Response to FCC Questions

0165-EX-ST-2006 Text Documents

Mobile Satellite Ventures Subsidiary LLC

2006-05-31ELS_76298

Answers to FCC’s Questions Dated May 5, 2006 FCC File # 0165-EX-ST-2006 May 31, 2006 Question 1. Measured out-of-channel and out-of-band emissions data on its base station and customer premises equipment transmitters, including the frequencies of the second and third harmonics of the carrier frequency The following figure and tables provide measurement data for out-of-channel emissions (OOCE) and out-of-band emissions (OOBE) and subsequent analyses of OOCE and OOBE for the BTS and CPE. Figure 1 provides measurement data for the carrier spectrum mask, centered at 1553.00 MHz, at the output of the L-band Radio which is used for both BTS and CPE. The carrier bandwidth is 4.375 MHz. Therefore, the lower and upper edge of the carrier is at 1550.81 MHz and 1555.19 MHz, respectively. 1 For the BTS, in order to achieve higher data throughput while maintaining an adequate link margin for the downlink (BTS to CPE), the Radio output will be further amplified by a power amplifier (see Appendix 1 for PA specifications). Please note that the PA will be operating with an 8-10 dB back- off from the P1dB power level. Finally, to ensure that OOCE and OOBE requirements are met, a cavity filter is installed between the output of the PA and the input of the antenna (see Appendix 2 for cavity filter specifications). Please note that the measurements show the center marker at 1552.87MHz, instead of 1553.00MHz, as the latter is the DC tone and its amplitude is not indicative of traffic tones. 1 On this day, MSV has filed an amendment to its pending application to modify slightly its center frequency. The center frequency and frequency range listed in the original application were incorrectly specified due to miscommunication with the equipment manufacturer. Page 1 of 15

Figure 1: Carrier Spectrum Mask Measurements Page 2 of 15

BTS OOCE Analysis The following table provides analysis of OOCE from trial BTS into adjacent MSS L- band. Analysis of OOCE from BTS into Adjacent Band Parameter Trial Units Remarks Transmit Frequency 1553.0 MHz Number of BTS 1 BTS PA Output Power 10 dBW BTS Tx Bandwidth 4.375 MHz Transmission loss -2.0 dB BTS Tx PSD (at antenna input) 1.6 dBW/MHz Activation Loss -1.25 dB TDD 3:1 OOCE Rejection -45.3 dBc @ 1550.00MHz Additional Filter -25.0 dB @ 1550.00MHz Effective BTS OOCE power density -70.0 dBW/MHz OOCE Limit for L-band BTS -57.9 dBW/MHz (47 C.F.R. § 25.253(b)) Margin 12.1 dB CPE OOCE Analysis The following table provides analysis of OOCE from trial CPE into adjacent MSS L- band. Analysis of OOCE from CPE into Adjacent Band Parameter Trial Units Remarks Transmit Frequency 1553.0 MHz Number of CPEs 10 CPE PA Output -12 dBW CPE Tx Antenna Gain 12 dBi CPE Transmit EIRP 0 dBW CPE Tx Bandwidth 4.375 MHz CPE Tx PSD -6.4 dBW/MHz Activation loss -16.02 dB TDD 3:1; 10 CPEs in TDMA OOCE Rejection -45.3 dBc @ 1550.00MHz Effective CPE OOCE EIRP density -67.8 dBW/MHz OOBE Limit for Broadband PCS -43 dBW/MHz (47 C.F.R. § 24.238(a)) Margin 24.8 dB Page 3 of 15

BTS OOBE Analysis into GPS The following table provides analysis of OOBE from trial BTS into GPS band. Analysis of OOBE from BTS into GPS Parameter Trial Units Remarks Transmit Frequency 1553.0 MHz Number of BTS 1 BTS PA Output Power 10 dBW Transmission loss -2 dB BTS Tx Antenna Gain 16 dBi BTS Transmit EIRP 24 dBW BTS Tx Bandwidth 4.375 MHz BTS Tx PSD 17.6 dBW/MHz Activation Loss 0.00 dB OOBE Rejection in GPS band@1558.5MHz -60.5 dBc Additional Filter -60.0 dB Effective BTS OOBE EIRP density -102.9 dBW/MHz OOBE Limit for L-band BTS and User -70.0 dBW/MHz Terminals (47 C.F.R. § 25.253(c)(9), (g)(3)) Margin 32.9 dB Page 4 of 15

CPE OOBE into GPS The following table provides OOBE from trial CPE into GPS band. Analysis of OOBE from CPE into GPS Parameter Trial Units Remarks Transmit Frequency 1553.0 MHz Number of CPEs 10 CPE PA Output Power -12 dBW CPE Tx Antenna Gain 12 dBi CPE Transmit EIRP 0 dBW CPE Tx Bandwidth 4.375 MHz CPE Tx PSD -6.4 dBW/MHz Activation loss -12.04 dB TDD 3:1; 10 CPEs in TDMA OOBE Rejection in GPS band@1558.5MHz -60.5 dBc Effective CPE OOBE EIRP density -79.0 dBW/MHz OOBE Limit for L-band BTS and User -70 dBW/MHz Terminals (47 C.F.R. § 25.253(c)(9), (g)(3)) Margin 9.0 dB Regarding the second and third harmonics power density, measurement data in Figure 1 show that the power density of the second and third harmonics of the carrier are at a noise level of approximately -106.00 dBW/MHz. Page 5 of 15

Question 2. Indicate the latitude/longitude/elevation coordinates of its base station transmitting antenna and the azimuth of the peak of the main lobe of the base station antenna The specifics of the BTS are: • Coordinates: o Latitude: 38 deg 56 min 44 sec N o Longitude: 77 deg 18 min 58 sec W • Elevation: 367 ft AMSL • Antenna radiation center: ~90 ft AGL • Azimuth of peak antenna gain: 200 deg. TN • Address: 10780-10790 Parkridge Blvd Reston, VA 10191 Page 6 of 15

Question 3. Clarify its base station transmitting antenna pattern with regard to beamwidth in the vertical and horizontal planes. The BTS antenna specifications are: • Peak gain: 16 dBi • Vertical beamwidth: 7 degrees • Horizontal beamwidth: 63 degrees • Tx Polarization: Left hand circular Page 7 of 15

Question 4. Provide the maximum EIRP of its customer premise equipment transmitters. The maximum EIRP of the CPE is set at 0 dBW (1Watt). Page 8 of 15

Question 5. Provide the geographic boundaries inside which it will operate its customer premises equipment transmitters in terms of latitude/longitude coordinates. The table below provides the link budget for both the downlink (BTS to CPE) and uplink (CPE to BTS). As for most wireless systems, the coverage radius of this trial network is also limited by the uplink path, due to the lower CPE EIRP relative to that of the BTS. The radius also depends on the height of the CPE. Based on the link budget shown, the service radius for this experiment ranges from 1.1 km (assuming a CPE antenna height of 1.5 meters) to 2.1 km (assuming a CPE antenna height of 5 meters). The effective service area of the BTS is also determined by the BTS transmit/receive antenna’s physical and electrical characteristics. As indicated in sections above, the BTS transmit and receive antennas have 60 degree beamwidth and will be pointed at 200 degree TN. The predicted coverage area is depicted in Figure 2. Page 9 of 15

Frequency band (MHz) 1553 Forward Link Budget Units BTS RF PA output dBm 50 50 Tx Backoff (peak-to-average) dB 10 10 Average BTS RF PA output dBm 40 40 BTS antenna gain (dBi) dBi 16 16 Incoherent power gain (4 antennas) dB 0 0 BTS Cable loss dB 1.5 1.5 BTS EIRP dBm 54.5 54.5 MS antenna gain (dBi) dBi 12.0 12.0 Coherent gain dB 0 0 Channel bandwidth MHz 4.375 4.375 FFT size 256.0 256.0 Active Subcarriers 200.0 200.0 Oversampling 5.00 5.00 Subcarrier spacing Hz 19531.25 19531.25 MS noise figure dB 4 4 Thermal noise dBm/Hz -174 -174 Modulation scheme QPSK-1/2 QPSK-1/2 MS SNR requirement for QPSK 1/2 dB 5.5 5.5 Noise floor dBm/Hz -170 -170 Required instantaneous signal level dBm -98.1 -98.1 Log-Normal Fade Margin dB 7.0 7.0 Rayleigh fade margin dB 0.0 0.0 Penetration loss( in-building/in-car) dB 0 0 Interference Margin dB 0.0 0.0 Max path loss based on traffic EIRP dB 157.6 157.6 Reverse Link Budget Units MS average PA output dBm 18.0 18.0 MS antenna gain (dBi) dBi 12.0 12.0 MS EIRP dBm 30.0 30.0 Coherent gain dB 0.0 0.0 BTS cable loss dB 1.5 1.5 BTS Receive antenna gain (dBi) dBi 16 16 Number of subcarriers/subchannel 200 200 Subchannelization gain dB 0.00 0.00 MRC (diversity) gain dB 0 0 BTS SNR requirement for QPSK 1/2 dB 5.5 5.5 BTS noise figure dB 4 4 Required signal strength dBm -98.1 -98.1 Log-Normal Fade Margin dB 7.0 7.0 Rayleigh fade margin dB 0.0 0.0 In-Building penetration loss dB 0.0 0.0 Interference Margin dB 0.0 0.0 Max path loss based on traffic EIRP dB 135.6 135.6 CPE Antenna Height 1.5 m 5m Estimated Coverage Radius km 1.11 2.11 Page 10 of 15

Figure 2: Predicted Coverage Area Predicted Coverage Area 1 in = 0.7km 38o 56’ 27” 77o 19’ 29” 38o 56’ 24” 77o 18’ 57” 38o 56’ 07” 38o 55’ 50” 77o 19’ 48” 77o 19’ 06” 38o 55’ 45” 77o 19’ 34” Page 11 of 15

Question 6. Provide an analysis showing that the reverse-band operation is no more interfering than forward-band operation The proposed experimental operations are neither “reverse-band” nor “forward- band,” as those terms have been defined by the FCC. 2 Rather, the proposed experimental network is based on the WiMAX 802.16d standard and uses the Time Division Duplex (TDD) access scheme. With TDD, both the BTS and CPE transmit and receive in the same frequency band. For this proposed experiment, both the BTS and CPE will transmit and receive using the following frequencies in the 1.5 GHz MSS L band downlink: 1550.81-1555.19 MHz. The carrier frequency is 4.375MHz wide and centered at 1553.00 MHz. There will be no transmissions in the L band MSS uplink (1.6 GHz). Moreover, the BTS and CPE will operate in terrestrial mode only; there will be no satellite operations pursuant to this experiment. The proposed experimental TDD network will cause no more interference than that permitted by the forward-band ATC network permitted by the FCC’s rules. Pursuant to the FCC’s rules, MSV is permitted to operate an unlimited number of L band ATC base stations in the 1.5 GHz band at a maximum EIRP of 31.9-10*log (number of carriers) dBW/200kHz, per sector, for each carrier. 3 Under the proposed experimental operation, MSV will operate a total of 11 transmitters in the 1.5 GHz band using its licensed frequencies at temporary fixed locations at an EIRP well below that permitted by the FCC’s rules for ATC base stations. Moreover, the one BTS used for this experiment will transmit in one 60º sector only, thereby further limiting the potential for interference. 2 The FCC has explained that with “reverse band” operations, mobile terminals transmit in the downlink band and base stations transmit in the uplink band. With “forward band” operations, mobile terminals transmit in the uplink band and base stations transmit in the downlink band. See Flexibility for Delivery of Communications by MSS Providers, Report and Order, IB Docket No. 01-185, 18 FCC Rcd 1962 (February 10, 2003) (“ATC Order”), at Appendix C1 at § 1.0. 3 See 47 C.F.R. § 25.253(d)(1); see also Mobile Satellite Ventures Subsidiary LLC, Order and Authorization, DA 04-3553 (Chief, International Bureau, November 8, 2004) (“MSV ATC Decision”), at ¶ 83. Page 12 of 15

Appendix 1: BTS PA Specifications Page 13 of 15

Appendix 2: BTS Filter Specifications Page 14 of 15

Page 15 of 15


Document Created: 2006-05-31 17:25:43
Document Modified: 2006-05-31 17:25:43
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