RF Exposure

FCC ID: LDKSKMAA2017

RF Exposure Info

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FCCID_4432620

EDCS – (17745507) Maximum Permissible Exposure Study - Engineering Analysis AIR-AP1840I-B-K9 (Dual Band WLAN, BLE) FCC ID: LDKSKMAA2017 2400-2483.5 MHz, 5150-5250 MHz, 5250-5350 MHz, 5470-5725 MHz, 5725-5850 MHz Against the following Specifications: 47 Code of Federal Regulations 2.1091 Cisco Systems 170 West Tasman Drive San Jose, CA 95134 Author: Julian Land Approved By: Gerard Thorpe Tested By: Julian Land Title: Compliance Manager Revision: 1.2 This report replaces any previously entered test report under EDCS – 17745507. This test report has been electronically authorized and archived using the CISCO Doc Central. Test Report Template EDCS# 11556830.

EDCS – (17745507) Attestation Statement of Compliance The AIR-AP1840I-B-K9 has been evaluated for Maximum Permissible Exposure in compliance with 47 Code of Federal Regulations [Part 1.1307(b) (for fixed devices), Part 2.1091 (for mobile devices), and Part 2.1093 (for portable devices)]. Part 1.1307(b) refers to limits in Part 1.1310 and 2.1093. The evaluation was in accordance with methodology as referenced in KDB 447498 D01 General RF Exposure Guidance v06. This report serves as the additional technical analysis of the Cisco radio modules. This study addresses the following transmitters using the data derived in these test reports:  BLE report EDCS# 17812900  2.4GHz DTS report EDCS# 17745506  5GHz UNII-1 report EDCS# 17660837  5GHz UNII-2 report EDCS# 17660838  5GHz UNII-2ext report EDCS# 17660839  5GHz UNII-3 report EDCS# 17660840 The limits used for this evaluation are in line with the recommendations of the World Health Organizations (WHO) International Committee on Non-Ionizing Radiation Protection (ICNIRP) as well as the American National Standards Institute (ANSI) C95.1. The limits chosen are of General Population/Uncontrolled Exposure. The following case scenarios were used:  BLE  2.4GHz WLAN  5GHz WLAN This device must be installed to provide a separation distance of at least 20 cm from all persons. Installers must be provided with antenna installation and transmitter operating conditions for satisfying RF exposure compliance. Based on the study this case scenario, the General Population/Uncontrolled Exposure and the minimum recommended distance is around 20cm (8 inches) from the antenna.

EDCS – (17745507) 1.0 EUT Description AIR-AP1840I is a dual band wireless access point which supports 802.11 a, b, g, n, ac. It features a 2x2 2.4GHz radio, a 4x4 5GHz radio, and a BLE radio. The AIR-AP1840I-B-K9 Supports the following radio modes: 802.11b 802.11g 802.11a Duplicate mode NonHT40 Duplicate mode NonHT80 802.11n20 802.11n40 802.11ac40 802.11ac80 The following antennas are supported by this product series. The data included in this report represent the worst case data for all antennas. Highest Antenna Gain Frequency Port Antenna Type (dBi) 2.4GHz / 5GHz Antenna 1 Internal dual band omni directional 4.4/5.6 2.4GHz / 5GHz Antenna 2 Internal dual band omni directional 4/5.7 BLE / 5GHz Antenna 3 Internal dual band omni directional 4.1/5.6 5GHz Antenna 4 Internal single band omni directional 5.4

EDCS – (17745507) 2.0 Methodology All calculations were made in accordance with ANSI C95.1. Measurement Uncertainty Values Parameter Max MU from Declared MU standard Occupied Channel Bandwidth +/- 5% +/-2% RF Output Power, conducted +/- 1,5dB +/-1.4dB Power Spectral Density, conducted +/- 3dB +/- 2dB Unwanted emissions, conducted +/- 3dB +/- 2dB All emissions, radiated +/- 6dB +/- 3.2dB Temperature +/- 3C +/- 0.7C Supply Voltages +/- 3% +/- 2.5% Time +/- 5% +/-2%

EDCS – (17745507) 3.0 Technical Requirements 3.1 Single Band Operation – Limits FCC Limits for Maximum Permissible Exposure (MPE) (A) Limits for Occupational/Controlled Exposure Frequency Electric Field Magnetic Field Power Density Averaging Time Range Strength (E) Strength (H) (S) |E|2, |H|2 or S (MHz) (V/m) (A/m) (mW/cm2) (minutes) 0.3-3.0 614 1.63 (100)* 6 3.0-30 1842/f 4.89/f (900/f2)* 6 30-300 61.4 0.163 1.0 6 300-1500 -- -- f/300 6 1500-100,000 -- -- 5 6 (B) Limits for General Population/Uncontrolled Exposure Frequency Electric Field Magnetic Field Power Density Averaging Time Range Strength (E) Strength (H) (S) |E|2, |H|2 or S (MHz) (V/m) (A/m) (mW/cm2) (minutes) 0.3-1.34 614 1.63 (100)* 30 1.34-30 824/f 2.19/f (180/f2)* 30 30-300 27.5 0.073 0.2 30 300-1500 -- -- f/1500 30 1500-100,000 -- -- 1.0 30 f = frequency in MHz *Plane-wave equivalent power density NOTE 1: See Section 1 for discussion of exposure categories. NOTE 2: The averaging time for General Population/Uncontrolled exposure to fixed transmitters is not applicable for mobile and portable transmitters. See 47 CFR §§2.1091 and 2.1093 on source- based time-averaging requirements for mobile and portable transmitters.

EDCS – (17745507) 4.0 Calculations Given E=√(30*P*G)/d and S=E^2/3770 where E=Field Strength in Volts/meter P=Power in Watts G=Numeric Antenna Gain d=Distance in meters S=Power Density in mW/cm^2 Combine equations and rearrange the terms to express the distance as a function of the remaining variables: d=√((30*P*G)/(3770*S)) Changing to units of power in mW and distance in cm, using: P(mW)=P(W)/1000 d(cm)=100*d(m) yields d=100*√((30*(P/1000)*G)/(3770*S)) d=0.282*√(P*G/S) where d=Distance in cm P=Power in mW G=Numeric Antenna Gain S=Power Density in mW/cm^2 Substituting the logarithmic form of power and gain using: P(mW)=10^(P(dBm)/10) G(numeric)=10^(G(dBi)/10) yields d=0.282*10^((P+G)/20)/√S Equation (1) and s=((0.282*10^((P+G)/20))/d)^2 Equation (2) where d=MPE distance in cm P=Power in dBm G=Antenna Gain in dBi S=Power Density in mW/cm^2

EDCS – (17745507) 5.0 Results Equation (1) and the measured peak power are used to calculate the MPE distance. Note that for mobile or fixed location transmitters such as an access point, the minimum separation distance is 20 cm even if the calculations indicate that the MPE distance may be less. S=1mW/cm^2 maximum. Using the peak power levels recorded in the test report along with Equation 1 above, the MPE distances are calculated as follows. MPE Calculations: Power Transmit Antenna MPE Frequency Density Power Gain Distance Limit Margin (MHz) (mW/cm2) (dBm) (dBi) (cm) (cm) (cm) BLE 0.000 -1 4.1 0.40 20 19.60 2.4GHz DTS 0.123 19.9 8* 7.00 20 13.00 UNII-1 0.587 22.7 12* 15.32 20 4.68 UNII-2 0.093 20.7 6* 6.10 20 13.90 UNII-2c 0.123 21.9 6* 7.00 20 13.00 UNII-3 0.689 23.4 12* 16.61 20 3.39 *Correlated Gain To maintain compliance, installations will assure a separation distance of at least 20 cm. Using Equation 2, the MPE levels (s) at 20 cm are calculated as follows: MPE Transmit Antenna Power Frequency Distance Power Gain Density Limit Margin (MHz) (cm) (dBm) (dBi) (mW/cm2) (mW/cm2) (mW/cm2) BLE 0.40 -1 4.1 0.000 1 1.000 2.4GHz DTS 7.00 19.9 8* 0.123 1 0.877 UNII-1 15.32 22.7 12* 0.587 1 0.413 UNII-2 6.10 20.7 6* 0.093 1 0.907 UNII-2c 7.00 21.9 6* 0.123 1 0.877 UNII-3 16.61 23.4 12* 0.689 1 0.311 * Correlated Gain

EDCS – (17745507) Calculations with additional transmitters The FCC's MPE limits vary with frequency. Therefore, in mixed or broadband RF fields where several sources and frequencies are involved, the fraction of the recommended limit (in terms of power density or square of the electric or magnetic field strength) incurred within each frequency interval should be determined, and the sum of all fractional contributions should not exceed 1.0, or 100% in terms of percentage. Worst Case Scenario: BLE (Highest power) 2.4GHz WLAN (Highest power) 5GHz WLAN (Highest power) Total Power Densities (Percentages) = 2.4GHz Power Density % + 5GHz Power Density % + BLE Power Density % Total Relative Power Densities (Percentages) = (0.123/1.0)*100 + (0.689/1.0)*100 + (0.00/1.0)*100 = 12.3 % + 68.9 % + 0.0% = 81.2% Distance (estimate) = 20* % = 20*(0.812)^0.5 = 18.03 cm The calculated separation distance of 18.03 cm is less than the 20 cm recommended distance. The configuration above co-location calculation is for General Population/Uncontrolled exposure. The minimum distance recommended is 20 cm (8 inches) when all antennas are within 20 cm of each other.

EDCS – (17745507) References American National Standards Institute (ANSI), "Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz," ANSI/IEEE C95.1-1992 (previously issued as IEEE C95.1-1991). Copyright 1992 by the Institute of Electrical and Electronics Engineers, Inc. (IEEE), New York, N.Y. 10017. For copies contact the IEEE: 1-800-678-4333 or 1-908-981-1393. American National Standards Institute (ANSI), "Recommended Practice for the Measurement of Potentially Hazardous Electromagnetic Fields - RF and Microwave”. ANSI/IEEE C95.3-1992. Copyright 1992, The Institute of Electrical and Electronics Engineers, Inc. (IEEE), New York, NY 10017. For copies contact the IEEE: 1-800-678-4333 or 1-908-981-1393.


Document Created: 2019-09-06 05:03:58
Document Modified: 2019-09-06 05:03:58
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