RF Interpretations

Have you interpreted the FCC's RF-exposure guidelines correctly?

For more than a year, providers have been trying to interpret the FCC's guidelines on RF exposure. Now it's Sept. 1 — the deadline for compliance — and your time is up. At the heart of this is the FCC Office of Engineering and Technology's Bulletin 65, Edition 97-01, an 85-page document that has left even seasoned engineers scratching their heads. Did your engineers interpret the guideline accurately? Are you in compliance?

Interpretation
Dr. Robert Cleveland Jr., FCC Office of Engineering & Technology senior scientist, said interpreting the guidelines should not be difficult for RF engineers. Cleveland is one of the writers of the revised guidelines.

Originally created in 1985 and revised in 1997, Bulletin 65's main objective is to encourage RF safety training, exposure mitigation and emissions surveys. The bulletin requires providers to follow maximum permissible exposure (MPE) limits as defined by the National Council on Radiation Protection and the IEEE.

"It took us almost six months to figure out what we should and shouldn't do, and how we should interpret it," said Wayne Leuck, US West vice president of wireless engineering and technology. "It wouldn't surprise me that there are some people out there that don't understand it."

According to Jeff Chaltas, Sprint PCS spokesperson, providers initially might think the bulletin is designed to limit RF emissions. It is not.

The guidelines are in place to ensure that RF signals don't affect the human environment negatively. But if it's a health issue, why isn't the Occupational Safety and Health Administration (OSHA) in charge of this mandate? According to Wes McGee, SiteSafe president & CEO, the FCC probably was given the task of enforcing the guidelines because it has more power over RF-service providers. With the FCC enforcing these rules, violators could face more than just fines; they could be shut down temporarily or even permanently.

Because of the fear of losing a site, some providers are playing it safe by implementing stricter internal guidelines.

"We interpret those a little differently than others," Leuck said. "We decided to take a harder stance on everything the FCC is saying."

For example, Leuck said US West conducts more radial measurements than the guideline suggests. Instead of only measuring 360-degree patterns, US West engineers take additional vertical-pattern measurements on all the company's antennas, because directional antennas still can contribute to effective radiated power (ERP) summation for other directions. The guideline, however, only recommends that sectorized antennas be measured.

One key area of confusion is whether a provider is exempt or not. Section 1 of the guidelines states: "...the FCC requires that tower-mounted installations be evaluated if antennas are mounted lower than 10 meters above ground and the total power of all channels being used is over 1,000W ERP, or 2,000W ERP for broadband PCS."

According to SiteSafe's McGee, this doesn't mean that providers with installations taller than 10 meters are automatically excluded from adhering to the guidelines. In fact, adhering to MPE limits still is required. This exemption only relates to RF-emission evaluations on towers less than 10 meters tall.

"There is a big difference between total exclusion and emission surveys on towers," McGee said. "There are a lot of operators out there that think they are excluded but aren't. You really have to read all the way through the guideline to fully understand the scope of it."

Underscoring McGee's warning, one provider representative attending the Site Owners and Managers Alliance (SOMA) conference held in May mistakenly said her company was categorically exempt due to its use of towers more than 10 meters high. Further, she said she expected the company's infrastructure vendor to make sure the company met all FCC requirements. Clearly, the provider didn't know that the FCC mandate held the provider, not the manufacturer, responsible for meeting the requirements. She wasn't alone in her misunderstanding. Several site owners misinterpreted their roles as well. They thought they could be fined if they didn't control access to antennas adequately.

Any provider thinking it's exempt should hire a consultant before disregarding any FCC requirement, Leuck suggested.

Providers' Responsibilities
According to Bulletin 65 Appendix A, spectrum licensees should:

• Take actual measurements of the RF field when predictions are slightly greater or slightly less than the threshold for excessive exposure or when fields are likely to be seriously distorted by objects in the field

• Evaluate emissions through calculation, computer models, field measurements and portable devices

• Mitigate exposure through specific training as part of an RF safety program and incorporate time averaging

• Make workers aware of the potential for RF exposure in the workplace or similar environment

• Affix warning signs and labels to establish awareness as long as they provide information, in a prominent manner, on risk of potential exposure and instructions on methods to minimize such exposure risk.

Licensees are required to:

• Follow MPE limits for occupational and public exposure as set forth in the guidelines

• Maintain a statement or certification confirming compliance with MPE limits

• Prepare an environmental assessment (EA) if a particular facility, operation or transmitter would cause human exposure to levels of RF electromagnetic fields in excess of MPE limits.

Providers said the majority of the guidelines' directives have been implemented for the past several years because they make good sense. For many, compliance certification and EAs are the only new changes to come about because of the mandate.

According to Sprint PCS's Chaltas, most engineers would rather select another location than submit an EA.

"An EA is like admitting you are not in compliance," Les Wilding, BellSouth senior engineer said. "You never want to do that."

In most cases, providers get help from vendors to maintain com-pliance. BellSouth recently purchased an RF-safety-training course to help engineers understand MPE limits and time averaging. The course, available on CD-ROM, takes approximately four hours to complete. Currently, there is no FCC guideline on how often employees should be retrained, but BellSouth requires all of its engineers to be recertified annually.

Several vendors offer RF-exposure solutions, such as emission-prediction software, safety training and time-averaging computations, to help providers meet the FCC requirements.

Help from vendors, however, doesn't mean they are responsible for your employees' mistakes.

"I'm sure we could be one of the many names named on a suit," McGee said. "But we would not really have any kind of liability. In most circumstances, it's the provider who is liable."

Third-Party Owners & Managers
Site and tower owners and managers that spoke at the SOMA conference debated their roles in RF-exposure compliance. Most agreed their main purpose was to facilitate communications between co-located tenants and help monitor antenna access.

Michael Elford, CenturyTel director of engineering and construction, said communications with its competition on co-located sites was not a big issue, but was something he would rather avoid. He said wherever possible CenturyTel uses a third party such as a site owner to coordinate with other providers.

Appendix A doesn't require owners to act as go-betweens for providers on co-located sites, but it does recommend owners assist in controlling access.

According to Bulletin 65, "Where feasible, (owners) should encourage co-location of transmitters and common solutions for controlling access to areas where the RF-exposure limits might be exceeded."

The main area of concern for site managers is controlling access. One site manager told a story about a site owner that thought it had a secure rooftop. The rooftop was locked, and there was only one key. However, the key was kept with the building's resident manager, who kept it on a hook in plain sight and regularly gave the key to anyone who asked. The door to the rooftop had no warning signs, and the resident manager clearly didn't know anything about MPE schedules. An engineer making an antenna adjustment went to the rooftop to find a resident sunning herself in the midst of several RF antennas. Fortunately, no one was harmed, but if this had occurred after Sept. 1, providers could have been fined or even shut down.

From the beginning, the FCC has been honest about its ability to enforce its own guidelines actively. The FCC's Cleveland said the commission doesn't have the resources to enforce compliance on its own. Instead, he said the commission will allow outside agencies and consumer groups to bring possible violations to its attention. Cleveland said OSHA will be one of the driving forces behind guideline enforcement. The safety organization currently conducts inspections of towers and rooftops, and easily could disseminate information to the FCC. One vendor said providers should expect labor unions to push the guidelines, too.

Enforcement issues are compounded by the fact that the FCC has not yet defined fines. Cleveland said there is no precedent for fines, but once the deadline arrives and a violation is encountered, fines will be created.

With no routine inspections or fines in place, guideline enforcement still is a little shaky. Many in the industry believe that in the first few months after the deadline, the FCC will turn up a few violators and make an example of them.

US West's Leuck expects that the FCC will incorporate RF-compliance audits with tower-ID audits and equipment-registration audits. The commission will be watching the industry closely, he said.

"The FCC will not audit all the towers and sites, but it will do a small percentage of them in the beginning," Leuck said. "And they are going to start dinging people for (violations)."

Cleveland agreed, saying if providers don't believe that the FCC is watching, they need only wait and see what happens to providers not in compliance after the deadline.