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RF Safety at Wireless Sites

Bob Johnson, L-3 Communications Narda Safety Test Solutions. RF Safety at Wireless Sites. Presentation Overview. FCC Limits Rooftops and Towers RF Safety Compliance AT&T vs. Orchitt and other legal happenings The Golden Two Rules Questions and Answers. Graphical Limits.

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RF Safety at Wireless Sites

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  1. Bob Johnson, L-3 Communications Narda Safety Test Solutions RF Safety at Wireless Sites

  2. Presentation Overview • FCC Limits • Rooftops and Towers • RF Safety Compliance • AT&T vs. Orchitt and other legal happenings • The Golden Two Rules • Questions and Answers

  3. Graphical Limits 47 CFR 1.1310 Radio-frequency exposure limits (in terms of equivalent power density) 1000 = Controlled/Occupational Environments = Uncontrolled/General Public Environments H 100 E 10 S 1.0 0.1 3 10 30 100 300 mW/cm2 1 3 10 30 100 300 1 3 10 30 100 300 GHz kHz MHz

  4. Important Points About Compliance • Note that limits are specified in “Controlled/Occupational” and “Uncontrolled/General Population”. A fence does not make your facility “Controlled/Occupational”. • Your property is an “Uncontrolled” environment without an RF safety plan. • IEEE C95.7 recommends that you initiate an RF safety program, and appoint an RFSO, if you exceed similar “Action” level.

  5. Engineering Controls • Elevate Antennas • Reduce power • Relocate Antennas • Increase distance between antennas

  6. Administrative Controls • Posting Signage • Installing Barriers • Employing Personal Monitors • Specific Site Safety Rules

  7. Barriers An attempt to comply was made, however restricted areas must be maintained! Note, status of plastic chain fencing

  8. EME Action Thresholds Only Fools Allowed Post Warning Signs 1000% RF Qualified And Trained Worker EME Protective Clothing High Level Site Specific Awareness Post Caution Sign 300% 100% Site Worker Post Notice Sign, EME Guidelines. General EME Awareness 20% General Public No Procedures Required

  9. Performing Surveys • Many have purchased “broadband equipment”. This system reads out directly in terms of “% of Std.”. • In this case, that is % of FCC limits for Occupational/Controlled” environments. • Therefore, any readings above 20% means a safety plan is required, with additional controls above 100%.

  10. Performing Surveys • At Multiple emitter sites, broadband equipment cannot adequately measure 5% contributors. • Narrowband equipment such as the SRM-3000 can measure all emitters individually without turning any emitters off. • This type of a system is being trialed by the FCC Enforcement Bureau, now.

  11. Personal RF Monitors • Wearable monitors are available for qualified person use in areas where high levels are known to exist, like on towers. • Models can be supplied with climbing pouches and higher alarm levels for use with suits. • Always worn on outside!

  12. Review • Find out what the field levels are at your site. • Get proper signs, and install them in the right place. • Remember to spatially average readings, don’t overly restrict your emissions. • Remember 5% rule. • Follow-up with readings when antennas are changed or anything that could alter your action areas.

  13. Recent Litigation • August 20, 2007 - Decision of The Supreme Court of the State of Alaska No. 6139 - July 6, 2007 AT&T Alascom and Ward North America, Inc., v. John Orchitt; and The State of Alaska, Department of Labor and Workforce Development, Division of Workers' Compensation. Alaska Supreme Court Upholds Award for RF Radiation Injury Below Thermal Exposure Level.

  14. The Golden Rules • In order to comply with FCC RF Exposure regulations, you only need to do two things: • Insure your employees cannot be over-exposed by any entities emitters • Insure no person is over-exposed by your emitters • Safety programs must be in place for areas where the action (“Uncontrolled/ General Public”) level is exceeded.

  15. Questions? • World leaders in RF safety programs, products and support for FCC licensees. • For help with your program, (even if your not buying anything!) give us a call at (631) 231-1700 Extensions 230 or 434. • www.narda-sts.us • Nardasts@L-3com.com

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