Exhibit 4 Interference Analysis

0174-EX-PL-2005 Text Documents

TowerStream Corp.

2005-06-10ELS_71325

Interference Analysis Exhibit 4 Page 1 of 8 Study Methodology TowerStream Corp. Protection of Existing FSS and Federal Government Facilities San Francisco, CA The facilities proposed herein by TowerStream have been designed to operate without causing interference to existing FSS earth stations and Federal Government operations in the 3650 - 3700 MHz band. Rules for the deployment of such facilities have been adopted by the Commission in its Report And Order And Memorandum Opinion And Order, FCC 05-56, (ET Docket No. 04-151) adopted March 10, 2005 ("R&O"). In the instant proposal, permission is requested to conduct tests within the 150 km protection zone of existing grandfathered FSS stations. Otherwise, and as described earlier, all base stations and remote devices utilized by TowerStream for these will operate in compliance with Part 15 and within the parameters and power levels adopted in the R&O. To demonstrate protection of incumbent FSS stations in the 3650 - 3700 MHz band located within 150 km of the requested facilities, a detailed interference analysis was conducted to predict the worst-case impact of the proposed operations. The methodology for this analysis involved - identification of all facilities to be studied, - calculation of worst-case antenna patterns for both FSS and proposed facilities, - establishing sample and worst-case test points to model proposed CPE emissions, - selecting an appropriate terrain and propagation model to calculate path losses and - compiling the worst-case parameters of the proposed system elements for use in the studies. Identification of Facilities To Be Considered In Studies No Federal Government radiolocation stations were identified within 80 km of the proposed facilities. The following grandfathered FSS stations were found within 150 km of the proposed service area: Call Sign, File No.: . . . . . . . . . E950208, SESMOD2001032600656 Location . . . . . . . . . . . . . . . . . . THREE PEAKS, CA: 38-8-52, 122-47-38 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.6 km (32.1 miles) . . 320° Call Sign, File No.: . . . . . . . . . E6241, SESMOD2000112902270 Location . . . . . . . . . . . . . . . . . . SAN RAMON, CA: 37-45-40, 121-47-57 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.3 km (33.7 miles) . . . 94° Call Sign, File No.: . . . . . . . . . KA232, SESLIC1997103001576 Location . . . . . . . . . . . . . . . . . . LIVERMORE, CA: 37-45-40, 121-47-53 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.4 km (33.8 miles) . . . 94° Call Sign, File No.: . . . . . . . . . KA86, SESMOD2000022200265 Location . . . . . . . . . . . . . . . . . . MOUNTAIN HOUSE, CA: 37-45-2, 121-35-39 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.4 km (45.0 miles) . . . 94° SAN0605 ComSpec

Interference Analysis Exhibit 4 Page 2 of 8 Study Methodology TowerStream Corp. Protection of Existing FSS and Federal Government Facilities San Francisco, CA Call Sign, File No.: . . . . . . . . . KA206, SESMOD2000022200272 Location . . . . . . . . . . . . . . . . . . MOUNTAIN HOUSE, CA: 37-45-1, 121-35-38 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.4 km (45.0 miles) . . . 94° Call Sign, File No.: . . . . . . . . . KA371, SESRWL1999101201864 Location . . . . . . . . . . . . . . . . . . SALT CREEK (SCK 3A), CA: 38-56-20, 122-8-48 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129.3 km (80.4 miles) . . . 10° Call Sign, File No.: . . . . . . . . . KA372, SESRWL2003103101527 Location . . . . . . . . . . . . . . . . . . SALT CREEK (SCK 1A), CA: 38-56-21, 122-8-49 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129.3 km (80.4 miles) . . . 10° Call Sign, File No.: . . . . . . . . . KA373, SESRWL2000121502350 Location . . . . . . . . . . . . . . . . . . SALT CREEK (SCK 2A), CA: 38-56-22, 122-8-50 Distance, Bearing to: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129.4 km (80.4 miles) . . . 10° --------------------------------- Fixed Satellite Antenna Patterns The antenna pattern and gain for each fixed satellite system receiving antenna was calculated based on the method in the Report and Order and Memorandum Opinion and Order, Appendix D. The antenna pattern is a worst case or maximum envelope pattern which assumes that the antenna is always oriented along the arc at the position which produces the highest gain toward the horizon. For each fixed station, the visible arc with a minimum elevation of five degrees (5º) above the horizon was determined. The antenna was assumed to point first to the Easternmost point on the visible arc. Horizontal azimuths were considered from a bearing of True North or 0º clockwise to 359º at one degree increments. The antenna gain was calculated based on Equations 4 and 5 in Appendix D, implementing Section 25.209(a)(2). The fixed station was then incremented one degree of azimuth along the geostationary orbital arc and the antenna gain was calculated at 360 points around the antenna. The receiving antenna was incremented throughout the viewable arc to the Westernmost point, producing a matrix of antenna gains. Then, for each azimuth around the fixed station antenna, the maximum horizontal gain was extracted to form the antenna pattern. The FSS antenna pattern plots and tabulated data compiled for each facility are provided in Exhibit 2. SAN0605 ComSpec

Interference Analysis Exhibit 4 Page 3 of 8 Study Methodology TowerStream Corp. Protection of Existing FSS and Federal Government Facilities San Francisco, CA Base Station and Customer Premise Equipment Antenna Patterns The antenna patterns for the fixed base station and fixed customer premise equipment antennas were derived from manufacturer's data. The patterns are maximum envelope patterns which are smoothed to incorporate major and minor lobes. The pattern was made symmetrical to allow for inverted installation. The CPE and base station antenna pattern plots and tabulated data are provided in Exhibit 2. Location of Test Points The proposed base station is a high elevation location chosen to provide 16.1 kilometer (10 mile) coverage. The boundary of the proposed service area is a 16.1 kilometer radius circle which is reduced where there are terrain or other obstructions preventing service. Test points are located on the service area boundary beginning at True North (0º) and then at 10º increments for 36 locations. Note that because the boundary is reduced by terrain obstructions, test points which are at reduced distance follow the highest elevation profile around the base station. Two additional points are studied for each fixed satellite station, the theoretical worst case points. One point is located at the service area boundary at its closest point to the fixed satellite station. That is the point nearest to the fixed satellite station where the attenuation due to distance will be at its minimum. The second point is diametrically opposite the closest point. At the farthest point, the customer premises equipment antenna is oriented directly toward the fixed station satellite antenna and therefore provides no antenna pattern discrimination to reduce the signal toward the fixed station antenna. SAN0605 ComSpec

Interference Analysis Exhibit 4 Page 4 of 8 Study Methodology TowerStream Corp. Protection of Existing FSS and Federal Government Facilities San Francisco, CA Propagation parameters The studies were conducted using the Longley-Rice propagation model v1.2.2 as implemented in EDX SignalPro. The terrain data was extracted at 100 meter increments from a 3 arcsecond terrain database. The study uses 4/3 earth radius, ground conductivity of 8.0 mS/M, ground dielectric constant of 15.0, non atmospheric absorption, continental temperate climate, with land use clutter loss and height, ground reflection, and Fresnel zone loss. Rain outage is based on Crane's methods, using Crane 1996 data for region A. Proposed System Parameters The fixed base stations were modeled at an EIRP of 6 watts in 6 MHz. The customer premise equipment was modeled with a directional maximum EIRP of 1 watt in 1 MHz and an antenna height of 31 meters AGL. The customer premise equipment was oriented toward the base station antenna in both azimuth and elevation. The operating power of the customer premise equipment was fixed at its maximum without use of adaptive power control in order to provide a worst case signal toward the fixed satellite station. The allowable interference level, based on ITU-R S.1432, to reach delta T/T of 0.5% is -170.1 dBW. A summary of the study results for each FSS location is provided on the following pages. Details of the path studies for both the base station and CPE test locations are attached as Annex 1. SAN0605 ComSpec

Interference Analysis Exhibit 4 Page 5 of 8 TowerStream Corp. Customer Terminal Test Location Information San Francisco, CA Customer North Latitude West Longitude Site Received Azimuth to Elevation Distance CT001 37-48-32.54 122-24-51.44 1.9 -58.4 180.0 5.2 1.8 CT002 37-56-9.19 122-22-57.22 0.0 -72.2 190.0 0.6 16.1 CT003 37-55-45.64 122-21-6.47 14.9 -72.2 199.9 0.5 16.1 CT004 37-55-7.18 122-19-22.56 29.3 -72.2 209.9 0.5 16.1 CT005 37-54-14.99 122-17-48.64 45.8 -72.2 219.9 0.4 16.1 CT006 37-53-10.65 122-16-27.56 69.4 -72.1 229.9 0.3 16.1 CT007 37-51-56.12 122-15-21.8 94.0 -72.1 239.9 0.2 16.1 CT008 37-50-33.65 122-14-33.34 73.2 -72.1 250.0 0.3 16.1 CT009 37-49-5.76 122-14-3.67 56.0 -72.1 260.0 0.4 16.1 CT010 37-47-35.12 122-13-53.68 51.6 -72.1 270.0 0.4 16.1 CT011 37-46-4.48 122-14-3.67 0.0 -72.2 280.1 0.6 16.1 CT012 37-44-36.59 122-14-33.34 0.0 -72.2 290.1 0.6 16.1 CT013 37-46-44.23 122-23-0.36 0.0 -59.6 300.1 3.0 3.1 CT014 37-46-17.95 122-22-55.45 0.0 -60.6 310.1 2.5 3.7 CT015 37-45-59.15 122-23-9.97 0.3 -60.9 320.1 2.4 3.9 CT016 37-43-1.62 122-21-32.47 0.0 -67.9 330.1 1.0 9.7 CT017 37-43-44.58 122-23-5.7 40.5 -65.7 340.1 0.9 7.6 CT018 37-42-42.62 122-23-46.45 61.9 -105.1 350.0 0.6 9.2 CT019 37-41-41.73 122-24-51.44 120.5 -68.8 0.0 0.2 10.9 CT020 37-41-55.84 122-26-6.82 228.8 -68.6 10.0 -0.4 10.6 CT021 37-44-29.21 122-26-16.7 170.2 -63.7 19.9 -0.1 6.1 CT022 37-44-57.8 122-26-45.89 240.5 -63.1 29.9 -0.8 5.6 CT023 37-45-23.96 122-27-10.12 215.9 -62.5 39.9 -0.6 5.3 CT024 37-45-17.55 122-28-18.03 171.5 -64.4 49.9 -0.1 6.6 CT025 37-45-15.75 122-29-55.63 42.4 -66.8 59.9 0.8 8.6 CT026 37-45-58.71 122-30-25.21 29.3 -66.9 69.9 0.9 8.7 CT027 37-46-50.8 122-30-8.2 120.9 -65.9 80.0 0.3 7.9 CT028 37-47-35.12 122-28-46.26 54.7 -63.4 90.0 1.1 5.7 CT029 37-48-7.02 122-28-39.46 47.3 -63.3 100.1 1.2 5.7 CT030 37-49-34.56 122-31-44.94 49.1 -68.7 110.1 0.6 10.7 CT031 37-49-53.7 122-29-53.92 179.3 -66.6 120.1 -0.1 8.5 CT032 37-50-44.7 122-29-36.13 190.6 -67.2 130.1 -0.2 9.1 CT033 37-54-14.99 122-31-54.24 64.6 -72.2 140.1 0.4 16.1 CT034 37-54-36.44 122-29-57.96 93.8 -71.5 150.1 0.3 15.0 CT035 37-53-18.48 122-27-28.92 124.7 -69.1 160.1 0.2 11.3 CT036 37-48-35.78 122-25-4.92 5.1 -57.8 170.1 4.7 1.9 CT116 37-43-46.3 122-15-0.24 0.0 -72.2 296.1 0.6 16.1 CT153 37-42-57.69 122-21-53.31 0.0 -67.8 333.1 1.0 9.6 CT156 37-43-43.36 122-22-41.42 59.4 -66.0 336.1 0.8 7.8 CT273 37-47-46.5 122-28-45.82 42.6 -63.4 93.5 1.2 5.7 CT283 37-48-51 122-31-45.59 0.0 -68.4 103.0 0.9 10.4 CT318 37-51-24.11 122-29-11.25 41.7 -67.6 138.1 0.7 9.5 CT328 37-54-57.8 122-30-40 59.6 -72.2 148.1 0.4 16.1 CT336 37-53-32.77 122-28-12.09 121.0 -69.7 156.1 0.2 12.1 CT362 37-56-16.8 122-24-28.48 46.5 -72.2 182.0 0.4 16.1 CT093 37-47-3.25 122-13-54.9 31.9 -72.2 273.6 0.5 16.1 CT120 37-46-44.23 122-23-0.36 0.0 -59.6 300.1 3.0 3.1 CT300 37-49-53.7 122-29-53.92 179.3 -66.6 120.1 -0.1 8.5 SAN0605 ComSpec

Interference Analysis Exhibit 4 Page 6 of 8 TowerStream Corp. Study #1: Three Peaks, CA: E950208 San Francisco, CA Received Margin Distance Signal (dB) Azimuth to Three Level Relative Customer Azimuth to Three Peaks Path loss from CT to -170.1 Terminal to hub Peaks (km) (dB) (dBW) dBW CT001 180.0 318.7 50.2 243.5 -289.6 119.5 CT002 190.0 303.3 43.0 242.7 -282.4 112.3 CT003 199.9 302.2 45.7 241.6 -274.8 104.7 CT004 209.9 301.8 48.5 242.5 -275.5 105.4 CT005 219.9 302.0 51.3 242.5 -275.5 105.4 CT006 229.9 302.7 54.0 240.8 -274.1 104.0 CT007 239.9 303.8 56.6 238.0 -268.5 98.4 CT008 250.0 305.2 59.0 246.5 -277.5 107.4 CT009 260.0 306.9 61.2 242.4 -274.0 103.9 CT010 270.0 308.8 63.1 241.4 -265.9 95.8 CT011 280.1 310.9 64.7 242.3 -265.3 95.2 CT012 290.1 313.1 66.0 240.5 -262.2 92.1 CT013 300.1 318.9 54.5 244.5 -259.4 89.3 CT014 310.1 319.3 55.2 244.6 -252.1 82.0 CT015 320.1 320.0 55.4 244.9 -250.3 80.2 CT016 330.1 321.6 61.2 246.8 -254.1 84.0 CT017 340.1 322.3 58.5 247.5 -262.1 92.0 CT018 350.0 324.4 59.7 251.4 -277.8 107.7 CT019 0.0 326.6 60.3 252.7 -279.5 109.4 CT020 10.0 327.9 59.0 252.2 -284.0 113.9 CT021 19.9 325.5 54.9 251.6 -288.1 118.0 CT022 29.9 325.6 53.8 251.5 -288.2 118.1 CT023 39.9 325.6 52.8 251.6 -291.3 121.2 CT024 49.9 327.2 52.0 251.6 -291.6 121.5 CT025 59.9 329.5 50.8 250.2 -290.7 120.6 CT026 69.9 329.4 49.3 250.1 -290.6 120.5 CT027 80.0 328.0 48.1 251.5 -297.8 127.7 CT028 90.0 325.2 48.1 251.5 -297.3 127.2 CT029 100.1 324.3 47.4 250.9 -298.2 128.1 CT030 110.1 327.1 42.6 249.7 -297.5 127.4 CT031 120.1 323.7 43.6 247.3 -294.4 124.3 CT032 130.1 322.0 42.7 253.8 -297.4 127.3 CT033 140.1 319.8 35.5 234.8 -276.1 106.0 CT034 150.1 315.8 36.9 233.3 -275.5 105.4 CT035 160.1 314.5 41.2 233.6 -278.7 108.6 CT036 170.1 318.9 49.9 243.2 -289.2 119.1 CT140 320.1 320.0 55.4 244.9 -250.3 80.2 CT320 140.1 319.8 35.5 234.8 -276.1 106.0 Max 128.1 Min 80.2 Mean 108.1 Note: Details of these path studies are attached as Annex 1-1. SAN0605 ComSpec

Interference Analysis Exhibit 4 Page 7 of 8 TowerStream Corp. Study #2: Salt Creek, CA: KA371, KA372, KA373 San Francisco, CA Received Margin Distance Signal (dB) Azimuth to Salt Level Relative Customer Azimuth to Salt Creek Path loss from CT to -170.1 Terminal to hub Creek (km) (dB) (dBW) dBW CT001 180.0 10.4 127.7 248.9 -296.4 126.3 CT002 190.0 10.4 113.4 247.4 -293.1 123.0 CT003 199.9 9.0 113.6 246.2 -293.9 123.8 CT004 209.9 7.7 114.4 242.5 -293.3 123.2 CT005 219.9 6.4 115.7 260.4 -311.2 141.1 CT006 229.9 5.4 117.5 255.9 -306.7 136.6 CT007 239.9 4.5 119.7 259.2 -308.3 138.2 CT008 250.0 3.9 122.1 260.1 -309.3 139.2 CT009 260.0 3.5 124.8 261.1 -304.2 134.1 CT010 270.0 3.3 127.6 261.3 -304.4 134.3 CT011 280.1 3.3 130.4 257.6 -300.7 130.6 CT012 290.1 3.6 133.1 256.4 -299.5 129.4 CT013 300.1 9.0 130.6 249.9 -293.0 122.9 CT014 310.1 8.9 131.3 248.8 -288.7 118.6 CT015 320.1 9.0 132.0 250.6 -290.5 120.4 CT016 330.1 7.7 137.0 242.0 -273.4 103.3 CT017 340.1 8.7 136.1 249.5 -279.5 109.4 CT018 350.0 9.0 138.1 252.2 -272.2 102.1 CT019 0.0 9.5 140.2 248.3 -260.5 90.4 CT020 10.0 10.3 140.1 251.0 -260.8 90.7 CT021 19.9 10.7 135.5 250.5 -262.2 92.1 CT022 29.9 11.1 134.8 247.3 -266.9 96.8 CT023 39.9 11.4 134.1 248.3 -278.1 108.0 CT024 49.9 12.0 134.6 250.2 -281.1 111.0 CT025 59.9 13.0 135.2 245.0 -284.4 114.3 CT026 69.9 13.4 134.1 249.6 -289.0 118.9 CT027 80.0 13.4 132.4 254.5 -296.4 126.3 CT028 90.0 12.7 130.6 248.1 -290.9 120.8 CT029 100.1 12.8 129.6 250.5 -293.3 123.2 CT030 110.1 15.0 128.1 256.9 -299.4 129.3 CT031 120.1 13.9 126.8 249.8 -293.3 123.2 CT032 130.1 13.9 125.2 248.8 -297.5 127.4 CT033 140.1 16.1 119.8 251.0 -299.3 129.2 CT034 150.1 14.9 118.4 249.3 -299.6 129.5 CT035 160.1 13.0 119.9 246.7 -297.1 127.0 CT036 170.1 10.6 127.7 250.5 -299.5 129.4 CT_10 190.0 10.4 113.4 247.4 -293.1 123.0 CT190 10.0 10.3 140.1 251.0 -260.8 90.7 max 141.1 min 90.4 mean 119.9 Note: Details of these path studies are attached as Annex 1-2. SAN0605 ComSpec

Interference Analysis Exhibit 4 Page 8 of 8 Study #3: San Ramon - Livermore - Mountain House, CA TowerStream Corp. E6241,KA232, KA86, KA206 San Francisco, CA Received Margin Distance Signal (dB) Azimuth to San Level Relative Customer Azimuth to San Ramon Path loss from CT to -170.1 Terminal to hub Ramon (km) (dB) (dBW) dBW CT001 180.0 95.5 54.3 232.3 -264.6 94.5 CT002 190.0 110.6 54.8 238.6 -277.5 107.4 CT003 199.9 110.9 52.0 239.7 -278.7 108.6 CT004 209.9 110.7 49.2 239.9 -278.8 108.7 CT005 219.9 109.9 46.5 244.8 -288.1 118.0 CT006 229.9 108.3 43.9 246.6 -290.7 120.6 CT007 239.9 106.0 41.8 243.0 -288.0 117.9 CT008 250.0 103.0 40.0 238.2 -282.0 111.9 CT009 260.0 99.3 38.8 238.9 -278.5 108.4 CT010 270.0 95.2 38.2 233.0 -269.7 99.6 CT011 280.1 91.0 38.3 229.6 -263.5 93.4 CT012 290.1 87.0 39.0 224.5 -258.2 88.1 CT013 300.1 92.0 51.4 230.9 -268.7 98.6 CT014 310.1 91.1 51.2 231.4 -268.6 98.5 CT015 320.1 90.5 51.6 231.8 -266.7 96.6 CT016 330.1 84.2 49.5 220.5 -249.6 79.5 CT017 340.1 85.9 51.6 220.9 -246.6 76.5 CT018 350.0 83.9 52.8 234.1 -256.9 86.8 CT019 0.0 82.1 54.6 223.1 -244.2 74.1 CT020 10.0 82.8 56.3 220.3 -242.0 71.9 CT021 19.9 87.6 56.2 222.4 -248.9 78.8 CT022 29.9 88.5 56.9 221.8 -245.8 75.7 CT023 39.9 89.3 57.4 224.9 -249.7 79.6 CT024 49.9 89.1 59.1 238.6 -255.8 85.7 CT025 59.9 89.1 61.5 241.9 -256.6 86.5 CT026 69.9 90.3 62.2 233.1 -240.9 70.8 CT027 80.0 91.8 61.8 230.9 -231.1 61.0 CT028 90.0 93.2 59.9 230.8 -228.6 58.5 CT029 100.1 94.2 59.8 230.8 -229.5 59.4 CT030 110.1 96.2 64.5 239.9 -244.2 74.1 CT031 120.1 97.1 61.9 223.7 -240.7 70.6 CT032 130.1 98.6 61.7 218.7 -239.5 69.4 CT033 140.1 103.7 66.2 226.5 -249.9 79.8 CT034 150.1 104.9 63.7 227.5 -259.8 89.7 CT035 160.1 103.6 59.6 225.4 -258.5 88.4 CT036 170.1 95.5 54.6 232.8 -265.1 95.0 CT273 93.5 93.7 38.1 234.5 -268.4 98.3 CT093 273.6 93.5 59.9 231.0 -229.0 58.9 max 120.6 min 58.5 mean 87.9 Note: Details of these path studies are attached as Annex 1-3. SAN0605 ComSpec


Document Created: 2005-06-09 16:50:05
Document Modified: 2005-06-09 16:50:05
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC