Cellular Communication Sites

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Federal Guidelines for Local and State Government Authority over the Siting of Personal Wireless Service Facilities

Section 704 of the Telecommunications Act of 1996 governs federal, state and local government oversight of siting of “personal wireless service” facilities.

The 1996 Act established a comprehensive framework for the exercise of jurisdiction by state and local zoning authorities over the construction, modification and placement of facilities. (Towers for cell, personal communication service (PCS) and specialized mobile radio (SMR),

Preserves local zoning authority, but clarifies when the exercise of local zoning may be preempted by the FCC,

Prohibits discrimination between different providers of personal wireless services, such as cell, wide-area SMR and broadband PCS,

Prohibits any action that would ban altogether the construction, modification or placement of these kinds of facilities in a particular area,

Preempts state and local government regulation on the basis of the environmental effects of radio frequency emissions that comply with FCC regulations.

The Federal Government “a Higher Authority” says you can’t stop the installation of personal wireless service facilities, but allows state or local zoning authority over placement, construction, and modification of personal wireless services (Aesthetics)

HIGHER AUTHORITY AND ESTHETICS

New York State Building Code (BCNYS) addresses cell towers when installed on a building and when a free-standing tower is accompanied by a building for equipment, the building is regulated by the code,

BCNYS; Chapter 15 contains requirements for rooftop structures (1509), Chapter 16 contains seismic requirements for buildings, Section 3108.4 towers designed to resist wind loads in accordance with generally accepted standard EIA/TIA 222-E.

How does it work?How does it work?

You can find cell phone antenna arrays on virtually any type of building in your response area,

The community you live in may indicate the type of antenna setup you will encounter, for e.g.,

in rural areas, you may see tall stand-alone towers with antennas on the top along the countryside,

In urban and sub-urban areas, they can be found on rooftops of apartment houses, office buildings, municipal buildings, and even fire stations.

A cell site is a term used to describe a site where antennas and electronic communications equipment are placed, usually on a radio mast, tower or other high place, to create a cell (or adjacent cells) in a cellular network.

The elevated structure typically supports antennas, and one or more sets of transmitter/receivers transceivers, digital signal processors, control electronics, a GPS receiver for timing, primary and backup electrical power sources, and sheltering.

What is a cell site?

The antenna arrays need to be located high enough so they can adequately cover the area,

Usually range in height from 50 – 200 feet,

Communicate with nearby towers mainly through radio frequency (RF) waves, a form of energy between FM radio and microwaves,

The waves are forms of “non-ionizing” radiation, this means they cannot cause cancer by directly damaging DNA,

At very high levels, RF waves can heat up body tissue, but the levels used by cell phones and towers are much lower.

Cell Cell TowersTowers

A cell phone tower consists of the following components;

1. the Tower,2. the Equipment,3. the Antennas, and4. the Utilities.

There are four different types of towers;

1. the Monopole tower,2. the Lattice tower,3. the Guyed tower, and4. the Camouflaged or Stealth tower.

The Monopole Tower-

a monopole tower is a single tube tower,

it requires one foundation and typically does not exceed 200‘,

the antennas are mounted on the exterior of the tower.

The Lattice Tower –

there are three and four sided towers,

can be seen along interstate highways

The Guyed Tower –

Guyed towers used to be the cheapest tower to construct, but require the greatest amount of land. for taller heights (300' and greater) it is much cheaper to build a guyed tower, most radio and television towers are guyed towers, a guyed tower is a straight tower supported by guy wires to the ground which anchor the tower.

The Camouflaged Tower –

Camouflaged towers are typically required by zoning, they are always more expensive than the other types of towers, more often than not they require additional material to “Stealth" their appearance and typically don't provide the same amount of capacity for tenants.

The EquipmentThe Equipment

The Equipment –

each tenant who mounts their antenna on the cell phone tower uses transmitters installed in cabinets or in shelters,

different wireless carriers use different means of protecting their equipment. Many place outdoor cabinets on concrete pads, while others use pre-manufactured equipment shelters,

this equipment is also called the "Base Transmitter Station".

equipment located at the base of the tower,

the box houses the radio transmitters and receivers that let the tower communicate with the phones. The radios connect with the antennae on the tower through a set of thick cables,

the tower and all of the cables and equipment at the base of the tower are heavily grounded,

the plate in this photo with the green wires bolting onto it is a solid copper grounding plate.

The AntennasThe Antennas

The Antennas –

each carrier will typically use multiple antennas on the tower, sometimes there are as few as three antennas, sometimes as many as eighteen antennas per carrier, as additional subscribers come onto the carriers system, the carriers need additional antennas to handle the added capacity.

The UtilitiesThe Utilities

The Utilities –

almost every cell phone tower site has utilities installed at the site for use by the carriers,

typically each carrier has power run to the site as well as phone service,

120 to 240 volt (50 to 200 amps) power supply,

An AC/DC rectifier coverts AC power to DC power needed for the electronic circuits.

Camouflaged TowersCamouflaged Towers

Building Cell SitesBuilding Cell Sites

Building cellular systems consist of four major components;

a base station, primary and secondary electrical power, coaxial cable, and the antenna.

There are two types of base stations; interior and roof mounted.

The base station is comprised of;

the transmitting and receiving antennas,

a radio room that houses all of the electronic equipment,

a coaxial cable for connecting them,

a power supply, and a backup power supply.

The radio room houses all of the base station electrical components,

the room may be located on the roof or within the building,

this structure, when located on the roof, near the antennas, most likely will be mounted on steel I-beams secured to the parapet,

it will have it’s own power supply to give power to the antenna’s electronic components,

regardless of where this room is located, it must have its own 120 to 240 volt AC power supply,

a rectifier system converts the AC power to DC power needed by the system’s electronic circuits,

power is needed to maintain large air-conditioning units in the utility room and to give power to the antenna’s electronic components,

there will also be an uninterruptible power supply (UPS) system, which is essentially a battery backup system,

the Federal Communications Commission (FCC) requires that a UPS system be available to provide at least a 12-hour backup for the cellular site,

battery backup will allow the base station to continue operating if the power fails,

it may also have a diesel, natural gas powered generator, or Hydrogen Fuel Cell installed, for prolonged power failures,

the site may be part of a US Dept of Energy grant, with Hydrogen fuel cells present.

The coaxial cable is similar to the average television or computer coaxial cable, but it is substantially larger. The standard coaxial cable is approximately 1 5⁄8” in diameter,

only a small amount of electricity is running through it, usually three to four watts,

are easily identifiable and traceable,

are easily identifiable and traceable,

the coaxial exits the radio room, and travels to the antennas,

on the roof, the cable travels through the cable trays to the antennas.

Cable trays are used to protect cables on the exterior of the building;

are usually aluminum or lightweight metal, lying flat on the roof or attached to the side of the building,

are normally not secured to the roof, held in place by gravity,

coaxial cable is secured to the cable tray with zip ties,

the cable tray and all other components of the base station are grounded to prevent electrical shock and protect from lightning strikes.

Roof Mounted SitesRoof Mounted Sites

In sub-urban and urban areas, antennas are normally found in rooftop installations,

Roof mounted base units are generally designed to be suspended over the roof by one or more I-beams,

Large base units can span the entire width of the roof, small base units may be located in the corner of the roof,

Antennas may be mounted to a building by u-clamps and bolts to the parapet facade,

Antennas may also be ballast sled mounted, held in place by concrete blocks and gravity.

Backup PowerBackup Power

Backup power can be:

Batteries

Diesel Generator

Natural Gas Generator

Hydrogen Fuel Cell

Hydrogen Fuel cells are beginning to come into the DC power picture,

Fuel cells are in their infancy, and there are many concerns about fuel safety, fuel delivery, and on-site fuel storage,

Fuel cells are cleaner to operate and require less maintenance than engine generators. Also, new fuel cell technologies under development promise to remove the need to store highly combustible hydrogen in unsecured deployment locations.

Cell SiteCell SiteSafety ConcernsSafety Concerns

Operating in and around base station equipment has many hazards, such as Electrical, Hazardous Materials, Products of Combustion,

The radio room houses all the base stations electrical components,

Always assume that all antennas are transmitting, remember (Time, Distance and Shielding),

Cable trays, under smoke conditions, can increase tripping hazards,

Never touch the antennas, PPE does not protect RF burns,

Fire DepartmentFire DepartmentOperationsOperations

Notify IC when you become aware of the cell site,

Locate ALL main and UPS power shutoffs,

Anticipate forcible entry problems into cell room due to fire rated door assembly and security,

Wear full PPE and SCBA when operating in the cell room with smoke,

Never cut coaxial cable, if cut end came in contact with a body part, it could cause burns,

Have sufficient light during night ops on roof level to alleviate tripping hazard,

Utilize proper portable extinguisher for quick extinguishment of incipient fires,

Be careful operating around batteries, they can fail and leak acid,

Roof mounted base stations increase the dead load,

Cell towers can and do collapse due to fire, fatigue, bad construction, and weather conditions.

PreplanningPreplanning

Cellular contact telephone numbers,

Electrical (main & UPS) shutoff locations,

Location of base stations within the building,

Some base stations may have suppression systems, learn what and how they operate,

Cell carriers make every effort to avoid penetrating the roof when installing stations, learn where cable trays run from base station within the building to roof antennas (shafts, chutes, outside the building),

How are the antennas attached to the building?,

Are antennas camouflaged?,

What is the secondary (UPS) power supply (batteries, generator) and where are they located?,

Determine roof mounted base station support for structural collapse potential and dead load,

Schedule fire company drills at site,

Notify dispatch for transmittals of information and carrier emergency phone numbers.

SummarySummary

Notify the IC of site presences,

The base station is energized, be careful with metal tools and water,

Identify all power shutoffs as soon as possible,

Preplanning is essential,

Always assume that all antennas are transmitting stay at least 10 ft away (time, distance & shielding),

At tower fires, if there are no life hazards, don’t jeopardize FF lives, let it burn………..

Prepared by Thomas BartschChief Fire Inspector (ret)

October 2012