Radio frequency exposure compliance

Abstract

In certain aspects, a method for wireless communication includes transmitting a first transmission with a first transmitter capable of operating according to a first radio technology, and transmitting a second transmission with a second transmitter after completion of the first transmission, the second transmitter capable of operating according to a second radio technology. The method may also include delaying transmission of the second transmission by a predetermined latency after completion of the first transmission, if the first radio technology is a radio frequency (RF) exposure time averaging technology and the second radio technology is a non-time averaging RF exposure technology. The method may also include, if the first radio technology is a non-time-averaged RF exposure technology and the second radio technology is a time-averaged RF exposure technology, transmitting the second transmission at a limited peak power over a predetermined period of time for at least a portion of the second transmission.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to pending U.S. non-provisional application No. 17 / 952,166, filed on September 23, 2022, which is assigned to the assignee of the present application and is hereby expressly incorporated herein by reference as if fully set forth below and for all applicable purposes. background Technical Field

[0004] Aspects of the present disclosure relate generally to wireless devices and, more particularly, to accounting for and limiting radio frequency (RF) exposure from wireless devices. Background Art

[0005] Modern wireless devices (e.g., cellular phones) are often required to limit user exposure to RF radiation according to radio frequency (RF) exposure limits set by various regulations. In order to ensure that wireless devices comply with RF exposure limits, technologies have been developed that enable wireless devices to assess RF exposure from the wireless device in real time and adjust the transmit power of the wireless device accordingly to comply with the RF exposure limits. Summary of the invention

[0006] The following content presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is neither intended to identify the key or important elements of all embodiments, nor to describe the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a preface to the more detailed description presented subsequently.

[0007] A first aspect relates to a wireless device. The wireless device includes a plurality of transmitters, the plurality of transmitters including a first transmitter and a second transmitter, wherein each of the plurality of transmitters is configured to transmit a signal according to a corresponding radio technology in a plurality of radio technologies, and wherein the plurality of radio technologies include a first radio technology with a time-averaged radio frequency (RF) exposure technology and a second radio technology with a non-time-averaged RF exposure technology. The wireless device also includes a processor coupled to the plurality of transmitters. The processor is configured to cause the first transmitter to transmit a first transmission, and to cause the second transmitter to transmit a second transmission after the first transmission is completed. The processor is also configured to: when the first transmitter is capable of operating according to the first radio technology and the second transmitter is capable of operating according to the second radio technology, cause the second transmitter to transmit the second transmission after a predetermined waiting time after the first transmission is completed; and when the first transmitter is capable of operating according to the second radio technology and the second transmitter is capable of operating according to the first radio technology, cause the second transmitter to transmit at least a portion of the second transmission with a limited peak power within a predetermined time period after the first transmission is completed.

[0008] A second aspect relates to a method for wireless communication. The method includes sending a first transmission using a first transmitter capable of operating according to a first radio technology, and sending a second transmission using a second transmitter after the first transmission is completed, the second transmitter being capable of operating according to a second radio technology. The method also includes: delaying the transmission of the second transmission by a predetermined waiting time after the first transmission is completed, when the first radio technology is a radio frequency (RF) exposure time averaging technology and the second radio technology is a non-time-averaged RF exposure technology; and sending the second transmission at a limited peak power within a predetermined time period for at least a portion of the second transmission, when the first radio technology is a non-time-averaged RF exposure technology and the second radio technology is a time-averaged RF exposure technology.

[0009] A third aspect relates to a wireless device. The wireless device includes a plurality of transmitters, wherein each of the plurality of transmitters is configured to transmit a signal according to a corresponding radio technology among a plurality of radio technologies, and wherein the plurality of radio technologies include a time-averaged radio frequency (RF) exposure technology and a non-time-averaged RF exposure technology. The wireless device also includes a processor coupled to the plurality of transmitters. The processor is configured to: during a period in which the time-averaged RF exposure technology is active on a transmission time window, set a transmission level limit of the non-time-averaged RF exposure technology to a predetermined backoff level; determine an RF exposure profile of the non-time-averaged RF exposure technology on the transmission time window; and control the transmission of transmitters among the transmitters that are capable of operating according to the time-averaged RF exposure technology based on the RF exposure profile.

[0010] A fourth aspect relates to a method for wireless communication. The method includes: setting a transmission level limit of a non-time-averaged RF exposure technique to a predetermined back-off level during a period in which the time-averaged RF exposure technique is active on a transmission time window; determining an RF exposure profile of the non-time-averaged RF exposure technique on the transmission time window; and controlling transmission of a transmitter capable of operating according to the time-averaged RF exposure technique based on the derived RF exposure profile.

[0011] To achieve the aforementioned and related purposes, one or more embodiments include the features fully described below and specifically pointed out in the claims. The following description and the accompanying illustrations set forth in detail certain illustrative aspects of the one or more embodiments. However, these aspects are merely indicative of several of the various ways in which the principles of the various embodiments may be employed, and the embodiments are intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 An example of a wireless device is shown in which aspects of the present disclosure may be implemented.

[0013] Figure 2A A graph of SAR exposure over time for radio access technologies is shown.

[0014] Figure 2B A graph showing SAR exposure to one or the other of two radio access technologies at a specific time in a system where simultaneous transmissions from both radio access technologies are excluded to control RF exposure.

[0015] Figure 2C A graph showing SAR exposure of a combination of at least two radio access technologies at a specific time in a system that excludes simultaneous transmissions from the two radio access technologies to control RF exposure.

[0016] Figure 2D An example of determining a wait time between completion of a transmission using an RF exposure time averaging technique and a transmission using an RF exposure non-time averaging technique in accordance with certain aspects is shown.

[0017] Figure 3 A flow chart illustrating a method for controlling transmission of time-averaged and non-time-averaged RF exposure techniques in accordance with certain aspects of the present disclosure is illustrated.

[0018] Figure 4 A flow chart illustrating another method for controlling transmission of time-averaged and non-time-averaged RF exposure techniques in accordance with certain aspects of the present disclosure.

[0019] Figure 5 A flow chart illustrating yet another method for controlling transmission of time-averaged and non-time-averaged RF exposure techniques in accordance with certain aspects of the present disclosure.

[0020] Fig. 6A An example normalized visual representation of WLAN exposure taking into account WWAN transmissions is shown in accordance with certain aspects of the present disclosure.

[0021] Figure 6B A visual representation of an example WLAN exposure taking into account WWAN transmissions and different WLAN transmission frequencies is shown in accordance with certain aspects of the present disclosure.

[0022] Figure 7 is an exemplary block diagram of an apparatus for exercising control of a transmitter in a wireless device.

[0023] Figure 8 is a flow chart illustrating an exemplary method for wireless communication according to aspects of the present disclosure.

[0024] Fig. 9 is a flow chart illustrating an example method for controlling transmissions in a wireless device to ensure compliance with RF exposure limits in accordance with certain aspects of the present disclosure. DETAILED DESCRIPTION

[0025] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. In order to provide a comprehensive understanding of the various concepts, the specific embodiments include specific details. However, it is apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, in order to avoid obscuring such concepts, well-known structures and components are shown in block diagram form.

[0026] Figure 1 An example of a wireless device 100 is shown in which aspects of the disclosure described herein may be implemented. The wireless device 100 may include a mobile wireless device (eg, a cellular phone), a laptop, a wireless access point, or some other wireless device.

[0027] Specifically, the wireless device 100 includes a processor 110 and a memory 115 coupled to the processor 110. The memory 115 may store instructions that, when executed by the processor 110, cause the processor 110 to perform one or more of the operations described herein. The memory 115 may include a random access memory (RAM), a read-only memory (ROM), a flash memory such as a NAND storage device, or any combination thereof. The processor 110 may be implemented using a general purpose processor, a digital signal processor (DSP), a baseband modem, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate logic, discrete hardware components, or any combination thereof configured to perform one or more of the operations described herein.

[0028] The wireless device 100 also includes a plurality of transmitters 120-1 to 120-N, a plurality of antennas 122-1 to 122-N, and a bus 140 coupling the processor 110 and the plurality of transmitters 120-1 to 120-N. Figure 1 In the example shown, the output of each transmitter of transmitters 120-1 to 120-N is coupled to the corresponding antenna of antennas 122-1 to 122-N and is configured to output the corresponding RF signal to the corresponding antenna of antennas 122-1 to 122-N for transmission. Antennas 122-1 to 122-N can be arranged in a one-dimensional array, a two-dimensional array, or a three-dimensional array. Each antenna of antennas 122-1 to 122-N can be implemented using a patch antenna or another type of antenna. Transmitters 120-1 to 120-N may also be referred to as a transmission chain or another term, and antennas 122-1 to 122-N may also be referred to as antenna elements.

[0029] In some aspects, transmitters 120-1 to 120-N are configured to transmit signals via respective antennas 122-1 to 122-N using one or more radio access technologies, including but not limited to third generation (3G) technologies (e.g., CDMA), fourth generation (4G) technologies (also known as long term evolution (LTE)), fifth generation (5G) technologies such as 5G NR, one or more technologies based on one or more IEEE 802.11 protocols (e.g., IEEE 802.11ac, IEEE 802.11n, IEEE 802.11ad, IEEE802.11ax, IEEE802.11ay, IEEE 802.15 protocols, IEEE 802.16 protocols, etc.), and / or one or more other technologies. In some aspects, wireless device 100 transmits data to another wireless device (not shown) in a multiple input multiple output (MIMO) transmit mode to increase throughput between wireless device 100 and the other wireless device. In the MIMO transmit mode, the transmitters 120-1 to 120-N transmit multiple signals via antennas 122-1 to 122-N, wherein each antenna in the transmitters 120-1 to 120-N transmits a corresponding signal in the multiple signals via a corresponding antenna 122-1 to 122-N. The transmitters 120-1 to 120-N may transmit the multiple signals at the same frequency. The MIMO transmit mode may employ spatial multiplexing, diversity coding, precoding, beamforming, multi-user MIMO, and the like. In some aspects, the transmitters 120-1 to 120-N may be configured to transmit signals via antennas 122-1 to 122-N using beamforming to direct the transmission toward another wireless device (e.g., in the MIMO transmit mode). In these aspects, the transmission may be electrically steered by adjusting the relative phase and / or amplitude of the transmit signals of the different antennas 122-1 to 122-N.

[0030] The processor 110 interfaces with the transmitters 120-1 to 120-N via the bus 140. In some aspects, the bus 140 includes a plurality of signal lines 142-1 to 142-N between the processor 110 and the transmitters 120-1 to 120-N, wherein each of the signal lines 142-1 to 142-N is coupled between the processor 110 and the input of a corresponding transmitter in the transmitters 120-1 to 120-N. In order to transmit data, the processor 110 may process the data into one or more signals (e.g., baseband signals or intermediate frequency (IF) signals). The processing performed by the processor 110 may include decoding the data and modulating the decoded data (e.g., using any of a variety of different modulation schemes (including BPSK, QPSK, QAM, etc.)). For the example of MIMO, the processor 110 may also perform MIMO pre-coding, spatial processing, etc. The processor 110 outputs the one or more signals to the transmitters 120-1 to 120-N via the bus 140. In one example, the one or more signals include a plurality of signals, wherein the processor 110 outputs each of the plurality of signals to a corresponding transmitter among the transmitters 120-1 to 120-N via corresponding signal lines 142-1 to 142-N. In this example, each of the plurality of signals may include a corresponding data stream among a plurality of data streams. In another example, the processor 110 may output the same signal to the transmitters 120-1 to 120-N or a subset of the transmitters 120-1 to 120-N.

[0031] Each of the transmitters 120-1 to 120-N is configured to process a corresponding signal from the processor 110 into a corresponding RF signal for transmission via the corresponding antennas 122-1 to 122-N. The processing performed by each of the transmitters 120-1 to 120-N may include up-conversion, power amplification, etc. For the example of MIMO, the RF signals output by the transmitters 120-1 to 120-N may have the same transmission frequency.

[0032] In some aspects, the processor 110 may set the transmit power level of each of the antennas 122-1 to 122-N by correspondingly setting the gain of the amplifiers in the corresponding transmitters 120-1 to 120-N. The processor 110 may set the gain of each of the amplifiers using a corresponding gain control signal. In this example, the processor 110 may independently set the transmit power level of the antennas 122-1 to 122-N by setting the gain of the corresponding amplifiers using the corresponding gain control signals.

[0033] In another example, the processor 110 outputs a plurality of signals to the transmitters 120-1 to 120-N, wherein each of the plurality of signals corresponds to a corresponding antenna among the antennas 122-1 to 122-N. In this example, the processor 110 sets the transmit power level of each of the antennas by setting the amplitude of the corresponding signal accordingly. It should be understood that the present disclosure is not limited to the above examples, and the processor 110 may employ other techniques to set the transmit power level of the antennas 122-1 to 122-N.

[0034] In certain aspects, the processor 110 may use an open power control loop and / or a closed power control loop to set the transmit power levels of the antennas 122-1 to 122-N. For the example of an open power control loop, the wireless device 100 may receive a pilot signal from another wireless device (not shown) via a receiver (not shown). In this example, the processor 110 estimates the channel conditions between the wireless device 100 and the other wireless device based on the received pilot signal, and sets the transmit power levels of the antennas 122-1 to 122-N based on the estimated channel conditions. For the example of a closed power control loop, the wireless device 100 receives a feedback signal from the other wireless device via a receiver (not shown), wherein the feedback signal indicates the channel conditions between the wireless device 100 and the other wireless device. In this example, the processor 110 sets the transmit power levels of the antennas 122-1 to 122-N based on the indicated channel conditions.

[0035] In addition, the processor 110 can set the transmit power levels of the antennas 122-1 to 122-N to keep the RF exposure from the wireless device 100 within the RF exposure limits set by the regulator (e.g., FCC), as will be discussed further below. In this case, the transmit power levels of the antennas 122-1 to 122-N are constrained by the RF exposure limits.

[0036] In some wireless devices such as 5G NR devices, it is possible that the device (e.g., device 100) may simultaneously transmit at frequencies less than 6 GHz (i.e., below 6 GHz) (which may require an RF exposure assessment in terms of specific absorption rate (i.e., SAR in W / kg)) and at frequencies greater than 6 GHz (i.e., mmWave) (which may require an RF exposure assessment in terms of power density (i.e., in terms of mW / cm 2The exposure is evaluated in terms of "PD" (units of power). Due to regulations on simultaneous exposure, this limits the maximum transmit (Tx) power of wireless devices for both sub-6 GHz and greater than 6 GHz bands. In order to maximize Tx power, it is known to utilize real-time RF exposure algorithms that determine the time-averaged SAR and time-averaged PD exposure over a given time window in real time to determine future sub-6 GHz and mmWave antenna power limits in real time using pre-stored SAR values ​​and PD values ​​and / or distributions.

[0037] To assess RF exposure of transmissions from the wireless device 100, the wireless device 100 may include a plurality of SAR distributions (also referred to as SAR maps) stored in the memory 115. Each of these SAR distributions may correspond to a respective transmission scenario of a plurality of transmission scenarios supported by the wireless device 100. The transmission scenarios may correspond to various combinations of antennas 122-1 through 122-N, frequency bands, channels, and / or body locations, as discussed further below.

[0038] The SAR distribution for each transmission scenario may be generated based on measurements (e.g., electric field measurements) performed in a test lab using a human body model. After the SAR distribution is generated, the SAR distribution is stored in the memory 115 to enable the processor 110 to evaluate the RF exposure in real time, as discussed further below. Each SAR distribution includes a set of SAR values, where each SAR value may correspond to a different location (e.g., on a human body model). Each SAR value may include a SAR value averaged over a mass of 1 g or 10 g at the corresponding location.

[0039] As discussed previously, the wireless device 100 may support multiple transmission scenarios. In some aspects, the transmission scenario may be specified by a parameter set. The parameter set may include one or more of the following: antenna parameters indicating one or more antennas (i.e., active antennas) used for transmission, band parameters indicating one or more frequency bands (i.e., active bands) used for transmission, channel parameters indicating one or more channels (i.e., active channels) used for transmission, body position parameters indicating the position of the wireless device 100 relative to the user's body position (head, torso, away from the body, etc.), the distance of human tissue from the device, and / or other parameters. In the case where the wireless device 100 supports a large number of transmission scenarios, it may be very time-consuming and expensive to perform measurements for each transmission scenario in a test environment (e.g., a test laboratory). In order to reduce the test time, measurements may be performed on a subset of transmission scenarios to generate a SAR distribution for the subset of transmission scenarios. In this example, the SAR distribution of each transmission scenario in the remaining transmission scenarios may be generated by combining two or more SAR distributions in the SAR distribution of the subset of transmission scenarios. For example, SAR measurement may be performed for each of the antennas 122-1 to 122-N to generate a SAR distribution for each of the antennas 122-1 to 122-N. In this example, a SAR distribution for a transmission scenario in which two or more of the antennas 122-1 to 122-N are active may be generated by combining the SAR distributions of the two or more active antennas.

[0040] In another example, SAR measurements may be performed for each of the plurality of frequency bands to generate a SAR distribution for each of the plurality of frequency bands. In this example, a SAR distribution for a transmission scenario in which two or more frequency bands are active may be generated by combining the SAR distributions of the two or more active frequency bands.

[0041] It should be understood that assessing RF exposure is not limited to the example of SAR distribution. For example, in some implementations, a single SAR value may be used instead of a SAR distribution including multiple SAR values ​​to assess RF exposure. In this example, a SAR value may be measured for each of one or more of the exemplary scenarios discussed above, and the SAR value may be stored in the memory 115 to enable the wireless device 100 to assess RF exposure for various scenarios, as further discussed below. It should also be understood that the wireless device 100 may also assess RF exposure based on power density (PD) and / or a combination of SAR and PD. Therefore, it should be understood that the present disclosure is not limited to a particular type of RF exposure measurement, and aspects of the present disclosure are generally applicable to other types of RF exposure measurements.

[0042] In addition, the wireless device may need to be compliant for the total time-averaged RF exposure from transmitters of all radio access technologies in the device (e.g., WWAN, 5GNR, WLAN, and BT transmitters). If any of these technologies are not part of the time-averaged, such as WLAN (e.g., WLAN third-party chips), the traditional approach to achieving compliance is to statically split or divide the total RF exposure margin into the non-time-averaged technology (e.g., WLAN) and all other radio access technologies, meaning that none of these technologies (e.g., 5G NR) can exceed that portion of the limit, thereby always providing less power for transmission regardless of, for example, the current level of WLAN exposure.

[0043] Further with respect to the traditional approach to RF exposure compliance, the time-averaged RF exposure of some technologies (such as WWAN) and the RF exposure from the remaining technologies (such as WLAN) should be less than or equal to the limit in total. For this particular example, the approach can be expressed by the following relationship: Time-averaged RF exposure of WWAN (+5G NR) + RF exposure from WLAN ≤ 100%. Compliance can then be achieved by splitting the margin into "A" and "B" parts. Specifically, this can be determined based on the following conditions:

[0044] Time-averaged RF exposure for WWAN (e.g., “5G NR”) ≤ A

[0045] RF exposure from WLAN ≤ B

[0046] A+B≤100%

[0047] A disadvantage of this approach is that the margin is reduced to a set value "A" or "B" that is less than the total margin (ie, 100%) regardless of whether a particular radio technology is on or off.

[0048] Another alternative approach to attempting to comply with RF exposure limits is to prevent simultaneous transmissions by time-averaging technologies (e.g., WWAN) and non-time-averaging technologies (e.g., WLAN). By limiting simultaneous transmissions, one could theoretically provide 100% margin for each individual radio technology (e.g., WWAN and WLAN), but this does not guarantee time-averaging compliance, as will be discussed below with respect to Figures 2A to 2C Explained.

[0049] Figure 2AA graph illustrating SAR levels of different technologies over time when utilizing an approach to prevent simultaneous transmission of time-averaged technologies (e.g., WWAN) and non-time-averaged technologies (e.g., WLAN) is shown. The theoretical total RF exposure compliance without regard to a particular radio technology is shown at 202, where a SAR limit 204 is transmitted for one time window (e.g., 100 seconds) specified by the regulator for average RF exposure. Thus, the total available SAR margin is illustrated by a time window 206.

[0050] Figure 2B A diagram illustrating two different scenarios 208 and 210 is illustrated, wherein the method of limiting simultaneous transmissions is used to make transmissions comply with exposure limits, which method provides Figure 2A In scenario 208, a time-averaged technology such as a WWAN technology transmits at a level 212 above the SAR limit 204, but continuously below Figure 2A In the example, the call is placed at time t 1 The total SAR exposure time window 214 is equal to Figure 2A Note that because the radio technology is time-averaged, such that the transmission time is reduced in scenario 208, the total SAR exposure (i.e., window 214) when averaged over a time window (e.g., 100 seconds) is within the total limit (e.g., Figure 2A Within the window 206 in FIG. 2 , the SAR level 212 may exceed the SAR limit 204.

[0051] In another RF exposure compliance scenario 210, assume that a non-time-averaged technology such as WLAN transmits at level 216 over a 100 second period under SAR limit 204. Since no other technology is transmitting simultaneously during this time, time window 218 is equivalent to Figure 2A . In the present disclosure, the SAR limit (or 100% RF exposure margin) may be equal to the regulatory SAR limit set by a regulatory body (e.g., the Federal Communications Commission). In some aspects, the SAR limit may be set to a lower value than the regulatory SAR limit to account for device uncertainty and / or to reserve sufficient SAR margin to comply with the total RF exposure in simultaneous technologies with other transmitters (e.g., Bluetooth to comply with the total RF exposure compliance in WWAN+Bluetooth and WLAN+Bluetooth scenarios). Therefore, in the present disclosure, the SAR limit may be equal to or lower than the regulatory SAR limit.

[0052] Figure 2CA scenario 240 is illustrated in which two technologies (i.e., a time-averaged technology and a non-time-averaged technology) transmit at different times in an attempt to comply with RF exposure limits. However, in scenario 240, although the time-averaged RF exposure of the first time-averaged technology (such as WWAN) is less than or equal to 100% and the RF exposure of the second non-time-averaged technology (such as WLAN) is also less than or equal to 100%, the RF exposure of the system will not comply with the RF exposure limits. As seen at 242, the time-averaged technology, such as the WWAN technology, transmits at a level 244 that is above the SAR limit 204, but is continuously less than Figure 2A In this example, the WWAN call is terminated at time t 1 The interruption is such that, through time averaging of the WWAN technology, the total SAR exposure time window 246 is less than 100% of the total RF exposure limit.

[0053] At time t 1 After the transmission using the first technology (ie, WWAN) at t is terminated, the transmission using the non-time averaging technology (eg, WLAN) begins. In the example shown at 248, under the SAR limit 204 from t 1 The WLAN transmission 250 for 100 seconds produces an RF exposure time window 252. The time averaged WWAN exposure shown at 242 and the WLAN exposure shown at 248 are each less than Figure 2A However, the sum of the RF exposures (WLAN + WWAN) is greater than 100% over the 100 second period, and thus the system as a whole does not comply with the RF exposure limits.

[0054] In view of the above methods, further methods and apparatus are disclosed herein to provide dynamic adjustment of Tx power limits for transmissions of non-time averaging technologies to optimize RF exposure margin and obtain greater RF exposure margin for active transmissions of time averaging technologies (e.g., WWAN, 5G NR, etc.) to improve overall device performance.

[0055] According to some aspects, in a system where simultaneous transmission of a time-averaged RF exposure technology (e.g., WWAN) and a non-time-averaged RF exposure technology (e.g., WLAN) is not allowed, a time delay may be added before switching between the time-averaged technology and the non-time-averaged technology. For example, if the WWAN technology is turned off, the WLAN technology will not be turned on immediately, but will be controlled to wait to turn on after the expiration of a predetermined time delay. According to other aspects, the predetermined time delay may be calculated based on the amount or level of past exposure from the time-averaged technology (e.g., WWAN). For Figure 2C In the example illustrated in Figure 2, this would be equal to 1The delay between the transmission of non-time-averaged RF exposure technology (e.g., WLAN) and 100 seconds (i.e., equal to 100 seconds – t 1 The time delay may be calculated based on an RF exposure margin sent by a previous time-averaged RF exposure technique (e.g., WWAN). As used herein, a time-averaged RF exposure technique is a radio technology that uses time averaging over a time window to ensure that the RF exposure from the radio technology complies with predefined RF exposure limits.

[0056] Figure 3 A flow chart illustrating a method 300 for controlling transmission of time-averaged and non-time-averaged RF exposure techniques in a wireless device (e.g., device 100) according to an aspect is illustrated. In method 300, a first transmitter (e.g., 120-1) transmits using a time-averaged RF exposure technique (e.g., WWAN), as shown at block 302. While the time-averaged RF exposure technique is transmitting, a check is performed to determine whether the first transmitter and the companion technology are turned off, as indicated by decision block 304. If the first transmitter is not turned off (i.e., the first transmitter is still transmitting using the time-averaged RF exposure technique (e.g., WWAN)), method 300 may loop back to block 302 until the first transmitter is turned off.

[0057] If at decision block 304 the first transmitter is turned off (i.e., the first transmitter stops transmitting using the time-averaged RF exposure technique (e.g., WWAN)), flow may then proceed to optional block 306 where a predetermined time period for waiting is calculated based on the amount of exposure from the time-averaged RF technique from the previous transmission at block 302. In other aspects, a set predetermined time period may be utilized rather than calculating a value at block 306.

[0058] Regardless of whether the predetermined time period is calculated in block 306 or a set predetermined time period is utilized, flow proceeds to block 308 where the wireless device waits or delays transmission of the next technique (such as a non-time-averaged RF exposure technique) for the duration of the predetermined time period, thereby more likely ensuring that RF exposure limits will not be exceeded, such as in Figure 2C After the predetermined time period has elapsed in block 308, flow proceeds to block 310 where the second transmitter (eg, 120-2) transmits using a non-time-averaged RF exposure technique (eg, WLAN).

[0059] As discussed above, in optional block 306, a predetermined time period for waiting may be calculated. In one example, if a transmitter using a time-averaged RF technique (e.g., a WWAN) at block 302 Figure 2C, then for RF exposure compliance, the wireless device may calculate a predetermined time window minus t1 (e.g., 100 seconds - t1), where t1 is the amount of time that the transmitter using the time averaging RF technique transmits at level 244. In another example, at block 302, a transmitter using the time averaging technique (e.g., WWAN) transmits at power level 207 (corresponding to Figure 2C 204) or less. In this example, a transmitter using a non-time averaging RF technology (e.g., WLAN) does not need to wait until after time t1 to transmit because the transmitter using the non-time averaging RF technology can transmit at or below the power level 207 and still be compliant.

[0060] Figure 2D Another example for determining a waiting period (ie, a time period for waiting) in accordance with certain aspects is illustrated. Figure 2D A first graph of RF exposure 260 is shown including an RF exposure profile 262 for a time averaging technique (eg, WWAN) and an RF exposure profile 266 for a non-time averaging technique (eg, WWAN). In this example, the transmission of the time averaging technique ends at time t1.

[0061] In this example, the processor 110 may determine a wait time at approximately time t1, wherein the processor 110 may determine the RF exposure profile 266 of the time averaging technique based on previous transmit power levels of the time averaging technique known to the processor 110. For example, the previous transmit power levels may be stored in a memory and accessed by the processor 110. Furthermore, in this example, the processor 110 may assume that the non-time averaging technique transmits at a power level corresponding to the RF exposure limit (e.g., the SAR limit 204).

[0062] In this example, the processor 110 may select a wait time (e.g., a wait time that is less than the time window −t1) and calculate an RF exposure profile over the time window (e.g., set by a regulator). The processor 110 may then compare the RF exposure profile over the time window with the total RF exposure margin (e.g., 206) and determine whether to use the wait time in box 308 based on the comparison (e.g., use the wait time if the RF exposure profile is equal to or less than the total RF exposure margin (e.g., 206)). In this example, a portion of the RF exposure profile includes an RF exposure profile from a time averaging technique and an RF exposure profile from a non-time averaging technique with a wait time between them. In some aspects, the processor 110 may shift the time window 268 to multiple time locations. In this regard, Figure 2DAn example 270 of one of the shifts in which the time window 268 is shifted to the right is shown. In this example, the processor 110 may calculate the RF exposure profile on the time window 268 for each of the shifts, compare each of the RF exposure profiles with the total RF exposure margin (e.g., 206), and determine whether to use a wait time in block 308 based on the comparison (e.g., use a wait time if each of the RF exposure profiles is equal to or less than the total RF exposure profile). If one or more of the calculated RF exposure profiles exceeds the total RF exposure margin, the processor 110 may select another wait time (e.g., a longer wait time) and repeat the above process using the other wait time.

[0063] In yet other aspects, if a non-time averaging technology (e.g., WLAN) is transmitting and is then turned off, the time averaging technology (e.g., WWAN) may be immediately turned on. However, in this case, the time averaging technology may be operated such that the peak Tx power is limited to the maximum time averaged Tx power level 207 (i.e., the Tx power level corresponding to the SAR limit). In certain aspects, the peak Tx power of the time averaging technology (e.g., WWAN) may be limited (e.g., limited to a power level corresponding to the SAR limit) for a predetermined period of time to ensure RF exposure compliance of the time averaging technology. In one example, the period of time may be equal to a time window (e.g., 100 seconds). As an example, in Figure 2C If a non-time-averaged RF exposure technology (e.g., WLAN) is first detected at 0 seconds and at time t 1 transmits under the SAR limit and turns off at time t1, and the time-averaged RF exposure technology (e.g., WWAN) at time t 1 If the RF exposure is maintained within the time interval t, the time averaging technique can be used to 1 With t 1 + a time window (e.g., t 1 +100 seconds) is limited to a peak Tx power level 207 (i.e., a maximum time-averaged Tx transmit level 207 corresponding to the SAR limit 204). In this example, the time window may correspond to a time-averaged window as defined by a regulator (e.g., Figure 2C100 seconds in the example in ). In another example, if the time-averaging technology (e.g., WWAN) transmits at low power (i.e., below power level 207) during the time (i.e., after time t1 and until the predetermined time period expires), the predetermined time period may be less than a window. For example, the processor 110 may determine the RF exposure profile of the non-time-averaging technology based on previous transmit power levels of the non-time-averaging technology known to the processor 110. For example, the previous transmit power levels may be stored in the memory 115 and accessed by the processor 110. In this example, the processor 110 may determine the time period based on the RF exposure profile of the non-time-averaging technology (e.g., a shorter time period for a lower RF exposure profile and a longer time period for a high RF exposure profile).

[0064] In another example, the processor 110 may input the RF exposure profile of the non-time-averaged technology into an algorithm that evaluates the RF exposure compliance of the time-averaged technology over a time window and sets the transmit power level of the time-averaged technology based on the evaluation. This allows the algorithm (which may be executed by the processor 110) to consider the RF exposure profile of the non-time-averaged technology when evaluating the RF exposure compliance over the time window. The RF exposure profile of the non-time-averaged technology may be input into an existing algorithm that evaluates the RF exposure compliance of the time-averaged technology over a time window, where the algorithm treats the RF exposure profile of the non-time-averaged technology the same as the RF exposure profile of the time-averaged technology (e.g., the algorithm does not distinguish between the RF exposure of the non-time-averaged technology and the time-averaged technology when evaluating the RF exposure compliance over the time window). In some examples, the RF exposure profile of the non-time-averaged technology input to the existing algorithm that evaluates the RF exposure compliance of the time-averaged technology over the time window assumes that the non-time-averaged technology transmits at maximum power for the entire time that it is turned on.

[0065] Figure 4A flow chart illustrating another method 400 for controlling transmission of time-averaged and non-time-averaged RF exposure techniques in a wireless device (e.g., device 100) according to an aspect is illustrated. In method 400, a first transmitter (e.g., 120-2) transmits a signal using a non-time-averaged RF exposure technique (e.g., WLAN), as shown at block 402. After the transmission of the first transmitter is turned off (as determined at decision block 404), the flow proceeds to block 406, where a second transmitter transmitting using a time-averaged RF exposure technique (e.g., WWAN) is performed. In addition, it is noted that the transmission shown at block 406 includes transmission at a limited transmit peak power within a predetermined time period (e.g., the peak transmit power is limited to the maximum time-averaged Tx power level 207). In some aspects, in the case where the second transmitter transmits at a low power (i.e., below the power level 207, including a zero power level representing a delayed transmission using a time-averaged technique (e.g., WWAN)), the predetermined time period can be a time window (e.g., 100 seconds) or less than a time window. After the predetermined time period expires or expires (as determined at decision block 408), flow proceeds to block 410 where the second transmitter may be allowed to revert to normal time averaging and power levels based on a particular time averaging algorithm or method employed in the wireless device and / or the second transmitter.

[0066] Figure 5 A method 500 for controlling transmission of time-averaged and non-time-averaged RF exposure techniques in a wireless device (e.g., device 100) according to yet another aspect is illustrated, the method combining Figure 3 and Figure 4Method 500 is a method that can be used in a system in which a non-time-averaged RF exposure technology (e.g., WLAN) and a time-averaged RF exposure technology (e.g., WWAN) are not transmitting at the same time (as in methods 300 and 400). Method 500 includes first determining whether the current transmission is from a transmitter (e.g., 120-1) using a non-time-averaged RF exposure technology or from a transmitter (e.g., 120-2) using a time-averaged RF exposure technology, as shown at decision block 502. If the current transmission is performed using a non-time-averaged RF exposure technology (e.g., WLAN), the flow proceeds to block 504, where the transmitter transmits a signal using the non-time-averaged RF exposure technology (e.g., WLAN). After the first transmitter is turned off (as determined at decision block 506), the flow proceeds to block 508, where the transmission using the transmitter using the time-averaged RF exposure technology (e.g., WWAN) is performed. Additionally, it is noted that the transmission shown at block 508 includes transmission at a limited transmit peak power for a predetermined time period (e.g., the peak transmit power is limited to the maximum time-averaged Tx power level 207). In some aspects, the predetermined time period may be a time window (e.g., 100 seconds) or less in the case where the second transmitter transmits at a low power (i.e., below the power level 207, including a zero power level representing a delayed transmission using a time averaging technique (e.g., WWAN)). After the predetermined time period of block 508 expires, the flow proceeds to block 510, where the transmitter using the time-averaged RF exposure technique may be allowed to revert to normal time-averaged and transmit power levels based on a particular time-averaging algorithm or method employed in the wireless device or transmitter.

[0067] In the alternative, if a time-averaged RF exposure technique (e.g., WWAN) is currently being used to transmit signals (as determined at block 502), flow proceeds to transmitting using a transmitter (e.g., 120-2) capable of operating in accordance with at least one radio access technology (RAT) that utilizes time averaging for RF exposure compliance, as shown in block 512. While the time-averaged RF exposure technique is transmitting, a check is performed to determine if the transmitter and accompanying technology are turned off (as indicated by decision block 514), and execution loops back to block 512 until the technology is turned off.

[0068] Flow then proceeds to block 516 where the wireless device is configured to wait or delay the transmission of the next RF exposure technology, such as a non-time-averaged RF exposure technology (e.g., WLAN), for the duration of the predetermined time period, thereby more likely ensuring that the RF exposure limit will not be exceeded. Further note that the process of block 512 may include calculating the predetermined time period for waiting based on the amount of exposure from the time-averaged RF technology (e.g., WWAN) that previously transmitted at block 512. In other aspects, a set predetermined time period may be utilized rather than calculating a value at block 512.

[0069] After expiration of the predetermined time period in block 516, flow proceeds to block 518 where transmission utilizing a transmitter (eg, 120-1) capable of operating according to a non-time-averaged RF exposure technique (eg, WLAN) is then performed.

[0070] In yet other aspects, in conjunction with methods 300, 400, or 500, note that if a time averaging algorithm or method for a time averaging technology (e.g., WWAN) is configured to receive input information about whether a non-time averaging technology (e.g., WLAN) is turned on or off, the time averaging algorithm can be configured to account for the non-time averaging technology (e.g., WLAN) RF exposure by assuming that the non-time averaging technology transmits at maximum power at all times when the non-time averaging technology transmitter is turned on. In this way, the time averaging algorithm can provide an appropriate Tx power limit for the time averaging technology (e.g., WWAN) based on the history of the non-time averaging transmitter activity, i.e., adjust the time delay before the high power transmission of the time averaging technology transmitter. In one example, processes 406 and 508 can utilize this further method to determine the predetermined time delay.

[0071] According to further aspects, if the time averaging algorithm is configured to be able to, for example, communicate a back-off or reduced power limit to the non-time averaging technology (e.g., WLAN) transmitter, and is aware of whether the non-time averaging technology transmitter is on or off, the non-time averaging technology RF exposure may be more accurately accounted for. In one aspect, when the time averaging technology (e.g., WWAN) transmitter is active, the non-time averaging technology (e.g., WLAN) transmitter may always be limited to an "x" dB back-off level (i.e., the maximum RF exposure from the non-time averaging technology (e.g., WLAN) will be "x" dB lower than level 207). In a particular aspect, when the RF exposure level is normalized by the SAR limit (i.e., level 207), then the non-time averaging technology normalized RF exposure may be set equal to 10 -x / 10. In addition, when the time-averaging technology (e.g., WWAN) transmitter is off and the non-time-averaging technology (e.g., WLAN) transmitter is active, then the non-time-averaging technology (e.g., WLAN) transmitter is assumed to transmit at maximum power (i.e., the "x" decibel (dB) back-off level is zero, and therefore, WLAN normalized RF exposure = 1). The assumption that the non-time-averaging technology transmitter is transmitting at maximum power (i.e., in a simultaneous transmission scenario, WLAN normalized RF exposure = 1 or = 10 -x / 10 ) represents the worst case RF exposure, and therefore represents a conservative estimate, since a transmitter of a non-time averaging technique may transmit at a lower power level during this time period than this worst case assumption.

[0072] As a visual example, Fig. 6A Timelines 602, 604, and 606 are shown, illustrating different aspects of WLAN (non-time-averaged in this example) signaling over a time window (e.g., a 100 second window) occurring immediately prior to the current time. Note that while the discussion of WLAN and WWAN Fig. 6A , but these techniques are merely exemplary and the concepts illustrated are more generally applicable to both non-time-averaged RF exposure techniques and time-averaged RF exposure techniques. More specifically, in Fig. 6A In the examples in , the discussion in conjunction with WLAN is generally applicable to other non-time-averaged RF exposure technologies (e.g., Bluetooth technology), and the discussion in conjunction with WWAN is generally applicable to other time-averaged RF exposure technologies. In other examples, WWAN operates as a non-time-averaged technology, and WLAN and / or Bluetooth operate as time-averaged technologies. Therefore, Fig. 6A The concepts illustrated in are not limited to WLAN and WWAN, and can be applied to other non-time-averaged RF exposure techniques and time-averaged RF exposure techniques.

[0073] In addition, it should be understood that Figure 2A , Figure 2B , Figure 2C , Fig. 6A and Figure 6BAll exposure levels depicted in the present application may correspond to continuous transmission (e.g., frequency division duplex (FDD) schemes such as WCDMA) or may correspond to burst transmissions (e.g., time division duplex (TDD) schemes such as GSM). It will also be understood that a duty cycle of transmission may be implemented. As used herein, a duty cycle of transmission may refer to a portion (e.g., 5 ms) of a particular time period (e.g., 500 ms) in which one or more signals are transmitted. In other words, the duty cycle of transmission may represent a percentage or fraction of the time during which one or more signals are transmitted. In some cases, the duty cycle may be standardized (e.g., predetermined) for a particular radio access technology and / or may change over time, for example due to changes in radio conditions, mobility, and / or user behavior. The duty cycle may apply to all exposure levels discussed in this application. For example, if transmission occurs with a duty cycle of z%, where z% is less than 100%, then Figure 2A , Figure 2B , Figure 2C , Fig. 6A and Figure 6B The exposure level in would be the exposure level at 100% duty cycle * z%. In other words, this particular radio may transmit at a higher peak Tx power level corresponding to the continuous Tx power level at 100% duty cycle * 1 / z%.

[0074] exist Fig. 6A 6, timeline 602 illustrates a specific example of an on and off period of a WLAN transmitter, where the WLAN transmitter is either on or off (i.e., the "on" or "off" state as indicated in the "y" axis). Timeline 604 illustrates the WLAN transmission exposure based on an exemplary series of states of WLAN transmission. Specifically, the values ​​in the "y" axis are the WLAN normalized exposure over time in the "x" axis. The normalized exposure values ​​are based on the dB relationship 10 -x / 10 and depends on the WWAN on or off state. Thus, as can be seen in timeline 604, as an example, when the WWAN is off, the normalized value of WLAN exposure is 1.0, as shown at 608, and when the WWAN is on, the normalized value of WLAN exposure decreases to a value of 10 for a predetermined x dB backoff or attenuation value. -x / 10 , as shown at 610.

[0075] Timeline 606 is effectively a combination or composite of timelines 602 and 604 to derive a normalized WLAN transmit exposure profile that can be used as input information for a time averaging method for WWAN (as one example). As shown, when the WWAN is off and the WLAN is on or active, the normalized WLAN transmit exposure profile will have a value of "1", as seen at reference numeral 612. Similarly, when the WLAN is off and the WWAN is on or off, the normalized WLAN transmit exposure profile will have a value of "0", as seen at reference numerals 614 and 616, as long as the WLAN is off. During the period when both the WLAN and the WWAN are on, the corresponding normalization of the WLAN signal is set equal to 10 for a predetermined x dB backoff value. -x / 10 , as shown at reference numerals 618 and 620. In one aspect, the exposure profile generated in this manner may be generated by a processor (eg, processor 110) or logic using knowledge of when the WLAN is on and off and knowledge of the x dB backoff.

[0076] The WLAN transmit exposure profile may be used by a processor (e.g., a processor) to determine the amount of RF exposure margin (e.g., 206) used by the WLAN transmit over the time window. This allows the processor to consider the RF exposure from the WLAN transmit in the calculation of the transmit power level limit of the WWAN transmit. For example, the processor may combine the RF exposure profile of the WLAN over the time window with the RF exposure profile of the WWAN over the time window to obtain a combined RF exposure profile, and use the combined RF exposure profile to determine the total amount of RF exposure margin (e.g., 206) used by both the WLAN and the WWAN, and thus determine the remaining RF exposure margin for RF exposure compliance. The processor may use the remaining RF exposure margin to determine the transmit power level limit of the WWAN transmit that provides RF exposure compliance. The processor may determine the RF exposure profile of the WWAN by tracking the transmit power level of the WWAN over the time window and using the tracked transmit power level to determine the RF exposure profile of the WWAN.

[0077] By considering the back-off of WLAN transmission when both WLAN and WWAN are active (i.e., turned on), compared to blindly assuming that WLAN transmissions are transmitted at 100% (e.g., a power level corresponding to the SAR limit), which overestimates the RF exposure margin for WLAN, Fig. 6A The RF exposure profile illustrated in provides the processor with a more accurate representation of the RF exposure margin used by the WLAN. This allows the device to use more of the RF exposure margin for active transmissions of time-averaged technologies (such as WWAN or 5G NR), thereby providing better overall device performance.

[0078] The back-off value discussed above may be determined based on one or more factors. In one example, the back-off value may be determined based on the spatial overlap between the RF exposure from the WLAN transmission and the RF exposure from the WWAN transmission. In this example, the RF exposure overlap may be larger (e.g., when the WLAN transmitter and the WWAN transmitter transmit in the same general direction), and the RF exposure overlap may be smaller (e.g., when the WLAN transmitter and the WWAN transmitter transmit in different directions (e.g., the antenna for the WLAN and the antenna for the WWAN are oriented in different directions on the wireless device)). In this example, when the spatial overlap is larger, the back-off value may be larger. In another example, the back-off value may be determined based on the priority of the WLAN transmission and the WWAN transmission. For example, when the WWAN transmission has a higher priority than the WLAN transmission, the back-off value may be larger, and when the WLAN transmission has a higher priority than the WWAN transmission, the back-off value may be smaller. For the case where the WLAN transmission has a higher priority, the peak power level of the WWAN transmission may be limited to ensure RF exposure compliance. In some aspects, simulations and / or tests may be performed to find back-off values ​​that result in RF exposure compliance for simultaneous WLAN transmission and WWAN transmission in one or more scenarios.

[0079] In yet another aspect, it is known that a WLAN transmitter (e.g., a non-time averaging technique in this example) is capable of transmitting in both, for example, the 2.4 GHz and 5 GHz bands, and the relevant regulators (e.g., the Federal Communications Commission (FCC), international committees, etc.) have specified different corresponding time averaging windows for different bands (i.e., 100 seconds for 2.4 GHz and 60 seconds for 5 GHz). If the time averaging algorithm knows whether the WLAN transmitter activity is in the 2.4 GHz band or the 5 GHz band or both bands (assuming the worst case in a 60 second time window in this case), then each moment of the WLAN exposure profile determined in timeline 606 can be considered in a 100 second time window (for 2.4 GHz transmissions only) or in a 60 second time window (for 5 GHz transmissions or 2.4 GHz+5 GHz transmissions). However, if the time averaging algorithm does not know the transmission frequency of the WLAN transmitter, then according to certain aspects, the WLAN exposure can be segmented into a 2.4 GHz time window and a 5 GHz time window. As an example of segmenting the WLAN exposure, Figure 6B The example assumes that Fig. 6A Timeline 606 shows a timeline of an exemplary transmission of a WLAN exposure profile. Figure 6BIn the example shown, a "worst case" scenario of transmissions occurring in the past 100 seconds for both the 2.4 GHz and 5.0 GHz bands is assumed over the past 100 second time window, as shown in timeline 640. In this timeline 640, transmissions in the 2.4 GHz WLAN band are assumed for the past 100 seconds to 60 seconds, as shown at 642. Similarly, transmissions in the 5.0 GHz WLAN band are assumed for the past 60 seconds prior to the current time, as shown at 644. While this example shows transmissions being split by time based on the FCC-mandated time average window time for the different bands, it should be noted that the present disclosure is not limited to this example, and other time splits may be used.

[0080] Based on the worst case assumed during the frequency band windows 642 and 644, the WLAN exposure shown in the timeline 606 is split between 2.4 GHz and 5.0 GHz as shown in timelines 646 and 648, respectively. The time portion 650 for the time-averaged WLAN exposure in the timeline 606 that coincides with the window 642 (i.e., from the past 100 seconds to the past 60 seconds) is allocated as the WLAN 2.4 GHz exposure for that time period and is shown in the timeline 646. Similarly, the time portion 652 for the time-averaged WLAN exposure in the timeline 606 that coincides with the window 644 (i.e., from the past 60 seconds to the current time) is allocated as the WLAN 5.0 GHz exposure for that time period and is shown in the timeline 648.

[0081] Figure 7 An example method for implementing a wireless device such as Figure 1 1 is an exemplary block diagram of an apparatus 700 for controlling a transmitter in a device 100 in a processor 110. The apparatus 700 includes a time average operator 702, a transmitter controller 704, a first transmitter 706, and a second transmitter 708. For example, the time average operator 702 and the transmitter controller 704 may be implemented by the processor 110, in separate components, and / or any one or more transmitters of the transmitters 120-1 to 120-N. The first transmitter 706 and the second transmitter 708 may be implemented in any one or more transmitters of the transmitters 120-1 to 120-N.

[0082] The time average operator 702 may constitute hardware or other logic, or alternatively, software running on a dedicated processor (not shown), wherein the time average operator 702 is configured to perform time averaging operations to enforce RF exposure and / or SAR compliance of a transmitter (such as the second transmitter 708 in one example) capable of operating according to the RF exposure time averaging technique.

[0083] The transmitter controller 704 may further be implemented as hardware or logic or software configured to control transmitters in the wireless device, such as transmitters 706 and 708. The transmitter controller 704 may be implemented within a processing circuit of the wireless device, or in an RF front-end component of the wireless device. The transmitter controller 704 is communicatively coupled with the transmitters 706 and 708, as represented by couplings 710 and 712, respectively. In certain aspects, the transmitter controller 704 may impose transmit power limits or signal timing limits, etc., on either of the transmitters 706 and 708, which may further be based on inputs from the time average operator 702, as will be discussed in further detail below.

[0084] According to an aspect, assuming that the first transmitter 706 is capable of operating with a non-time-averaged RF exposure technique (e.g., WLAN), information regarding whether the first transmitter 706 is on or off (and may include transmit frequency information, such as 2.4 GHz and 5 GHz band activity) may be provided from the transmitter 706 to the time averaging operator 702 via the communication coupling 714. Note that the information regarding the on / off state of the first transmitter 706 may alternatively be provided from the transmitter controller 704, for example, via the communication coupling 716, or from some other component in the wireless device, such as a host processor or a digital signal processor (DSP) (not shown).

[0085] In addition, in order to achieve the combination Fig. 6A and Figure 6B In order to describe the RF exposure profile of a non-time-averaged RF exposure technology (e.g., WLAN) discussed above, the time average operator 702 can be configured to transmit a back-off power limit to the first transmitter 706, such as via the transmitter controller 704. According to certain aspects, the time average operator 702 can be configured to limit the first transmitter 706 to a predetermined back-off level (e.g., "x" dB and 10 -x / 10 Normalized value). Additionally, assuming the second transmitter 708 is a time-averaged RF exposure technology such as WWAN or 5G NR, the time-average operator 702 may apply the back-off level when the second transmitter 708 is active and transmitting.

[0086] In other aspects, when the second transmitter 708 in this example is in an "off" state and the first transmitter 706 is active, the time average operator 702 can be configured to assume that the transmission level of the first transmitter 706 is at maximum power to anticipate a worst-case scenario to best ensure compliance with RF exposure limits when ultimately calculating the transmission power limit of the second transmitter 708 (e.g., WWAN transmitter) based on or taking into account the transmission of the first transmitter 706 (e.g., WLAN transmitter). In addition, the time average operator 702 can be configured to split between transmissions in the 2.4 GHz or 5 GHz bands, as previously described with respect to Figure 6B Discussed.

[0087] exist Figure 7 In the example of FIG. 7 , based on the on / off state of the first transmitter and the second transmitter, the predetermined back-off level of the first transmitter when the second transmitter is active, the assumption of the worst-case RF exposure including the split between different frequency bands, the time averaging operator 702 and / or the transmitter controller 704 can then dynamically control the transmission of the first transmitter 706. Specifically, the transmission power of the first transmitter 706 capable of operating according to a non-time averaging technology such as WLAN is controlled. This provides for obtaining an RF exposure margin, wherein the increased RF exposure margin can then be used for the transmission of the second transmitter 708 capable of operating according to a time averaging technology (e.g., WWAN, 5G NR, etc.). As an example of this benefit, as previously described herein, a conventional method of splitting the margin between the time-averaged RF exposure of a time-averaging technology (such as WWAN and / or 5GNR) (less than or equal to "A") and the RF exposure of a non-time averaging technology (such as WLAN) (less than or equal to "B") involves ensuring that the total A+B is less than or equal to 100%. The presently disclosed methods and apparatus allow the value B, for example, to be minimized, thereby allowing the time-averaged technical value "A" to be increased or maximized when active.

[0088] Further note, Figure 7 The device in can also implement Figures 3 to 5Any of the methods and the accompanying processes therein. For example, the time averaging operator 702 and the transmitter controller 704 may be used to implement the determination and application of a predetermined waiting period or delay such as shown in blocks 306, 308, or 516. In addition, the time averaging operator 702 and the transmitter controller 704 may be used to calculate a predetermined time period and implement transmission using the time-averaged RF exposure technique with a limited Tx peak power over the predetermined time period, as shown in blocks 406 or 508. In yet another example, the time averaging operator 702 and the transmitter controller 704 may be used to implement a normal time averaging algorithm and method of the time averaging RF exposure technique, as well as a process of returning a transmitter using the time averaging RF exposure technique to a power level determined by the time averaging algorithm after expiration of the predetermined time period, as indicated at blocks 410 or 510.

[0089] Figure 8 An exemplary method 800 for wireless communication is illustrated. The method 800 includes transmitting a first transmission utilizing a first transmitter capable of operating according to a first radio technology, as shown in block 802. The first transmitter may correspond to any one or more of transmitters 120-1 through 120-N, 706, and 708.

[0090] Method 800 also includes transmitting a second transmission using a second transmitter capable of operating according to a second radio technology after the first transmission is completed, as shown in block 804. The second transmitter may correspond to any one or more of transmitters 120-1 through 120-N, 706, and 708.

[0091] The method 800 may also include, if the first radio technology is a radio frequency (RF) exposure time averaging technology and the second radio technology is a non-time averaging RF exposure technology, delaying the transmission of the second transmission by a predetermined wait time after the first transmission is completed, as shown in block 806. For example, the second transmission may be delayed by the processor 110, the transmitter controller 704, and / or any one or more of the transmitters 120-1 to 120-N, 706, and 708. The RF exposure time averaging technology may include one or more WWAN technologies and 5G New Radio (NR) technologies, and the RF exposure non-time averaging technology may include one or more of a WLAN technology and a Bluetooth technology.

[0092] The method 800 may also include, if the first radio technology is a non-time-averaged RF exposure technology and the second radio technology is a time-averaged RF exposure technology, transmitting the second transmission at a limited peak power for at least a portion of the second transmission for a predetermined period of time, as shown in block 808. For example, the second transmission may be transmitted at a limited peak power by the processor 110, the transmitter controller 704, and / or any one or more of the transmitters 120-1 to 120-N, 706, and 708. The RF exposure time-averaged technology may include one or more WWAN technologies and 5G New Radio (NR) technologies, and the RF exposure non-time-averaged technology may include one or more WLAN technologies and Bluetooth technologies.

[0093] Fig. 9 An exemplary method 900 for controlling transmissions in a wireless device to ensure compliance with RF exposure limits is illustrated. Note that, in particular, method 900 provides control over RF transmissions to obtain better overall RF exposure compliance while obtaining more RF exposure margin by particularly considering RF exposure from transmissions from technologies that are not part of the time averaging technology (i.e., non-time averaging RF exposure technologies such as WLAN).

[0094] As shown in block 902, the method 900 for controlling transmission includes setting a limit on the transmission level of a non-time-averaged technology (i.e., a "first radio access technology") to be equal to a predetermined backoff level when the time-averaged RF exposure technology is active over a transmission time window, such as described above in conjunction with Fig. 6A In a further aspect, the transmission level limit in the process of block 902 may be set as determined by the relationship 10 -x / 10 The normalized value determined is , where "x" is a predetermined back-off level in decibels. The limits on the transmit levels may be set, for example, by the processor 110 and / or the transmitter controller 704.

[0095] The method 900 also includes determining an RF exposure profile for the non-time-averaged RF exposure technique over the transmit time window, as shown at block 904. The determination of the RF exposure profile is based on the determined transmit limit level during the active transmit period of the non-time-averaged RF exposure technique over the transmit time window and the active time of the time-averaged RF exposure technique over the transmit time window. As an example of this determination, Fig. 6AThe RF exposure profile shown in timeline 606 of the example illustrates that the profile is based on a composite of the active transmission period of the non-time-averaged RF exposure technology shown in timeline 602 over a transmission time window, which is a 100-second elapsed time window in the example given above, but is not necessarily limited to such. In some aspects, the RF exposure profile may be determined based on the assumption that when the time-averaged RF exposure technology (e.g., WWAN) is inactive (i.e., turned off), the non-time-averaged RF exposure technology (e.g., WLAN) transmits at 100% (e.g., a power level corresponding to the SAR limit), and when the time-averaged RF exposure technology (e.g., WWAN) is active (i.e., turned on), the non-time-averaged RF exposure technology (e.g., WLAN) transmits at a predetermined backoff level from 100%. The RF exposure profile may be determined by the processor 110. For example, the RF exposure profile may be determined by the processor 110, the time averaging operator 702, and / or the transmitter controller 704.

[0096] In an alternative, method 900 may further include segmenting the RF exposure profile over the transmit time window according to frequency bands, as shown at block 906. Specifically, the RF exposure profile may be segmented based on frequency bands such as 2.4 GHz and 5.0 GHz (or based on actual knowledge of WLAN transmit frequencies if the time averaging operator receives this information from the WLAN transmitter), as previously described with respect to Figure 6B 646 and 648. The RF exposure profile may be segmented, for example, by processor 110, time averaging operator 702, and / or transmitter controller 704.

[0097] Finally, the method 900 includes controlling the transmission of the transmitter based on the RF exposure profile determined in blocks 904 and / or 906 at block 908. In some aspects, controlling the transmission of the transmitter (e.g., the transmitter of the time-averaged RF exposure technique) may include setting the transmission power level limit of the transmitter in consideration of the RF exposure profile determined in blocks 904 and / or 906. For example, the processor 110 may combine the RF exposure profile determined in blocks 904 and / or 906 with the RF exposure profile of the time-averaged RF exposure technique (e.g., WWAN) over the transmission time window to obtain a combined RF exposure profile, and use the combined RF exposure profile to determine the total amount of RF exposure margins (e.g., 206) used by the non-time-averaged RF exposure technique and the time-averaged RF exposure technique and determine the remaining RF exposure margin for RF exposure compliance. The processor 110 may use the remaining RF exposure margin to determine the transmission power level limit of the WWAN transmission that provides RF exposure compliance. The transmission of the transmitter may be controlled, for example, by the processor 110 and / or the transmitter controller 704.

[0098] In certain aspects disclosed herein, the processor 110 may evaluate the time-averaged RF exposure compliance by calculating the time-averaged SAR distribution over an averaging time window (e.g., 60 seconds, 100 seconds, 6 minutes, 30 minutes, etc.), and then comparing the peak value in the time-averaged SAR distribution to the RF exposure limit to evaluate the time-averaged RF exposure compliance. If the peak value is equal to or less than the RF exposure limit, the processor 110 may determine the time-averaged RF exposure compliance. If the time-averaged SAR distribution is normalized, the RF exposure limit may be one.

[0099] It should be understood that the processor 110 is not limited to the above examples for evaluating time-averaged RF exposure compliance. For example, the processor 110 may evaluate time-averaged RF exposure compliance (e.g., at a single location) by calculating a time-averaged SAR value over an average time window, and then comparing the time-averaged SAR value to an RF exposure limit to evaluate time-averaged RF exposure compliance. If the time-averaged SAR value is equal to or less than the RF exposure limit, the processor 110 may determine time-averaged RF exposure compliance. It should also be understood that the processor 110 may also evaluate RF exposure based on power density (PD) and / or a combination of SAR and PD. Therefore, it should be understood that the processor 110 is not limited to a particular type of RF exposure measurement for evaluating time-averaged RF exposure, and other types of RF exposure measurements may be used.

[0100] Although various aspects of the present disclosure are discussed above using WLAN as an example of a non-time-averaged RF exposure technology and WWAN as an example of a time-averaged RF exposure technology, it should be understood that various aspects of the present disclosure are more generally applicable to non-time-averaged RF exposure technologies and time-averaged RF exposure technologies. More specifically, the various aspects discussed above using the example of WLAN as a non-time-averaged RF exposure technology are generally applicable to other non-time-averaged RF exposure technologies (e.g., Bluetooth technology), and the various aspects discussed above using the example of WWAN as a time-averaged RF exposure technology are generally applicable to other time-averaged RF exposure technologies. In some other examples, WWAN may be operated as a non-time-averaged technology, while WLAN and / or Bluetooth may be operated as time-averaged technologies.

[0101] In certain other aspects, the memory 115 may include a computer-readable medium having stored thereon instructions that, when executed by the processor 110, cause the processor 110 to perform the methods and operations described herein. By way of example, the computer-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 drives, or any other tangible, non-transitory storage medium, or any combination thereof.

[0102] Specific implementation examples are described in the following numbered clauses:

[0103] 1. A wireless device, comprising:

[0104] A plurality of transmitters, the plurality of transmitters including a first transmitter and a second transmitter, wherein each of the plurality of transmitters is configured to transmit a signal according to a corresponding radio technology of a plurality of radio technologies, and wherein the plurality of radio technologies includes a first radio technology having a time-averaged radio frequency (RF) exposure technology and a second radio technology having a time-averaged radio frequency (RF) exposure technology.

[0105] A second radio technology that is a non-time-averaged RF exposure technology; and

[0106] a processor coupled to the plurality of transmitters, wherein the processor is configured to:

[0107] causing the first transmitter to transmit a first transmission;

[0108] causing the second transmitter to send a second transmission after the first transmission is completed;

[0109] In a case where the first transmitter is capable of operating according to the first radio technology and the second transmitter is capable of operating according to the second radio technology, causing the second transmitter to transmit the first signal after the first transmission is completed.

[0110] sending the second transmission after the first determined waiting time has elapsed; and

[0111] Where the first transmitter is capable of operating according to the second radio technology and the second transmitter is capable of operating according to the first radio technology, causing the second transmitter to transmit at least a portion of the second transmission at a limited peak power within a predetermined time period after completion of the first transmission.

[0112] 2. The wireless device of clause 1, wherein the processor is further configured to determine the predetermined waiting time based on an amount of RF exposure caused by the first transmission by the first transmitter.

[0113] 3. A wireless device according to clause 1 or 2, wherein the processor is further configured to: determine the predetermined time period based on an amount of RF exposure caused by the first transmission performed by the first transmitter.

[0114] 4. A wireless device according to any of clauses 1 to 3, wherein the processor is configured to cause the second transmitter to transmit according to the first radio technology at a normal power level determined by time averaging after expiration of the predetermined time period.

[0115] 5. A wireless device according to any one of clauses 1 to 4, wherein the first radio technology comprises one or more of a wireless wide area network (WWAN) technology and a 5G new radio (NR) technology, and the second radio technology comprises one or more of a wireless local area network (WLAN) technology and a Bluetooth technology.

[0116] 6. A wireless device as described in any of clauses 1 to 5, wherein the processor is further configured to:

[0117] receiving information regarding on and off states of transmitters capable of operating according to the second radio technology;

[0118] as well as

[0119] A transmit power limit for one or more transmitters operable according to the first radio technology is set based on the information regarding the on and off states of the transmitters operable according to the second radio technology.

[0120] 7. A wireless device as described in clause 6, wherein the processor is further configured to:

[0121] determining a history of the transmitter capable of operating according to the second radio technology based on the received information regarding the on and off states of the transmitter capable of operating according to the second radio technology; and

[0122] At least one of a transmit power level of the one or more transmitters capable of operating according to the first radio technology and the predetermined time period is adjusted based on the determined history.

[0123] 8. A method for wireless communication, the method comprising:

[0124] transmitting a first transmission using a first transmitter capable of operating according to a first radio technology;

[0125] After the first transmission is completed, a second transmission is sent using a second transmitter, the second transmitter being able to

[0126] operating according to a second radio technology;

[0127] Where the first radio technology is a radio frequency (RF) exposure time averaging technology and the second radio technology is a non-time averaging RF exposure technology, delaying the transmission of the second transmission after the first transmission is completed

[0128] a predetermined waiting period; and

[0129] Where the first radio technology is a non-time-averaged RF exposure technology and the second radio technology is a time-averaged RF exposure technology, the second transmission is transmitted at a limited peak power for a predetermined time period for at least a portion of the second transmission.

[0130] 9. The method of clause 8, further comprising determining the predetermined wait time based on an amount of RF exposure caused by the first transmission by the first transmitter when the first radio technology comprises the time-averaged RF exposure technique.

[0131] 10. The method of clause 8 or 9, further comprising determining the predetermined time period based on an amount of RF exposure caused by the first transmission by the first transmitter when the first radio technology comprises the non-time-averaged RF exposure technology.

[0132] 11. A method according to any one of clauses 8 to 10, further comprising: when the second radio technology is the time-averaged RF exposure technology, after expiration of the predetermined time period, using the second transmitter to transmit at least a portion of the second transmission at a normal power level as determined by time averaging.

[0133] 12. A method according to any one of clauses 8 to 11, wherein the time-averaged RF exposure technology includes one or more of a wireless wide area network (WWAN) technology and a 5G new radio (NR) technology, and the radio frequency (RF) exposure non-time-averaged technology includes one or more of a wireless local area network (WLAN) technology and a Bluetooth technology.

[0134] 13. The method according to any one of clauses 8 to 12, further comprising:

[0135] receiving information regarding on and off states of transmitters operable according to the non-time-averaged RF exposure technique; and

[0136] A transmit power limit for one or more transmitters operable according to the time-averaged RF exposure technique is set based on the information regarding the on and off states of the transmitters operable according to the non-time-averaged RF exposure technique.

[0137] 14. The method according to clause 13, further comprising:

[0138] determining a history of the transmitter capable of operating according to the non-time-averaged RF exposure technique based on the received information regarding the on and off states of the transmitter capable of operating according to the second radio technology;

[0139] as well as

[0140] At least one of a transmit power level of a transmitter operable according to the time-averaged RF exposure technique and the predetermined time period is adjusted based on the determined history.

[0141] 15. A wireless device, comprising:

[0142] A plurality of transmitters, wherein each of the plurality of transmitters is configured to transmit signals according to a corresponding radio technology of a plurality of radio technologies, and wherein the plurality of radio technologies includes a time-averaged radio frequency (RF)

[0143] Exposure techniques and non-time-averaged RF exposure techniques; and

[0144] a processor coupled to the plurality of transmitters, wherein the processor is configured to:

[0145] setting a transmit level limit of the non-time-averaged RF exposure technique to a predetermined backoff level during a period in which the time-averaged RF exposure technique is active over a transmit time window;

[0146] determining an RF exposure profile of the non-time-averaged RF exposure technique over the transmit time window;

[0147] as well as

[0148] Transmission of transmitters of the transmitters operable according to the time-averaged RF exposure technique is controlled based on the RF exposure profile.

[0149] 16. The wireless device of clause 15, wherein the non-time-averaged RF exposure technique transmits using a plurality of frequency bands, and the processor is further configured to segment the RF exposure profile over the transmit time window based on the plurality of frequency bands.

[0150] 17. The wireless device of clause 16, wherein the plurality of frequency bands comprises a 2.4 GHz frequency band and a 5.0 GHz frequency band.

[0151] 18. A wireless device according to clause 16 or 17, wherein the RF exposure profile is segmented into a first portion and a second portion, the first portion and the second portion corresponding to a first time portion and a second time portion of the transmit time window, respectively.

[0152] 19. The wireless device of clause 18, wherein the RF exposure profile is segmented into the first portion and the second portion based on received information of an active frequency band of the non-time-averaged RF exposure technique.

[0153] 20. A wireless device according to any one of clauses 15 to 19, wherein the processor is further configured to: -

[0154] x / 10 The predetermined back-off level is determined by , where x is the back-off value in decibels.

[0155] 21. A wireless device as described in any of clauses 15 to 20, wherein the processor is further configured to determine the RF exposure profile by assuming that the transmit level limit set during the inactive period of the time average RF exposure technique is a maximum transmit power.

[0156] 22. A wireless device according to any of clauses 15 to 21, wherein the time-averaged RF exposure technology includes one or more of a wireless wide area network (WWAN) technology and a 5G new radio (NR) technology, and the non-time-averaged RF exposure technology includes one or more of a wireless local area network (WLAN) technology and a Bluetooth technology.

[0157] 23. A wireless device according to any of clauses 15 to 22, wherein the processor is further configured to:

[0158] receiving information regarding on and off states of the transmitter operable according to the non-time-averaged RF exposure technique; and

[0159] The RF exposure profile of the non-time-averaged RF exposure technique is determined further based on the received information regarding the on and off states.

[0160] 24. The wireless device of clause 23, wherein the RF exposure profile is segmented into a first portion and a second portion based on received information of an active frequency band of the non-time-averaged RF exposure technique.

[0161] 25. A wireless device according to any of clauses 15 to 24, wherein the processor is configured to set the transmit level limit of the non-time-averaged RF exposure technology to a power level during a period when the time-averaged RF exposure technology is inactive on the transmit time window, and the back-off level is equal to the power level minus the back-off value.

[0162] 26. A method for wireless communication, the method comprising:

[0163] setting a transmit level limit of the non-time-averaged RF exposure technique to a predetermined backoff level during a period in which the time-averaged RF exposure technique is active over the transmit time window;

[0164] determining an RF exposure profile for the non-time-averaged RF exposure technique over the transmit time window; and controlling transmission of a transmitter operable according to the time-averaged RF exposure technique based on the derived RF exposure profile.

[0165] 27. The method of clause 26, further comprising segmenting the RF exposure profile over the transmit time window based on a plurality of frequency bands in which the non-time averaged RF exposure technique is capable of transmitting.

[0166] 28. The method of clause 27, wherein the plurality of frequency bands includes a 2.4 GHz frequency band and a 5.0 GHz frequency band.

[0167] 29. The method of clause 27 or 28, wherein the RF exposure profile is segmented into a first portion and a second portion, the first portion and the second portion corresponding to a first time portion and a second time portion of the transmission time window, respectively.

[0168] 30. A method according to any one of clauses 26 to 29, further comprising: -x / 10 The predetermined back-off level is determined by , where x is the back-off value in decibels.

[0169] 31. A method as recited in any of clauses 26 to 30, wherein determining the RF exposure profile comprises assuming that a transmit level limit set during an active period of the time-averaged RF exposure technique is a maximum transmit power.

[0170] 32. A method according to any one of clauses 26 to 31, wherein the time-averaged RF exposure technology includes one or more of a wireless wide area network (WWAN) technology and a 5G new radio (NR) technology, and the non-time-averaged RF exposure technology includes one or more of a wireless local area network (WLAN) technology and a Bluetooth technology.

[0171] 33. A method according to any one of clauses 26 to 32, further comprising:

[0172] receiving information regarding on and off states of the transmitter operable according to the non-time-averaged RF exposure technique; and

[0173] The RF exposure profile of the non-time-averaged RF exposure technique is determined further based on the received information regarding the on and off states.

[0174] 34. The method of clause 33, wherein the RF exposure profile is segmented into a first portion and a second portion based on received information regarding an active frequency band of the non-time-averaged RF exposure technique.

[0175] 35. A method according to any one of clauses 26 to 34, the method further comprising: setting the transmission level limit of the non-time-averaged RF exposure technology to a power level during a period when the time-averaged RF exposure technology is inactive on the transmission time window, and the back-off level is equal to the power level minus the back-off value.

[0176] It should be understood that the present disclosure is not limited to the exemplary terms used above to describe various aspects of the present disclosure, and the present disclosure encompasses equivalent terms. For example, it should be understood that distribution may also be referred to as map, scan, or another term. For another example, it should be understood that antenna may also be referred to as antenna element or another term. For another example, it should be understood that maximum allowable power level may also be referred to as power level limit or another term.

[0177] As used herein, the term "about" with respect to a specified value or property is intended to indicate within 10% of the specified value or property.

[0178] Any reference to an element using designations such as "first," "second," etc. herein does not generally limit the number or order of those elements. Rather, these designations are used herein as a convenient method of distinguishing two or more elements or instances of elements. Thus, reference to a first element and a second element does not mean that only two elements can be used or that the first element must be located before the second element.

[0179] Within this disclosure, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Any specific implementation or aspect described herein as "exemplary" is not necessarily to be construed as preferred or superior to other aspects of the disclosure. Likewise, the term "aspect" does not require that all aspects of the disclosure include the discussed feature, advantage, or mode of operation.

[0180] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wireless device, comprising: a plurality of transmitters, the plurality of transmitters comprising a first transmitter and a second transmitter, wherein each transmitter of the plurality of transmitters is configured to transmit signals according to a respective radio technology of a plurality of radio technologies, and wherein the plurality of radio technologies comprises a first radio technology having a time-averaged radio frequency (RF) exposure technology and a second radio technology having a non-time-averaged RF exposure technology; and a processor coupled to the plurality of transmitters, wherein the processor is configured to: causing the first transmitter to transmit a first transmission; causing the second transmitter to send a second transmission after the first transmission is completed; where the first transmitter is capable of operating in accordance with the first radio technology and the second transmitter is capable of operating in accordance with the second radio technology, causing the second transmitter to transmit the second transmission after completion of a predetermined waiting time after completion of the first transmission; as well as Where the first transmitter is capable of operating according to the second radio technology and the second transmitter is capable of operating according to the first radio technology, causing the second transmitter to transmit at least a portion of the second transmission at a limited peak power within a predetermined time period after completion of the first transmission. 2 . The wireless device of claim 1 , wherein the processor is further configured to determine the predetermined waiting time based on an amount of RF exposure caused by the first transmission by the first transmitter. 3 . The wireless device of claim 1 , wherein the processor is further configured to determine the predetermined time period based on an amount of RF exposure caused by the first transmission by the first transmitter.

4. The wireless device of claim 1, wherein the processor is configured to cause the second transmitter to transmit according to the first radio technology at a normal power level determined by time averaging after expiration of the predetermined time period.

5. The wireless device of claim 1 , wherein the first radio technology comprises one or more of a wireless wide area network (WWAN) technology and a 5G new radio (NR) technology, and the second radio technology comprises one or more of a wireless local area network (WLAN) technology and a Bluetooth technology.

6. The wireless device of claim 1 , wherein the processor is further configured to: receiving information regarding on and off states of transmitters capable of operating according to the second radio technology; and A transmit power limit for one or more transmitters operable according to the first radio technology is set based on the information regarding the on and off states of the transmitters operable according to the second radio technology.

7. The wireless device of claim 6, wherein the processor is further configured to: determining a history of the transmitter capable of operating according to the second radio technology based on the received information regarding the on and off states of the transmitter capable of operating according to the second radio technology; and At least one of a transmit power level of the one or more transmitters capable of operating according to the first radio technology and the predetermined time period is adjusted based on the determined history.

8. A method for wireless communication, the method comprising: transmitting a first transmission using a first transmitter capable of operating according to a first radio technology; after the first transmission is completed, transmitting a second transmission using a second transmitter, the second transmitter being capable of operating according to a second radio technology; where the first radio technology is a radio frequency (RF) exposure time averaging technology and the second radio technology is a non-time averaging RF exposure technology, delaying the transmission of the second transmission by a predetermined waiting time after the first transmission is completed; as well as Where the first radio technology is a non-time-averaged RF exposure technology and the second radio technology is a time-averaged RF exposure technology, the second transmission is transmitted at a limited peak power for a predetermined time period for at least a portion of the second transmission.

9. The method according to claim 8, further comprising: When the first radio technology includes the time-averaged RF exposure technique, the predetermined wait time is determined based on an amount of RF exposure caused by the first transmission by the first transmitter.

10. The method according to claim 8, further comprising: When the first radio technology includes the non-time-averaged RF exposure technology, the predetermined time period is determined based on an amount of RF exposure caused by the first transmission by the first transmitter.

11. The method of claim 8, further comprising, when the second radio technology is the time-averaged RF exposure technology, transmitting at least a portion of the second transmission using the second transmitter at a normal power level as determined by time averaging after expiration of the predetermined time period.

12. The method of claim 8, wherein the time-averaged RF exposure technology comprises one or more of a wireless wide area network (WWAN) technology and a 5G new radio (NR) technology, and the non-time-averaged RF exposure technology comprises one or more of a wireless local area network (WLAN) technology and a Bluetooth technology.

13. The method according to claim 8, further comprising: receiving information regarding on and off states of transmitters operable according to the non-time-averaged RF exposure technique; as well as A transmit power limit for one or more transmitters operable according to the time-averaged RF exposure technique is set based on the information regarding the on and off states of the transmitters operable according to the non-time-averaged RF exposure technique.

14. The method according to claim 13, further comprising: determining a history of the transmitter capable of operating according to the non-time-averaged RF exposure technique based on the received information regarding the on and off states of the transmitter capable of operating according to the second radio technology; as well as At least one of a transmit power level of a transmitter operable according to the time-averaged RF exposure technique and the predetermined time period is adjusted based on the determined history.

15. A wireless device, comprising: a plurality of transmitters, wherein each transmitter of the plurality of transmitters is configured to transmit signals according to a respective radio technology of a plurality of radio technologies, and wherein the plurality of radio technologies includes a time-averaged radio frequency (RF) exposure technology and a non-time-averaged RF exposure technology; and a processor coupled to the plurality of transmitters, wherein the processor is configured to: setting a transmit level limit of the non-time-averaged RF exposure technique to a predetermined backoff level during a period in which the time-averaged RF exposure technique is active over a transmit time window; determining an RF exposure profile of the non-time-averaged RF exposure technique over the transmit time window; and Transmission of transmitters of the transmitters operable according to the time-averaged RF exposure technique is controlled based on the RF exposure profile.

16. The wireless device of claim 15, wherein the non-time-averaged RF exposure technique uses a plurality of frequency bands for transmission, and the processor is further configured to segment the RF exposure profile over the transmission time window based on the plurality of frequency bands.

17. The wireless device of claim 16, wherein the plurality of frequency bands include a 2.4 GHz frequency band and a 5.0 GHz frequency band.

18. The wireless device of claim 16, wherein the RF exposure profile is segmented into a first portion and a second portion, the first portion and the second portion corresponding to a first time portion and a second time portion of the transmission time window, respectively.

19. The wireless device of claim 18, wherein the RF exposure profile is segmented into the first portion and the second portion based on received information of an active frequency band of the non-time-averaged RF exposure technique.

20. The wireless device of claim 15, wherein the processor is further configured to: - x / 10 The predetermined back-off level is determined by , where x is the back-off value in decibels.

21. The wireless device of claim 15, wherein the processor is further configured to determine the RF exposure profile by assuming that the transmit level limit set during an inactive period of the time-averaged RF exposure technique is a maximum transmit power.

22. The wireless device of claim 15, wherein the time-averaged RF exposure technology comprises one or more of a wireless wide area network (WWAN) technology and a 5G new radio (NR) technology, and the non-time-averaged RF exposure technology comprises one or more of a wireless local area network (WLAN) technology and a Bluetooth technology.

23. The wireless device of claim 15, wherein the processor is further configured to: receiving information regarding on and off states of transmitters operable according to the non-time-averaged RF exposure technique; and The RF exposure profile of the non-time-averaged RF exposure technique is determined further based on the received information regarding the on and off states.

24. The wireless device of claim 23, wherein the RF exposure profile is segmented into a first portion and a second portion based on received information of an active frequency band of the non-time-averaged RF exposure technique.

25. A wireless device according to claim 15, wherein the processor is configured to set the transmission level limit of the non-time-averaged RF exposure technology to a power level during a period of time when the time-averaged RF exposure technology is inactive on the transmission time window, and the back-off level is equal to the power level minus the back-off value.

26. A method for wireless communication, the method comprising: setting a transmit level limit of the non-time-averaged RF exposure technique to a predetermined backoff level during a period in which the time-averaged RF exposure technique is active over the transmit time window; determining an RF exposure profile of the non-time-averaged RF exposure technique over the transmit time window; and Transmissions of a transmitter operable according to the time-averaged RF exposure technique are controlled based on the RF exposure profile.

27. The method of claim 26, further comprising segmenting the RF exposure profile over the transmit time window based on a plurality of frequency bands in which the non-time averaged RF exposure technique is capable of transmitting.

28. The method according to claim 26, further comprising: - x / 10 The predetermined back-off level is determined by , where x is the back-off value in decibels.

29. The method of claim 26, wherein determining the RF exposure profile comprises assuming that a transmit level limit set during an active period of the time-averaged RF exposure technique is a maximum transmit power.

30. The method of claim 26, further comprising: The transmit level limit of the non-time-averaged RF exposure technique is set to a power level during periods of inactivity of the time-averaged RF exposure technique over the transmit time window, and the backoff level is equal to the power level minus a backoff value.

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