电力线宽带bpl报告第二阶段第一卷

POTENTIAL INTERFERENCE FROMBROADBAND OVER POWER LINE (BPL)SYSTEMS TO FEDERAL GOVERNMENTRADIOCOMMUNICATION SYSTEMSAT 1.7 - 80 MHz Phase 2 Study VOLUME Itechnical report NTIA Report 08-450 POTENTIAL INTERFERENCE FROM BROADBAND OVERPOWER LINE (BPL) SYSTEMS TO FEDERALGOVERNMENT RADIOCOMMUNICATION SYSTEMS AT1.7 - 80 MHz Phase 2 Study VOLUME I James C. RichardsJonathan V. Williams U.S. Department of CommerceCarlos M. Gutierrez, SecretaryJohn M. R. Kneuer, Assistant Secretaryfor Communications and Information October 2007 ACKNOWLEDGEMENTS The authors would like to thank the many organizations and persons whocontributed to the completion of this report. In particular, we wish to thank the federalagency representatives on the Interdepartment Radio Advisory Committee for providingvital comments, information, and review of this report. We also wish to thank the following NTIA personnel who contributedsubstantially to this report and to the underlying studies: Alakananda Paul Cou-WayWang, and Edward Drocella. PREFACE This report contains two volumes. Volume I presents the main text and VolumeII contains appendixes that provide additional technical supporting information that issummarized in Volume I. EXECUTIVE SUMMARY On October 14, 2004, the Federal Communications Commission (Commission orFCC) adopted a Report and Order that defined new Part 15 rules for Access Broadbandover Power Line (BPL) systems. The National Telecommunications and InformationAdministration (NTIA) contributed to the Commission’s work by providing analysis tosupport recommendations for refinements in the rules and measurement guidelines incomments and staff correspondence filed in response to the Commission’s earlier BPLNotice of Proposed Rulemaking (NPRM). The NTIA Phase 2 study of Access BPLsystems expands on its earlier Phase 1 study by providing additional modeling results andanalyses to evaluate the effectiveness of the FCC’s rules and measurement guidelines inminimizing the potential for harmful interference to federal radiocommunication systemsunder worst-case conditions. NTIA’s simulations of overhead Medium Voltage (MV) power lines show thataspects of the measurement guidelines addressed in the BPL Report and Order, such asmeasurement distance, locations, height and height correction factor, and antenna type,effectively estimate the peak electric field strength that might be experienced in thevicinity of the Access BPL energized power line. These simulations employ theNumerical Electromagnetic Code (NEC) software package to model a variety of powerline configurations. NTIA investigated the Commission’s new methodology forextrapolating field strength limits when measurements must be made at distances otherthan those specified in the rules. NTIA’s simulations confirm that the extrapolationmethodology provides a reasonable approximation of the predicted rate of field strengthroll-off with distance in close proximity to the BPL device and its associated power lines. The FCC’s rules include special mechanisms for minimizing the likelihood ofharmful interference to critical federal radiocommunication systems in addition to thebaseline protection afforded by field strength limits, prohibition of harmful interferencefrom Access BPL systems, and compliance measurement provisions. These specialprotection provisions have the following forms: geographic consultation areas, whereinBPL deployments at any frequency in those areas must be preceded by consultationsbetween BPL operators and nearby radio operators; excluded bands, in which certainfrequencies are not to be used by BPL in any geographic area; and small geographicexclusion zones, wherein BPL emissions are forbidden at specified frequencies. NTIA’sanalysis shows that, at the distances corresponding to these protection areas, BPLemissions are expected to result in only small increases in the noise floor of protectedcommunications receivers, or power flux density levels that fall below the interferenceprotection requirement for sensitive radioastronomy or over-the-horizon radar receivers. This Phase 2 report illustrates the application of the rules and measurementguidelines in a case study. Using the NEC software package, NTIA created an elaboratepower line model that approximates an existing overhead Access BPL power linestructure. After applying the emissions limits and methodology from the BPLmeasurement guidelines, NTIA analyzed the noise floor increase expected in nearbyreceivers as a result of BPL operations. In addition, NTIA used this power line model to analyze the BPL emission levels that might be seen at more distant receivers. The resultsof the case study are consistent with NTIA’s earlier analyses using simple power linemodels. NTIA’s Comments in response to the BPL NPRM included a preliminary analysisof the aggregation of overhead Access BPL emissions via ionospheric propagation in the1.7 to 30 MHz frequency range. That analysis has been further refined in this r