WP7700 Module FCC MPE Evaluation

FCC ID: N7NWP77

RF Exposure Info

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FCCID_3875534

MPE Evaluation for WP7700 Radio Module May 31, 2018

1. Introduction In this application we seek modular approval for the WP7700 radio module for use in standalone and collocated simultaneous transmission under mobile and fixed configurations. This Maximum Permissive Exposure (MPE) report demonstrates compliance analysis for WP7700 radio module with FCC CFR 47 §2.1091 and IC RSS-102 for standalone and collocated transmission in the exposure conditions where 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. The MPE analysis is limited for US / Canada bands only. The general population/uncontrolled exposure limits are applicable to situations in which the general public may be exposed or in which persons who are exposed as a consequence of their employment may not be made fully aware of the potential for exposure or cannot exercise control over their exposure.

2. RF Exposure Limits and Equations FCC Limits: According to FCC OET Bulletin 65 Supplement C, the criteria listed in Table 1 shall be used to evaluate the environmental impact of human exposure to radio frequency (RF) radiation as specified in §1.1307. Table 1 : Limits for Maximum Permissible Exposure (MPE) IC Limits: IC has adopted the RF field strength limits established in Health Canada’s RF exposure guideline. The limits are shown in Table 2 below per RSS-102. Table 2 : RF Field Strength Limits for Devices Used by the General Public (Uncontrolled Environment)

In the frequency range of 300-6000 MHz, the IC limits are more stringent than the FCC limits. The MPE evaluation in this report will be based on the IC limits, so the deduced output power and antenna gain limits will guarantee compliance with both FCC and IC requirements. EQUATIONS: EIRP (dBm) = Conducted Power (dBm) + Antenna Gain (dBi) Power density is given by : S = EIRP / (4 π * D^2) where S = Power density (mW/cm^2) EIRP = Equivalent Isotropic Radiated Power (mW) D = Separation distance (cm)

3. WP7700 Product Specifications WP7700 will transmit on only one band and mode of operation at any one time. Table 3 lists the supported frequency bands in Canada/USA and the maximum power in each of those bands. Technology Band UL Freq. (MHz) Max Power (dBm) 2 1850 – 1910 24 4 1710 – 1755 24 5 824 – 849 24 LTE CAT-M1/NB1 12 699 – 716 24 13 777 – 787 24 17 704 – 716 24 26 814 – 849 24 Table 3: WP7700 Frequency Bands and Output Power 4. Stand-Alone Transmission When WP7700 module transmits as a stand-alone mobile device, the source-based time-averaged EIRP is calculated by summing up conducted power and antenna gain. A 100% duty cycle is used for the calculations in LTE mode to present a worse-case analysis. The actual duty cycle is much smaller. The antenna gains are chosen so that the resulted radiated power levels are within the limits specified by the FCC rules and IC Radio Standards Specifications (RSS). The IC exemption limits for routine RF exposure evaluation are calculated using the lowest frequency of the operating band presenting the most stringent limits. As shown in Table 2 below, the resulted EIRP are always below the IC exemption limits for all the operating modes. Source- Max Max Based Time- Time- Max IC Time- TX Freq Range Avg Avg Ant Duty Exemption ERP/EIRP Operating Mode Averaged (MHz) Cond Cond Gain Cycle Limit Limits Max Power Power (dBi) (EIRP) EIRP (dBm) (W) 2W LTE Band 2 1850 1910 24 0.25 9 100% 33.00 33.50 EIRP 1W LTE Band 4 1710 1755 24 0.25 6 100% 30.00 33.27 EIRP 7W LTE Band 5 824 849 24 0.25 7 100% 31.00 31.10 ERP 3W LTE Band 12 699 716 24 0.25 6 100% 30.00 30.61 ERP 3W LTE Band 13 777 787 24 0.25 6 100% 30.00 30.93 ERP 3W LTE Band 17 704 716 24 0.25 6 100% 30.00 30.63 ERP

7W LTE Band 26 814 849 24 0.25 6 100% 30.00 31.06 ERP Table 2: WP7700 Stand-Alone Transmission 5. Collocated Transmission When WP7700 module co-transmits with radio transmitter(s) as a mobile device, per KDB 447498 D01, simultaneous transmission MPE test exclusion applies when the sum of the MPE ratios for all simultaneous transmitting antennas incorporated in a host device, based on the calculated/estimated, numerically modeled or measured field strengths or power density, is ≤ 1.0. The evaluation here considers a WiMAX or WLAN transmitter, and a Bluetooth transmitter as collocated transmitters. Their radiated output power levels are listed in Table 3 below. The MPE ratio is defined by the ratio of power density to MPE limit. The sum of the MPE ratios is calculated as follows: ∑𝑀𝑃𝐸 𝑅𝑎𝑡𝑖𝑜 = Max (WP7700 MPE ratio) + Max (WLAN/WiMax MPE ratio) + BT MPE Ratio = 0.864+0.121+0.012=0.997 < 1.0 Source- Max Max Based Time- Max Power IC Time-Avg Time- IC Power TX Freq Range Avg Ant Duty Density MPE Operating Mode Cond Averaged Density (MHz) Cond Gain Cycle @20 cm Limit Power Max MPE Ratio Power (dBi) (W/m^2) (W/m2) (W) EIRP (dBm) LTE Band 2 1850 1910 24 0.25 8 100% 32.00 3.15 4.48 0.704 LTE Band 4 1710 1755 24 0.25 6 100% 30.00 1.99 4.24 0.469 LTE Band 5 824 849 24 0.25 6 100% 30.00 1.99 2.58 0.772 LTE Band 12 699 716 24 0.25 6 100% 30.00 1.99 2.30 0.864 LTE Band 13 777 787 24 0.25 6 100% 30.00 1.99 2.47 0.804 LTE Band 17 704 716 24 0.25 6 100% 30.00 1.99 2.31 0.860 LTE Band 26 814 849 24 0.25 6 100% 30.00 1.99 2.55 0.779 WLAN 2.4 GHz 2400 2500 100% 25 0.63 5.35 0.118 WLAN 5 GHz 5150 5850 100% 27 1.00 9.01 0.111 2300 2400 100% 25 0.63 5.19 0.121 WiMAX 2500 2700 100% 25 0.63 5.50 0.114 3300 3800 100% 25 0.63 6.65 0.095 Bluetooth 2400 2500 100% 15 0.06 5.35 0.012 Table 3: WP7700 Collocated Transmission

6. Conclusion The analysis presented in this report concludes that the WP7700 radio module, when transmitting either in standalone or simultaneously with other co-located radio transmitters within a host device, is compliant with the FCC/IC RF exposure requirements in mobile exposure condition, provided the conducted power and antenna gain do not exceed the limits in Table 4 for each given frequency band and operating mode. Antenna Gain Limits EIRP Limits of TX Freq Range (dBi) Collocated Radio Operating Mode (MHz) Stand- Transmitters Collocated (dBm) Alone LTE Band 2 1850 1910 9 8 LTE Band 4 1710 1755 6 6 WP7700 LTE Band 5 824 849 7 6 LTE Band 12 699 716 6 6 6 6 LTE Band 13 777 787 6 6 LTE Band 17 704 716 LTE Band 26 814 849 7 6 WLAN 2.4 GHz 2400 2500 25 Collocated Radio Transmitters WLAN 5 GHz 5150 5850 27 2300 2400 25 WiMAX 2500 2700 25 3300 3800 25 Bluetooth 2400 2500 15 Table 4: WP7700 RF Exposure Conditions


Document Created: 2018-05-31 14:00:35
Document Modified: 2018-05-31 14:00:35
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