# US 11,115,073 B2 · Method and device for decreasing electromagnetic radiation specific absorption rate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,073 B2 - Document ID: US11115073B2 - Status: Granted - Kind: B2 - Application number: 17/040,357 - Filed: 2018-04-20 - Published: 2021-02-25 - Granted: 2021-09-07 - Earliest claimed: 2018-04-20 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Meng Hou; Hai Zhou - Web page: https://patentgrep.com/patent/US11115073B2 ## CPC - H04B 1/3838: {Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use} - H04W 52/0261: {managing power supply demand, e.g. depending on battery level} - H04W 52/367: {Power values between minimum and maximum limits, e.g. dynamic range} - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method includes separately collecting, by a terminal, a transmit power of the terminal at different time points in a second duration after a first duration from a power-on moment to obtain a plurality of transmit powers, calculating an average transmit power of the transmit powers, determining based on the average transmit power, a specific absorption rate (SAR) corresponding to the average transmit power, and decreasing a transmit power of the terminal after the second duration when the terminal determines that the SAR is greater than a preset threshold. ## Claims ### Claim 1 A method implemented by a terminal, wherein the method comprises: separately collecting a transmit power of the terminal at different time points during a second duration after a first duration from a power-on moment to obtain a plurality of transmit powers; calculating an average transmit power of the transmit powers; determining, based on the average transmit power, an electromagnetic radiation specific absorption rate (SAR) corresponding to the average transmit power; determining that the electromagnetic radiation SAR is greater than a preset threshold; and decreasing the transmit power after the second duration in response to determining that the electromagnetic radiation SAR is greater than the preset threshold. ### Claim 2 (depends on 1) The method of claim 1, further comprising disabling a broadband WI-FI function. ### Claim 3 (depends on 1) The method of claim 1, further comprising forbidding establishing a new Radio Resource Control (RRC) connection or an application communication connection, wherein the application communication connection indicates a communication connection performed using an application program, and wherein the application communication connection comprises an application voice connection, an application data connection, and an application video connection. ### Claim 4 (depends on 1) The method of claim 1, further comprising forming a beam that points away from a human body by controlling a phased-array antenna of the terminal. ### Claim 5 (depends on 1) The method of claim 1, further comprising transmitting a signal using an antenna that is away from a human body and that is one of a plurality of antennas installed on the terminal. ### Claim 6 (depends on 1) The method of claim 1, further comprising: calculating a difference between the preset threshold and the electromagnetic radiation SAR; determining, based on the difference, a specified value to decrease the transmit power after the second duration; and decreasing the transmit power after the second duration by the specified value. ### Claim 7 (depends on 6) The method of claim 6, further comprising: decreasing a maximum transmit power of a physical random-access channel (PRACH) by a first preset value; decreasing a power headroom reported to a network by a second preset value; increasing a quantity of uplink hybrid automatic repeat request (HARQ) times by a third preset value; decreasing a total quantity of connections to a network device during soft handover by a fourth preset value; or decreasing a codec data rate of a voice connection by a fifth preset value. ### Claim 8 (depends on 1) The method of claim 1, further comprising: obtaining one-to-one correspondences between a plurality of average transmit powers and a plurality of electromagnetic radiation SARs; and determining, from the one-to-one correspondences and the average transmit power, the electromagnetic radiation SAR corresponding to the average transmit power. ### Claim 9 (depends on 8) The method of claim 8, further comprising: obtaining the one-to-one correspondences between the average transmit powers and the electromagnetic radiation SARs from a local storage of the terminal; or receiving the one-to-one correspondences from a network device. ### Claim 10 (depends on 1) The method of claim 1, further comprising entering the terminal in a call state after the first duration. ### Claim 11 A terminal comprising: a transceiver configured to wirelessly receive and transmit a signal; and a processor coupled to the transceiver and configured to: separately collect, at different time points during a second duration after a first duration from a power-on moment of the terminal, a transmit power used by the transceiver to send the signal to obtain a plurality of transmit powers; calculate an average transmit power of the transmit powers; determine based on the average transmit power, an electromagnetic radiation specific absorption rate (SAR) corresponding to the average transmit power; determine that the electromagnetic radiation SAR is greater than a preset threshold; and decrease the transmit power after the second duration in response to determining that the electromagnetic radiation SAR is greater than the preset threshold. ### Claim 12 (depends on 11) The terminal of claim 11, wherein the processor is further configured to disable a broadband WI-FI function. ### Claim 13 (depends on 11) The terminal of claim 11, wherein the processor is further configured to forbid establishing a new Radio Resource Control (RRC) connection or an application communication connection, wherein the application communication connection indicates a communication connection performed using an application program, and wherein the application communication connection comprises an application voice connection, an application data connection, and an application video connection. ### Claim 14 (depends on 11) The terminal of claim 11, further comprising a phased-array antenna, wherein the processor is further configured to form a beam that points away from a human body using the phased-array antenna. ### Claim 15 (depends on 11) The terminal of claim 11, further comprising a plurality of antennas, wherein the processor is further configured to transmit a second signal using an antenna that is away from a human body and that is one of the antennas. ### Claim 16 (depends on 11) The terminal of claim 11, wherein the processor is further configured to: calculate a difference between the preset threshold and the electromagnetic radiation SAR; determine, based on the difference, a specified value to decrease the transmit power after the second duration ; and decrease the transmit power after the second duration by the specified value. ### Claim 17 (depends on 16) The terminal of claim 16, wherein the processor is further configured to: decrease a maximum transmit power of a physical random-access channel (PRACH) by a first preset value; decrease power headroom reported to a network by a second preset value; increase a quantity of uplink hybrid automatic repeat request (HARQ) times by a third preset value; decrease a total quantity of connections between the transceiver and a network device during soft handover of the terminal by a fourth preset value; or decrease a codec data rate of a voice connection of the transceiver by a fifth preset value. ### Claim 18 (depends on 11) The terminal of claim 11, wherein the processor is further configured to: obtain one-to-one correspondences between a plurality of average transmit powers and a plurality of electromagnetic radiation SARs; and determine, from the one-to-one correspondence and the average transmit power, the electromagnetic radiation SAR corresponding to the average transmit power. ### Claim 19 (depends on 18) The terminal of claim 18, wherein the processor is further configured to: obtain the one-to-one correspondences from a local storage of the terminal; or receive, using the transceiver, the one-to-one correspondences from a network device. ### Claim 20 A computer program product comprising computer-executable instructions that are for storage on a non-transitory medium and that, when executed by a processor, cause an apparatus to: separately collect a transmit power of the apparatus at different time points during a second duration after a first duration from a power-on moment to obtain a plurality of transmit powers; calculate an average transmit power of the transmit powers; determine, based on the average transmit power, an electromagnetic radiation specific absorption rate (SAR) corresponding to the average transmit power; determine that the electromagnetic radiation SAR is greater than a preset threshold; and decrease the transmit power after the second duration in response to determining that the electromagnetic radiation SAR is greater than the preset threshold.