Attachment ex parte comments

ex parte comments

Ex PARTE PRESENTATION NOTIFICATION LETTER submitted by BeamReach Networks

ex parte comments

2001-08-21

This document pretains to SAT-STA-20010712-00063 for Special Temporal Authority on a Satellite Space Stations filing.

IBFS_SATSTA2001071200063_456848

2i/zoer 15:08 «cssessece rax manure C t & EX PARTE OR LATE FILED &BeamReach RECEIVED Rraiche BeamReach 193 Nent oits Avcmse Senmale ® Aus 21 2001 Cuirs w bamreatinetverks raim. cumevon cuesn ‘as s se 100 com omencrne surena Magalic Roman Salas, Secreury August21" 2001 Federal Communications Commission 445 Tweltth Szeet SW Washington, DC 20554 Wrinen Ex Parte Comments XMRadio,Inc. request for STA, File No. SAT—STA—20010712—00063 Sirius Satelite Radio,Inc. request for STA, File No. SAT—$TA—20010724—00064 1B Docket No. 95—91 — Establishment of Rules and Policesfor the Digital Audio Radio Satelite Service in the 2310 — 2360 MB Frequency Band Dear Ms. Salas, Please acceptth attiched Ex Parte Commentsinto the Record under the above mentioned Proceeding. The Comments are riggered by therecenty fled requests of SDARS Licensees to commence commercial operation ofteestial repeaters under Special Temporary Asthoriy. Any questions can be addressed to the undersigned. Yourssincerely Randall Schwartz Director, Regulatoryand Standards RSchwarne@ReamBReachNetworks.com Tel: 408—860—8782

Before the —FEDERAL COMMUNICATIONS comMissION Washington, D.C. 20554 In the Mater of: XM Radio, Inc. request for STA, File No. SAT—8TA—20010712—00063 Sirius Satelite Radio,Inc. request for STA, File No. SAT—STA—20010724—00084 Estabishment of Rules and Policies forthe Digital Audio Radio Satelite Service in the 2310—2350 MHz Frequency Band, 1B Docket No. 9—91 EX—PARTE COMMENTS OF BEAMREACH NETWORKS INC. BeamReach Networks Inc. (‘BeamReach‘) hereby submits ExParte comments on the above—referenced proceedingin ight of recent SDARS Licensees‘requestsfor Special Temporary Authorly to operate (high power) terrestalrepeaters within ther frequency band and the potential impact on icensees in the WCS and MMDSMTES bands.. in pertcular, BeamReach addresses the systemevel impact of terrestral repeaters on WCS deployments. 1. Introduction BeamBReach Networks Inc. is a privately held company based in Sunnywale, Calfomia, BeamReach developed its spectraly—effcient Adaptive Multbeam OFDM wreless technology for the provision of broadtend wreless access (BWA) services in frequencies below 6 GHz. For addiional information about the company andlor is technology, please refer to the BeamReach Reply Comments and Ex Parte presentation in the recent ECC 3650 MHz proceeding‘,the BeamReach comments previously fled in is Docker‘, ovist wwbeamreachnetworks.com. BeamReach Networks is designing a product specficaly to delver BWA services in the WCS band and thus BeamReach has detaled knowedge ofthe technicaregulations and implcations for manutacturing a product to delver services in tis band. The next generalion WCS equipment BeamReach Networks is developing is designed to meet or exceed all of the Commission‘s rules governing transmissions in the Wes bang. Given the technical specfications provided in the STAs fied by the SDARS operators‘, BeamReach has 1. Decket ET96—237 : Reply Comments of BeamReach Networks Inc, fled 18th December 2000 and Ex Parle Presentation on 3tst January 2001. 2.. Docket 1B05—91 : Comments of BeamReach Networks Inc., led 23rd May 2001. 3.. SAT—TA20010712—00063 fied 12" July 2001 by XM Radie, Inc. and SAT—$TA20010724—00084 (continued...) 2

enalyzed the proposed deployment of terrestrialrepeaters and assessed the impact on a WCS service providers deployment of BeamReach‘s equipment in the greater Boston area.. This analysis concludes that the proposed deployment of high power SDARS repeaters wil severely impair the use of the WCS bend for emerging2—way broadband services BeemReach has undertaken the folowing technica! analyses to evaluate the proposed deployments of high and medium power trrestril repeaters: a) Signal Strength Prediction Using Longley—Rice Model — Greater Boston Te proposed deployment of Siius and XM SDARS repeatersin the Boston Metro area was analyzed using a terein—based propagetion modaing tool. The transmiter locations, output powers (EIRP), antenna patterns and transmiter heights were inputs t his tool. This analysis determined the extent of the proposed coverage and produced a map ofthe signalstrength usingthe Longley—Rice propagation modet b) Generalized Quantiative Analysis of Excluded Households A generalized modelof the intermodulation distortion caused by the proposed Sirus and XM repeaters was used to determine the percentage of households that would be prevented from sccessing BWA services in the WCS band. 2. BeamReach CPE Receiver Characteristics Te performance characteristies ofthe BeamReach customer premises equipment (CPE), specitcall the CPE noise foor, tird order intercapt point, and 1 48 desensiization level due to blocking signals w in the RF passband are provided in Table 1 below.. These figures will be utlized in the intermoculation enalysis provided in the nextsection Table 1 BeamReach Residential CPE RF Parameters Radio Parameter Duplexing Method TOD, A pai, B pair, and C/D used for TxRx Noise Figure 508 IF Bendwith 1.25 MHz (Continued from previous page) fied 12" July 2001 by Sinus Satelte Radio.

Frequency Range WCGS Bands A, B, C, D Input IP3 for signals within RF BPF —7 dam RF Preselection Fitter, Bandpass 55 MHz centered on WCS band Characteristics Antenna Beamwidth 18° —3 dB points, 36° to sidelobe level it should be noted that tfrequency spacing between the proposed XM and Siius repeaters is such that 3rd order ntermadulation products of thase two signals wil land directly n the WCS band — speciicaly the A, B, C, and D blocks.. From the values in Table 1, Table 2 can be derived. The radiated susceptbilty ue to blocking and due to intermadulation ditorion are shoun, as is the noise level causing a 1 0B degradation in the sensitviy. Table 2. Impairment Onset Levels Coreceo [E Rediated Susceptibiity, Blocking —30 dm Rediated Susceptbiity, IMD, Two signals within —50 dBm signal 1, —80 dBm signal 2 the me Ressbans —£0 dm signal 1,—60 dBm signal 2 —70 dBm signal 1, —40 dBm signal 2 Broadband IMD noise. allowable, 1. 08 —114 dbm degradation Radiated Suscepibily, IMD as listed above defines the minimum level of signal received from both repeaters atthe WCS CPE that wil cause Broadband IMD at the level shown above._ Said another way, IMD interference wil occur when both SDARS operators are operating terrestralrepeaters the same market wih overiapping signalstrength in excess of those values shoun in the Table above. 3. Coverage and Propagation Analysis Analysis ofthe proposed deplayment of Srivs and XM repeaters in the greater Boston area, as fied wih the FCC, was undertaken by BeamReach Neworks using the Commtudy terrain based propagetion modelng tool. The location, call signature, antenna height above ground level, antenna model and ERP a

values were taken from Siius and XM Radio‘s requestsfor STA® as inputs int this tol. This analysis determined the extent of the proposed coverage and the resuling signal srenghh from the proposed Sirus and XM Radio repeaters in the Massechusetts area surrounding Boston using the LongleyRice propagation model. The Longley:Rice propagation model was used to model the attenvation effects caused by distance and terrai. The BeamReach CPE antenna was assumed to be at the nominal antenna height, 20 feet above ground level (approximataly roottop level for a single story home) 4. Technical Analysis — Intermodulation "The frequency spacing between XM and Siius repeaters ensures that 3rd order intermodlation products between these two signals wil land cirecty i the WCS band — A, B, C, and D blocks. Any market where both operators are deployed wilrestrctthe usabily of the WCS band. Fipure 1 depicts the signal strength from the proposed Situs repeater in the area surrounding Boston using the Longley Rice model. For reference, the three closest XM Radio repeaters are shoun on the plot, but do not contribute tothe signalstrength shown for the Situs repeater. 4. SAT—STA20010712—00083 fled 12" July 2001 by XM Radio, Inc. and SAT—STA—20010724—00084 fied 12" July 2001 by Sirus Satelte Radio.

m + s a a o a « & + ;z pormemmmmsmene «n mm as an s smes Figure 1. Contour of Sirs Coverage Causing IMD (> —60 dBm) Fiqure 2 depicts the signal strengih from three of the propased XM Radio repeaters in the area surrounding Boston usingthe Longley—Rice model. The Sits repeater is also shown on the plot but does not contrbute to the signal strength forthe XM repeaters.

as 1 an an an snas Figure 2. Contour of XM Radio Coverage Causing IMD (> —80 dBm) The shading indicates the regions in which signal stength from the SDARS terrestral repeaters is in excess of—60 dBm. To determine the regionin which interference from intermodulation products causes degradation in the WCS band at the BeamReach CPE, the intersection of regions above —60 dBm is determined. Thus, regions which are shaded on both plots are regions in which CPE experience atter performance degradation or outage due to XMSiius incuced IMD. When these two plots are overiaid on each other, a signticant porton of the suburban and urban regions of greater Boston wil see a power levelin excess of —60 dBm from both SDARS service providers Adding further complexiy is the fact that other signal strength combinations from XM and Sirus repeaters produce similer performance impacts.. For instance, two signals of —50 dBm and —80 dam respectvely produce the same results as —60 dém and —60 dam

BeamReach has attempled to quantfy: the number of houscholds that would be affected by intermoulation interference using a generalized model emulating the proposed XMSitus deployment with our own equipment in the oof Boston. in anabzing the intermodulation products which resultfrom miing the SDARS: transmissions at the WCS recaiver, ther is vitually an infite number of scenarios, each with different geogrephic spacing between SDARS terrestral repeaters, WCS base stations and CPE. The one scenari that can be analyzed is that where the BeamReach cals are located i the seme service area as nterfering repeaters being operated by SDARS operators, such that the BeamReach CPE "see‘with both SDARS repeaters "The analysisis based on IMD limting and assumes that both XM and Sirus operate in the same market, cover the same region, and operale atthe same powerleve. in this calculaion,the 3" order IMD product produced in the GPE front.end is the limting factor. The unfortunate frequency spacing between XM and Sirus repeaters ensures that 3" order intermodulation products produced by these two signals will land directlyin e WCS banc. The threshold crteria assumed the BWA sensitity was degraded beyond an allowance of 1 dB. The melhodology assumed the BWA system covered the Boston region using a celluarzed leyout wih BeemReach system peremeters,ink budgets, coverage margins and fade margins. The Hata COST 231 Suburban model was used to determine the BWA cell rdius. From the cell redius, the number of subscribers in the addressed market was computed from the demographics of the area Te number of households denied access was then determined by using the susceptbity ofthe GPE and the EIRof trepeaters. An addiional 10 dB of repeater suppression was added due to CPE sideiobe performance.. The height of trepeater was taken as the average antenna height used in the proposed Baston deployment, approximately 60 meters, and each repeater EIRP was set at2,000 watls, then each set to 20,000 wats. Table 4 ilustrates the percentage of households excluded due to medium and high power repeater operaton. The percentages represent the areas where the interference caused by the repeaters is tco great to alow reflable operation of the BWA system in the adjacent WCS band.. Of partcular note, two operetors utliing 20,000 wett ransmiters in the same market destroys the use of the WCS market for broadband wireless access.. Even 2.000 wett operation in this scenario excludes 18% of the adcressed market

Table 4 Households Excluded Due to SDARS Repeater Operation (IMD) 2,000 wats, IMD 20,000 watts, IMD 72 "The direct result of the blocking iterference will bea signiicant increase i the cificuly of marketng and deploying the WCS service. Specifcaly, it wil be more dificulfothe WCS service provider to determine whether a partculr customer location can be served at the point the potental customer enguires about service. The service providerwl not be able to ensure a potental customer tnat sevice can be provided untia site survey has been completed, which increases the cost of service deployment. 5. Conclusions and Recommendations in summary, BeamReach Networks has undertaken an analysis of the SDARS terrestil repeater deployment proposed by XM Radio for the Boston market as part o ts STA applcation. analsis concurs with comments previously submited that SDARS repeaters wil cause blocking interference in the WCS band and that SDARS transmissions mixing with WCS transmissions wil create 3" and 5" order intermodutation products within the WCS band?. Te analysis also shows that when botn SDARS fcensees utlizeterestral repeaters in the same market,the 3° order intermodulation products resuling from miing of both SDARS frequencies at the WCS receiver have an even greater impact.. This phonomenon wil occur within a WCS receiver (such as BeamReach‘s) when the interfering SDARS signals exceed — 60 dBm, resuling in exclusion zones much larger than previously noted wihin this Docket. The provimity of these bands is too close to allow for economicalfitering. As such, grantingthe SDARS leensees‘ proposals to use high powered (greater than 2.000 W EIRP per 5 MHz) terestral repeaters would render WCS specitum useless and eliminate the option of using the WCS band for compettive broadband services. BeamReach offers tfallowing conclusions from our anal 1. The use of terrestrial repeaters signiicanty impacts the deployment of broadband wreiess access in the WCS band.. Interference effects ue to blocking and intermodiulaion are both 5.. Docket 19591 Comments of Wireless Communications Association Intemational, Inc. fled 15th December 2000.

observed. This wilresultin exclusion zones for he WCS service of signiicant size. The propased SDARS repeaterfrequency spacing yelds 3" order intermodulation products in the WCS band. Te proximify of these bands is too close for economicalfitering. For 2.000 W EIRP repeaters, 18% of households wil be affected. For 20,000 W EIRP repeaters, the intermodulation wil block out 72% of houscholds it wil be extremely dificut, i not impossile, to effectvely plan the deployment of a WCS network (select base station sites and identfy exclusion zones) in the presence of 2000 Watt EIRP repeaters, uniess steps are taken to ensure adequale spacing between repeaters belonging to diferent SDARS operator. BeamReach Networks urges the Commission to reject he STA applcations currenty under consideration and repidy complete the proceeding under this Docket establishing rules for the deployment of SDARS terrestra repeaters.. BeamReach makes the following recommendations related to the SDARS repeater rules to enable WCS service providers to imthe addressable market lost due to SDARS operatin: 1 Output power of he repeaters should be limited to 2,000 W EIR® per 5 MFiz (no more than 400 W per MHz) and SDARS licenseesshould be required to pre—coordinate deployments win WCS service providers Moreover, pre—coordination between XM and Sirus should be requied to ensure that their repeater locations, power levels and antenna heights produce overlapping contours effecting no more that 2% of the households.. These contours should be —50 dBm80 dam, —60 dBm—40 «@im, and 70 dam—40 dam. The proposed outotband suppression requrements of 75 + 10log(P) dB for SDARS transmissions mean that WCS lcensees would be held to a higher standard. SDARS licensees should be required to abide by the same WCS requirement of 80 + 101og(P) dB or reief should be granted to WCS lcensees. BeamReach agrees wih the previous comments of AT&T Wireless Services, BellSouth, Verizon, WCA, Meicom and WorldCom that the rules for SDARS terrestrial repeaters should be determined in consideration ofthe rules applicable to the acjacent WCS band. In partculr, SDARS repeaters should be limed to the same meximum power emissions as other WCS band transmiters (2.000 W per 5 Mz equivalentto 400 W per MHz). Respectfully Submited, 10

BeamReach Networks Inc 755 North Mathilda Avenue Sunnyvale California saves Tel: 408 869 8700 Fax: 408 860 8701 Regulatory Contact : Randall Schwartz rschwartz@beamreachnetworks.com 11


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Document Modified: 2005-09-28 14:18:31
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