gain for the serving RAN node 202-1 due to transmitting the high priority packet with the increased, or boosted, transmit power, Pboost. If o’² is small relative to interference, there is no gain (but also no loss) for the serving RAN node 202-2 due to transmitting the high priority packet with the increased, or boosted, transmit power, Pboost. Note that as high priority packets are rare, this scenario becomes unlikely.

In Figure 3C, the serving RAN node 202-1 has a low priority packet but the interfering RAN nodes 202-2, 202-3 have high priority packets. Here performance for the serving RAN node 202-1 will be degraded in line with the lower priority of the packet.

Figures 3A, 3B, and 3C also show the respective SINR for each of the three different scenarios. SINR₀ is the signal to interference and noise ratio of the wireless communication device 212. In the formula of SINR (shown in Figures 3A, 3B, and 3C), and PLi is the pathloss from the RAN node 202-i to the wireless communication device 212, <j² is the noise at the receiver of the wireless communication device 212 which depends on thermal noise, noise figure and other factors. P_nom is the nominal output power/PSD for normal packets (i.e., (non-prioritized) packets in which the transmit power is not boosted in accordance with the present disclosure). P_boost is the boosted output power/PSD for high priority packets. D_o is the distortion created by nonlinearities of the transmitters in the system (except for the serving RAN 202-1). In general, D_o depends in a complex way on the output power of all transmitters, the PL_ir the utilization and other factors. 5(P) is the distortion created by "own transmission." It is, essentially, a function of PL_t and the transmission power, and is due to EVM (e.g., from clipping). In general, £>(P) increases with P (as was discussed in the background section). In general, P_nom of the serving RAN node 212-1 is set so that D_o contributes very little to SINR, and so that D(P_nom) and P_nombalances to a good SINR p P_nom) being much smaller than noise and interference. If P_nom would be increased further (everything else including PA equal), D_o and D P_nom) would start to dominate SINR for some users, and performance may be degraded. Note that this is extra evident for typical Mobile BroadBand (MBB) packets because link adaptation is designed opportunistically to match SINR precisely with little margin for fading.

Embodiments of the present disclosure may increase the self-interference because D(P_b00St) > D(P_nom). For high priority packets, this is acceptable because the transmission format needs to be chosen to match a low SINR (due to unpredictable channel fading and interference levels). Hence, the power-distortion trade-off for the high priority packets is different compared to low priority packets.

Embodiments of the present disclosure may also increase D_o (which also includes Adjacent Channel Leakage Ratio (ACLR) from other carriers). However, because high priority packets are relatively rare, it may be assumed that this increase is insignificant from the system perspective.

One aspect of embodiments of the present disclosure is that interference towards other wireless communication devices with typical/low priority packets will cause the SINR for those wireless communication devices to decrease. This is inherently the cost of increasing priority to some packets.

To summarize, the present disclosure may allow for increased priority of certain packets in the presence of interference with no need for coordination. Note that the arguments above also show that there would be no benefit of raising the nominal power (i.e., on non-prioritized packets) level beyond P_nom.

Figure 4 illustrates a flow chart of a RAN node 202 (e.g., the RAN node 202-1) in accordance with some embodiments in the present disclosure.

In step 400, the RAN node 202 determines whether to use increased transmission power for a packet to be transmitted based on a priority of the packet and, optionally, a bandwidth requirement for transmission of the packet. In one embodiment, step 400 comprises two steps, namely, step 401 and step 402. In step 401, the RAN node 202 determines the priority of the packet. The priority of the packet may be determined based on the following factors: (a) a higher layer application transmitting or receiving the packet, (b) a service level, subscription, or device type of the wireless communication device 212 to which the packet is to be transmitted, (c) a delay tolerance of a service for which the packet is being transmitted (e.g., a URLLC service or a eMBB service), (d) a maximum number of transmission attempts of the packet, (e) deep packet inspection, and (f) a power to transmit a fraction of total packets.

In general, high priority packets are uncommon and/or small and, therefore, constitute only a limited part of the total traffic (a fraction of total packets). The power to transmit the fraction of total packets may be measured over a time interval. Also, the priority of the packet may be determined by determining whether the packet belongs to a control channel. For example, the priority of the packet may be a first (higher) priority level if the package belongs to a control channel and otherwise be a second (lower) priority if the packet belongs to a data channel. Further, a latency requirement may be used to determine whether to use an increased transmission power. The increased transmission power is a transmission power (Pboost in the examples above) that is higher than a nominal transmission power for transmitting nonprioritized packets.

Optionally, in step 402, the RAN node 202 may determine whether a full bandwidth or close to the full bandwidth (e.g., of a carrier) is needed to meet a requirement to transmit the packet. For example, the step 402 of determining whether a full bandwidth or close to the full bandwidth is needed to meet a requirement to transmit the packet may comprise a step of estimating a block error probability for a size of the packet. The required bandwidth is "close to" the full bandwidth if the required bandwidth is a threshold amount of the full bandwidth of the associated carrier (e.g., at least 75% of the full bandwidth).

Optionally, in step 404, the RAN node 202 may determine whether a transport format of the packet supports the increased transmission power. The transport format includes parameters such as modulation order (QPSK, 16QAM, etc.), code rate of the channel code, and also bandwidth of each transmission. For example, as shown in Figure 5, it may be known that a "modulation order" of a particular transport format supports a "transmission power offset" that relates to the increased transmission power. Thus, a transport format of the packet may be determined whether it supports the increased transmission power based on the known power offset of the modulation order of the transport format. Also, other parameters of the transport format (code rate of the channel code and bandwidth of each transmission) may be considered in determining whether the transport format having those parameters support the increased transmission power. It may be known whether those parameters are good enough (e.g., tolerable against high noise levels or EVM caused by the increased transmission power) for the increased transmission power.

Optionally, in step 406, when it is determined in the step 404 that the transport format of the packet does not support the increased transmission power, the RAN node 202 determines a new transport format for the packet that supports the increased transmission power.

In step 408, the RAN node 202 transmits, to the UE (212), the packet with the increased transmission power, responsive to the step 400 of determining to use the increased transmission power (e.g., the step 404 of determining whether a transport format of the packet supports the increased transmission power.) When the transport format of the packet does not support the increased transmission power (in step 404) and a new transport format of the packet is determined to support the increased transmission power (in step 406), the packet is transmitted in the new transport format with the increased transmission power. Some aspects of the above steps are further discussed below.

Aspects of Step 401 (Determination of Priority of a Packet)

Priority of packets may be determined based on the higher layer application transmitting/receiving them. A Higher Reliability Low-Latency Communication (HRLLC) or Ultra Reliability Low-Latency Communication (URLLC) (e.g., control loops, public safety, ...) application/use case may have higher priority/more stringent latency requirements than a MBB application (e.g., YouTube or similar streaming services) that may be much more delay tolerant.

Priority of packets may be determined based on a service level of a terminal or subscription, a service type, or a type of terminal. Priority of packets may be based on the delay tolerance of a service.

Priority level of packets may be determined based on a maximum number of transmission attempts of the packet. For example, the last transmission from the latency budget may provide the highest priority. For example, the lower number of transmission attempts of the packet, the higher priority is given to the packet. For example, if there is constrained latency budget in the packet, a higher priority is given to that packet. Priority levels of packets may be determined based on deep packet inspection. Priority levels may be signaled from higher layers. Priority may be determined by determining if a packet belongs to a control channel.

Priority (and threshold for the boosted power) may be determined based on a fraction of the total packets. This is to ensure distortions created by the power boosting only affects system as a whole in a limited way (the "DO" in the SINR expressions above). The determination of the priority is not dependent on the fraction of total packets, but on the decision to adopt a higher transmission power. So, in effect, if it turns out that a fraction of packets gets a high priority, the requirement for increasing the transmission power is increased and thus, higher power is needed.

Aspects of Step 402 (Bandwidth)

What is meant by "power" in the present disclosure is PSD, which is the power per unit of frequency, averaged over a unit in time (e.g., a slot). For a fixed bandwidth, PSD is proportional to output power.

In one embodiment, the power increase is only performed on packets that are allocated on close to the full bandwidth.

In another embodiment, the power is increased even if non-prioritized packets (with low priority) are allocated in the same slot. These packets may then be interfered due to distortion, and this may or may not be compensated for when determining their transport format. If not, similar improvement to detection probability could be achieved by increasing bandwidth (with constant PSD). Full bandwidth may be assumed if packet is large enough and reliability requirements are stringent enough. The reliability requirement may be due to the requirements of a service or is determined based on a UE identifier and then inherited by the packet.

In another embodiment, the bandwidth rather corresponds to a subset of the available bandwidth where this subset is used for transmitting the high priority packet whereas the remaining bandwidth is used for transmitting normal packets. An example of this would be, e.g., the case that one component carrier is used for transmitting the high priority packet whereas other component carriers are used for transmitting normal packets.

Bandwidth is, in turn, determined by estimating block error probabilities for the size of the packet and different bandwidths and transmission formats. It is not always necessary to have the full bandwidth or close to the full bandwidth in order to meet requirements such as latency, or reliability (e.g., Block Error Rate (BLER)). In scenarios with extremely high interference and noise level, adjusting the SINR with bandwidth adaptation to a very low number of Physical Resource Blocks (PRBs) may be a good solution to ensure the required reliability.

Aspects of Step 404 and Step 406 (Transport Format)

Different transport formats may tolerate different levels of EVM. A mapping (e.g., a function or a table) may therefore be designed which will be used for determining if a given transport format is applicable for a higher power transmission or not. As an example, for transport formats corresponding to full bandwidth transmission increasing the transmit power may be applicable for QPSK but not for 16 Quadrature Amplitude Modulation (QAM).

In some embodiments, the mapping may also indicate different levels of power boosting corresponding to different transport formats. As an example, for transport formats corresponding to full bandwidth transmission it may be applicable to increase the power with X dB for QPSK and with Y dB for 16QAM where X>Y.

In yet another embodiment, a high priority packet and a normal packet are transmitted on two different subsets of the total available bandwidth. In such case, the mapping may depend on both transport formats. Figure 5 illustrates an example of a mapping for two component carriers. In Figure 5, each row represents one situation in terms of how the two component carriers interact.

In yet another embodiment, the mapping will also depend on variables not related to the transport format (e.g., temperature or system load).

Aspects of Step 408 (Transmission of High Priority Packet with Higher Power)

The transmission may be done by the RAN node 202 using an increased power as measured on an interface inside the RAN node 202 or at the antenna port (Over-The- Air (OTA) or not). The transmission may be done by the wireless communication device 212, where the transmission power is signaled in a control message (e.g., Downlink Control Information (DCI) transmitted by the RAN node 202 (e.g., gNB).

The output power may be increased by increasing an Energy Per Resource Element (EPRE). The output power may be increased by signaling so over an interface. The boosted output power P_boost may be determined such that the link SINR is optimized, e.g., by optimizing

for some conservative assumption on pathloss to interferers. It may also be designed to meet EVM requirements given some assumed maximum proportion of the high priority packets. The SINR in this scenario may also include the EVM (self-interference).

Further Description

Figure 6 is a schematic block diagram of the RAN node 202 (e.g., the RAN node 202-1) according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The radio access node 202 may be, for example, a base station 202 or 206 or a network node that implements all or part of the functionality of the base station 202 or gNB described herein. As illustrated, the radio access node 202 includes a control system 602 that includes one or more processors 604 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory 606, and a network interface 608. The one or more processors 604 are also referred to herein as processing circuitry. In addition, the radio access node 202 may include one or more radio units 610 that each includes one or more transmitters 612 and one or more receivers 614 coupled to one or more antennas 616. The radio units 610 may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s) 610 is external to the control system 602 and connected to the control system 602 via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) 610 and potentially the antenna(s) 616 are integrated together with the control system 602. The one or more processors 604 operate to provide one or more functions of a radio access node 202 as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory 606 and executed by the one or more processors 604.

Figure 7 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node 202 according to some embodiments of the present disclosure. This discussion is equally applicable to other types of network nodes. Further, other types of network nodes may have similar virtualized architectures. Again, optional features are represented by dashed boxes.

As used herein, a "virtualized" radio access node is an implementation of the radio access node 202 in which at least a portion of the functionality of the radio access node 202 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node 202 may include the control system 602 and/or the one or more radio units 610, as described above. The control system 602 may be connected to the radio unit(s) 610 via, for example, an optical cable or the like. The radio access node 202 includes one or more processing nodes 700 coupled to or included as part of a network(s) 702. If present, the control system 602 or the radio unit(s) are connected to the processing node(s) 700 via the network 702. Each processing node 700 includes one or more processors 704 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 706, and a network interface 708.

In this example, functions 710 of the radio access node 202 described herein are implemented at the one or more processing nodes 700 or distributed across the one or more processing nodes 700 and the control system 602 and/or the radio unit(s) 610 in any desired manner. In some particular embodiments, some, or all of the functions 710 of the radio access node 202 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 700. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 700 and the control system 602 is used in order to carry out at least some of the desired functions 710. Notably, in some embodiments, the control system 602 may not be included, in which case the radio unit(s) 610 communicate directly with the processing node(s) 700 via an appropriate network interface(s).

In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 202 or a node (e.g., a processing node 700) implementing one or more of the functions 710 of the radio access node 202 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

Figure 8 is a schematic block diagram of the radio access node 202 according to some other embodiments of the present disclosure. The radio access node 202 includes one or more modules 800, each of which is implemented in software. The module(s) 800 provide the functionality of the radio access node 202 described herein. This discussion is equally applicable to the processing node 700 of Figure 7 where the modules 800 may be implemented at one of the processing nodes 700 or distributed across multiple processing nodes 700 and/or distributed across the processing node(s) 700 and the control system 602.

Figure 9 is a schematic block diagram of a wireless communication device 212 according to some embodiments of the present disclosure. As illustrated, the wireless communication device 212 includes one or more processors 902 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 904, and one or more transceivers 906 each including one or more transmitters 908 and one or more receivers 910 coupled to one or more antennas 912. The transceiver(s) 906 includes radio-front end circuitry connected to the antenna(s) 912 that is configured to condition signals communicated between the antenna(s) 912 and the processor(s) 902, as will be appreciated by on of ordinary skill in the art. The processors 902 are also referred to herein as processing circuitry. The transceivers 906 are also referred to herein as radio circuitry. In some embodiments, the functionality of the wireless communication device 212 described above may be fully or partially implemented in software that is, e.g., stored in the memory 904 and executed by the processor(s) 902. Note that the wireless communication device 212 may include additional components not illustrated in Figure 9 such as, e.g., one or more user interface components (e.g., an input/output interface including a display, buttons, a touch screen, a microphone, a speaker(s), and/or the like and/or any other components for allowing input of information into the wireless communication device 212 and/or allowing output of information from the wireless communication device 212), a power supply (e.g., a battery and associated power circuitry), etc.

In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the wireless communication device 212 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

Figure 10 is a schematic block diagram of the wireless communication device 212 according to some other embodiments of the present disclosure. The wireless communication device 212 includes one or more modules 1000, each of which is implemented in software. The module(s) 1000 provide the functionality of the wireless communication device 212 described herein.

Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).

At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).

3GPP Third Generation Partnership Project 4G Fourth Generation

5G Fifth Generation

5GC Fifth Generation Core

5GS Fifth Generation System

ACLR Adjacent Channel Leakage Ratio

AF Application Function

AMF Access and Mobility Function

AN Access Network

AP Access Point

ASIC Application Specific Integrated Circuit

AUSF Authentication Server Function

BLER Block Error Rate

CFR Crest Factor Reduction

CPU Central Processing Unit

DCI Downlink Control Information

DN Data Network

DSP Digital Signal Processor eNB Enhanced or Evolved Node B

EPRE Energy Per Resource Element

EPC Evolved Packet Core

EPS Evolved Packet System

E-UTRA Evolved Universal Terrestrial Radio Access

EVM Error Vector Magnitude

FPGA Field Programmable Gate Array gNB New Radio Base Station gNB-DU New Radio Base Station Distributed Unit

HRLLC Higher Reliability Low-Latency Communication

HSS Home Subscriber Server

IFFT Inverse Fast Fourier Transform loT Internet of Things

IP Internet Protocol

LTE Long Term Evolution

MAC Medium Access Control MBB Mobile BroadBand

MIMO Multiple-Input-Multiple-Output

MME Mobility Management Entity

MTC Machine Type Communication

MU-MIMO Multi-User Multiple-Input-Multiple-Output

NEF Network Exposure Function

NF Network Function

NR New Radio

NRF Network Function Repository Function

NSSF Network Slice Selection Function

OFDM Orthogonal Frequency-Division Multiplexing

OTA Over the Air

OTT Over-the-Top

PA Power Amplifier

PAPR Peak to Average Power Ratio

PC Personal Computer

PCF Policy Control Function

PDSCH Physical Downlink Shared Channel

P-GW Packet Data Network Gateway

PRB Physical Resource Block

PRS Positioning Reference Signal

PSD Power Spectral Density

QAM Quadrature Amplitude Modulation

QoS Quality of Service

QPSK Quadrature Phase Shift Keying

RAM Random Access Memory

RAN Radio Access Network

RE Resource Element

ROM Read Only Memory

RP Reception Point

RRH Remote Radio Head

RTT Round Trip Time

SCEF Service Capability Exposure Function • SINR Signal to Interface and Noise Ratio

• SMF Session Management Function

• SNR Signal to Noise Ratio

• TCI Transmission Configuration Indicator

• TP Transmission Point

• TRP Transmission/Reception Point

• UDM Unified Data Management

• UE User Equipment

• UPF User Plane Function

• URLLC Ultra Reliability Low-Latency Communication

Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

1. A method performed by a Radio Access Network, RAN, node (202) configured to communicate with a User Equipment, UE, (212), the method comprising: determining (400) whether to use an increased transmission power based on a priority of a packet, the increased transmission power being a transmission power that is higher than a nominal transmission power for transmitting non-prioritized packets; and responsive to determining (400) to use the increased transmission power, transmitting (408), to the UE (212), the packet with the increased transmission power.

2. The method of claim 1 further comprising determining (404) whether a transport format of the packet supports the increased transmission power, wherein transmitting (408), to the UE (212), the packet with the increased transmission power further comprises transmitting (408), to the UE (212), the packet with the increased transmission power, responsive to determining (404) whether a transport format of the packet supports the increased transmission power.

3. The method of claim 1, determining (400) whether to use an increased transmission power based on a priority of a packet comprises determining (401) the priority of the packet.

4. The method of claim 1, determining (400) whether to use an increased transmission power based on a priority of a packet comprises determining (402) whether a full bandwidth or close to the full bandwidth is needed to meet a requirement to transmit the packet.

5. The method of claim 4, wherein the requirement to transmit the packet to the UE (212) comprises a latency requirement and/or a reliability requirement.

6. The method of claim 5, wherein the latency requirement is used in the step of determining (401) whether to use an increased transmission power based on a priority of a packet.

7. The method of claim 5 or 6, wherein the reliability requirement is due to a service or is determined based on a UE identifier.

8. The method of any of claims 1 to 7, further comprising: determining (404) that the transport format of the packet does not support the increased transmission power; and responsive to determining (404) that the transport format of the packet does not support the increased transmission power, determining (406) a new transport format of the packet at least based on the increased transmission power; wherein transmitting (408) the packet with the increased transmission power comprises transmitting the packet, in the new transport format, with the increased transmission power.

9. The method of any of claims 1 to 8, wherein determining (404) whether the transport format of the packet supports the increased transmission power for transmitting the packet comprises determining (404) whether the transport format of the packet supports the increased transmission power for transmitting the packet based on a level of Error Vector Magnitude, EVM, tolerated by the transport format.

10. The method of any of claims 3 to 9, determining (401) a priority of a packet comprises determining the priority of the packet based on a higher layer application transmitting or receiving the packet.

11. The method of any of claims 3 to 9, determining (401) a priority of a packet comprises determining the priority of the packet based on a service level of a terminal, a subscription of the terminal, a service type, or a type of terminal.

12. The method of any of claims 3 to 9, determining (401) a priority of a packet comprises determining the priority of the packet based on a delay tolerance of a service.

13. The method of any of claims 3 to 9, determining (401) a priority of a packet comprises determining the priority of the packet based on a maximum number of transmission attempts of the packet.

14. The method of any of claims 3 to 9, determining (401) a priority of a packet comprises determining the priority of the packet based on deep packet inspection.

15. The method of any of claims 3 to 9, determining (401) a priority of a packet comprises determining the priority of the packet by determining whether a packet belongs to a control channel.

16. The method of any of claims 3 to 9, determining (401) a priority of a packet comprises determining a priority of the packet so that a fraction of total packets receives an elevated priority.

17. The method of claim 16, wherein the power to transmit the fraction of total packets is measured over a time interval.

18. The method of any of claims 1 to 17, determining (402) whether a full bandwidth or close to the full bandwidth is needed to meet a requirement to transmit the packet comprises estimating a block error probability for a size of the packet.

19. The method of any of claims 1 to 18, determining (404) whether a transport format of the packet supports an increased transmission power comprises determining (404) whether the transport format of the packet supports the increased transmission power by using a table that includes correspondences between different transport formats and transmission power offsets.

20. The method of any of claims 1 to 19, wherein the increased transmission power is measured on an interface inside the RAN node (202) or an antenna port of the RAN node (202).

21. The method of any of claims 1 to 20, wherein the increased transmission power is determined by optimizing a Signal-to-Interference-and-Noise Ratio, SINR, of a link between the RAN node (202) and the UE (212).

22. The method of claim 21, wherein the SINR includes an Error Vector Magnitude, EVM.

23. The method of any of claims 1 to 22, wherein the packet is a New Radio, NR, transport block.

24. A Radio Access Network, RAN, node (202) configured to communicate with a User Equipment, UE, (212), the RAN node (202) adapted to: determine (400) whether to use an increased transmission power based on a priority of a packet, the increased transmission power being a transmission power that is higher than a nominal transmission power for transmitting non-prioritized packets; and responsive to determine (400) to use the increased transmission power, transmit (408), to the UE (212), the packet with the increased transmission power.

25. The RAN node (202) of claim 24 wherein the RAN node (202) is further adapted to perform the method of any of claims 2 to 23.

26. A Radio Access Network, RAN, node (202) comprising processing circuitry configured to cause the RAN node (202) to: determine (400) whether to use an increased transmission power based on a priority of a packet, the increased transmission power being a transmission power that is higher than a nominal transmission power for transmitting non-prioritized packets; and responsive to determine (400) to use the increased transmission power, transmit (408), to a User Equipment, UE, (212), the packet with the increased transmission power.

27. The RAN node (202) of claim 26 wherein the processing circuitry is further configured to cause the RAN node (202) to perform the method of any of claims 2 to 23.