RF Exposure

FCC ID: 2AF6B-RAK724X

RF Exposure Info

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FCCID_4246353

RF Exposure Evaluation For FCC ID: 2AF6B-RAK724X Refer user manual this device is a Outdoor LoRa Gateway, and this device was designed used in Mobile devices that the minimum distance between human’s body is 20cm. Based on the 47CFR 2.1091, this device belongs to Mobile device. The definition of the category as following: Mobile Derives: CFR Title 47 §2.1091(b) (b) For purposes of this section, a mobile device is defined as a transmitting device designed to be used in other than fixed locations and to generally be used in such a way that a separation distance of at least 20 centimeters is normally maintained between the transmitter’s radiating structure(s) and the body of the user or nearby persons. FCC KDB 447498 D01 General RF Exposure Guidance v06 Limit Devices operating in standalone mobile exposure conditions may contain a single transmitter or multiple transmitters that do not transmit simultaneously. A minimum test separation distance ≥ 20 cm is required between the antenna and radiating structures of the device and nearby persons to apply mobile device exposure limits. The distance must be fully supported by the operating and installation configurations of the transmitter and its antenna(s), according to the source-based time-averaged maximum power requirements of § 2.1091(d)(2). In cases where cable losses or other attenuations are applied to determine compliance, the most conservative operating configurations and exposure conditions must be evaluated. The minimum test separation distance required for a device to comply with mobile exposure conditions must be clearly identified in the installation and operating instructions, for all installation and exposure conditions, to enable users and installers to comply with RF exposure requirements. For mobile devices that have the potential to operate in portable device exposure conditions, similar to the configurations described in § 2.1091(d)(4), a KDB inquiry is required to determine the SAR test requirements for demonstrating compliance. When the categorical exclusion provision of § 2.1091(c) applies, the minimum test separation distance may be estimated, when applicable, by simple calculations according to plane-wave equivalent conditions, to ensure the transmitter and its antenna(s) can operate in manners that meet or exceed the estimated distance. The source-based time-averaged maximum radiated power, according to the maximum antenna gain, must be applied to calculate the field strength and power density required to establish the minimum test separation distance. When the estimated test separation distance becomes overly conservative and does not support compliance, MPE measurement or computational modeling may be used to determine the required minimum separation distance.

According to FCC Part 1.1307, systems operating under the provisions of this section shall be operated in a manner the ensures that the public is not exposed to radio frequency energy level in excess of the commission’s guidelines. Limits for General Population/ Uncontrolled Exposure Frequency Range Electric Field Magnetic Field Power Density (MHz) Strength(E)(V/m) Strength (H)(A/m) (S)(mW/cm2) 0.3-1.34 614 1.63 (100)* 1.34-30 824/f 2.19/f (180/f2)* 30-300 27.5 0.073 0.2 300-1500 f/1500 1500-100,000 1.0 MPE calculation formula Where: S = power density P = output power (mW) G = power gain of the antenna in the direction of interest relative to an isotropic radiator R = Separation distance between radiator and human body (cm) Test data WCDMA Band2 Mode Low Channel Middle Channel High Channel EIRP (dBm) 25.43 24.91 25.74 Note: This report listed the worst case EIRP power value, please refer to RF report BL-SZ1920035-501. WCDMA Band4 Mode Low Channel Middle Channel High Channel EIRP (dBm) 26.08 24.71 24.87 Note: This report listed the worst case EIRPpower value, please refer to RF report BL-SZ1920035-501. WCDMA Band5 Mode Low Channel Middle Channel High Channel ERP (dBm) 24.68 25.81 27.07 Note: This report listed the worst case ERP power value, please refer to RF report BL-SZ1920035-501.

LTE Band2 Bandwidth (MHz) 5 UL Channel Middle Channel UL Modulation QPSK EIRP (dBm) 27.99 LTE Band4 Bandwidth (MHz) 3 UL Channel Low Channel UL Modulation Q16 EIRP (dBm) 27.80 LTE Band5 Bandwidth (MHz) 1.4 UL Channel Low Channel UL Modulation Q16 ERP (dBm) 27.05 LTE Band12 Bandwidth (MHz) 10 UL Channel Middle Channel UL Modulation Q16 ERP (dBm) 22.47 LTE Band13 Bandwidth (MHz) 5 UL Channel High Channel UL Modulation QPSK ERP (dBm) 24.65 Note: This report listed the worst case ERP/EIRP power value, please refer to RF report BL-SZ1920035-501. 2.4 G WLAN Average Power (dBm) Mode Low Middle High 802.11b 16.57 15.75 15.54 802.11g 14.15 13.16 13.22 802.11n-20 12.84 11.56 11.58 802.11n-40 12.17 10.99 10.96 Note: This report listed the worst case Average power value, please refer to RF report BL-SZ1920035-601. Lora O-QPSK Mode Low Channel Middle Channel High Channel Peak Power (dBm) 10.32 11.20 12.34

Note: This report listed the worst case peak power value, please refer to RF report BL-SZ1920035-602. Turn-up power Mode ERP/EIRP Tune up Limit (dBm) WCDMA Band2 26.00 WCDMA Band4 26.50 WCDMA Band5 27.50 LTE Band2 28.50 LTE Band4 28.00 LTE Band5 27.50 LTE Band12 23.00 LTE Band13 25.00 Mode Average Power Tune up Limit (dBm) 802.11b 17.00 802.11g 15.00 802.11n-20 13.00 802.11n-40 12.50 Mode Peak Power Tune up Limit (dBm) Lora 12.50

Test result Maximum Antenna Limit of Total Power Power Evolution ERP/EIRP Gain Distance Power Power Density Density/ Verdict mode power (typical) (cm) Density (mw) (mW/cm²) Limit (dBm) (dBi) (mW/cm²) WCDMA 26.00 3.0 794.33 20 1 0.1580 0.1580 Pass Band2 WCDMA 26.50 3.0 891.25 20 1 0.1773 0.1773 Pass Band4 WCDMA 27.50 1.0 707.95 20 0.551 0.1408 0.2555 Pass Band5 LTE 28.50 3.0 1412.54 20 1 0.2810 0.2810 Pass Band2 LTE 28.00 3.0 1258.93 20 1 0.2505 0.2505 Pass Band4 LTE 27.50 1.0 707.95 20 0.550 0.1408 0.2560 Pass Band5 LTE 23.00 1.0 251.19 20 0.468 0.0500 0.1068 Pass Band12 LTE 25.00 1.0 398.11 20 0.521 0.0792 0.1520 Pass Band13 Maximum Antenna Limit of Total Power Power Evolution Average Gain Distance Power Power Density Density/ Verdict mode power (typical) (cm) Density (mw) (mW/cm²) Limit (dBm) (dBi) (mW/cm²) 2.4 G 17.00 3.5 112.20 20 1 0.0223 0.0223 Pass WLAN Maximum Antenna Limit of Total Power Power Evolution Peak Gain Distance Power Power Density Density/ Verdict mode power (typical) (cm) Density (mw) (mW/cm²) Limit (dBm) (dBi) (mW/cm²) Lora 12.50 5.5 63.10 20 0.601 0.0126 0.0210 Pass Collocated Power Density Calculation Σ(Power Density / Limit) Power of Evolution mode Frequency(MHz) Verdict Density/Limit WWAN + Bluetooth + Zigbee WWAN 1850MHz ~ 1910MHz 0.2810 Pass (LTE Band2) 0.3243 2.4 G WLAN 2400MHz ~ 2483.5MHz 0.0223 Pass Lora 902MHz ~ 928MHz 0.0210 Pass

Note: 1. Σ(Power Density / Limit): This is a summation of [(power density for each transmitter/ antenna included in the simultaneous transmission)/ (corresponding MPE limit)], for WWAN + 2.4G WLAN + Lora. 2. WWAN, 2.4G WLAN and Lora can transmit simultaneously, the formula of calculated the MPE is CPD1 / LPD1 + CPD2 / LPD2 + ……etc. < 1 CPD = Calculation power density LPD = Limit of power density 3. The worst-case situation is 0.3243, which is less than “1”. This confirmed that the device comply with FCC 1.1310 MPE limit. 4. The Outdoor LoRa Gateway work frequency range used is 1850 MHz ~ 1910 MHz, 1710 MHz ~ 1755 MHz, 824 MHz ~ 849 MHz, 699 MHz ~ 716 MHz, 777 MHz ~ 787 MHz, 2400 MHz ~ 2483.5 MHz, 902 MHz ~ 928 MHz the result close to the limit by the above formula so, we select worst case power to calculate the exclusion power threshold. 5. More power list please refer to RF test report. Conclusion: RF exposure Evaluation Results: Compliance


Document Created: 2019-04-15 22:00:57
Document Modified: 2019-04-15 22:00:57
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