WO2024196821A1

WO2024196821A1 - Transmitting data from energy-harvesting devices

Info

Publication number: WO2024196821A1
Application number: PCT/US2024/020304
Authority: WO
Inventors: Shiangrung YE
Original assignee: Google LLC
Current assignee: Google LLC
Priority date: 2023-03-17
Filing date: 2024-03-15
Publication date: 2024-09-26
Anticipated expiration: 2025-09-17

Abstract

A UE with limited power capability transmitting data in an uplink direction to a RAN. The UE receives (720), from the RAN, an indication of a first resource associated with a higher power requirement and an indication of a second resource associated with a lower power requirement. The UE determines (730) a resource selection factor including at least one of (i) an amount of power currently available at the UE for transmission to the RAN, or (ii) an amount of data associated with the transmission. The UE selects (730) either the first resource or the second resource in view of the resource selection factor, and transmits (740) the data to the RAN using the selected first resource or the second resource

Description

TRANSMITTING DATA FROM ENERGY-HARVESTING DEVICES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of the filing date of provisional U.S. Patent Application No. 63/491,046, titled "Transmitting data from energy-harvesting devices," filed on March 17, 2023 and U.S. Patent Application No. 63/493,996, titled "Transmitting data from energy-harvesting devices," filed on April 3, 2023. The entire contents of these provisional application are hereby expressly incorporated herein by reference.

FIELD OF THE DISCLOSURE

[0002] This disclosure generally relates to transmitting data from an energy-harvesting device and, more particularly, to managing resources for such transmissions.

BACKGROUND

[0003] This background description is provided for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0004] One of the objectives behind developing the fifth generation (5G) technology is to provide a unified framework for such types of communication as enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), massive machine type communication (mMTC), Narrowband Internet-of-Thing (NB-IoT), enhanced Machine Type Communication (eMTC), etc. NB-IoT and eMTC technologies are expected to be particularly suitable for loT devices operating in remote areas with limited or no terrestrial connectivity. Such loT devices can be used in a variety of industries including for example transportation (maritime, road, rail, air) and logistics; solar, oil, and gas harvesting; utilities; farming; environmental monitoring; and mining.

[0005] Some of these loT devices are energy-harvesting devices, i.e., devices that are not equipped with traditional batteries or do not have access to permanent sources of power such as an electrical (alternating current, AC) grid. These devices can include mechanical, chemical, and/or electronic elements for harvesting or scavenging power available in the environment, such as solar power, wind power, or thermal power for example. An industrial facility can have tens of thousands of unmonitored assets that can be configured to operate as energy-harvesting devices. A typical food and beverage facility has 300 steam traps and over a thousand machines; a typical chemical refinery has about 2,000 steam traps and over 3,000 motors; and a large oil refinery has over 20,000 steam traps.

[0006] It is not clear how energy-harvesting devices should transmit information (e.g., data) to the network when the available power at these devices is limited. In particular, a network allocates, to user equipment devices (UEs), time-frequency resources for transmissions that require a certain amount of power, which an energy-harvesting device may lack at the allocated time.

[0007] More specifically, if the base station allocates resource blocks according to the power headroom report from the UE, but the power at the UE drops abruptly (e.g., because a cloud obscures the photovoltaic module powering the UE), the UE may not have sufficient power to transmit data during the allocated resource block. Without sufficient transmit power, the UE may not be able to transmit the data successfully.

SUMMARY

[0008] A network (e.g., a RAN or one or more base stations operating in the RAN) allocates a higher-power resource and/or a lower-power resource for an uplink transmission of data from a UE with limited power capability, such as an energy-harvesting UE for example. The UE can select one of these resources in view of the power currently available at the UE and/or the amount of data to be transmitted.

[0009] An example embodiment of these techniques is a method implemented in a UE with limited power capability. The method is for transmitting data in an uplink direction to a RAN. The method includes receiving, from the RAN, an indication of a first resource associated with a higher power requirement and an indication of a second resource associated with a lower power requirement; determining a resource selection factor including at least one of (i) an amount of power currently available at the UE for transmission to the RAN, or (ii) an amount of data associated with the transmission; selecting either the first resource or the second resource in view of the resource selection factor; and transmitting the data to the RAN using the selected first resource or the second resource.

[0010] Another example embodiment of these techniques is a UE comprising a transceiver and processing hardware configured to implement the method above. [0011] Yet another example embodiment of these techniques is a method for receiving data from a UE with limited power capability. The method is implemented in a RAN and comprises allocating a first resource associated with a higher power requirement and a second resource associated with a lower power requirement; providing an indication of the first resource and an indication of the second resource to the UE; and receiving, from the UE, data over the first resource or the second resource.

[0012] Another example embodiment of these techniques is a RAN comprising transceiver and processing hardware configured to implement the method above.

BRIEF DESCRIPTION OF THE DRAWIGS

[0013] Fig. 1 is a block diagram of an example wireless communication system in which a user device and a base station of this disclosure can implement the resource management techniques of this disclosure;

[0014] Fig. 2 is a messaging diagram of an example scenario in which the base station of Fig. 1 allocates a high-power resource and a low-power resource for uplink transmission, and the UE selects one of the two resources in view of the power available at the UE;

[0015] Figs. 3A-F schematically illustrate several resource allocation schemes which the UE and the base station of Fig. 1 can use;

[0016] Fig. 4 illustrates an example subframe with multiple timeslots made of OFDM symbols, which the devices of Fig. 1 use in resource allocation;

[0017] Figs. 5A and 5B illustrate example allocation of resources for transmitting downlink control information for a high-power resource and a low-power resource, respectively;

[0018] Figs. 6A-C schematically illustrate several schemes for repeating a transmission when the base station of Fig. 1 provides two resources to the UE;

[0019] Fig. 7 is a flow diagram of an example method for transmitting data to a network from a UE in view of the available power, which the UE of Fig. 1 can implement;

[0020] Fig. 8 is a flow diagram for selecting a resource in view of the available power, which the UE of Fig. 1 can implement; and

[0021] Fig. 9 is a flow diagram of an example method for receiving data from a UE after allocating multiple resources to the UE, which the base station of Fig. 1 can implement. DETAILED DESCRIPTION

[0001] Referring to Fig. 1, an example wireless communication system 100 includes a UE 102, a base station (BS) 104, and a core network (CN) 110. The base station 104 operates in a radio access network (RAN) 105 that includes any suitable number of base stations. Although shown as a terrestrial base station, the base station 104 can be implemented as a non-terrestrial network (NTN) base station satellite, aircraft, balloon, or drone. The CN 110 can be implemented as an evolved packet core (EPC) or a fifth generation (5G) core (5GC), for example. The CN 110 can also be implemented as a sixth generation (6G) core in another example. The UE 102 can support at least a 5G NR (or simply, “NR”) or E-UTRA air interface to communicate with the base station 104.

[0002] The base station 104 provides coverage in at least one cell. If the base station 104 is a gNB, the cell 124 is an NR cell. If the base station 104 is an ng-eNB, the cell 124 is an evolved universal terrestrial radio access (E-UTRA) cell. In general, the base station 104 can cover one, two, three, or any other suitable number of cells. The base station 104 can connect to the CN 110 via an interface (e.g., SI or NG interface). The base station 104 also can connect to other base stations via an interface (e.g., X2 or Xn interface) for interconnecting NG RAN nodes.

[0003] The UE 102 is equipped with processing hardware 130 that can include one or more general-purpose processors such as CPUs and non-transitory computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and/or special-purpose processing units. The processing hardware 130 in an example implementation includes a processor to process data that the UE 102 will transmit in the uplink direction, or process signals received by UE 102 in the downlink direction. The UE 102 implements, among other components, a Tx scheduling module 136 configured to select a resource in view of the power availability.

[0004] The UE 102 also includes an energy source 132 such as photovoltaic component to convert solar energy to electricity, a turbine to convert wind energy to electricity, a geothermal converter, etc. Further, the 102 also can include specialized hardware 134 such as a sensor or a gauge for example, which can be specific to the industry in which the UE 102 is deployed. Depending on the implementation, the UE 102 can include the specialized hardware 134 or be communicatively coupled to a device such as a rain gauge, forming a system including the UE 102 and an IOT device. For simplicity, the description below refers to all such systems as the UE 102.

[0005] The UE 102 further includes a transceiver 138 configured to receive and transmit data over a radio interface. The UE 102 can support one or multiple radio access technologies (RATs) to communicate in NR, EUTRA, and/or other types of cells.

[0006] The base station 104 is equipped with processing hardware 140 that can include one or more general-purpose processors (e.g., CPUs) and a non-transitory computer-readable memory storing instructions that the one or more general-purpose processors execute, as well as a transceiver 148. The base station 104 implements, among other components, a Tx scheduling module 146 configured to configure an energy-harvesting UE with at least two resources, a higher-power resource and a lower-power resource.

[0007] In operation, the base station 104 provides, on a downlink channel, an indication of a higher-power resource 152 and an indication of a lower-power resource 154. The UE 102 selects one of these resources in view of the current power availability and transmits data in the uplink direction to the base station 104 using the selected resource.

[0008] Fig. 2 illustrates an example scenario 200 in which the UE 102 and the RAN 105 use resource management techniques to efficiently utilize the power available at the UE 102. The UE 102 can exchange messages with one base station in the RAN 105, e.g., the base station 104, or multiple base stations.

[0009] The scenario 200 begins with the RAN 105 transmitting 202 an initial configuration to the UE 102. The initial configuration indicates how the UE 102 can acquire uplink synchronization and attempt initial access to the RAN 105. For example, the initial configuration can indicate a Physical Random Access Channel (PRACH) occasion, or a timefrequency resource for an initial transmission such as a random preamble, for example.

[0010] The RAN 105 can additionally or alternatively indicate a RACH preamble for use during the initial access to the RAN 105. The RAN 105 can indicate the RACH preamble in an information element or reference a RACH preamble stored at the UE 102, depending on the implementation. The RAN 105 can dedicate the indicated RACH preamble specifically to energy-harvesting devices. In this manner, the RAN 105 can determine the UE 102 is an energy-harvesting device in response to receiving the RACH preamble from the UE 102 during a random access procedure. The RAN 105 can transmit 202 the initial configuration using broadcast, multicast, or unicast mechanisms. [0011] The UE 102 initiates 204 access to the RAN 105 for a data transmission, e.g., by initiating a random access procedure. For example, the UE 102 can transmit 204 a random access preamble, and/or transmit a random access preamble during the PRACH occasion, which the RAN 105 indicated in an earlier transmission 202. The random access procedure can be a two-step random access procedure or a four-step random access procedure, for example.

[0012] The UE 102 in some implementations or scenarios indicates to the RAN 105 that the UE 102 is an energy-harvesting device. To this end, the UE 102 can include a certain field in a Medium Access Control (MAC) control element (CE) in a message of the random access procedure, after transmitting 204 the random access procedure. In another implementation, the UE 102 includes this indicator in a message that conforms to a protocol for controlling radio resources, e.g., Radio Resource Control (RRC). More particularly, the UE 102 can include this indicator in a UECapahilily Information information element (IE).

[0013] The field can indicate only that the UE 102 is an energy-harvesting device or, in another implementation, the field includes additional information such as the type of energy the UE 102 is configured to harvest, e.g., solar, water, thermal, or wind. The UE 102 can provide this additional information to facilitate more efficient allocation of resources at the RAN 105.

[0014] The RAN 105 then allocates or selects 210 resources for the UE 102 using the knowledge that the UE 102 is an energy-harvesting device (and, in some cases, the type of energy the UE 102 harvests). The RAN 105 allocates the higher-power resource 152 and the lower-power resource 154 (see Fig. 1), and the UE 102 determines which of these allocated resources is more suitable for the uplink transmission. The examples below refer to two resources, but in general the RAN 105 can allocate a larger number of resources corresponding to different power requirements.

[0015] In some implementations, when the RAN 105 is aware of the type of energy the UE 102 harvests, the RAN 105 allocates the resources in view of the likelihood that the UE 102 will harvest sufficient power for the higher-power resource. As discussed below, the UE 102 also can provide a power headroom report. The RAN 105 for example can assign a higher probability to the event that the UE 102 will reach a certain power level if the energy harvesting is geothermal, and a lower probability to the same event if the energy harvesting is solar. Moreover, the RAN 105 in the latter can account for the time of day, the current weather conditions, etc.

[0016] In an example scenario, the RAN 105 allocates a larger number of time-frequency resource blocks to the higher-power resource 152 than to the lower-power resource 154. A resource block includes a set of resource elements, each resource element in turn including a subcarrier component and an OFDM symbol time component. The power the UE 102 expends to transmit in the uplink direction is given by 3 GPP specifications such as

in 3GPP TS 38.213 and is related to the number of resource block M involved in the transmission. Accordingly, the UE 102 requires more power using the higher-power resource 152 than the lower-power resource 154.

[0017] Figs. 3A-F illustrate several example allocation schemes, according to which the RAN 105 allocates resource blocks “1” to the higher-power resource 152 and resource blocks “2” to the lower-power resource 154. According to an allocation scheme 310 of Fig. 3 A, the resource blocks of the lower-power resource 154 are a subset of the resource blocks of the higher-power resource 152. According to an allocation scheme 320 of Fig. 3B, the set of resource blocks of the lower-power resource 154 partially overlap the set of resource blocks of the higher-power resource 152. According to an allocation scheme 330 of Fig. 3C, the set of resource blocks of the lower-power resource 154 and the set of resource blocks of the higher-power resource 152 do not overlap, and the two sets correspond to the same frequency band or bandwidth part (BWP) at different times. According to an allocation scheme 340 of Fig. 3D, the set of resource blocks of the lower-power resource 154 and the set of resource blocks of the higher-power resource 152 do not overlap, and the two sets correspond to different frequency bands or BWPs and different times.

[0018] Further, according to allocation schemes 350 of Fig. 3E and 360 of Fig. 3F, the set of resource blocks of the lower-power resource 154 are in a lower frequency band (e.g., sub- 6GHz) than the set of resource blocks of the higher-power resource 152 (e.g., mmWave). The resource blocks of the higher-power resource 152 can at least partially overlap-in-time the resource blocks of the lower-power resource 154 (Fig. 3E) or not have any overlap-intime with the resource blocks of the lower-power resource 154 (Fig. 3F). The number of resource blocks of the two allocated resources may be different (Figs. 3A-3E) or the same (Fig. 3F).

[0019] Still further, the two resources can correspond to different modulation schemes associated with different respective power requirements. For example, the higher-power resource 152 corresponds to a higher-order modulation scheme, and the lower-power resource 154 corresponds to a lower-order modulation scheme. In yet another implementation or scenario, the two resources correspond to different coding rates associated with different respective power requirements. For example, the higher-power resource 152 corresponds to a higher coding rate, and the lower-power resource 154 corresponds to a lower coding rate.

[0020] As illustrated in Fig. 4, the RAN 105 in some cases allocates the high-power resource 152 and the lower-power resource 154 in adjacent timeslots within the same subframe 400. Each of the timeslots includes multiple OFDM symbols.

[0021] With continued reference to Fig. 2, the RAN 105 transmits 220 an indication of the higher-power resource 152 and the lower-power resource 154 to the UE 102. The RAN 105 can transmit 220 these indications on a Physical Downlink Control Channel (PDCCH).

[0022] For example, the RAN 105 can transmit a first downlink control indicator (DCI) to specify the higher-power resource 152 and a second DCI to specify the lower-power resource 154. The RAN 105 can be configured to always transmit the second DCI with the first DCI. Thus, if the UE 102 receives the first DCI, the UE 102 expects to also receive the second DCI.

[0023] To allow the UE 102 to conserve more power, the RAN 105 can transmit the two DCIs using time-frequency resources adjacent to each other in frequency (resource allocation scheme 510 of Fig. 5 A) or time (resource allocation scheme 520 of Fig. 5B).

[0024] In another implementation, the RAN 105 transmits a single DCI that references both the higher-power resource 152 and the lower-power resource 154. For the higher- power resource 152, the DCI can indicate a set of numbered resource elements. For the lower-power resource 154, the DCI can indicate a pattern according to which the UE 102 selects a subset of the resource elements from the set of numbered resource elements corresponding to the higher-power resource 152. See FIG. 3 A, for example. As a more specific example, for the lower-power resource 154, the DCI can indicate a certain number N, so that the lower-power resource 154 is made up of every Nth resource element within the higher-power resource 152. As another example, for the lower-power resource 154, the DCI can indicate a certain number K, so that the lower-power resource 154 is made up of the first K resource elements within the higher-power resource 152.

[0025] To continue with the example in which the RAN 105 transmits a single DCI referencing both resources, the DCI can further indicate one or more of the following: a first modulation scheme for the higher-power resource 152 and a second modulation scheme for the lower-power resource 154, a first coding rate for the higher-power resource 152 and a second coding rate for the lower-power resource 154, or a first HARQ redundancy version for the higher-power resource 152 and a second HARQ redundancy version for the lower- power resource 154.

[0026] When the RAN 105 addresses the DCI to the UE 105 using a certain Radio Network Temporary Identifier (RNTI), such as a Configured Scheduling RNTI (CS-RNTI) or a Semi-Persistent Scheduling RNTI (SPS-RNTI), the UE 105 can store the indications of the higher-power resource 152 and the lower-power resource 154 in the memory and then use one of these resources at a time the RAN 105 previously scheduled.

[0027] Referring still to Fig. 2, the UE 102 selects 230 the higher-power resource 152 or the lower-power resource 154 for transmitting data to the RAN 105. In particular, the UE 102 can calculate the amount of transmission power PH associated with the higher-power resource 152 using the formula for PPUSCH above or a suitable approximation. The UE 102 compares the currently available power PA to PH and, if PA > PH, the UE 102 can use the higher-power resource 152 for transmitting 240 data to the RAN 105. Otherwise, if PA < PH, the UE 102 can calculate the amount of transmission power PL associated with the lower- power resource 152, in a manner similar to calculating PH. If PA > PL, the UE 102 can use the lower-power resource 154 for transmitting 240 data to the RAN 105.

[0028] If PA < PL, the UE 102 can omit or delay the transmission of the data. In another implementation, the UE 102 unconditionally uses the lower-power resource 154 to attempt a transmission, even when PA < PH. In still other implementations, the UE 102 selects a resource from among the resources 152 and 154 based on whether 17^ - PH\ is within a certain threshold value, and/or whether | PA - PL\ is within the same or different threshold value.

[0029] In another implementation, the UE 102 selects the higher-power resource 152 or the lower-power resource 154 further in view of the amount of the data awaiting transmission. The UE 102 for example can select the lower-power resource 154 even if the available power PA sufficiently exceeds the power requirement PH of the higher-power resource 152, if the UE 102 determines that it can transmit all of the data currently in the buffer using the lower- power resource 154. The amount of power available at the UE and/or the amount of data for transmission in the uplink direction can be referred to as the resource selection factor.

[0030] The UE 102 transmits 240 data to the RAN 105 using the selected the higher-power resource 152 or the lower-power resource 154. In some implementations, the UE 102 transmits 240 an indication of whether the UE 105 has selected the selected higher-power resource 152 or the lower-power resource 154. For example, the UE 102 can transmit a first pre-defmed PHY-level pattern at the beginning of the transmission 240 to indicate the selection of the higher-power resource 152, and a second pre-defmed PHY-level pattern at the beginning of the transmission 240 to indicate the selection of the lower-power resource 154. In another implementation, the UE 102 transmits a third pre-defmed PHY-level pattern at the beginning of the transmission 240 to indicate the selection of both resources.

[0031] In another implementation, the RAN 105 uses signal strength to automatically detect which of the higher-power resource 152 or the lower-power resource 154 the UE 102 used to transmit 240 the data. The RAN 105 measures the signal strength associated with the resource elements associated with the resources 152 and 154. For example, if resource elements REi, RE2, RE3, and RE4 belong to the higher-power resource 152, but only resource elements REi and RE2 belong to the lower-power resource 154, the RAN 105 determines that the UE 102 used the higher-power resource 152 for the transmission 240 if the received signal strength associated with the resources RE3 and RE4 is above a certain threshold value.

[0032] In another implementation, the RAN 105 uses the location of a certain reference signal within the resources to automatically detect which of the higher-power resource 152 or the lower-power resource 154 the UE 102 used to transmit 240 the data. The reference signal can be a demodulation reference signal, for example. If the RAN 105 detects the reference signal within a resource element that belongs to the higher-power resource 152, the RAN 105 determines that the UE 102 used the higher-power resource 152 for the transmission 240. Otherwise, the RAN 105 determines that the UE 102 used the lower-power resource 154 for the transmission 240.

[0033] In some implementations, the RAN 105 further configures 202 the UE 102 to repeat the first transmission immediately after the end of the first transmission. The RAN 105 for example can configure the UE 102 to use the transmission time interval (TTI) bundling mechanism. According to one such implementation, if the UE 102 selects the higher-power resource 152 or the lower-power resource 154, the UE 102 continues to use the selected resource for each repetition, as illustrated in Fig. 6A. According to another implementation, for each repetition of the transmission 240, the UE 102 selects the higher-power resource 152 or the lower-power resource 154 in view of the current power level at the UE 102. Thus, for example, the UE 102 can select the higher-power resource 152 for the first instance of the transmission in view of the available power, determine that the remaining power no longer allows the UE 102 to use the higher-power resource 152, and transmit the repetitions using the lower-power resource 154, as illustrated in Fig. 6B. The instantaneous power availability in various scenarios can result in other patterns, as illustrated in Fig. 6C.

[0034] When transmitting 240 data to the RAN 105, or in response to other events, the UE 102 can provide a power headroom report to the RAN 105, to indicate the remaining power. In some implementations, the UE 102 includes the power headroom report in the transmission 240 only if the available power level drops below a certain threshold value, and/or if the available power level exceeds another threshold value. In other implementations, the UE includes the power headroom report in the transmission 240 unconditionally.

[0035] Because the UE 102 is associated with a power-scavenging device that can continue to harvest energy during or after the transmission 240, the remaining power can be an estimate of the maximum achievable power. For example, the UE 102 can calculate the remaining power as the difference between the amount the UE 102 expended to transmit 240 the data and the maximum transmit power the UE 102 can achieve in view of the current environmental conditions. In another implementation, however, the UE 102 calculates the amount of power that remains after allocating the necessary power for the transmission 240 and reports the difference in the power headroom report, without estimating subsequent harvesting. Further, in some implementations, the power headroom report indicates a range of the maximum transmit power, which the UE 102 can calculate in view of the environmental conditions or without accounting for the environmental conditions.

[0036] In addition to providing a power headroom report to the RAN 105 with the transmission 240, the UE 102 can transmit a PHY signal or a MAC CE to the RAN 105 responsive to detecting that the power currently available at the UE 102 is below the first threshold, or responsive to detecting that the power currently available at the UE 102 is above the second threshold. Moreover, when the UE 102 determines that the current power level at the UE 102 is below a third threshold or above a fourth threshold, the UE 102 can initiate a random access procedure to report the power level in message Msg3 of the four-step random access procedure or message MsgB of the two-step random access procedure.

[0037] Next, Fig. 7 illustrates an example method 700 for transmitting data from a UE, such as the UE 102, to a network, such as the RAN 105, in view of the available power. The UE can implement the method 700 as a set of software instructions stored on a non-transitory computer-readable medium and executable by one or more processors, for example.

[0038] The method 700 begins at block 702, where the UE receives a configuration indicating a resource for initiating uplink communication (event 202). At block 704, the UE indicates to the network that the UE is an energy-harvesting device (event 204). Next, at block 720, the UE receives (event 220) an indication of at least two resources for an uplink transmission, such as a higher-power resource (resource 152) and a lower-power resource (resource 154). At block 730, the UE selects one of these resources in view of the amount of power current available at the UE and/or the amount of data the UE has to transmit in the uplink direction (event 230). At block 740, the UE transmits the data using the selected resource (event 240). In some cases, the UE repeats the transmission at block 750 using the same resource or the other resource, as discussed above.

[0039] Fig. 8 illustrates an example method 800 for selecting a resource in view of the available power, which the UE can implement as a set of software instructions stored on a non-transitory computer-readable medium and executable by one or more processors, for example. The UE can invoke the method 800 when executing blocks 730 and 740 discussed above.

[0040] At block 832, the UE determines the amount of power associated with transmitting data using the higher-power resource. If the UE determines, at block 834, that the currently available power is at least within a certain threshold of the determined amount of power, the flow proceeds to block 842, where the UE transmits the data using the higher-power resource. Otherwise, at block 836, the UE determines the amount of power associated with transmitting data using the lower-power resource. If the UE determines, at block 838, that the currently available power is at least within a certain threshold of the determined amount of power, the flow proceeds to block 844, where the UE transmits the data using the lower-power resource. [0041] If the UE determines that the power currently available at the UE satisfies neither the requirement of the higher-power resource nor the lower-power resource, the UE can omit the transmission at block 846. Alternatively, the UE can attempt a transmission using the lower-power resource. As yet another alternative, the flow can proceed directly from the decision block 834 to block 844, if the UE determines that it cannot transmit using the higher-power resource.

[0042] Finally, Fig. 9 is a flow diagram of an example method 900 for receiving data from a UE after allocating multiple resources to the UE, which a network element, such as one or more base stations, can implement as, for example, a set of software instructions stored on a non-transitory computer-readable medium and executable by one or more processors.

[0043] At block 902, the RAN broadcasts, multicasts, or unicasts a configuration indicating a resource for initiating uplink communication (event 202). At block 904, the RAN receives an indication that the UE is an energy-harvesting device (event 204). At block 910, the RAN selects at least two resources for an uplink transmission, including a higher- power resource and a lower-power resource (event 210). Next, at block 920, the RAN provides an indication (event 220) of at least two resources for an uplink transmission, such as a higher-power resource (resource 152) and a lower-power resource (resource 154). As mentioned previously, this generic indication for two resources may be implemented as two stand-alone indications, one stand-alone indication and one indication that depends on the stand-alone indication, or as a single indication with two portions. At block 940, the receives the data using the selected resource (event 240).

[0044] The following list of examples reflects a variety of the embodiments explicitly contemplated by the present disclosure.

[0045] Example 1. A method implemented in a user equipment (UE) with limited power capability, for transmitting data in an uplink direction to a radio access network (RAN), the method comprising: receiving, from the RAN, an indication of a first resource associated with a higher power requirement and an indication of a second resource associated with a lower power requirement; determining a resource selection factor including at least one of (i) an amount of power currently available at the UE for transmission to the RAN, or (ii) an amount of the data; selecting either the first resource or the second resource in view of the resource selection factor; and transmitting the data to the RAN using the selected first resource or the second resource. [0046] Example 2. The method of example 1, further comprising, prior to the receiving the indication of the first resource and the indication of the second resource: receiving, from the RAN, an indication of an occasion for initiating access to the RAN, the occasion dedicated to energy -harvesting devices.

[0047] Example 3. The method of example 1 or 2, further comprising, prior to the receiving the indication of the first resource and the indication of the second resource: receiving, from the RAN, an indication of a random access preamble for initiating the access to the RAN, the random access preamble dedicated to energy-harvesting devices.

[0048] Example 4. The method of any of the preceding examples, further comprising, prior to the receiving the indication of the first resource and the indication of the second resource: indicating, to the RAN, that the UE is an energy-harvesting device.

[0049] Example 5. The method of example 4, wherein the indicating includes indicating a type of energy the UE harvests.

[0050] Example 6. The method of example 4 or 5, wherein the indicating includes: transmitting an indicator that the UE is the energy-harvesting device in a message that conforms to a protocol for controlling radio resources.

[0051] Example 7. The method of example 6, wherein the indicating further includes transmitting the indicator in a UECapabilitylnformation information element.

[0052] Example 8. The method of example 2, wherein the receiving of the indication includes receiving a message that conforms to a protocol for controlling radio resources.

[0053] Example 9. The method of example 2, wherein the indicating includes transmitting an indicator that the UE is the energy -harvesting device in a Medium Access Control (MAC) control element (CE).

[0054] Example 10. The method of any of the preceding examples, wherein receiving the indication of the first resource includes receiving a first downlink control information (DCI); and receiving the indication of the second resource includes receiving a second DCI.

[0055] Example 11. The method of example 10, wherein the first DCI and the second DCI are associated with respective time-frequency resources adjacent in a frequency domain.

[0056] Example 12. The method of example 10, wherein the first DCI and the second DCI are associated with respective time-frequency resources adjacent in a time domain. [0057] Example 13. The method of any of examples 1-9, wherein receiving the indication of the first resource includes and receiving the indication of the second resource includes receiving a shared downlink control information (DCI).

[0058] Example 14. The method of any of the preceding examples, wherein: the first resource includes a first set of resource blocks; and the second resource includes a second set of resource blocks.

[0059] Example 15. The method of example 14, wherein the first set of resource blocks is larger than the second set of resource blocks.

[0060] Example 16. The method of example 15, wherein: the second set of resource blocks is a subset of the first set of resource blocks.

[0061] Example 17. The method of example 15, wherein the first set of resource blocks and the second set of resource blocks do not overlap in a time domain.

[0062] Example 18. The method of example 15, wherein the first set of resource blocks and the second set of resource blocks do not overlap in a frequency domain.

[0063] Example 19. The method of example 14, wherein the first set of resource blocks is associated with a higher frequency band; and the second set of resource blocks is associated with a lower frequency band non-adjacent to the higher frequency band.

[0064] Example 20. The method of example 14, wherein the first set of resource blocks is associated with a higher-order modulation scheme; and the second set of resource blocks is associated with a lower-order modulation scheme.

[0065] Example 21. The method of example 14, wherein: the first set of resource blocks is associated with a higher coding rate; and the second set of resource blocks is associated with a lower coding rate.

[0066] Example 22. The method of any of the preceding examples, wherein the selecting of the first resource or the second resource includes: in response to determining that the amount of power currently available at the UE is at least within a threshold of the higher power requirement, selecting the first resource.

[0067] Example 23. The method of example 22, wherein the selecting of the first resource or the second resource includes: in response to determining that the amount of power currently available at the UE is below the threshold of the higher power requirement, selecting the second resource.

[0068] Example 24. The method of example 22, wherein the transmitting of the data includes: providing, to the RAN, an indication that the UE selected the first resource.

[0069] Example 25. The method of example 24, wherein the providing of the indication that the UE selected the first resource includes: transmitting a pre-defined pattern to the RAN.

[0070] Example 26. The method of any of the preceding examples, further comprising: determining the higher power requirement based on a number of resource blocks included in the first resource; and determining the lower power requirement based on a number of resource blocks included in the second resource.

[0071] Example 27. The method of any of the preceding examples, further comprising: repeating the transmitting of the data N times using the selected first resource or the second resource.

[0072] Example 28. The method of any examples 1-26, further comprising repeating the transmitting of the data at least once using a different one of the selected first resource or the second resource.

[0073] Example 29. The method of any of the preceding examples, further comprising: transmitting a power headroom report for the UE along with the data.

[0074] Example 30. A UUE comprising: a transceiver; and processing hardware configured to implement according to any of the preceding claims.

[0075] Example 31. A method for receiving data from a UE with limited power capability, the method implemented in a RAN and comprising: allocating, to the UE, a first resource associated with a higher power requirement and a second resource associated with a lower power requirement; providing, to the UE, an indication of the first resource and an indication of the second resource; and receiving, from the UE, data over the first resource or the second resource.

[0076] Example 32. The method of example 31, wherein the providing of the indication includes: broadcasting the indication. [0077] Example 33. The method of example 31 or 32, further comprising: receiving, from the UE, an indication that the UE is an energy -harvesting device.

[0078] Example 34. The method of example 33, wherein: the indication that the UE is the energy-harvesting device includes an indication of a type of energy the UE harvests.

[0079] Example 35. The method of example 33 or 34, wherein the allocating is based on the indication.

[0080] Example 36. The method of example 33, wherein the receiving of the indication incudes receiving the indication in a message that conforms to a protocol for controlling radio resources.

[0081] Example 37. The method of example 36, wherein the receiving of the indication incudes receiving the indication in a UECapabilitylnformation information element.

[0082] Example 38. The method of example 33, wherein the receiving of the indication incudes receiving the indication in a MAC CE.

[0083] Example 39. The method of any of examples 31-38, wherein the providing of the indication of the first resource includes transmitting a first DCI; and the providing of the indication of the second resource includes transmitting a second DCI.

[0084] Example 40. The method of example 39, wherein: the first DCI and the second DCI are associated with respective time-frequency resources adjacent in a frequency domain.

[0085] Example 41. The method of example 39, wherein the first DCI and the second DCI are associated with respective time-frequency resources adjacent in a time domain.

[0086] Example 42. The method of any of examples 31-38, wherein the providing of the indication of the first resource and the providing of the indication of the second resource includes transmitting a shared DCI.

[0087] Example 43. The method of any of examples 31-42, wherein the first resource includes a first set of resource blocks; and the second resource includes a second set of resource blocks.

[0088] Example 44. The method of example 43, wherein the first set of resource blocks is larger than the second set of resource blocks.

[0089] Example 45. The method of example 44, wherein the second set of resource blocks is a subset of the first set of resource blocks. [0090] Example 46. The method of example 44, wherein the first set of resource blocks and the second set of resource blocks do not overlap in a time domain.

[0091] Example 47. The method of example 43, wherein the first set of resource blocks and the second set of resource blocks do not overlap in a frequency domain.

[0092] Example 48. The method of example 43, wherein the first set of resource blocks is associated with a higher frequency band; and the second set of resource blocks is associated with a lower frequency band non-adjacent to the higher frequency band.

[0093] Example 49. The method of example 43, wherein the first set of resource blocks is associated with a higher-order modulation scheme; and the second set of resource blocks is associated with a lower-order modulation scheme.

[0094] Example 50. The method of example 43, wherein the first set of resource blocks is associated with a higher coding rate; and the second set of resource blocks is associated with a lower coding rate.

[0095] Example 51. The method of any of examples 31-50, further comprising determining whether the UE selected the first resource or the second resource based on whether a predefined pattern is received with the data.

[0096] Example 52. The method of any of examples 31-50, further comprising: determining whether the UE selected the first resource or the second resource based on a signal strength associated with the first resource.

[0097] Example 53. A radio access network (RAN) comprising: a transceiver; and processing hardware configured to implement according to any of examples 31-52.

[0098] The following description may be applied to the description above.

[0099] Generally speaking, description for one of the above figures can apply to another of the above figures. Examples, implementations and methods described above can be combined, if there is no conflict. An event or block described above can be optional or omitted. For example, an event or block with dashed lines in the figures can be optional. In some implementations, “message” is used and can be replaced by “information element (IE)”, and vice versa. In some implementations, “IE” is used and can be replaced by “field”, and vice versa. In some implementations, “configuration” can be replaced by “configurations” or “configuration parameters”, and vice versa. [0100] A user device in which the techniques of this disclosure can be implemented (e.g., the UE 102) can be any suitable device capable of wireless communications such as a smartphone, a tablet computer, a laptop computer, a mobile gaming console, a point-of-sale (POS) terminal, a health monitoring device, a drone, a camera, a media-streaming dongle or another personal media device, a wearable device such as a smartwatch, a wireless hotspot, a femtocell, or a broadband router. Further, the user device in some cases may be embedded in an electronic system such as the head unit of a vehicle or an advanced driver assistance system (ADAS). Still further, the user device can operate as an internet-of-things (loT) device or a mobile-internet device (MID). Depending on the type, the user device can include one or more general-purpose processors, a computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.

[0101] Certain embodiments are described in this disclosure as including logic or a number of components or modules. Modules may can be software modules (e.g., code, or machine- readable instructions stored on non-transitory machine-readable medium) or hardware modules. A hardware module is a tangible unit capable of performing certain operations and may be configured or arranged in a certain manner. A hardware module can comprise dedicated circuitry or logic that is permanently configured (e.g., as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), a digital signal processor (DSP), etc.) to perform certain operations. A hardware module may also comprise programmable logic or circuitry (e.g., as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. The decision to implement a hardware module in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations.

[0102] The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination, unless expressly indicated otherwise, mutually exclusive, or indicated otherwise by context. Therefore, herein, the expression “A or B” means “A, B, or both A and B.”

[0103] When implemented in software, the techniques can be provided as part of the operating system, a library used by multiple applications, a particular software application, etc. The software can be executed by one or more general-purpose processors or one or more special-purpose processors.

Claims

What is claimed is:

1. A method implemented in a user equipment (UE) with limited power capability, for transmitting data in an uplink direction to a radio access network (RAN), the method comprising: receiving, from the RAN, an indication of a first resource associated with a higher power requirement and an indication of a second resource associated with a lower power requirement; determining a resource selection factor including at least one of (i) an amount of power currently available at the UE for transmission to the RAN, or (ii) an amount of the data; selecting either the first resource or the second resource in view of the resource selection factor; and transmitting the data to the RAN using the selected first resource or the second resource.

2. The method of claim 1, further comprising, prior to the receiving the indication of the first resource and the indication of the second resource: receiving, from the RAN, an indication of an occasion for initiating access to the RAN, the occasion dedicated to energy-harvesting devices.

3. The method of claim 1 or 2, further comprising, prior to the receiving the indication of the first resource and the indication of the second resource: receiving, from the RAN, an indication of a random access preamble for initiating the access to the RAN, the random access preamble dedicated to energy-harvesting devices.

4. The method of any of the preceding claims, further comprising, prior to the receiving the indication of the first resource and the indication of the second resource: indicating, to the RAN, that the UE is an energy -harvesting device.

5. The method of any of the preceding claims, wherein: receiving the indication of the first resource includes receiving a first downlink control information (DCI); and receiving the indication of the second resource includes receiving a second DCI.

6. The method of claim 5, wherein: the first DCI and the second DCI are associated with respective time-frequency resources adjacent in one of a frequency domain or a time domain.

7. The method of any of claims 1-4, wherein: receiving the indication of the first resource includes and receiving the indication of the second resource includes receiving a shared downlink control information (DCI).

8. The method of any of the preceding claims, wherein: the first resource includes a first set of resource blocks; and the second resource includes a second set of resource blocks.

9. The method of claim 8, wherein: the first set of resource blocks is associated with a higher frequency band; and the second set of resource blocks is associated with a lower frequency band nonadj acent to the higher frequency band.

10. The method of claim 9, wherein: the first set of resource blocks is associated with a higher-order modulation scheme; and the second set of resource blocks is associated with a lower-order modulation scheme.

11. The method of claim 9, wherein: the first set of resource blocks is associated with a higher coding rate; and the second set of resource blocks is associated with a lower coding rate.

12. The method of any of the preceding claims, wherein the transmitting of the data includes: providing, to the RAN, an indication that the UE selected the first resource.

13. The method of claim 12, wherein the providing of the indication that the UE selected the first resource includes: transmitting a pre-defined pattern to the RAN.

14. The method of any of the preceding claims, further comprising: transmitting a power headroom report for the UE along with the data.

15. A UE compri sing : a transceiver; and processing hardware configured to implement according to any of the preceding claims.