任务3后的频谱管道再分配工程研究——识别监管约束

MAR242015 RE: Commercial Operations in the3550-3650MHz Band (GN Docket No. 12-354) Dear Mr. Knapp: The National Telecommunications and Information Administration (NTIA)appreciates that the Federal Communications Commission (FCC) will soon adopt final rules inthe above-referenced proceeding to facilitate sharing between a new Citizens Broadband RadioService (CBRS) and federal incumbents in the3550-3650MHz band (3.5 GHz Band).1Thisrulemaking addresses advanced sharing with commercial operations to improve wirelessbroadband connectivity.NTIA's2010Fast Track Reportidentified the 3.5 GHz Band aspotentially suitable for commercial broadband use, subject to certain geographiclimitations?The 3.5 GHz Band is oneofthe candidate bands identified by NTIA in response to thePresident'sinitiative to make available500megahertzofspectrum for commercial wirelessbroadband.3 The 3.5 GHz Band is well suited to exploring the next generationofshared spectrumtechnologies, driving greater productivity and efficiency in spectrum use. In this letter, NTIAresponds to the3.5 GHz BandFNPRMfor the purposes of:(1)proposing specific changes to theregulatory frameworkofthe spectrum sharing model to effectively protect federal operations andmaximize available spectrum available for commercial broadband; (2) outlining a phasedimplementation and approval process for commercial access to the 3.5 GHz Band;(3) designating smaller zones for the protectionoffederal systems based onnewtechnicalanalysis; (4) addressing protectionofcommercial operations in the 3.5 GHz Band from federalradar systems; and (5) correcting the rules regarding an active protected federal radar site in the3650-3700MHz band. Regulatory Framework The functional elementsoftheCBRSregulatory framework in the 3.5 GHz Band asproposed by the FCC include: the Spectrum Access System(SAS),Citizens Broadband RadioService Device (CBSD), and user equipment (UE). As described below, we agree with thisfunctional characterizationoftheCBRS,but recommend the additionofa fourth component,which we call the"EnvironmentalSensingCapability"(ESC). We believe that these fourfunctional elements, acting in concert under the rules, can enable an advanced sharing regimethat effectively protects federal operations while maximizing spectrum available for commercialuse. Spectrum Access System.TheSASis the network-based system for authorizingcommercial useoftheband, acting as the frequency coordinator forPriorityAccess(PA)andGeneral Authorized Access (GAA) tier users. We recommend that the FCC require anySAStohave the following capabilities: •AuthorizeCBSDsto operate at a given location given certain parameters such as theoperating frequency and maximum transmit power level;•Ensure thatPA and GAA users do not operate in the exclusion zones established toprotect federal radar systems;•Synchronize with otherSASsto ensure protectionoffederal systems;•Operate without any connectivity to any military or other sensitive federal databases orsystems;•Ensure operational information(e.g.,on the movements or positionsoffederal systems)is not stored, retained, transmitted, or disclosed;•Providefor manual override by area or time that has the capability to trigger changes incommercial use necessary to comply with general FCC enforcement actions or torespond to emergency instructions from thePresidentofthe United States,oranotherdesignated federal government entity, issued pursuant to Section606oftheCommunications Act, as amended.4 In general, we believe theSASswith these capabilities can play an important role to enablespectrum sharing between federal and non-federal users in the band. Citizens Broadband Service Device.The termCBSDrefers to network infrastructurenodes(i.e.,a base stationorgroupofbasestations). TheCBSDtransmits local data(e.g.,geo-location) to theSASand receives authorization instructions from theSAS.ACBSDmaintainspower control over connectedUEsat all times. User Equipment.UEsare the end user devices(i.e.,mobile handsets) that communicatewith the CBSD. TheUEsoperate at low power and are authorized and power controlled by aCBSD.5 Environmental SensingCapability.NTIA recommends that anESCshould be included asan optional functional elementofthe regulatory framework.NTIA'sreviewofthe public recordindicates that many commenters proposed employing sensing technologies to augment theSAS,better enabling cooperative, opportunistic access to the spectrum.6NTIA agrees with thesecommenters and believes that sensing will help provide maximum flexibility to commercialPAand GAA tier users as well as allow for the continued protection and evolutionoffederal use inthe 3.5 GHz Band. Based onESCinputs, theSASwould instruct commercial users to vacate achannel when proximity to federal use (in frequency, location, or time) presents a risk ofharmfulinterference. The inputs from theESCcan be used by theSASto direct thePA and GAA tierusers to another channel or,ifnecessary, to cease transmissions to avoid potential h