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Broadband Over Power Line National Telecommunications and Information Administration U.S. Department of Commerce May 25, 2005.

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Presentation on theme: "Broadband Over Power Line National Telecommunications and Information Administration U.S. Department of Commerce May 25, 2005."— Presentation transcript:

1 Broadband Over Power Line National Telecommunications and Information Administration U.S. Department of Commerce May 25, 2005

2 2 Scope BPL in the Context of Power Line Emissions* BPL in the Context of Power Line Emissions* Findings Of NTIA BPL Phase 1 Study* Findings Of NTIA BPL Phase 1 Study* Subsequent Technical Findings* Subsequent Technical Findings* Framework of FCC BPL Rules Framework of FCC BPL Rules NTIA’s On-going Study Priorities NTIA’s On-going Study Priorities ___________ ___________ *See publications, NTIA BPL Phase 1 Report and Comments to FCC *See publications, NTIA BPL Phase 1 Report and Comments to FCCwww.ntia.doc.gov

3 3 BPL in the Context of Power Line Emissions Without BPL, power line emissions exceed FCC Part 15 field strength limits and interfere in some cases Without BPL, power line emissions exceed FCC Part 15 field strength limits and interfere in some cases Diagnosis and repair of noise emissions can be time-consuming and costly Diagnosis and repair of noise emissions can be time-consuming and costly Some federal radio operators routinely police local power lines for noise emissions, diagnose high emission levels, and work cooperatively with the utility or electricity user to eliminate interference Some federal radio operators routinely police local power lines for noise emissions, diagnose high emission levels, and work cooperatively with the utility or electricity user to eliminate interference

4 4 Some Receiver Antennas are Close to Power Lines

5 5 NTIA BPL Study Findings NTIA Coordinated its studies with FCC/OET NTIA Coordinated its studies with FCC/OET BPL (and other) power line radiated emissions do not emanate from a point source BPL (and other) power line radiated emissions do not emanate from a point source Multiple points sources (impedance discontinuities)Multiple points sources (impedance discontinuities) Traveling wave modes of high radiation intensityTraveling wave modes of high radiation intensity Measurements & modeling Measurements & modeling Radiation and local groundwave propagation - Numerical Electromagnetics Code (NEC) ver. 4.1Radiation and local groundwave propagation - Numerical Electromagnetics Code (NEC) ver. 4.1 Local spacewave propagation toward aircraft – Matlab model using NEC radiation predictionsLocal spacewave propagation toward aircraft – Matlab model using NEC radiation predictions HF ionospheric propagation - VOACAP softwareHF ionospheric propagation - VOACAP software Phase 1 study addressed potential local interference Phase 1 study addressed potential local interference

6 6 Example NEC Analysis (Spatial Distribution of E Field)

7 7 Distances From BPL Power Lines Within Which Interference Is Likely LOW – MODERATE MODERATE - HIGH Land Mobile Station 125 m 55 m Fixed or Base Station (for Mobile) 770 m 450 m Maritime Shipborne Station 135 m 85 m Aircraft 6 km alt: in Flight 12 km alt. 33 km > 50 km 12 km - Service Desired Signal Level

8 8 NTIA Phase 1 Study Findings Many interference prevention and mitigation techniques exist: advance consultations and BPL frequency agility Many interference prevention and mitigation techniques exist: advance consultations and BPL frequency agility Greatest interference risks stem from compliance measurement provisions: Greatest interference risks stem from compliance measurement provisions: In situ measurement procedures not well defined (ANSI C63 and CISPR 16 & 22)In situ measurement procedures not well defined (ANSI C63 and CISPR 16 & 22) Irregular spatial distribution of field strength greatly complicates compliance measurementsIrregular spatial distribution of field strength greatly complicates compliance measurements

9 9 Subsequent Study Findings Relatively high levels of field strength are spatially confined Relatively high levels of field strength are spatially confined A practical compliance measurement procedure for Access BPL systems can reliably identify the field strength level that is not exceeded at 80% of possible receiver antenna locations at the specified measurement distance from the radiating structure – this is the procedure that was specified in the FCC Report & Order A practical compliance measurement procedure for Access BPL systems can reliably identify the field strength level that is not exceeded at 80% of possible receiver antenna locations at the specified measurement distance from the radiating structure – this is the procedure that was specified in the FCC Report & Order Ionospheric propagation and aggregation of BPL emissions is not a near-term issue: millions of BPL devices can be deployed before the onset of any such interference problem Ionospheric propagation and aggregation of BPL emissions is not a near-term issue: millions of BPL devices can be deployed before the onset of any such interference problem  Should not delay rulemaking for further study

10 10 Framework of FCC BPL Rules Access BPL emission frequencies must be fungible Access BPL emission frequencies must be fungible Access BPL devices are subject to certification Access BPL devices are subject to certification In-House BPL compliance measurement procedures improved via requirement to measure along outdoor power service lines In-House BPL compliance measurement procedures improved via requirement to measure along outdoor power service lines

11 11 NTIA’s On-Going Study Priorities Update interference risk analyses based on new FCC rules for Access BPL systems Update interference risk analyses based on new FCC rules for Access BPL systems Provide additional guidance: Provide additional guidance: Prevention of interferencePrevention of interference Suspected interferenceSuspected interference Prevention of significant noise floor increase via ionospheric propagation Prevention of significant noise floor increase via ionospheric propagation


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