Radio frequency exposure management for authorization exceptions

Abstract

Techniques and apparatus for managing exceptions to radio frequency (RF) exposure compliance are described. An example method of wireless communication by a wireless device generally includes detecting that a transmission is associated with an authorization exception for RF exposure compliance. The method also includes determining an allowed transmit power level for a time interval independent of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorization exception. The method also includes transmitting a signal in the time interval based on the allowed transmit power level.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application Serial No. 18 / 390,591, filed on December 20, 2023, which claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 476,611, filed on December 21, 2022, and both of these applications are hereby incorporated by reference in their entireties for all applicable purposes. Background Art Technical Field

[0004] Aspects of the present disclosure relate to wireless communication and, more particularly, to exceptions to radio frequency (RF) exposure compliance.

[0005] Related Art

[0006] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, etc. Modern wireless devices such as cellular phones are typically required to meet radio frequency (RF) exposure limits set by certain government and international standards and regulations. To ensure compliance, such devices typically undergo extensive certification processes before being shipped to the market. To ensure that wireless devices comply with RF exposure limits, techniques have been developed that enable wireless devices to evaluate RF exposure from the wireless device and accordingly adjust the transmit power of the wireless device to comply with the RF exposure limits. Summary of the Invention

[0007] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the appended claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," one will understand how the features of the present disclosure provide various advantages.

[0008] Certain aspects of the subject matter described in the present disclosure may be implemented in a method for wireless communication by a wireless device. The method generally includes detecting a transmission associated with an authorized exception to radio frequency (RF) exposure compliance. The method further includes determining an allowed transmit power level for a time interval independent of a time - averaged RF exposure limit in response to detecting that the transmission is associated with the authorized exception. The method further includes transmitting a signal in the time interval based on the allowed transmit power level.

[0009] Certain aspects of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus includes: one or more memories that collectively store executable instructions; and one or more processors that are coupled to the one or more memories. The one or more processors are collectively configured to execute the executable instructions so that the apparatus: detects that a transmission is associated with an authorized exception to radio frequency (RF) exposure compliance; determines an allowed transmit power level for a time interval independently of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorized exception; and transmits a signal in the time interval based on the allowed transmit power level.

[0010] Certain aspects of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus includes components for detecting that a transmission is associated with an authorized exception to radio frequency (RF) exposure compliance. The apparatus also includes components for determining an allowed transmit power level for a time interval independently of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorized exception. The apparatus also includes components for transmitting a signal in the time interval based on the allowed transmit power level.

[0011] Certain aspects of the subject matter described in the present disclosure may be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium has instructions stored thereon that, when executed by a device, cause the device to perform operations. The operations include detecting that a transmission is associated with an authorized exception to radio frequency (RF) exposure compliance. The operations also include determining an allowed transmit power level for a time interval independently of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorized exception. The operations also include transmitting a signal in the time interval based on the allowed transmit power level.

[0012] Other aspects provide: an apparatus operable to, configured to, or otherwise adapted to perform any one or more of the foregoing methods and / or those described elsewhere herein; a non-transitory computer-readable medium comprising instructions that, when executed by a processor of the apparatus, cause the apparatus to perform the foregoing methods and those described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising: code for performing the foregoing methods and those described elsewhere herein; and / or an apparatus comprising components for performing the foregoing methods and those described elsewhere herein. By way of example, an apparatus may include a processing system, a device having a processing system, or a processing system cooperating through one or more networks.

[0013] To achieve the foregoing and related purposes, one or more aspects include the features described comprehensively below and particularly pointed out in the claims. The following description and the drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only some of the various ways in which the principles of the various aspects may be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To obtain a more particular description of the above - outlined aspects briefly summarized above, reference may be made to some aspects illustrated in the drawings. It should be noted, however, that the drawings illustrate only certain typical aspects of the disclosure and are thus not to be considered as limiting its scope, as the specification may admit other equally effective aspects.

[0015] Figure 1 is a block diagram conceptually illustrating an example wireless communication network.

[0016] Figure 2 is a block diagram conceptually illustrating the design of an example base station (BS) and user equipment (UE).

[0017] Figure 3 is a block diagram of an example radio frequency (RF) transceiver.

[0018] Figure 4A 、 Figure 4B and Figure 4C are diagrams illustrating examples of transmit power over time that complies with time - averaged RF exposure limits.

[0019] Figure 5 is a flowchart illustrating an example operation for managing time - averaged RF exposure assessment for an authorization exception in accordance with certain aspects of the disclosure.

[0020] Figure 6 illustrates a graph of an example (normalized) transmit power over time relative to a maximum time - averaged transmit power level in accordance with certain aspects of the disclosure.

[0021] Figure 7A is an example graph illustrating the instantaneous normalized exposure over time associated with a wireless device in accordance with certain aspects of the disclosure.

[0022] Figure 7B is an example graph illustrating the time - averaged normalized exposure corresponding to Figure 7A in accordance with certain aspects of the disclosure.

[0023] Figure 8 is a flowchart illustrating an example operation for wireless communication by a wireless device in accordance with certain aspects of the disclosure.

[0024] Figure 9Illustrated is a communication device (e.g., UE) that may include various components configured to perform operations of the techniques disclosed herein.

[0025] For ease of understanding, the same reference numerals have been used, where possible, to denote the same elements common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without detailed recitation. Detailed Description

[0026] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for managing exceptions to radio frequency (RF) exposure compliance.

[0027] A wireless communication device may use time-averaged operation over a runtime window (e.g., 4 seconds for millimeter wave (mmWave), 2 seconds for the 60 gigahertz (GHz) band, 100 or 360 seconds for bands less than or equal to 6 GHz, etc.) to evaluate RF exposure compliance. The wireless device may perform an RF exposure assessment of past RF exposure within a given time window to determine a maximum allowable transmit power for a future time interval within that time window. The time-averaged RF exposure assessment may allow the wireless device to output high-power transmit bursts that comply with the time-averaged RF exposure limit. For example, the high-power transmit bursts may use most or all of the exposure margin associated with the time-averaged RF exposure limit in a short duration relative to the time window. In some cases, after a high-power transmit burst, the wireless device may avoid transmitting (e.g., hanging up a call) or maintain the transmit power at a reserved level for the remainder of the time window to ensure compliance with the time-averaged RF exposure limit. In such cases, the wireless device may be unable to make or maintain an emergency transmission, such as a 9-1-1 call or other emergency transmissions as further described herein, until the time-averaged RF exposure margin resumes after the passage of the time window, which in some cases may be up to six minutes.

[0028] Aspects of the present disclosure provide apparatus and methods for managing exceptions to RF exposure compliance. A wireless device may apply a temporary exception to a time-averaged RF exposure limit for certain transmissions, such as emergency transmissions. For example, in response to detecting an authorized exception to RF exposure compliance (e.g., an emergency transmission), the wireless device may output an emergency transmission at a power level that violates the time-averaged RF exposure limit, given the past exposure of the given wireless device. In some cases, the power level may be the maximum instantaneous transmission power that the wireless device is capable of outputting or a power level determined by a regulatory body or standards group. In certain cases, the power level may be at a level corresponding to the time-averaged RF exposure limit. The wireless device may allow the time-averaged RF exposure to violate the time-averaged RF exposure limit within a particular duration, such as a time window associated with the time-averaged RF exposure limit, or until a transmission is successfully received.

[0029] The apparatus and methods for managing exceptions to RF exposure compliance described herein may enable a wireless device to communicate with another wireless device in an emergency situation (or other authorized exception scenario), regardless of past exposure generated by the wireless device. For example, assuming that the wireless device has consumed all or most of its exposure margin in a time window associated with the time-averaged RF exposure limit, the wireless device may output an emergency transmission (or other authorized exception transmission), regardless of the past RF exposure generated by the wireless device.

[0030] The following description provides examples of RF exposure compliance in a communication system and is not intended to limit the scope, applicability, or examples set forth in the claims. Changes may be made to the functionality and arrangement of the elements discussed without departing from the scope of the present disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, the methods described may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with respect to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement an apparatus or practice a method. Further, the scope of the present disclosure is intended to cover such apparatus or methods practiced using other structures, functionality, or a combination of structure and functionality that supplement or replace various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure herein may be embodied by one or more elements of the claims. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

[0031] Generally, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific radio access technology (RAT) and can operate on one or more frequencies. The RAT can also be referred to as radio technology, air interface, etc. The frequency can also be referred to as carrier, sub-carrier, frequency channel, tone, sub-band, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs, or can support multiple RATs.

[0032] The techniques described herein can be used for various wireless networks and radio technologies. Although aspects may be described herein using terms typically associated with third generation (3G), fourth generation (4G), and / or new radio (NR) (e.g., fifth generation (5G) NR) wireless technologies, aspects of the present disclosure can be applied to communication systems based on other generations and / or to wireless technologies such as 802.11, 802.15, etc.

[0033] NR access can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeted at wide bandwidth (e.g., 80 megahertz (MHz) or greater), millimeter wave (mmWave) targeted at high carrier frequencies (e.g., 24 GHz to 53 GHz or greater), massive machine type communication (MTC) (mMTC) targeted at non-backward compatible MTC technologies, and / or mission critical targeted at ultra-reliable low latency communication (URLLC). These services can include latency and reliability specifications. These services can also have different transmission time intervals (TTIs) to meet the corresponding quality of service (QoS) requirements. In addition, these services can coexist in the same subframe. NR supports beamforming and can dynamically configure the beam direction. Pre-coded multiple input multiple output (MIMO) transmission can also be supported as multi-layer transmission. Aggregation of multiple cells can be supported.

[0034] Example Wireless Communication Networks and Devices

[0035] Figure 1 An example wireless communication network 100 in which aspects of the present disclosure can be implemented is illustrated. For example, the wireless communication network 100 can be a NR system (e.g., 5G NR network), an evolved universal terrestrial radio access (E-UTRA) system (e.g., 4G network), a universal mobile telecommunications system (UMTS) (e.g., second generation (2G) / third generation (3G) network), or a code division multiple access (CDMA) system (e.g., 2G / 3G network), or can be configured to communicate according to IEEE standards (such as one or more of the 802.11 standards). As Figure 1As shown, in accordance with aspects of the present disclosure, UE 120a includes an RF exposure manager 122 that manages authorization exceptions for time-averaged RF exposure compliance. UE 120a may be configured to communicate with multiple radio access networks (RANs), such as a 5G network and a WiFi network, or may be configured to communicate with a single RAN, such as only with a WiFi network or only with a Bluetooth network.

[0036] As Figure 1 illustrated, the wireless communication network 100 may include multiple BSs 110a - 110z (each also referred to herein individually as BS 110, or collectively as BS 110) and other network entities. A BS 110 may provide communication coverage for a particular geographic area (sometimes referred to as a “cell”), which may be stationary or may move according to the location of the mobile BS. In some examples, the BSs 110 may be interconnected with each other and / or connected to one or more other BSs or network nodes (not shown) in the wireless communication network 100 using any suitable transport network via various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.). In Figure 1 the example shown, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more cells.

[0037] The BS 110 communicates with UEs 120a - 120y in the wireless communication network 100 (each also referred to herein individually as UE 120 or collectively as UE 120). The UEs 120 (e.g., 120x, 120y, etc.) may be scattered throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. The wireless communication network 100 may also include a relay station (e.g., relay station 110r) (also referred to as a relay, etc.), which receives a transmission of data and / or other information from an upstream station (e.g., BS 110a or UE 120r) and transmits the data and / or other information to a downstream station (e.g., UE 120 or BS 110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0038] In some aspects, UE 120a may act as an access point (AP) (such as a soft AP) and communicate with other WiFi clients (e.g., augmented reality (AR) glasses or headsets, tablet computers, etc.) and use the wireless link to BS 110 as a backhaul to a network (e.g., the Internet). As an example, UE 120a may stream video from an AP (e.g., another UE or a base station) and have a Bluetooth link to a pair of headsets.

[0039] Network controller 130 may communicate with a set of BSs 110 and provide coordination and control for these BSs 110 (e.g., via the backhaul). In some cases, such as in a 5G NR system, network controller 130 may include a centralized unit (CU) and / or a distributed unit (DU). In some aspects, network controller 130 may communicate with a core network 132 (e.g., a 5G core network (5GC)), which provides various network functions such as access and mobility management, session management, user plane function, policy control function, authentication server function, unified data management, application function, network exposure function, network repository function, network slice selection function, etc.

[0040] In the present disclosure, the term "beam" may be used in various contexts. A beam may be used to mean a set of gains and / or phases (e.g., precoding weights or in-phase weights) applied to antenna elements in a UE and / or a BS for transmission or reception. The term "beam" may also refer to the antenna or radiation pattern of a signal transmitted when gains and / or phases are applied to the antenna elements. Other references to a beam may include one or more characteristics or parameters associated with an antenna (radiation) pattern, such as angle of arrival (AoA), angle of departure (AoD), gain, phase, directivity, beam width, beam direction in terms of azimuth and elevation (relative to a reference plane), peak sidelobe ratio, or an antenna port associated with the antenna (radiation) pattern. The term "beam" may also refer to the associated number and / or configuration of antenna elements (e.g., uniform linear array, uniform rectangular array, or other uniform arrays).

[0041] Figure 2 Illustrative example components of BS 110a and UE 120a (e.g., Figure 1 of the wireless communication network 100) that may be used to implement aspects of the present disclosure.

[0042] At BS 110a, the transmit processor 220 may receive data from the data source 212 and control information from the controller / processor 240. The control information may be used for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid automatic repeat request (HARQ) indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), etc. The data may be used for the physical downlink shared channel (PDSCH), etc. The medium access control (MAC)-control element (MAC-CE) is a MAC layer communication structure that may be used for the exchange of control commands between wireless nodes. The MAC-CE may be carried in a shared channel such as the PDSCH, physical uplink shared channel (PUSCH), or physical sidelink shared channel (PSSCH).

[0043] The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, and / or reference symbols (where applicable) and may provide the output symbol streams to the modulators (MOD) in the transceivers 232a-232t. Each modulator 232a-232t in the transceivers may process its respective output symbol stream (e.g., for orthogonal frequency division multiplexing (OFDM), etc.) to obtain an output sample stream. Each transceiver in the transceivers 232a-232t may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the transceivers 232a-232t may be transmitted via the antennas 234a-234t, respectively.

[0044] At UE 120a, antennas 252a - 252r can receive downlink (DL) signals from BS 110a and can provide the received signals to transceivers 254a - 254r, respectively. Transceivers 254a - 254r can condition (e.g., filter, amplify, down-convert, and digitize) the respective received signals to obtain input samples. Each demodulator (DEMOD) in transceivers 232a - 232t can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 can obtain the received symbols from all the demodulators in transceivers 254a - 254r, perform MIMO detection (where applicable) on the received symbols, and provide detected symbols. A receive processor 258 can process (e.g., demodulate, de-interleave, and decode) the detected symbols, provide the decoded data for UE 120a to data sink 260, and provide the decoded control information to controller / processor 280.

[0045] On the uplink, at UE 120a, a transmit processor 264 can receive and process data (e.g., for a physical uplink shared channel (PUSCH)) from a data source 262, and receive and process control information (e.g., for a physical uplink control channel (PUCCH)) from controller / processor 280. Transmit processor 264 can also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). Symbols from transmit processor 264 can be precoded by a TX MIMO processor 266 (if applicable), further processed by a modulator (MOD) in transceivers 254a - 254r (e.g., for single-carrier frequency-division multiplexing (SC-FDM), etc.), and transmitted to BS 110a. At BS 110a, an uplink (UL) signal from UE 120a can be received by an antenna 234, processed by a demodulator in transceivers 232a - 232t, detected by a MIMO detector 236 (if applicable), and further processed by a receive processor 238 to obtain the decoded data and control information transmitted by UE 120a. Receive processor 238 can provide the decoded data to data sink 239, and provide the decoded control information to controller / processor 240.

[0046] Memories 242 and 282 can store data and program codes for BS 110a and UE 120a, respectively. A scheduler 244 can schedule the UE for data transmission on the downlink and / or uplink.

[0047] The antennas 252, processors 266, 258, 264, and / or controller / processor 280 of UE 120a and / or the antennas 234, processors 220, 230, 238, and / or controller / processor 240 of BS 110a can be used to perform the various techniques and methods described herein. As Figure 2 shown, according to aspects described herein, the controller / processor 280 of UE 120a has an RF exposure manager 281 representing RF exposure manager 122. Although shown at the controller / processor, other components of UE 120a and BS 110a can be used to perform the operations described herein.

[0048] NR can utilize OFDM with a cyclic prefix (CP) on both the uplink and downlink. NR can use time-division duplex (TDD) to support half-duplex operation. OFDM and SC-FDM divide the system bandwidth into multiple orthogonal subcarriers, which are also often referred to as tones, frequency slots, etc. Each subcarrier can be modulated with data. Modulation symbols can be transmitted in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers can depend on the system bandwidth. The system bandwidth can also be divided into subbands. For example, one subband can cover multiple resource blocks (RBs).

[0049] Although UE 120a is described with reference to Figure 1 and Figure 2 as communicating with a BS and / or within a network, UE 120a can be configured to communicate directly with another UE 120 / transmit directly to that other UE, or communicate directly with another wireless device / transmit to that other wireless device without relaying the communication through a network. In some aspects, the Figure 2 BS 110a illustrated and described above is an example of another UE 120.

[0050] Example RF Transceiver

[0051] Figure 3 is a block diagram of an example RF transceiver circuit 300 according to certain aspects of the present disclosure. The RF transceiver circuit 300 includes at least one transmit (TX) path 302 (also referred to as a transmit chain) for transmitting signals via one or more antennas 306 and at least one receive (RX) path 304 (also referred to as a receive chain) for receiving signals via the antenna 306. When the TX path 302 and the RX path 304 share the antenna 306, these paths can be connected to the antenna via an interface 308, which can include any of various suitable RF devices such as switches, duplexers, diplexers, multiplexers, etc.

[0052] Receiving an in-phase (I) or quadrature (Q) baseband analog signal from a digital-to-analog converter (DAC) 310, TX path 302 may include a baseband filter (BBF) 312, a mixer 314, a driver amplifier (DA) 316, and a power amplifier (PA) 318. BBF 312, mixer 314, and DA 316 may be included in one or more radio frequency integrated circuits (RFICs). For some embodiments, PA 318 may be external to the RFIC.

[0053] BBF 312 filters the baseband signal received from DAC 310, and mixer 314 mixes the filtered baseband signal with a transmit local oscillator (LO) signal to convert the baseband signal of interest to a different frequency (e.g., up-converting from baseband to radio frequency). This frequency conversion process generates a sum frequency and a difference frequency between the LO frequency and the frequency of the baseband signal of interest. These sum and difference frequencies are referred to as beat frequencies. The beat frequencies are typically in the RF range, such that the signal output by mixer 314 is typically an RF signal, which may be amplified by DA 316 and / or by PA 318 before being transmitted via antenna 306. Although one mixer 314 is illustrated, several mixers may be used to up-convert the filtered baseband signal to one or more intermediate frequencies and then up-convert the intermediate frequency signals to the frequency for transmission.

[0054] RX path 304 may include a low noise amplifier (LNA) 324, a mixer 326, and a baseband filter (BBF) 328. LNA 324, mixer 326, and BBF 328 may be included in one or more RFICs, which may be the same RFIC as the RFIC including the TX path components or may be a different RFIC. The RF signal received via antenna 306 may be amplified by LNA 324, and mixer 326 mixes the amplified RF signal with a receive local oscillator (LO) signal to convert the RF signal of interest to a different baseband frequency (e.g., down-converting). The baseband signal output by mixer 326 may be filtered by BBF 328 before being converted to a digital I or Q signal by an analog-to-digital converter (ADC) 330 for digital signal processing.

[0055] Certain transceivers may employ a frequency synthesizer with a voltage controlled oscillator (VCO) to generate a stable, tunable LO with a specific tuning range. Thus, the transmit LO may be generated by TX frequency synthesizer 320, which may be buffered or amplified by amplifier 322 before being mixed with the baseband signal in mixer 314. Similarly, the receive LO may be generated by RX frequency synthesizer 332, which may be buffered or amplified by amplifier 334 before being mixed with the RF signal in mixer 326.

[0056] The controller 336 may direct the operation of the RF transceiver circuitry 300, such as transmitting signals via the TX path 302 and / or receiving signals via the RX path 304. The controller 336 may be a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic components, discrete hardware components, or any combination thereof. The memory 338 may store data and program code for operating the RF transceiver circuitry 300. The controller 336 and / or the memory 338 may include control logic. In some cases, the controller 336 may determine the transmit power applied to the TX path 302 (e.g., certain gain levels applied at the BBF 312, DA 316, and / or PA 318) in compliance with RF exposure limits set by country-specific regulations and / or international standards, as further described herein.

[0057] Example RF Exposure Compliance

[0058] RF exposure may be expressed in terms of the specific absorption rate (SAR), which measures the energy absorption of human tissue per unit mass and may have the unit of watts per kilogram (W / kg). RF exposure may also be expressed in terms of the power density (PD), which measures the energy absorption per unit area and may have the unit of milliwatts per square centimeter (mW / cm 2 ). In some cases, maximum permissible exposure (MPE) limits (in the form of PD) may be imposed on wireless devices using transmit frequencies above 6 GHz. The MPE limits are area-based exposure regulatory metrics, such as energy density limits, which are defined as the number X (watts per square meter (W / m 2 )) averaged over the defined area and time-averaged over a frequency-dependent time window to prevent human exposure hazards represented by tissue temperature changes.

[0059] The SAR may be used to evaluate RF exposure for transmit frequencies below 6 GHz, which cover wireless communication technologies such as 2G / 3G (e.g., CDMA), 4G (e.g., Long Term Evolution (LTE)), 5G (e.g., NR in the 6 GHz band), IEEE 802.11ac, etc. The PD may be used to evaluate RF exposure for transmit frequencies above 6 GHz, which cover wireless communication technologies such as IEEE 802.11ad, 802.11ay, 5G in the mmWave band, etc. Thus, different metrics may be used to evaluate RF exposure for different wireless communication technologies.

[0060] A wireless device (e.g., UE 120) can use multiple wireless communication technologies to transmit signals simultaneously. For example, the wireless device can use a first wireless communication technology operating below 6 GHz (e.g., 3G, 4G, 5G, etc.) and a second wireless communication technology operating above 6 GHz (e.g., mmWave 5G in the 24 GHz to 60 GHz band, IEEE 802.11ad or 802.11ay) to transmit signals simultaneously. In some aspects, the wireless device can use a first wireless communication technology (e.g., 3G, 4G, 5G, IEEE 802.11ac, etc. in the sub-6 GHz band) (where RF exposure is measured by SAR) and a second wireless communication technology (e.g., 5G, IEEE 802.11ad, 802.11ay, etc. in the 24 GHz to 60 GHz band) (where RF exposure is measured by PD) to transmit signals simultaneously. As used herein, the sub-6 GHz band can include, in some examples, a band from 300 MHz to 6,000 MHz, and in some examples, can include bands in the range of 6,000 MHz and / or 7,000 MHz.

[0061] In certain cases, compliance with RF exposure limits can be performed as a time-averaged RF exposure assessment within a specified time window (T) associated with the RF exposure limit (e.g., 4 seconds for mmWave, 2 seconds for the 60 GHz band, 100 or 360 seconds for bands less than or equal to 6 GHz, etc.).

[0062] Figure 4A FIG. 400A is a graph of the transmit power (P(t)) over time that varies within an operating time window (T) associated with a time-averaged RF exposure limit, in accordance with certain aspects of the present disclosure. As an example, at certain transmission instances within the time window (T), the instantaneous transmit power may exceed the maximum time-averaged transmit power level P limit . For certain durations, the transmit power can be greater than the maximum time-averaged transmit power level P limit . In certain cases, the wireless device can transmit at P max , where the P max is the maximum transmit power that the wireless device is capable of outputting. In certain cases, at certain transmission instances, the wireless device can transmit at a transmit power less than or equal to the maximum time-averaged transmit power level P limit . The maximum time-averaged transmit power level P limit represents the time-averaged threshold in terms of transmit power of the RF exposure limit within the time window (T). In certain cases, P limitMay be referred to as the maximum time-average power level or limit, or in terms of exposure, the maximum time-average RF exposure level or limit. Graph 400A also illustrates the gaps between transmission bursts, where these gaps represent periods during which no transmissions are output from the wireless device.

[0063] In some cases, the transmit power may be maintained at the maximum time-average transmit power level allowed for RF exposure compliance that enables continuous transmission during a time window (e.g., P limit ). For example, Figure 4B is a graph 400B of transmit power (P(t)) over time according to some aspects of the present disclosure, which graph illustrates an example where the transmit power is set to P limit . As shown, the UE can transmit continuously at P limit that complies with the time-average RF exposure limit.

[0064] Figure 4C is a graph 400C of transmit power (P(t)) over time illustrating a time-average mode according to some aspects of the present disclosure, which time-average mode provides reserved power to enable continuous transmission within a time window (T). As shown, the transmit power can be backed off from the maximum instantaneous power (P max ) to the reserved power (P reserve ), such that the UE can continue to transmit at a lower power (P reserve ) to maintain continuous transmission (e.g., maintain a radio connection with the receiving entity) during that time window. In Figure 4C , the area between P max and P max and P reserve during the time duration of P limit can be equal to the area between P reserve and P Figure 4C within the time window T, such that the area of the transmit power (P(t)) in limit is equal to the area of P reserve within the time window T. Such an area can be considered to use 100% of the energy (transmit power or exposure) to maintain compliance with the time-average RF exposure limit. In the absence of the reserved power P max , the transmitter can transmit at P reserve for a portion of the time window, and the transmitter is turned off for the remaining portion of the time window to ensure compliance with the time-average RF exposure limit. In some aspects, P maxThe transmission duration below can be referred to as the burst transmission time (or high power duration). When more margin is available in the future (after T seconds), the transmitter may be allowed to transmit again at a higher power (e.g., transmit in short bursts at P max below).

[0065] In some aspects, in the time-averaging mode exemplified in Figure 4C , the UE can transmit at a power higher than the average power level but less than P max . Although a single transmission burst is exemplified in Figure 4C , it should be understood that the UE can alternatively utilize multiple transmission bursts within a time window (T), e.g., as described herein with respect to Figure 4A , where these transmission bursts can be separated by periods during which the transmission power is maintained at or below P reserve . Additionally, it should be understood that the transmission power of each transmission burst can vary (within the burst and / or compared to other bursts), and at least a portion of the burst can be transmitted at a power higher than the maximum average power level (e.g., P limit ).

[0066] Although Figures 4A through 4C exemplifies continuous transmission within a window, timing, burst, etc., it should be understood that a transmission duty cycle can be implemented. In such embodiments, the transmission power can be zero during some portions of the duty cycle and maintained at a higher level during other portions of the duty cycle (e.g., at the level exemplified in Figures 4A through 4C ). As used herein, the duty cycle of a transmission can represent the portion (e.g., 5 ms) of a specific time period (e.g., 500 ms) during which one or more signals are transmitted. In some cases, this duty cycle can be normalized (e.g., pre-determined) with a specific RAT, and / or can change over time, e.g., due to changes in radio conditions, mobility, user behavior, channel availability, etc.

[0067] Time-averaged RF exposure assessment can allow a wireless device to output high-power transmission bursts that comply with time-averaged RF exposure limits (e.g., as in Figure 4A and Figure 4Cas depicted). A high-power transmit burst may use most or all of the exposure margin associated with the time-averaged RF exposure limit in a short duration relative to the time window. In some cases, after a high-power transmit burst, the wireless device may avoid transmitting (e.g., hanging up a call) for the remainder of the time window or maintain the transmit power at a reserved level to ensure compliance with the time-averaged RF exposure limit. For example, assume that the wireless device uses all available energy associated with the time-averaged RF exposure limit in the last time interval of the time window. If an emergency transmit is initiated at this time, the wireless device may delay the emergency transmit by almost one time window (e.g., six minutes). If the wireless device uses the reservation, the reserved power may be too low to communicate with another wireless device. In such cases, the wireless device may not be able to make an emergency transmit, such as a 9-1-1 call or other emergency transmits as further described herein, until the time-averaged RF exposure margin resumes after the passage of the time window, which in some cases can be up to six minutes.

[0068] Example Radio Administration of Authorized Exceptions for Radio Frequency Compliance

[0069] Aspects of the present disclosure provide apparatus and methods for managing exceptions to RF exposure compliance. A wireless device may apply a temporary exception to the time-averaged RF exposure limit for certain transmissions, such as emergency transmissions. For example, in response to detecting an authorized exception to RF exposure compliance (e.g., an emergency transmission), the wireless device may output an emergency transmission at a power level that violates the time-averaged RF exposure limit given the past exposure of the given wireless device. In some cases, the power level may be the maximum instantaneous transmit power that the wireless device is capable of outputting. In certain cases, the power level may be at a level corresponding to the time-averaged RF exposure limit or at some other predefined power level for such exceptions. The wireless device may allow the time-averaged RF exposure to violate the time-averaged RF exposure limit within a specific duration, such as the time window associated with the time-averaged RF exposure limit.

[0070] The apparatus and methods for managing exceptions to RF exposure compliance described herein may enable a wireless device to communicate with another wireless device in an emergency situation (or other authorized exception scenario) regardless of the past exposure generated by the wireless device. For example, assume that the wireless device has consumed all or most of the exposure margin in the time window associated with the time-averaged RF exposure limit. The wireless device may output an emergency transmission (or other authorized exception transmission) regardless of the past RF exposure generated by the wireless device. The apparatus and methods for managing exceptions to RF exposure compliance described herein may also allow the wireless device to switch between operating in compliance with the RF exposure limit and applying an authorized exception to RF exposure compliance.

[0071] In some aspects, a wireless device may, in response to detecting an authorized exception to RF exposure compliance, permit transmission of one or more signals at an exception transmit power level (P excep ). The exception transmit power level (P excep ) may cause the wireless device to temporarily fail to comply with the time-average RF exposure limit. In some cases, P excep may be the maximum transmit power that the wireless device is capable of outputting (e.g., P max ). In certain cases, the power level may be the maximum time-average transmit power level (P limit ) corresponding to the time-average RF exposure limit. For some aspects, the wireless device may select the power level of P limit to P max from a power range including P excep or select any transmit power level less than or equal to P max .

[0072] For some cases, the wireless device may temporarily stop (or suppress) performing the time-average RF exposure assessment during an emergency transmission, and the wireless device may resume performing the time-average RF exposure assessment in response to the end of the emergency transmission. In such scenarios, when the time-average RF exposure assessment resumes, the wireless device may replace the RF exposure history corresponding to the emergency transmission with one or more values that comply with the time-average RF exposure limit as described herein.

[0073] For some aspects, the wireless device may adjust the RF exposure history (or transmit power history) tracked for the time-average RF exposure assessment (e.g., in the case of an authorized exception scenario). Such adjustment may prevent the time-average RF exposure assessment from crashing (e.g., a major computational failure due to non-compliance with the RF exposure limit) or interfering with the emergency transmission (e.g., delaying the transmission or reducing P excep ). If the wireless device continuously maintains transmission at P excep , the time-average RF exposure assessment may crash without further action due to non-compliance with the RF exposure limit. For smooth operation from a software operation perspective, on the power reporting side, the wireless device may replace the actual transmit power report (which represents the past RF exposure generated by the wireless device in a running time window) with an alternative transmit power report that may comply with the time-average RF exposure limit or may otherwise prevent a crash. The alternative transmit power report may be an alternative (or replacement) or dummy (or simulated) report that can be used to determine the maximum allowable transmit power, and the maximum allowable transmit power may be replaced with the exception transmit power level, as described herein with respect to Figure 5 and Figure 6is further described. The wireless device may substitute one or more values that comply with the time-average RF exposure limit for past exposure or past transmit power. For example, the wireless device may set the actual past exposure to an amount less than the time-average RF exposure limit. In some cases, the wireless device may set the past exposure to a value indicating no exposure (e.g., an average of zero over a time window or zero for multiple time intervals associated with past exposure) or some other predefined value. In some cases, the wireless device may set the past exposure to a reserved power level (e.g., P reserve ).

[0074] In some cases, the wireless device may select an alternative power report from multiple values. For example, the wireless device may select the minimum of the actual transmit power report value and an alternative value for the alternative power report (e.g., min(actual transmit power report, the last calculated power level based on the allowed RF exposure margin to ensure that the time-average RF exposure complies with regulatory limits)). The alternative value may be a reserved level (e.g., P reserve ), which may be a transmit power level that is guaranteed to be available, a level lower than the reservation (e.g., zero), or a calculated level based on the allowed RF exposure margin for the time interval. The alternative value may be a value determined based on the allowed RF exposure margin to ensure that the time-average RF exposure is less than the time-average RF exposure limit. The alternative value may be a reserved power or lower, where the reserved power may be equal to the product of P limit and the reserved level (e.g., P reserve = P in milliwatts (mW) limit * the reserved level in linear units = P in dBm limit - the reserved level in dBm).

[0075] In some aspects, the wireless device may determine an exception transmit power level P excep to be a power level that complies with the time-average RF exposure limit associated with an occupational or controlled environment, and the exception transmit power level P excep may not comply with the public RF exposure limit. In some cases, the time-average RF exposure limit associated with an occupational or controlled environment is higher (e.g., up to five times) than the RF exposure limit associated with the public. The wireless device may apply a scaling factor to the maximum allowable transmit power (P max_allowed ) for a time interval determined based on the time-average RF exposure limit and past RF exposure. For example, the wireless device may increase the maximum allowable transmit power by the scaling factor. The scaling factor may be less than or equal to the ratio of the occupational RF exposure limit to the public RF exposure limit. In some aspects, the scaling factor may be a value specified or authorized by a regulatory agency or standards organization. The wireless device may determine P excep to be the scaling factor (e.g., ), and the maximum allowable transmit power (e.g., ). On the transmit power reporting side, the wireless device may replace the actual transmit power report with a reduced transmit power report. For example, the wireless device may reduce the actual transmit power report by a scaling factor (e.g., ).

[0076] Figure 5 is a flowchart illustrating example operation 500 for managing the time-averaged RF exposure assessment for an authorization exception. Operation 500 may be performed, for example, by a wireless device (e.g., UE 120a) and / or an RF transceiver circuit (e.g., RF transceiver circuit 300). Operation 500 is described with respect to Figure 6 which illustrates example (normalized) transmit power versus time relative to a maximum time-averaged transmit power level (P limit ), where an exception transmit power level (P excep ) may override the maximum allowable transmit power (P max_allowed ) determined according to the time-averaged assessment.

[0077] Operation 500 may optionally begin at block 502, where the wireless device may obtain the transmit power for a particular time interval (e.g., second time interval 608) within a runtime window (T) associated with the time-averaged RF exposure limit. The transmit power may be obtained from a transmit automatic gain control (TxAGC) module at layer 1 (L1) of the protocol stack. For example, L1 may include the physical radio layer (PHY) of the protocol stack. In some aspects, the controller 336 of the RF transceiver circuit 300 may obtain (or access) the transmit power for the particular time interval. The controller 336 may include the TxAGC module and track the transmit power output by the transmit path over time. A transmit power report of past transmit power (e.g., past transmit power 606) may represent the actual transmit power within the expected device uncertainty.

[0078] At block 504, the wireless device may determine a normalized power report for the past transmit power (e.g., past transmit power 606). The normalized power report for a particular time interval (e.g., second time interval 608) may be the past time-averaged transmit power during the time interval (e.g., second time interval 608) normalized using P limit . For example, the normalized power report may be equal to the past time-averaged transmit power during the second time interval 608 divided by P limit (e.g., normalized power report = Tx power report / P limit),(where the transmit power associated with the second time interval 608 is averaged over the second time interval 608. Such a normalized power report can be calculated and tracked for multiple time intervals belonging to the operating time window (T) (e.g., corresponding to the past transmit power 606). The wireless device can determine the average value of the normalized power report of the past transmit power 606.)

[0079] At block 506, the wireless device can adjust the normalized power report in response to detecting an authorized exception for RF exposure compliance (such as detecting an emergency transmission). The wireless device can adjust the normalized power report to comply with the time-averaged RF exposure limit, e.g., as described herein. The adjusted power report can be an alternative (or replacement) or dummy (or simulated) report for determining the maximum allowable transmit power (P max_allowed ) at block 510. As an example, the wireless device can select an alternative value for the normalized power report, where the alternative value can be selected as the minimum of the actual transmit power report and the last calculated power level based on the allowed RF exposure margin to ensure that the time-averaged RF exposure complies with regulatory or standardized limits.)

[0080] At block 508, the wireless device can perform a time-averaging operation based on the adjusted normalized power report. The wireless device can determine the normalized exposure margin allowed for the next time interval (e.g., the first time interval 604) in the time window (T) such that the time average of the adjusted version of the normalized power report and the exposure margin of the next time interval satisfy the time-averaged RF exposure limit. In some aspects, the exposure margin can be the maximum RF exposure that the wireless device can generate and satisfy the time-averaged RF exposure limit. The normalized exposure margin can be the percentage of exposure remaining relative to the normalized power report and the time-averaged RF exposure limit. For example, when the time average of the adjusted normalized power report and the exposure margin of the next time interval (e.g., the first time interval 604) is less than or equal to one (e.g., the normalized RF exposure limit), the time-averaged RF exposure limit can be satisfied. In terms of the allowed transmit power for the next time interval (e.g., the first time interval 604), the normalized exposure margin represents the percentage of the maximum time-averaged RF exposure power level P limit .

[0081] At block 510, the wireless device can determine the maximum allowable transmit power (P max_allowed ) for the next time interval (e.g., the first time interval 604). For example, the maximum allowable transmit power (P max_allowed ) can be equal to the product of the normalized exposure margin determined at block 508 and P limit .

[0082] At block 512, the wireless device may determine a maximum allowable transmit power for an authorization exception (e.g., an exception transmit power level P excep ). The wireless device may set the exception transmit power level P excep to be greater than P limit . In some cases, the exception transmit power level P limit may be selected from a power range including P max to P excep (the maximum instantaneous transmit power that the wireless device is capable of outputting). In some cases, the exception transmit power level P max_allowed may be determined by applying a scaling factor to the calculated maximum allowable transmit power (P excep ), as described herein. Referring to Figure 6 , the wireless device may use the exception transmit power level P excep as the maximum allowable transmit power for the first time interval 604.

[0083] At block 514, the wireless device may provide the exception transmit power level P excep 602 to a transceiver circuit (e.g., RF transceiver circuit 300). For example, the TxAGC module may obtain a scaled version of the exception transmit power level P excep 602 as digital RF information (e.g., a specific gain index associated with the output power of the transmit path 302), and the TxAGC module may control the gain applied to the circuits in the transmit path to output a signal (e.g., an analog RF signal) at the transmit power associated with the digital RF information.

[0084] In some aspects, operation 500 may optionally begin at block 512 in response to detecting an authorization exception for RF exposure compliance. The wireless device may adjust the transmit power report at block 506 until the transmission associated with the authorization exception has ended.

[0085] For some aspects, the wireless device may temporarily avoid performing the time-averaged RF exposure assessment described herein with respect to Figure 5 . For example, the wireless device may perform operations 500 at blocks 512 and 514 in response to detecting an authorization exception for RF exposure compliance. During the transmission associated with the authorization exception, the wireless device may avoid performing operations associated with any of blocks 502, 504, 506, 508, and 510.

[0086] Figure 7AFIG. 700A is an example graph illustrating the instantaneous normalized exposure over time associated with a wireless device. In this example, shortly before the 200 - second mark, the wireless device may output a transmission burst that uses all or most of the exposure margin associated with the time - averaged RF exposure limit. The instantaneous exposure 702 may correspond to the exposure generated by the transmission burst. To comply with the RF exposure limit, the wireless device may wait for the duration of the next time window to allow a subsequent transmission, or the wireless device may transmit at a reserved level for the remaining time of the time window (e.g., 100 seconds) before allowing continuous transmission at P limit as depicted at 706. In response to detecting an authorized exception for RF exposure compliance, the wireless device may transmit a signal at an exception transmit power (e.g., 0.8*P limit ). To ensure smooth operation of the time - averaged assessment, the wireless device may select the minimum of the actual exposure 704 and the exposure margin 706 determined by the time - averaging algorithm as an alternative for the transmit power report, e.g., as described herein with respect to Figure 5 . As more margin becomes available based on past exposures, the wireless device may adjust the exposure margin 706 over time. After the wireless device transmits while complying with the RF exposure limit, the wireless device may increase the exposure margin 706, e.g., as depicted at approximately the 280 - second mark. In some cases, when the past exposure associated with a transmission complies with the time - averaged RF exposure limit, the exposure margin 706 may be adjusted to equal P limit . For example, the exposure margin 706 may be adjusted to a value of 1.0 from 280 seconds to 600 seconds because the time - averaging algorithm allows the wireless device to transmit continuously at P limit in subsequent time windows.

[0087] Figure 7B FIG. 700B is an example graph illustrating the time - averaged normalized exposure corresponding to Figure 7A . Assuming the wireless device transmits at the same power level after the 200 - second mark (e.g., P excep = 0.8*P limit ), the time - averaged RF exposure 708 may exceed the maximum time - averaged transmit power level P limit 710 within a portion of the time window (e.g., less than 100 seconds). The time - averaged RF exposure 708 may drop below the maximum time - averaged transmit power level P limit 710 shortly before the 300 - second mark, where the time - averaged RF exposure may stabilize to the power level of the exception transmit power level P excep . In this example, the exception transmit power level may be equal to or less than the exposure margin 712, which allows for a remaining margin (e.g., (1 – 0.8)*P limit = 0.2*Plimit ) Can be used for other transmissions.

[0088] Figure 8 is a flowchart illustrating an example operation 800 for wireless communication in accordance with certain aspects of the present disclosure. Operation 800 can be performed, for example, by a wireless device (e.g., UE 120a in wireless communication network 100). Operation 800 can be implemented as a software component that executes and runs on one or more processors (e.g., Figure 2 controller / processor 280). Additionally, signal transmission and / or reception by the wireless device in operation 800 can be implemented, for example, by one or more antennas (e.g., Figure 2 antenna 252). In certain aspects, signal transmission and / or reception by the wireless device can be implemented by obtaining and / or outputting signals via a bus interface of one or more processors (e.g., controller / processor 280).

[0089] Operation 800 can optionally begin at block 802, where the wireless device can detect that a transmission is associated with an authorized exception for RF exposure compliance. An authorized exception for RF exposure compliance can allow the wireless device to temporarily exceed the time-averaged RF exposure limit, e.g., as described herein with respect to Figure 5 , Figure 6 , Figure 7A and Figure 7B . In certain aspects, the authorized exception can include an emergency transmission. In some cases, the wireless device can perform the detection prior to outputting a transmission, and the wireless device can perform one or more actions in response to the detection.

[0090] At block 804, the wireless device can determine an allowed transmit power level (e.g., P excep ) for a time interval (e.g., first time interval 604) independent of the time-averaged RF exposure limit in response to detecting that the transmission is associated with an authorized exception. For example, the wireless device can select a transmit power that is less than or equal to the maximum instantaneous transmit power that the wireless device is capable of outputting (e.g., P max ). The time interval can include at least a portion of the operating time window associated with the time-averaged RF exposure limit.

[0091] At block 806, the wireless device may transmit a signal based on an allowed transmit power level over a time interval. The wireless device may transmit the signal at a power level less than or equal to the allowed transmit power level. Transmitting the signal may include transmitting any one of a variety of communications, such as a text message, a video call, a voice call, data transmission, etc. The wireless device may transmit the signal to any of a variety of other wireless devices, such as a base station (e.g., BS 110a) or a user equipment (e.g., UE 120). Transmitting the signal may use any one of a variety of RATs, such as CDMA, E-UTRA, NR, IEEE 802.11, non-terrestrial network (NTN) communication, etc.

[0092] The wireless device may determine the allowed transmit power level (P excep ) as any one of a variety of power levels. In some cases, the wireless device may determine the allowed transmit power level to be equal to the power level associated with a transmit power limit corresponding to a time-averaged RF exposure limit (e.g., P limit ). In certain cases, the allowed transmit power level may be less than P limit . In some aspects, the wireless device may select the allowed transmit power level between the power level associated with a transmit power limit corresponding to a time-averaged RF exposure limit (e.g., P limit ) and the maximum instantaneous transmit power that the wireless device is capable of outputting (e.g., P max ). To determine the allowed transmit power level for an authorized exception transmission, the wireless device may allow non-compliance with the time-averaged RF exposure limit over the time interval based on past RF exposure and the transmit power over the time interval, e.g., as described herein with respect to Figure 7B .

[0093] In some aspects, from a software operation perspective, to allow smooth operation, the wireless device may adjust an RF exposure report or a transmit power report (e.g., an RF exposure report or a transmit power report associated with past transmit power 606) to comply with the time-averaged RF exposure limit, e.g., as described herein with respect to Figure 5 and Figure 6 . The RF exposure report or the transmit power report may indicate the RF exposure or the transmit power generated by the wireless device in an operating time window associated with the time-averaged RF exposure limit. In some cases, to adjust the RF exposure report or the transmit power report, the wireless device may select the minimum value among a plurality of values as the RF exposure report (e.g., min(transmit power report / P limit, the previously calculated exposure margin for time-averaged RF exposure compliance)) or the transmit power report (e.g., min(actual transmit power report, the last calculated power level based on the allowed RF exposure margin to ensure time-averaged RF exposure compliance with regulatory limits)). The multiple values can include the current value of the RF exposure report or the transmit power report and alternative values of the RF exposure report or the transmit power report. The wireless device can determine the alternative value as the value corresponding to the reserved power associated with the time-averaged RF exposure limit (e.g., P reserve )). In some cases, to adjust the RF exposure report, the wireless device can set the RF exposure report or the transmit power report to a specific value. The specific value can include a first value indicating no past RF exposure (e.g., zero, which is equivalent to disabling the time-averaged RF exposure assessment during authorized exception transmission) or a second value corresponding to the reserved power level (e.g., P reserve ).

[0094] The wireless device can use the transmit power determined at block 804 to cover the time-averaged RF exposure assessment, e.g., as described herein with respect to Figure 5 and Figure 6 . The wireless device can determine an initial transmit power level (e.g., P max_allowed ) based on the adjusted RF exposure report that complies with the time-averaged RF exposure limit. The wireless device can replace the initial transmit power level with an allowed transmit power level (e.g., P excep ), e.g., as described herein with respect to block 512. Instead of transmitting using the maximum allowed transmit power (P max_allowed ), the wireless device can use an exception transmit power level P excep , e.g., as described herein with respect to block 512.

[0095] In some aspects, the wireless device can apply RF exposure limits associated with occupational or controlled environments to determine the transmit power. For example, the wireless device can determine that the transmit power complies with a first RF exposure limit associated with an occupational or controlled environment, and the wireless device can allow the transmit power not to comply with a second RF exposure limit associated with a public environment. In some cases, to determine the transmit power that complies with the first RF exposure limit associated with an occupational or controlled environment, the wireless device can increase the maximum time-averaged RF exposure power level P by a scaling factor (e.g., limit ). In such cases, the maximum allowed transmit power (P max_allowed ) can be related to the maximum time-averaged RF exposure power level P limitAutomatically increase proportionally. For example, even if transmissions were below the first RF exposure limit or the second RF exposure limit in the past. The scaling factor can be less than or equal to the ratio of the occupational RF exposure limit to the public RF exposure limit, or the scaling factor can be a value specified or authorized by a regulatory agency or standards organization.

[0096] In other cases, the wireless device can maintain the maximum time-averaged RF exposure level P set according to the second RF exposure limit associated with the public environment limit , and increase the maximum allowable transmit power P according to a scaling factor (e.g., ), where the maximum allowable transmit power (P max_allowed ) is determined based on the time-averaged RF exposure assessment. The scaling factor can be less than or equal to the ratio of the occupational RF exposure limit to the public RF exposure limit, or the scaling factor can be a value specified or authorized by a regulatory agency or standards organization. For example, the wireless device can determine P max_allowed as the product of the scaling factor (e.g., excep ) and the maximum allowable transmit power (e.g., ). The wireless device can replace the actual transmit power report with a reduced transmit power report. For example, the wireless device can reduce the actual transmit power report according to a scaling factor (e.g., ). ).

[0097] In some aspects, the wireless device can apply different RF exposure limits based on a specific application / transmission scenario to determine the transmit power. For example, the wireless device can have dual authentication, where when the wireless device is used for certain applications (e.g., radio frequency identification (RFID) transmission or emergency communication, such as 9-1-1) in an occupational or controlled environment, the wireless device applies the (first) RF exposure limit associated with the occupational or controlled environment, and when the wireless device is used in a public environment, the wireless device applies the (second) RF exposure limit associated with the public environment.

[0098] For some aspects, the wireless device can avoid checking whether the transmission complies with the time-averaged RF exposure limit. The wireless device can temporarily avoid performing the time-averaged RF exposure assessment, e.g., as described herein with respect to Figure 5 and Figure 6 . The wireless device can avoid performing the time-averaged RF exposure assessment at least during the duration of the transmission.

[0099] In some aspects, in order to detect transmissions associated with an authorized exception, a wireless device may detect transmissions associated with an emergency. An emergency transmission may include a (video or voice) call or text to an emergency hotline (e.g., 9-1-1 in the United States). The wireless device may detect that a transmission is associated with an emergency based at least in part on at least one of the following: the recipient of the transmission, the destination phone number associated with the transmission, or the priority service associated with the transmission (e.g., a government-authorized priority service such as Wireless Priority Service). The wireless device may store or obtain information associated with the emergency transmission, where the information indicates which transmissions are eligible as emergency transmissions. The wireless device may examine the transmission to determine whether the transmission is eligible as an emergency transmission based on the information associated with the emergency transmission. For example, the wireless device may examine the phone number dialed for a call or text message, and when the number matches an emergency phone number (e.g., 9-1-1), the wireless device may apply a temporary exception to the time-averaged RF exposure limit for the emergency call, as described herein. The phone number or other exception identifier may be stored on the wireless device, e.g., in an initial configuration or based on information exchanged with (or obtained from) the radio access network (e.g., network-specific configuration). For example, when registering with the network, the network may provide the wireless device with a set of emergency contact information or authorized exceptions. In some examples, the network may respond to the received communication with an indicator (i.e., subsequent portions of the communication may be considered an authorized exception). In some examples, the authorized exception is only associated with one RAT (e.g., NTN) or with certain RATs. In some such examples, only certain communications on that RAT (e.g., 9-1-1 communications) may be an authorized exception. In other examples, as described herein, communications that meet certain criteria may be considered an authorized exception regardless of on which RAT such communications are transmitted.

[0100] The recipient of the transmission may include an identifier associated with the recipient, the recipient's address (e.g., Internet Protocol (IP) address, Media Access Control address, email address, etc.), the recipient's Uniform Resource Locator (URL), etc. In some cases where the emergency transmission is an Internet communication (e.g., an online chat service or video or voice over the Internet), the wireless device may detect the emergency transmission based on the recipient of the transmission. The recipient of the transmission may be associated with a particular online emergency service that may not be associated with a particular phone number. The wireless device may examine the header information of certain communication protocols, such as the Hypertext Transfer Protocol (HTTP) or Internet Protocol. For example, the wireless device may identify that the host of an HTTP request message (e.g., HTTP GET) matches the URL or IP address of an emergency service provider such as a police department or suicide prevention service. The wireless device may apply a temporary exception to the time-averaged RF exposure limit for the emergency transmission, as described herein.

[0101] The recipient or destination phone number of a transmission may correspond to at least one of the following: an emergency contact number, an emergency hotline, a police department, a fire department, a coast guard, border patrol, emergency medical care services, or ambulance services. The emergency hotline may include the 9-1-1 call center in the United States or Canada or a similar emergency call center in another country, such as 1-1-2 in France, Germany, or Italy (or other European countries), or emergency hotline numbers 1-2-0, 1-1-9, 1-1-0, and 1-2-2 in China. In some aspects, the emergency hotline may include, for example, a suicide prevention hotline or a poison control center. The wireless device may check the phone number dialed for a call, text, or other communication. When the dialed phone number matches an emergency phone number (e.g., a police department), the wireless device may apply a temporary exception to the time-averaged RF exposure limit for the emergency call, as described herein.

[0102] Priority services may provide priority to certain authorized users, such as first responders or government officials. Priority services may include the Wireless Priority Service in the United States or an equivalent service in another country. Authorized users may include, for example, federal, state, local, and tribal police departments, fire departments, public safety answering points or 9-1-1 call centers, emergency medical services, essential healthcare providers, or any other organization that uses telecommunications services for the maintenance of public health, safety, public order, or the enforcement of laws. An authorized user may receive call queue priority via the priority service by dialing a specific sequence (e.g., *272) before the destination phone number. The wireless device may check the phone number dialed for a call or text. When the dialed phone number begins with a priority service sequence (e.g., *272), the wireless device may apply a temporary exception to the time-averaged RF exposure limit for the emergency call, as described herein.

[0103] Although Figures 1 through 8 the examples depicted herein are described with respect to a UE performing various methods to facilitate understanding, aspects of the present disclosure may also be applied to other wireless devices that perform the methods described herein, such as wireless stations, access points, base stations, and / or customer premises equipment (CPE). Additionally, while the examples are described with respect to communication between a UE (or another wireless device) and a network entity, the UE or another wireless device may communicate with a device other than a network entity (e.g., another UE) or with another device in a user's home that is not a network entity. Similarly, while some aspects describe authorized exceptions in the context of an emergency transmission (such as a 9-1-1 call), it should be noted that the authorized exceptions may include any authorized transmission designated or authorized by a regulatory body or standards organization.

[0104] Example Communication Device

[0105] Figure 9 Illustrates a communication device 900 (e.g., UE 120) that may include various components (e.g., corresponding to component-plus-function components) configured to perform operations of the techniques disclosed herein, such as Figure 5 the illustrated operation 500, Figure 8 the illustrated operation, or other operations described herein for managing exceptions to RF exposure compliance. The communication device 900 includes a processing system 902 that may be coupled to a transceiver 908 (e.g., a transmitter and / or a receiver). The transceiver 908 is configured to transmit and receive signals for the communication device 900 via an antenna 910, such as the various signals described herein. The processing system 902 may be configured to perform the processing functions of the communication device 900, including processing signals received by and / or to be transmitted by the communication device 900.

[0106] The processing system 902 includes a processor 904 coupled to a computer-readable medium / memory 912 via a bus 906. In some aspects, the computer-readable medium / memory 912 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 904, cause the communication device 900 to perform Figure 5 the illustrated operation 500, Figure 8 the illustrated operation 800, or other operations for performing the various techniques discussed herein for managing exceptions to RF exposure compliance. In some aspects, the computer-readable medium / memory 912 stores code 914 for detection, code 916 for determination (or selection, adjustment, allowance, permission, setting, or replacement), code 918 for transmission (or output), or any combination thereof.

[0107] In some aspects, the processing system 902 has circuitry 920 configured to implement the code stored in the computer-readable medium / memory 912. In some aspects, the circuitry 920 is coupled to the processor 904 and / or the computer-readable medium / memory 912 via the bus 906. For example, the circuitry 920 includes circuitry 922 for detection, circuitry for determination (or selection, adjustment, allowance, permission, setting, or replacement), circuitry 926 for transmission (or output), or any combination thereof.

[0108] In some examples, the component for transmission or conveyance (or the component for output for transmission) may include Figure 2 the transceiver 254 and / or the antenna 252 of the illustrated UE 120 and / or Figure 9 the transceiver 908 and the antenna 910 of the communication device 900 in

[0109] In some cases, the device may not actually send, for example, signals and / or data, but may have an interface (a component for output) for outputting signals and / or data for transmission. For example, a processor may output signals and / or data for transmission to a radio frequency (RF) front end via a bus interface. Similarly, the device may not actually receive signals and / or data, but may have an interface (a component for acquisition) for acquiring signals and / or data received from another device. For example, a processor may acquire (or receive) signals and / or data from the RF front end via a bus interface for reception. In various aspects, the RF front end may include various components, including transmit and receive processors, transmit and receive MIMO processors, modulators, demodulators, etc., such as Figure 2 as depicted in the example of.

[0110] In some examples, the component for detection and / or the component for determination (or selection, adjustment, permission, licensing, setting, or replacement) may include various processing system components, such as: Figure 9 the processor 904 in; or Figure 2 aspects of the UE 120 depicted in, including a receive processor 258, a transmit processor 264, a TX MIMO processor 266, and / or a controller / processor 280.

[0111] Example Aspects

[0112] Specific implementation examples are described in the following numbered clauses:

[0113] Aspect 1: A method for wireless communication by a wireless device, the method comprising: detecting that a transmission is associated with an authorized exception for radio frequency (RF) exposure compliance; determining a permitted transmission power level for a time interval independent of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorized exception; and transmitting a signal in the time interval based on the permitted transmission power level.

[0114] Aspect 2: The method according to aspect 1, wherein determining the permitted transmission power level includes determining the permitted transmission power level to be equal to a power level associated with a transmission power limit corresponding to the time-averaged RF exposure limit.

[0115] Aspect 3: The method according to aspect 1, wherein determining the permitted transmission power level includes determining the permitted transmission power level to be the maximum instantaneous transmission power that the wireless device is capable of outputting.

[0116] Aspect 4: The method according to aspect 1, wherein determining the allowable transmit power level includes selecting the allowable transmit power level between a power level associated with a transmit power limit corresponding to the time-averaged RF exposure limit and the maximum instantaneous transmit power that the wireless device is capable of outputting.

[0117] Aspect 5: The method according to any one of aspects 1 to 4, wherein determining the allowable transmit power level includes allowing non-compliance with the time-averaged RF exposure limit during the time interval based on past RF exposure and the allowable transmit power level for the time interval.

[0118] Aspect 6: The method according to any one of aspects 1 to 5, the method further comprising avoiding performing a time-averaged RF exposure assessment at least during the duration of the transmission.

[0119] Aspect 7: The method according to any one of aspects 1 to 6, the method further comprising adjusting an RF exposure report or a transmit power report to comply with the time-averaged RF exposure limit.

[0120] Aspect 8: The method according to aspect 7, wherein determining the allowable transmit power level includes: determining an initial transmit power level based on an adjusted RF exposure report or an adjusted transmit power report that complies with the time-averaged RF exposure limit; and replacing the initial transmit power level with the allowable transmit power level.

[0121] Aspect 9: The method according to any one of aspects 7 to 8, wherein adjusting the RF exposure report or the transmit power report includes selecting the minimum value among a plurality of values as the RF exposure report or the transmit power report.

[0122] Aspect 10: The method according to aspect 9, wherein the plurality of values includes a current value of the RF exposure report or the transmit power report and an alternative value of the RF exposure report or the transmit power report.

[0123] Aspect 11: The method according to aspect 10, the method further comprising determining the alternative value as a value corresponding to a reserved power associated with the time-averaged RF exposure limit.

[0124] Aspect 12: The method according to any one of aspects 7 to 8, wherein adjusting the RF exposure report or the transmit power report includes setting the RF exposure report or the transmit power report to a specific value.

[0125] Aspect 13: The method according to aspect 12, wherein the specific value includes a first value indicating no past RF exposure or a second value corresponding to a reserved power level.

[0126] Aspect 14: The method according to any one of aspects 7 to 12, wherein the RF exposure report indicates the RF exposure generated by the wireless device in a running time window associated with the time-averaged RF exposure limit.

[0127] Aspect 15: The method according to any one of aspects 1 to 14, wherein determining the allowed transmit power level includes determining that the allowed transmit power level complies with a first RF exposure limit associated with a professional or controlled environment.

[0128] Aspect 16: The method according to aspect 15, wherein determining the allowed transmit power level includes allowing the allowed transmit power level not to comply with a second RF exposure limit associated with a public environment.

[0129] Aspect 17: The method according to aspect 15, wherein: determining that the allowed transmit power level complies with the first RF exposure limit includes determining the allowed transmit power level to be equal to a power level associated with a first transmit power limit corresponding to the time-averaged RF exposure limit; and the first transmit power limit is higher than a second transmit power limit corresponding to the time-averaged RF exposure limit.

[0130] Aspect 18: The method according to aspect 15, wherein: determining that the allowed transmit power level complies with the first RF exposure limit includes determining the allowed transmit power level to be equal to a first power level associated with a transmit power limit corresponding to the time-averaged RF exposure limit; and the first power level is higher than a second power level associated with a transmit power limit corresponding to a second RF exposure limit associated with a public environment.

[0131] Aspect 19: The method according to any one of aspects 1 to 18, wherein detecting that the transmission is associated with the authorization exception includes detecting that the transmission is associated with an emergency.

[0132] Aspect 20: The method according to aspect 19, wherein detecting that the transmission is associated with the emergency includes detecting that the transmission is associated with the emergency based at least in part on at least one of the following: the recipient of the transmission, the destination telephone number associated with the transmission, or the priority service associated with the transmission.

[0133] Aspect 21: The method according to aspect 20, wherein the recipient or the destination telephone number corresponds to at least one of the following: an emergency contact number, an emergency hotline, a police department, a fire department, a coast guard, border patrol, an emergency medical care service, or an ambulance service.

[0134] Aspect 22: The method according to aspect 20 or 21, wherein the prioritized service includes a wireless prioritized service.

[0135] Aspect 23: An apparatus, the apparatus comprising: one or more memories that collectively store executable instructions; and one or more processors coupled to the one or more memories, the one or more processors being collectively configured to execute the executable instructions and cause the apparatus to perform the method according to any one of aspects 1 to 22.

[0136] Aspect 24: An apparatus, the apparatus comprising components for performing the method according to any one of aspects 1 to 22.

[0137] Aspect 25: A non-transitory computer-readable medium, the non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors of a processing system, cause the processing system to perform the method according to any one of aspects 1 to 22.

[0138] Aspect 26: A computer program product embodied on a computer-readable storage medium, the computer program product comprising code for performing the method according to any one of aspects 1 to 22.

[0139] The techniques described herein can be used in various wireless communication technologies such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are often used interchangeably. CDMA networks may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers the IS-2000, IS-95, and IS-856 standards. TDMA networks may implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks may implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are UMTS versions that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). NR is an emerging wireless communication technology under development.

[0140] In 3GPP, the term "cell" can refer to the coverage area of a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In the NR system, the terms "cell" and BS, Next Generation NodeB (gNB or gNodeB), Access Point (AP), Distributed Unit (DU), carrier, or Transmission and Reception Point (TRP) can be used interchangeably. The BS can provide communication coverage for macro cells, picocells, femtocells, and / or other types of cells. A macro cell can cover a relatively large geographical area (e.g., with a radius of several kilometers) and can allow unrestricted access by UEs with a service subscription. A picocell can cover a relatively small geographical area and can allow unrestricted access by UEs with a service subscription. A femtocell can cover a relatively small geographical area (e.g., a home) and can allow restricted access by UEs associated with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs of users in a home, etc.). The BS for a macro cell can be referred to as a macro BS. The BS for a picocell can be called a pico BS. The BS for a femtocell can be referred to as a femto BS or a home BS.

[0141] A UE can also be referred to as a mobile station, terminal, access terminal, subscriber unit, station, customer premises equipment (CPE), cellular phone, smart phone, personal digital assistant (PDA), wireless modem, wireless device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, appliance, medical device or equipment, biometric sensor / device, wearable device (such as a smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.)), entertainment device (e.g., music device, video device, satellite radio, etc.), vehicle component or sensor, smart meter / sensor, industrial manufacturing equipment, global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. Some UEs can be considered Machine-Type Communication (MTC) devices or Evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node can provide a connection to or for a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs can be considered Internet of Things (IoT) devices, which can be NarrowBand IoT (NB-IoT) devices.

[0142] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication between some or all of the devices and equipment within the serving area or cell of that entity. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entities use the resources allocated by the scheduling entity. A base station is not the only entity that can be used as a scheduling entity. In some examples, a UE can be used as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs can utilize the resources scheduled by that UE for wireless communication. In some examples, a UE can be used as a scheduling entity in a peer-to-peer (P2P) network and / or a mesh network. In a mesh network example, in addition to communicating with the scheduling entity, UEs can also communicate directly with each other.

[0143] The methods disclosed herein include one or more steps or acts for implementing the method. The steps and / or acts of the method may be interchanged with each other without departing from the scope of the claims. In other words, unless a specific order of the steps or acts is specified, the order and / or use of the specific steps and / or acts may be modified without departing from the scope of the claims.

[0144] As used herein, the term "processor", "at least one processor", or "one or more processors" generally refers to a single processor configured to perform one or more operations or multiple processors configured to jointly perform one or more operations. In the case of multiple processors, the execution of one or more operations may be divided among different processors, but one processor may perform multiple operations and multiple processors may jointly perform a single operation. Similarly, the term "memory", "at least one memory", or "one or more memories" generally refers to a single memory configured to store data and / or instructions or multiple memories configured to jointly store data and / or instructions.

[0145] As used herein, the phrase referring to "at least one of" a list of items means any combination of those items (which includes a single member). For example, "at least one of a, b, or c" is intended to cover a, b, c, a - b, a - c, b - c, and a - b - c, as well as any combination with multiple identical elements (e.g., a - a, a - a - a, a - a - b, a - a - c, a - b - b, a - c - c, b - b, b - b - b, b - b - c, c - c, and c - c - c, or any other ordering of a, b, and c).

[0146] As used herein, the term "determine" encompasses a variety of actions. For example, "determine" can include calculating, computing, processing, deriving, generating, investigating, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, and the like. Additionally, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Further, "determine" can include parsing, selecting, picking, establishing, etc.

[0147] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, where the reference to an element in the singular is not intended to mean "one and only one" but rather "one or more" unless specifically stated otherwise. The term "some," unless specifically stated otherwise, means one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known or later will be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f), unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the phrase "step for."

[0148] The various operations of the foregoing method can be performed by any suitable component capable of performing the corresponding functions. The component can include various hardware and / or software components and / or modules, including but not limited to circuitry, an application specific integrated circuit (ASIC), or a processor. Generally speaking, where there are operations illustrated in the figures, those operations can have corresponding component-plus-function components with similar numbers.

[0149] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0150] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented utilizing a bus architecture. Depending on the particular application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits, including a processor, machine-readable media, and a bus interface. The bus interface may be used to connect a network adapter, etc. to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the physical (PHY) layer. In the case of a UE (see Figure 1 ) a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits, such as a timing source, peripherals, voltage regulators, power management circuits, and similar circuits, which are well known in the art and will not be described further herein. The processor may be implemented utilizing one or more general purpose processors and / or dedicated processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how best to implement the described functionality of the processing system depending on the particular application and overall design constraints imposed on the overall system.

[0151] If implemented in software, each function can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Software should be interpreted broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. A computer-readable medium includes both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. A processor may be responsible for managing the bus and general processing, including executing software modules stored on a machine-readable storage medium. The computer-readable storage medium may be coupled to the processor such that the processor can read information from and write information to the storage medium. In an alternative, the storage medium may be integral with the processor. By way of example, a machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium with instructions stored thereon that is separate from a wireless node, all of which may be accessed by the processor via a bus interface. Alternatively or in addition, a machine-readable medium or any portion thereof may be integrated into the processor, such as in the case of a cache and / or a general register file. By way of example, examples of a machine-readable medium may include RAM (Random Access Memory), flash memory, ROM (Read Only Memory), PROM (Programmable Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), registers, magnetic disks, optical disks, hard disk drives, or any other suitable storage medium, or any combination thereof. A machine-readable medium may be embodied in a computer program product.

[0152] Software modules may include a single instruction, or many instructions, and may be distributed over several different code segments, distributed among different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions that, when executed by an apparatus such as a processor, cause a processing system to perform various functions. Software modules may include a sending module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. By way of example, when a triggering event occurs, a software module may be loaded from a hard disk drive into RAM. During the execution of a software module, the processor may load some of the instructions into a cache to improve access speed. One or more cache lines may then be loaded into the general register file for the processor to execute. When referring to the functionality of a software module hereinafter, it will be understood that such functionality is implemented by the processor when executing instructions from the software module.

[0153] Moreover, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray ® disc, where disks typically reproduce data magnetically, while discs reproduce data optically with lasers. Thus, in some aspects, a computer-readable medium may include a non-transitory computer-readable medium (e.g., a tangible medium). Additionally, for other aspects, a computer-readable medium may include a transitory computer-readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

[0154] Accordingly, certain aspects may include a computer program product for performing the operations given herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded) thereon, the instructions (e.g., instructions for performing the operations described and Figure 8 illustrated herein) being executable by one or more processors to perform the operations described herein.

[0155] Furthermore, it should be understood that modules and / or other suitable components for performing the methods and techniques described herein may be downloaded and / or otherwise obtained by a user terminal and / or a base station, where applicable. For example, such devices may be coupled to a server to facilitate the transfer of components for performing the methods described herein. Alternatively, the various methods described herein may be provided via a storage component (e.g., RAM, ROM, or a physical storage medium such as a compact disc (CD) or a floppy disk) such that a user terminal and / or a base station may obtain the various methods when the storage component is coupled to or provided to the device. Additionally, any other suitable technique for providing the methods and techniques described herein to a device may be used.

[0156] It should be understood that the claims are not limited to the exact configurations and components illustrated above. Various modifications, variations, and alterations to the arrangements, operations, and details of the methods and apparatuses described above may be made without departing from the scope of the claims.

Claims

1. A method of wireless communication by a wireless device, the method comprising: Detecting that a transmission is associated with an authorization exception for radio frequency (RF) exposure compliance; Determining an allowed transmission power level for a time interval independently of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorization exception; and Transmitting a signal during the time interval based on the allowed transmission power level.

2. The method according to claim 1, wherein determining the allowed transmission power level comprises determining the allowed transmission power level to be equal to a power level associated with a transmission power limit corresponding to the time-averaged RF exposure limit.

3. The method according to claim 1, wherein determining the allowed transmission power level comprises determining the allowed transmission power level to be the maximum instantaneous transmission power that the wireless device is capable of outputting.

4. The method according to claim 1, wherein determining the allowed transmission power level comprises selecting the allowed transmission power level between a power level associated with a transmission power limit corresponding to the time-averaged RF exposure limit and the maximum instantaneous transmission power that the wireless device is capable of outputting.

5. The method according to claim 1, wherein determining the allowed transmission power level comprises allowing non-compliance with the time-averaged RF exposure limit during the time interval based on past RF exposure and the allowed transmission power level of the time interval.

6. The method according to claim 1, the method further comprising avoiding performing a time-averaged RF exposure assessment at least during the duration of the transmission.

7. The method according to claim 1, the method further comprising adjusting an RF exposure report or a transmission power report to comply with the time-averaged RF exposure limit.

8. The method according to claim 7, wherein determining the allowed transmission power level comprises: Determining an initial transmission power level based on an adjusted RF exposure report or an adjusted transmission power report that complies with the time-averaged RF exposure limit; And Replacing the initial transmission power level with the allowed transmission power level.

9. The method according to claim 7, wherein adjusting the RF exposure report or the transmission power report comprises selecting the minimum value among a plurality of values as the RF exposure report or the transmission power report.

10. The method according to claim 9, wherein the plurality of values comprises a current value of the RF exposure report or the transmission power report and an alternative value of the RF exposure report or the transmission power report.

11. The method according to claim 10, the method further comprising determining the alternative value to be a value corresponding to reserved power associated with the time-averaged RF exposure limit.

12. The method according to claim 7, wherein adjusting the RF exposure report or the transmission power report comprises setting the RF exposure report or the transmission power report to a specific value.

13. The method according to claim 12, wherein the specific value comprises a first value indicating no past RF exposure or a second value corresponding to a reserved power level.

14. The method according to claim 7, wherein the RF exposure report indicates the RF exposure generated by the wireless device in an operating time window associated with the time-averaged RF exposure limit.

15. The method according to claim 1, wherein determining the allowable transmit power level includes determining that the allowable transmit power level complies with a first RF exposure limit associated with a professional or controlled environment.

16. The method according to claim 15, wherein determining the allowable transmit power level includes allowing the allowable transmit power level not to comply with a second RF exposure limit associated with a public environment.

17. The method according to claim 15, wherein: determining that the allowable transmit power level complies with the first RF exposure limit includes determining the allowable transmit power level to be equal to a power level associated with a first transmit power limit corresponding to the time-averaged RF exposure limit; and the first transmit power limit is higher than a second transmit power limit corresponding to the time-averaged RF exposure limit.

18. The method according to claim 15, wherein: determining that the allowable transmit power level complies with the first RF exposure limit includes determining the allowable transmit power level to be equal to a first power level associated with a transmit power limit corresponding to the time-averaged RF exposure limit; and the first power level is higher than a second power level associated with a transmit power limit corresponding to a second RF exposure limit associated with a public environment.

19. The method according to claim 1, wherein detecting that the transmission is associated with the authorization exception includes detecting that the transmission is associated with an emergency.

20. The method according to claim 19, wherein detecting that the transmission is associated with the emergency includes detecting that the transmission is associated with the emergency based at least in part on at least one of the following: the recipient of the transmission, the destination telephone number associated with the transmission, or the priority service associated with the transmission.

21. The method according to claim 20, wherein the recipient or the destination telephone number corresponds to at least one of the following: an emergency contact number, an emergency hotline, a police department, a fire department, a coast guard, border patrol, an emergency medical care service, or an ambulance service.

22. The method according to claim 20, wherein the priority service includes a wireless priority service.

23. A device for wireless communication, the device comprising: one or more memories that jointly store executable instructions; and one or more processors coupled to the one or more memories, the one or more processors being jointly configured to execute the executable instructions to cause the device to: detect that a transmission is associated with an authorization exception for radio frequency (RF) exposure compliance; determine an allowable transmit power level for a time interval independently of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorization exception; and Transmit a signal based on the allowed transmission power level during the time interval.

24. The apparatus according to claim 23, wherein, in order to determine the allowed transmission power level, the one or more processors are jointly configured to execute the executable instructions to cause the apparatus to determine the allowed transmission power level to be equal to a power level associated with a transmission power limit corresponding to the time-averaged RF exposure limit.

25. The apparatus according to claim 23, wherein, in order to determine the allowed transmission power level, the one or more processors are jointly configured to execute the executable instructions to cause the apparatus to determine the allowed transmission power level to be the maximum instantaneous transmission power that the apparatus can output.

26. The apparatus according to claim 23, wherein, in order to determine the allowed transmission power level, the one or more processors are jointly configured to execute the executable instructions to cause the apparatus to select the allowed transmission power level between a power level associated with a transmission power limit corresponding to the time-averaged RF exposure limit and the maximum instantaneous transmission power that the apparatus can output.

27. The apparatus according to claim 23, wherein, in order to determine the allowed transmission power level, the one or more processors are jointly configured to execute the executable instructions to cause the apparatus to allow non-compliance with the time-averaged RF exposure limit during the time interval based on past RF exposure and the allowed transmission power level of the time interval.

28. The apparatus according to claim 23, wherein, in order to determine the allowed transmission power level, the one or more processors are jointly configured to execute the executable instructions to cause the apparatus to determine that the allowed transmission power level complies with a first RF exposure limit associated with a professional or controlled environment.

29. An apparatus for wireless communication, the apparatus comprising: means for detecting components associated with an authorization exception for radio frequency (RF) exposure compliance; means for determining an allowed transmission power level for a time interval independently of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorization exception; and and means for transmitting a signal based on the allowed transmission power level during the time interval.

30. A non-transitory computer-readable medium storing instructions that, when executed by an apparatus, cause the apparatus to perform operations including the following: detect that a transmission is associated with an authorization exception for radio frequency (RF) exposure compliance; determine an allowed transmission power level for a time interval independently of a time-averaged RF exposure limit in response to detecting that the transmission is associated with the authorization exception; and transmit a signal based on the allowed transmission power level during the time interval.

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