Written by Marshall Pearsall
Over the course of the last twenty years, we have become dependent upon wireless devices to keep us connected to our families, friends and work. As the demand for connectivity increases, the wireless industry is racing to expand the needed infrastructure. Wireless networks depend upon a rapidly expanding multitude of antennas that are required for the operation of our devices. Recently the wireless industry has begun to install antennas on utility poles and streetlights which creates a potential hazard for the linemen that maintain and operate the infrastructure. All wireless devices transmit radio frequency (RF) emissions which are electromagnetic waves that cannot be seen or felt. Although lineman will be at risk for exposure at these locations, it is a hazard that can be managed and mitigated.
The Federal Communications Commission (FCC) administers guidelines for worker safety as they relate to RF emissions exposure. Prior to activation of any FCC licensed antenna system, a study must be performed by the operator of the equipment to document the frequency and power levels of the equipment and delineate areas that can be safely accessed during the operation of the system. The studies identify two areas that surround the antenna: ‘General Population/Uncontrolled’, which can be accessed by untrained workers and the general public and ‘Occupational/Controlled’, that can only be accessed by trained workers.
Most commercial wireless devices, such as baby monitors, garage door openers and cells phones, produce RF emissions at such low power levels that they are not a safety hazard. These devices fall within the FCC’s General Population/Uncontrolled limits and do not require special training or notification. High power antenna locations are used for the transmission of radio, TV and cellular phone signals. These sites pose the greatest risk to worker safety, including the antennas systems that are proposed for utility structures. These high-power locations have an Occupational/Controlled area around the antenna that contain signage, barriers to restrict access, and can only be entered by workers that have taken RF safety training classes.
Due to changes in technologies, equipment and regulations, utility structures are now being considered for antenna installations. The wireless industry is focused on deploying small cells, which consist of compact equipment and antennas that can be easily installed on utility poles and streetlights.
Small cells are being installed on utility structures in the public rights-of-ways to achieve the following:
- add capacity to the existing wireless networks
- be closer to pedestrian and vehicular traffic
- accelerate cost effective deployments
Existing wireless networks are exhausted, and the industry lacks the ability to increase the capacity of the equipment in-place to meet customer demand. Utility structures in the public rights-of-ways are attractive since the installations have access to existing poles, commercial power and fiber. Additionally, the FCC has introduced regulations that facilitated the success of wireless equipment on regulated utility structures. The regulations established favorable timelines for the processing of applications and installations. Also, the regulations created very attractive reoccurring fees for the attachments.
Although the FCC’s authority is limited to regulated utility structures, the FCC’s wireless regulations will ultimately impact municipal electric entities. As wireless networks become more dependent upon small cell technologies, the wireless industry is going to push for expansion into non-regulated utility territories. If non-regulated entities allow small cell attachments on utility structures, a new workforce must be educated about and protected from RF emissions. There are several approaches that can be taken to protect workers from the hazards associated with RF emissions, including:
RF Safety Training: RF safety training is mandatory for workers that access Occupational/Controlled area to maintain and operate wireless equipment. This approach requires annual training and the use of a RF monitoring device every time a wireless antenna location is accessed. The training is costly, time consuming and requires the maintenance and certification of RF monitoring equipment. Due to the impact of the RF safety training on resources and the workforce, most utilities have decided to avoid this approach.
Separation: Another approach is to create an area of separation from the antenna and the lineman. The objective is to delineate a safe work zone for the lineman that is outside of the Occupational/Controlled area. This approach can be achieved by installing antennas above and away from the work zone. The distance of the antenna from the work zone is determined by the RF emissions study. In order to achieve the required separation, most installations require that the height of the poles be increased, thus resulting in pole replacements. Although a safe zone is being created, FCC signage is still required to warn the lineman of the potential hazard of the antennas.
Some utilities have taken the separation approach to protect its workforce, but it has not been well received by the wireless industry due to the costs associated with the pole replacements. Additionally, the approach does not allow for the installation of antennas in the communications space of a pole, since a lineman would have to pass by the antenna and through a designated Occupational/Controlled space to work on the electric infrastructure.
Although achieving separation from the antennas is a reasonable approach, it does not eliminate the potential risk of RF exposure. First, the RF emission study only takes into consideration a certain power level of the antenna. The antenna and equipment must be operating as intended and does not take into consideration operational errors or equipment malfunctions that may increase the power levels of the equipment above safe thresholds. Additionally, the approach does not prevent the operator of the bucket truck to inadvertently raise the bucket above the pole to a height that is within the Occupational/Controlled areas of the antenna.
Depowering of the RF Source: Depowering eliminates the RF source and the associated potential risk to linemen. Depowering is the most economical, least burdensome and efficient means to protect linemen. The approach simply requires cutting off the main disconnect of the electrical service for the equipment. Although depowering is very attractive, it is only effective if a lineman is aware of antennas and understands the process.
Training is the key to raising awareness about antennas, RF signage and the depowering process. Prior to starting work at any pole locations, visual inspections should be required to identify potential hazards. Training should include the identification of FCC signage that is required for every licensed site. If GIS databases are being accessed by the linemen, it would be very helpful to include information about the antennas in the system.
Additionally, the training should include an overview of procedures that need to be followed to depower the antenna system. This may include three tiers of notification, scheduled maintenance, non-emergency repair and emergency repair. Scheduled maintenance and non-emergency repairs would require that the lineman call the Network Operations Center (NOC) of the wireless operator to provide notice that the wireless device will be depowered as well as an estimated length of the outage. Emergency situations allow the lineman to immediately depower the equipment without notification.
The depowering process will require that the lineman shut off a simple electric disconnect device which may be located at ground level or on the pole beyond the reach of the general public. Most ground level mounted disconnects will be locked. These disconnects can be secured with a single combination lock or a shared combination configuration so that the pole owner can use a unique code for the lock.
Once the lineman has depowered the wireless device, all RF emissions have been eliminated, and the pole can be accessed without a RF monitoring device, RF safety training or certification. Unfortunately, this approach is not failsafe. Signage at the pole must be present, and the lineman must be trained to follow the depowering process.
If an electric municipal entity decides to allow antennas to be installed on poles and streetlights, the entity should develop and implement the best possible practices to protect its workforce from RF emissions. Additionally, language can be added to the Master License Agreements for collocations and attachments that clearly define the safety protocols for the poles and streetlights. Ultimately, municipal electric entities can support the initiatives of the wireless industry while at the same time ensure a safe work environment for its workforce.