Cellular Telephone Sites

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Transcript Cellular Telephone Sites

Cellular Communication Sites
10/12
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.
HIGHER AUTHORITY AND ESTHETICS
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)
 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?
 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.
What is a cell site?
 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.
 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 Towers
 A cell phone tower consists of the following
components;
1. the Tower,
2. the Equipment,
3. the Antennas, and
4. the Utilities.
 There are four different types of towers;
1. the Monopole tower,
2. the Lattice tower,
3. the Guyed tower, and
4. 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 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 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 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 Towers
Building 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 airconditioning 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 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 uclamps and bolts to the parapet facade,
 Antennas may also be ballast sled mounted, held
in place by concrete blocks and gravity.
Backup 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 Site
Safety 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 Department
Operations
 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.
Preplanning
 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.
Summary
 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 Bartsch
Chief Fire Inspector (ret)
October 2012