Attachment comments

comments

COMMENT submitted by Metricom, Inc

comments

2001-08-21

This document pretains to SAT-STA-20010724-00064 for Special Temporal Authority on a Satellite Space Stations filing.

IBFS_SATSTA2001072400064_456844

AxiN, GumP, Strauss, HaveR & FELD, L.L.R P <g ausrn arromiers ar aw ( erusse us rosert s. stmauss sucome onus 1393 new nampsnine avenue, ww wasnmoron, o.c. 2o09e oeiven toncon rax (202) ssz—a200 RECEIVED tos morues wmustpgnccon noscow Henvore avg 21 2001 hormer vnoma souss mmm ssonwnt 014 roms commevon oxamse rusoccenn ons aconcestivrengainpmnpcon sn mmone wreroeneen wasnnoron, o. smon aruare August 21, 2001 COURIER ug 2 Ms. Magalie Roman Salas Secretary Federal Communications Commission 445 Twelfth Street, S.W. Washington, D.C. 20554 Re:— Comments of Metricom,Inc., Debtor—In—Possession Request of Sirius Satellite Radio, Inc. for Special Temporary Authority to Operate Digital Audio Radio Service Terrestrial Repeaters SATESTA—20010712—00064 Dear Ms. Salas: Enclosed for filing are the Comments of Metricom, Inc., Debtor—In—Possession, opposing grant of the above—referenced request for special temporary authority. We have also included a copy of this filing to be date—stamped and returned with our waiting messenger. Please direct any questions or correspondence regarding this iling to the undersigned. Very truly yours, §_ C208« 3 *~. Tom W. Davidson, Es Erin L. Dozier, Esg. ces Service List Enclosures

RECEIVED Before the § FEDERAL COMMUNICATIONS COMMISSION aus 21 2001 Washington, DC 20554 some comememne omm oree cene uorenn ) In the Matter of ) ) Request of Siius Satellite Radio, Inc. ) ECC File No. SAT—STA—20010712—00064 for Special Temporary Authority ) to Operate Digital Audio Radio ) Service Terrestrial Repeaters ) To: the International Bureau INC., Metricom, Inc., Debtor—In—Possession, (*Metricom‘"),‘ licensee of Wireless Communications Service ("WCS") Stations KNLB207, KNLB205, KNLB296, KNLB297, KNLB298, KNLB299, KNLB300, and KNLB3O1,by its attomeys and in response to the Federal Communications Commission ("FCC" or "Commission®) Public Notice announcing acceptance ofthe above—captioned request for special temporary authority (the "Request")," hereby submits these comments opposing grant ofthe Request. As a WCS licensee authorized to ‘ On July2, 2001, Metricom, In. filed a pettion pursuantto Chapter 11 of the U.S. Bankeuptey Code (11 U C §§ 101—1330)i the United Saes Bankruptey Court ofthe Northem DistictofCalifrnia (th"Pettion). Metricom provided timely notfiction to the FCC of the ilng of ts Ptiion, and, on Jly 26,2001, Meticom filed a pro forma applcation for assignment of ts Heenses rom Metrcon, In. t Metricom, Inc. DebtonPossesion. Ste Commision,datedJuly17, 2001 (notfying the PCC of h flingofhe Petion}; FCC File No. 0000530648 (requesting FCC cansentto pro forma assignment ofleense). The RCC grantedis consent to this pro forma assignment on August 6, 2001 * The sutions authorise WCS operationsasfolows: KNLB2Oauthorizes operation on frequency block A in thSt Louis, MO Major Economic Area (‘MEA") using 10 MHz ofspectrum; KNLB29$ authorzes peration on frequency block A in the Portand, OR MEA using 10 Mitz ospectrums KNLB2YG authorizes operation on frequency block A in thSeatle,WA MEA using 10 MJtz opectrum; KNLB297 authorizes operation on frequency block D in the Northast RepionalEconomic Area Grouping (REAG")using 5 Mitz of spectrun: KNLB2® authorizes operationon frequency block C in the Cental REAG using 5 Mz ofspectrun;KNLB2% authorizes operation on frequency block D in the Cental REAG using5 Mitz of spectrum; KNLB300 authorizes operitionon frequency block in the West REAG using 5 MHz ofspectrum;KNLB201 authorizes operation on frequency block D in the West REAG using 5 Mz of pectrum. The Northeast REAG encompassehe following MEAs: Bosto, MA; New York Ciy, NYBufflo, NY, and Philadeipha,PA. The Cental REAG encompasses the fllowing MEAs: Houston, TX;Dalls—Fort Worth, TX Dever, CO; Omaba, NE; Wichi, KS; Tulss, OK; Olahoma Ciy, OK; San Antonic, TX; El Paso—Albuquergue, NM; and Phoenix, AZ. The West REAG encompassesthfollowing MEAs: Spokane.BillingsSaltLake Cit, UT; San Frncisco—Oakdand—SanJose, CA; Los Angeles—San Diego, CA; Porand, ORand Scatle, WA * see Notce, Report No. SAT—00077(el Jly 31,2001)

use spectrum adjacent to that allocated for the Satellite Digital Audio Radio Service ("SDARS®), Metricom is significantly affected by Sirius* proposed operation ofterrestrialrepeaters in the SDARS band. L Intreduction Metricom is a WCS licensee authorized to provide service within the Northeast, Central, and West Regional Economic Area Groups, as well as several Major Economic Areas (MEAs"). Metricom‘s authorized service area encompasses the following MEAs: Boston, MA; Dallas—Fort Worth, TX; Denver, CO; Houston, TX; Los Angeles—San Diego, CA; New York City, NY; Philadelphia, PA; Phoenix, CO; Salt Lake City, UT; San Francisco—Oakdand—San Jose, CA; Seattle, WA; St. Louis, MO; Portland, OR, Bufalo, NY, Omaha, NE; Wichita, KS; Tulsa, OK; Oklahoma City, OK; San Antonio, TX; El Paso—Albuquerque, NM; and Spokane—Billings. Metricom has developed a high—speed wireless Internet access service called "Ricochet." Subscribers communicate with the Ricochet network through a small transceiver for use with laptops and CE devices. The subscriber unit, a Part 15 device which fits in the Type II stot of laptops and CE devices, performs the function ofa modem and transmits the subscriber‘s data using packet—switched, frequency—hopping spread spectrum technology. The subscriber unit communicates with a nearby transceiver that is most often mounted on the mast arm of a street light pole (a "poletop" unit). The poletop unit can receive transmissions from subscriber modems located within approximately a quarter —mile radius. Communications proceed from poletop to poletop until they reach a wired access point ("WAP").. WAPs, typically located on building rooftops, are the points at which the wireless communications are transferzed to a wired frame relaynetwork. Once they have entered the wired network, communications may be transferred to an Intemet gateway, a corporate Intranet, or an ordinary telephone modem. Communications originating from any ofthese sources follow the reverse path to the Ricochet subscriber. The transmission of data between the subscriber modems and poletop units, from

poletop to poletop, and from poletop to WAP is accomplished using unlicensed frequencies purstant to Part 15 ofthe Commission‘s rules. Metricom recently suspended provision of is Ricochet service pending successful reorganization ofthe company pursuant to Chapter 11 ofthe U.S. Bankruptey Code (11 U.S.C. §§ 101—1330)." Prior to Metricom‘s suspension of service, it offered service to subscribers in the following markets: Atlanta, Baltimore, Boston, Chicago, Dallas‘Ft Worth, Denver, Detroit, Houston, Kansas City, Los Angeles, Miami, Minneapolis—St Paul, New York City, Philadeiphia, Phoenix, Salt Lake City, San Diego, the San Francisco Bay Area,Seattle, St. Louis, and the Washington, D.C. metropolitan area. Although Metricom‘s service network previously operated on unlicensed frequencies pursuant to Part 15 ofthe Commission‘s rules, Metricom already had developed and was implementing plans to commence operations using ts WCSlicenses in the following markets: Boston, Dellas—Fort Worth, Denver, Houston, Los Angeles, New York City, Philadelphia, Phocnix, Salt Lake City, San Diego, San Francisco—Oakdand—San Jose, Seattle,and St. Louis. Specifically, Metricom was implementing its plans to convert a portion of its unlicensed use of 2.4 GHz links between WAPs and poletops to licensed operations using its WCS spectrum. Consistent with this conversion plan, Metricom has deployed FCC—certified equipment to operate its network on WCS frequencies in several of these markets. Metricom has expended millions of dollars designing and developing equipment and systems to operate consistent with the technical parameters ofthe WCS service, and has obtained FCC approval for such equipment. Metricom‘s deployment of WCS operations has been halted due to ts Chapter 11 filing. However, if Metricom successfully reorganizes and resumes operations, Metricom fully intends to continue the process of converting its WAP—to—poletop links to WCS licensed operations, and to expand the Ricochet service network within each MEA using its WCS spectrum. Metricom * See sipre, Nore 2

also holds WCS authorizations for the following MEAs in which it has not yet deployed any licensed or unlicensed service: Portland, OR, Buffalo, NY, Omaha, NE; Wichita, KS; Tulsa, OK; Oklahoma City, OK; San Antonio, TX; El Paso—Albuquerque, NM; and Spokane—Billings. Although Metricom has not yet commenced service offerings in these areas, deployment of service to these markets was part of Metricom‘s business plan, and in the event of a successful reorganization, Metricom would continue the process of marketing and deploying its service to these arcas. On July 24, 2001, Siius Radio, Inc. ("Sitius"), one of two SDARS licensees in the United States, requested a 180—day Special Temporary Authority ("STA") to operate 151 terrestrial repeaters at power levels above 2 kW Effective Isotropic Radiated Power ("EIRP") as well as an undisclosed number of errestrial repeaters, which will operate at or below 2 kW EIRP. The STA Request seeks authority to operate terrestrial repeaters in some 70 different markets, including each of the twelve markets where Metricom already is poised to deploy service using its WCS spectrum, and five other markets in which Metricom is authorized to deploy WCS service. Because the Request provides no data regarding the locations ofany terrestrial repeaters operating at or below 2 kW EIRP, Metricom cannot determine whether its WCS operations will be affected in other markets. Metricom strongly opposes grant ofthe STA Request because: (1) Sirius® Request fails to make the requisite showing for an STA under Section 25.120 of the Commission‘s rules; and (2) grant ofthe Request will séverely prejudice the public interest by impeding deployment of WCS service. IfSirius successfully supplements ts STA Requestto provide the additional data needed forthe FCC to fully evaluate its Request, at a minimum, any STA grant must be subject to the conditions specified herein to protect the operations of WCS licensees.

L. Showing Sitns Requisite Under Section 25.120 ofthe Commission‘s rules, an STA only can be granted upon a finding that "there are extraordinary circumstances requiring temporary operations in the public interest and that delay in the institution ofthese temporary operations would seriously prejudice the public interest."" A request for STA "must contain the full particulars ofthe proposed operation including all facts sufficient to justify the temporary authority sought and the public interest therein."*. Sirius‘ STA Request is deficient with respect to all of these requirements. Sirius‘ Request provides no demonstration of extraordinary circumstances warranting the requested relief, nor does it explain how the public interest will be seriously prejudiced if the Request is not granted. Moreover, by failing to provide any data relating to ts use ofterrestrial repeaters that operate at or below 2 kW, Sirius has not provided facts sufficient o allow the Commission, other licensees in adjacent bands, o the public t ascertain the level ofiterference that will be created by such repeaters, which is necessary to properly evaluate its Request. Sirius‘ stated justifiation for ts Requestis that an STA will allow Sirius *imminently to initate uniformly high quality commercial satellite DARS programming nationwide."". Sirius also offers some very general explanations ofhow provision of SDARS will benefit the public. However, the fact that provision of SDARS generally is consistent with the public interest does not constitte an "extraordinary circumstance" that overrides the public interest i allowing the Commissionto complete its rulemaking process before SDARS licensees initite commercial service. The Request seeks to operate a SDARS terrestrial system in a manner thatisthe subject of an ongoing rulemaking proceeding.® The Commission has yet to determine whether the 5 see 47 casr 5 25,120 2000) ‘un " see STA Requesta 1. ° gee forthe AReport and Order and Further Notice ofPoposed Rulemaking, 1B Docket No. 9591,12 FICC. Red. 5754 (1997)(the SDARS proceeding") 5

operation of terrestrial repeaters in the manner proposed by SDARS licensees in both the rulemaking proceeding and in STA requests, is consistent with the public interest. Sirius offers no explanation of how the public interest will be prejudiced by rollout ofterrestrial SDARS service affer the Commission has determined what rules will gover the use ofterrestrial repeaters to augment SDARS. Sirius also states that grant of ts Request would ensure that there will be "no reduction in the quality of DARS service.". To the contrary, grant ofthe Request increases the chance that there will be a reduction in the quality ofSDARS service. First,if Sirius is operating consistent with the terms of its experimental license, it is not yet offering any service tothe public, so there can be no "reduction‘" in service quality. Second, notwithstanding Sitius‘ apparent confidence that the Commission will adopt rulesin the pending SDARS proceeding that are consistent with Sirius‘ proposals, the rulemaking proceeding remains pending. Should the Commission adopt terrestrial SDARS rulesthat adequately protect licensees in adjacent bands, Sirius will be required to redesign and re—deploy itsterrestrial system to comply with the Commission‘s rules. Because Sirius has developed all of ts business and operating plans around its own proposals,if Sirius has commenced service under the proposed STA, a return to the "drawing board" may result in delays in deployment of service or even service interruptions. The public interest is best served by allowing the Commission to implement a regulatory scheme for SDARS repeater operations before the rollout of SDARS service. In addition, it is well established that Commission licensees cannot use an STA to prematurely implement a new service or deploy new facilities that remain the subject of an ongoing rulemaking proceeding.. As a practical matter, grant of such a request prejudices the outcome ofthe proceeding. Despite any qualifications that maybe contained in the instrument ofauthorization, the licensee holding such authorization will invest financial and other resources in operations consistent with the STA, and consumer expectations will be raised. The 6

Commission‘s decision in the SDARS proceeding should be based on data in the record, and should not be tainted by issues resulting from the premature deployment ofterrestrialrepeaters. Even if Sitius‘ Request provided an adequate justification for an STA, the Request remains deficient because it fails to provide the "fill particulars"" of ts proposed STA operations, as required by Section 25.120 ofthe Commission‘s rules.. Although Siius has provided the geographic coordinates, antenna type, antenna orientation, antenna radiation pattem, otal EIRP, and height above ground level ("AGL®) for each of is proposed terrestrial repeaters operating above 2 kW EIRP, Sirius provides none ofthis data for terrestrial repeaters operating below 2 KW. Metricom‘s WCS system was designed to operate at or below 2 kW, in an environment where other licensees also operate ator below 2 kW, as provided by the Commission‘s technical rules for WCS service. Even in an environment where all lcensees are operating at or below 2 kW, WCS licensees must stil coordinate their operations to avoid interfering with each other. Since any STA operations that are authorized will be ona non—interference basis, Metricom needs site—specific information on the repeaters operating below 2 kW so that it can determine the source ofany interference to ts operations. Without this citical information, neither the Commission nor WCS licensees can fully evaluate the potentialinterference effects ofSirius‘ proposed STA operations and take steps to mitigate the effects ofsuch interference. Sirius® Request should therefore be denied on grounds that it fails to provide crtical information needed to determine how its proposed operations wl affect the operations ofother Commission licensees. H1L. Harm Because the operations proposed in the STA will preclude WCS operations in large portions ofthe MEAs that WCS licensees are authorized to serve, grant of the STA will harm the public interest. As the Commission has repeatedly recognized in numerous contexts, there is a eritical need to increase the availability of broadband technologies like Metricom‘s high—speed

wireless data network. The deployment of broadband wireless services by WCSlicensees is eriticalto achicving this goal. Grant ofthe Request will further impede deployment of broadband wireless services using WCS spectrum by drastically imiting the areas in which WCS licensees can offer service and by making rollout of service economically unfeasible. Metricom cannot fully evaluate the effect ofSirius‘ proposed operations because Sirus has failed to provide the relevant data for trrestrial repeaters operating at or below 2 kW EIRP. However, Metricom has attached an engineering exhibit analyzing the impact that Sirius® operation ofrepeaters at a variety ofpower levels would have on Metricom‘s ability to initite service using it allotted WCS spectrum. As Metricom has explained in ts comments in the SDARS proceeding, Metricom‘s system can accommodate operations of SDARS terrestrial repeaters at power levels at or below 2 kW EIRP." However,there is no technically feasible means by which Metricom can equip its stations to accommodate SDARS operations at levels ranging from over 2 kW to 40 kW EIRP, as proposed by Sirius in its STA Request. Even if such modifications were technically feasible, Metricom already has devoted extensive financial and. other resources to the design and deployment ofa system based on a 2 kW environment. Having designed and developed its system consistent with Commission rules, there is no reason that Metricom should be foreed to redevelop its system and redeploy its equipment. As demonstrated in the attached technical analysis, Sitius* proposed operations will preclude Metricom‘s use of WCS radios in substantial portions of nearly every MEA that Metricom is licensed to serve." Each terrestrial repeater operating at 2 kW EIRP will preclude WCS operations by Metricom within a 46 square mile geographic area or "exclusion zone.""" Each 10 kW repeater precludes operations within a 2 square mile area, each 20 kW repeater ° See forthe Polis Digal 2310 6 Erequency Comments ofMetvicons, nc (iled March 8, 2000};Sze also Not/icaion ofEx Parte CommunicationofAT&T Wireess Servies,Inc, Bel South Corporaton, Metricon,Inc. and Wireess Communicaions Association International (Aled Fob,1,2001); NotFiation ofEx Pare Communication ofAT&T Mireless Services, Inc. Bell South Corporation, and Metricom,Ic. (Rled Feb. 6 2001} 8

precludes operations within a 4.08 square mile area, and each 40 kW repeater procludes Metricom service within an .14 square mile area."" In marketslike Los Angeles, where Sirius proposes to operate 22 terrestrial repeaters at power levels above 2 kW EIRP, Metricom‘s ability to operate its WCS radios will be significantly curtailed. As Metricom and other WCSlicensees have explained throughout the SDARS proceeding, SDARS terrestrial operations above 2 kW EIRP severely impairs the ability of WCSlicensees to serve the public. Given the lack of a public interest justifiation for grant ofthe STA and the harm to the publicinterest that is certain to result from the severe impact ofthe SDARS terrestrial repeaters on WCS operations, the STA Request should be denied. IV. STA p Comis n i Detrmin Operationsis of WeS Li Conditions Assuming arguendo that Siius can supplement its Request to justify grant ofthe STA and provide information on terrestril repeaters that will operate below 2 kW, Metricom urges the Commission to place certain minimum conditions on any grant of the STA to protect the operations of WCS licensees. First, as a condition to grant ofthe Request, Sitius must be required to designate a contact representative to receive interference complaints arising from its operation of errestrial repeaters. Should a licensee in an adjacent band determine, after reasonable investigations, that a Sirius repeater is causing interference to its operations, the licensee would notify Sirius‘s contact representative. Upon receiptof such a notifieation, Sirius must be required to immediately turn off the offending repeater, without dispute. Further, any STA should provide that if Sirius disagrees with an interference claim, an uninterested third party will testthe interference at Sitius‘s expense, and the resultsofthe third party‘s interference analysis will be binding on both parties. Siius may not resume operation ofthe repeater until the dispute is resolved. Second, as Sirius has conceded, the Commission‘s action on its STA Request " See TeshnicalExtibit A ""1datFigure S. Seeals Table 1

should be without prejudice tothe outcome of the SDARS rulemaking proceeding. If the Commission determines that grant of an STA is in the public interest, Metricom urges the Commission to explicitly note that such grant is without prejudice to its determination in the SDARS proceeding. V. Conclusion Sirius has failed to provide any public interest justifieation for grant of ts STA Request, and, by failing to provide any data on its proposed operation of an undisclosed number of terrestril repeaters operating at or below 2 KW EIRP, has neglected to include information critial to an assessment ofthe impact ofis request on the operations oflcensed users of adjacent frequencies. While Sirius has failed to identify a public interest benefit from its operation oferrestrial repeaters, the harm to the public interest that will result from its operation ofterrestrial repeaters is clear. Grant of Sirius® Request will severely curtail the abilityo Metricom and other WCS licensees to deploy broadband wireless services to the public. Unless and until Siius justifies its need for an STA, the Request should be denied. Should the Commission determine in the future that an STA is warranted, the Commission should place conditions on grant of the STA to protect the operations of WCS licensees in adjacent bands 10

Respectfully submitted, METRICOM, INC., DEBTOR—IN—POSSESSION P o a t /‘ if} ay Mepuel L. "roun fa ALVU Michael K. Hamra, Esg. Director ofRegulatory and Govermment Alfairs Metricom, Inc. 1825 I Street, NW, Suite 400 Washington, B.C, 20006 202/419705 A By: ; Tom . Davidson, Esg\ > Efi;/f., Dozier, Esq. = Akin, Gump, Strauss, Haver & Feld, LLP 1333 New Hampshire Ave., N.W. Suite 400 Washington, D.C. 20036 202887—4000 Its Attomeys Dated: August 21, 2001 11

CERTIFICATE OF SERVICE 1, Erin Dozier, an employee of Akin, Gump, Strauss, Hauer & Feld, L.L.P.,certify that a copy of the foregoing Comments on behalfofMetricom, Inc., Debtor—In—Possession Opposing Grant ofthe Request of Sirius Satellite Radio, Inc. for Special Temporary Authority to Operate Digital Audio Radio Service Terrestrial Repeaters, was served via first class, postage prepaid mail on this 21"of August, 2001, upon the following: Donald Abelson Ron Repasi Interational Bureau Intemational Bureau Federal Communications Commission Federal Communications Commission 445 Twelfth Street, S.W. 445 Twelfth Street, S.W. Washington, DC 20584 Washington, DC 20554 Chris Murphy Jennifer Gilsenan Intemational Bureau Intemational Bureau Federal Communications Commission Federal Communications Commission 445 Twelfth Street, S.W. 445 Twelfth Street, S.W. Washington, DC 20554 Washington, DC 20554 Rosalee Chiara Ron Netro Intemational Bureau Interational Bureau Federal Communications Commission Federal Communications Commission 445 Twelfth Street, S.W. 445 Twelfth Street, S.W. Washington, DC 20554 Washington, DC 20554 John O‘Connor Rockie Patterson Wireless Telecommunications Bureau Interational Bureau Federal Communications Commission Federal Communications Commission 445 Twelfth Street, S.W. 445 Twelfth Street, S.W. Washington, DC 20554 Washington, DC 20554 Robert D. Briskman Technical Executive Sirius Satellite Radio, Inc. 1221 Avenof the Americas« New York, New York 10020 12

Exhibit A

Technical Analysis of Interference from High Power DARS Terrestrial Repeaters to Metricom‘s WCS Receivers Abstract The DARS satellite service operators have proposed to operate high power terrestrial repeaters with power levels up to 40 kW within 4 MHz of Metricom‘s WCS A, C and D blocks as shown in Fig 1. The Metricom system as shown in Fig. 2 uses the WCS band to communicate one way from building tops to radios typically mounted on street lights. Every Metricom radio mounted on a street light has a WCS receiver with an overload level of —25dBm at the input to the receiver and a 7 dBi gain antenna. These street light radios are typically installed at a density of6 to 8 radios per square mile. A signal from a DARS terrestrial repeater with a level of ~32 dBm at the antenna will degrade the performance of a radio on the street light. This analysis examines the impact of high power repeaters on the Metricom WCS receiver and shows that every 40 kW repeater creates an exclusion area that is 8 times greater than that created by a single 2 KW repeater. The interference to WCS operations caused by SDARS high power repeaters significantly outweighs any coverage benefit, because the same coverage can be achieved by using a greater number of SDARS terrestrial repeaters at or below 2 kW, which causes significantly less interference to WCS operations.. This is technically based on the faet that the exclusion area is based on line of sight conditions (pathloss exponent = 2.0) and the coverage area analysis is based on non line of sight conditions with higher pathloss exponents. x I% § | lt a $ 5 \a |% "f * al 0 < $ g) f al a a < ® |o o 8| o| < m | |"| I I [s ol &= £0= i: i1 := & $ i ifi 2 2 1i 2 & = §8 $§ i1 »§§% 1: ~8§._$i §8 Figure 1 WCS and DARS band

.fi ETdNHA High—speed Figure 2 Metricom System Architecture Exclusion Around each high power DARS repeater a circle can be drawn that represents the area that if a Metricom receiver lies within it and has line of sight to the DARS repeater site the performance of that Metricom receiver will be degraded. Given the Metricom receivers are mounted on street lights and are designed to have line of sight back to a building top there is a high probability that the radio will have line of sight to the DARS repeater. Using the equation for free space loss shown in Fig. 3 & m PL(d,exp) := 10—og —— td es [f-&-n a) Figure 3 Pathloss Equation

The radius of the exclusion area around a high power DARS repeater can be calculated given the EIRP ofthe DARS repeater and the gain of the Metricom WCS antenna. RSSI(EIRP ,d,ep) := EIRP + RxAnt+ PL(d,op) Figure 4 DARS Signal Level Eqn. The graph and table below (Fig. 5, Table 1) shows the radius ofthe exclusion zone vs. the transmit EIRP of the DARS repeater. The graph demonstrates that for 64B increase in power the exclusion radius doubles and given the area goes by the square ofthe radius the exclusion area quadruples. 49.115, 29 DARs Signal Level vs. Distance € § rssie,d,2.0) g RSSI(70,d,2.0) 0 hss 3 RSSI(63,0,20) § —— & —25 2 enc —20 4 T a ~30.906, mm l * 0.5 1 LS 2 01 d & Distance (miles) =——— 40 kW * 10 kw ——+— PKW =—— Overload Threshhold Figure 5 Exclusion Radius l Table 1 Exclusion Radius vs. Power Repeater Tx EIRP Exclusion Radius Exclusion Area ) 2 KW (63 dam) 036 m 046 m 4kW (66 dBm) 031 m 081 m 10 kW (70 dBm) 08T m 200 m 20W (73 dam) TT4m 408 m 10W (76 dBm) Lél m 814 m



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