# US 10,374,646 B1 · Crowd size estimation based on wireless signal absorption > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,646 B1 - Document ID: US10374646B1 - Status: Granted - Kind: B1 - Application number: 16/225,239 - Filed: 2018-12-19 - Published: 2019-08-08 - Granted: 2019-08-06 - Earliest claimed: 2018-02-07 - Assignees: Cubic Corporation - Applicants: Cubic Corporation - Inventors: Graham Fletcher - Web page: https://patentgrep.com/patent/US10374646B1 ## CPC - H04B 1/1018: {noise filters connected between the power supply and the receiver} - H04B 1/1027: {assessing signal quality or detecting noise/interference for the received signal} - H04B 1/16: Circuits - 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 Methods and devices for detecting wireless signal absorption using power sensing circuitry. One method includes receiving, by a receiving device having power sensing circuitry, a plurality of wireless signals from a plurality of transmitting devices. The power sensing circuitry may include a local oscillator, a mixer, and a band-pass filter. The method may also include detecting, by the power sensing circuitry, a plurality of power levels for the plurality of wireless signals, where each power level of the plurality of power levels corresponds one of the plurality of wireless signals. The method may further include analyzing, by one or more processors, the plurality of power levels to determine three characteristic power levels of the plurality of power levels. The method may further include calculating, by the one or more processors, an absorption amount based on the three characteristic power levels. ## Claims ### Claim 1 A method of estimating crowd size based on detected wireless signal absorption, the method comprising: receiving, by a receiving device, a plurality of wireless signals from a plurality of transmitting devices; detecting a plurality of power levels for the plurality of wireless signals, wherein each power level of the plurality of power levels corresponds to one of the plurality of wireless signals; analyzing, by one or more processors, the plurality of power levels to determine three characteristic power levels of the plurality of power levels; calculating, by the one or more processors, an absorption amount based on the three characteristic power levels; and estimating, by the one or more processors, a number of people based at least in part on the absorption amount. ### Claim 2 (depends on 1) The method of claim 1, wherein a first characteristic power level of the three characteristic power levels is a maximum power level of the plurality of power levels. ### Claim 3 (depends on 2) The method of claim 2, wherein: a second characteristic power level of the three characteristic power levels is a ⅔ percentile power level of the plurality of power levels; and a third characteristic power level of the three characteristic power levels is a ⅓ percentile power level of the plurality of power levels. ### Claim 4 (depends on 3) The method of claim 3, wherein calculating the absorption amount based on the three characteristic power levels includes: calculating a first difference between the first characteristic power level and the third characteristic power level; calculating a second difference between the first characteristic power level and the second characteristic power level; and calculating a ratio between the first difference and the second difference, wherein the absorption amount is calculated based on the ratio. ### Claim 5 (depends on 1) The method of claim 1, wherein the one or more processors are located within the receiving device. ### Claim 6 (depends on 1) The method of claim 1, wherein the one or more processors are located remote to the receiving device. ### Claim 7 A receiving device for estimating crowd size based on detected wireless signal absorption, the receiving device comprising: an antenna for receiving a plurality of wireless signals from a plurality of transmitting devices; power sensing circuitry for detecting a plurality of power levels for the plurality of wireless signals, wherein each power level of the plurality of power levels corresponds to one of the plurality of wireless signals; and one or more processors configured to perform operations including: analyzing the plurality of power levels to determine three characteristic power levels of the plurality of power levels; calculating an absorption amount based on the three characteristic power levels; and estimating a number of people based at least in part on the absorption amount. ### Claim 8 (depends on 7) The receiving device of claim 7, wherein a first characteristic power level of the three characteristic power levels is a maximum power level of the plurality of power levels. ### Claim 9 (depends on 8) The receiving device of claim 8, wherein: a second characteristic power level of the three characteristic power levels is a ⅔ percentile power level of the plurality of power levels; and a third characteristic power level of the three characteristic power levels is a ⅓ percentile power level of the plurality of power levels. ### Claim 10 (depends on 9) The receiving device of claim 9, wherein calculating the absorption amount based on the three characteristic power levels includes: calculating a first difference between the first characteristic power level and the third characteristic power level; calculating a second difference between the first characteristic power level and the second characteristic power level; and calculating a ratio between the first difference and the second difference, wherein the absorption amount is calculated based on the ratio. ### Claim 11 (depends on 7) The receiving device of claim 7, wherein the plurality of power levels are received from the power sensing circuitry via a wireless connection. ### Claim 12 A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform operations including: receiving a plurality of wireless signals from a plurality of transmitting devices; detecting a plurality of power levels for the plurality of wireless signals, wherein each power level of the plurality of power levels corresponds to one of the plurality of wireless signals; analyzing the plurality of power levels to determine three characteristic power levels of the plurality of power levels; calculating an absorption amount based on the three characteristic power levels; and estimating a number of people based at least in part on the absorption amount. ### Claim 13 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein a first characteristic power level of the three characteristic power levels is a maximum power level of the plurality of power levels. ### Claim 14 (depends on 13) The non-transitory computer-readable medium of claim 13, wherein: a second characteristic power level of the three characteristic power levels is a ⅔ percentile power level of the plurality of power levels; and a third characteristic power level of the three characteristic power levels is a ⅓ percentile power level of the plurality of power levels. ### Claim 15 (depends on 14) The non-transitory computer-readable medium of claim 14, wherein calculating the absorption amount based on the three characteristic power levels includes: calculating a first difference between the first characteristic power level and the third characteristic power level; calculating a second difference between the first characteristic power level and the second characteristic power level; and calculating a ratio between the first difference and the second difference, wherein the absorption amount is calculated based on the ratio. ### Claim 16 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the one or more processors are located within a receiving device. ### Claim 17 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the one or more processors are located remote to a receiving device.