HomeMy WebLinkAbout2011-09-06 Planning Board Supplemental Materials (63) TAB 7
❑� AFUR MAXIMUM PERMISSIBLE
communications EXPOSURE STUDY
at&t
Site Number: MA3469
Site Name: AWE-912008007
Latitude: 42.70776111
Longitude: -71.1143
Address: 723 Osgood Street,
North Andover, MA 01845
Conclusion: AT&T's proposed antenna installation is calculated to be within the FCC
Standard for Uncontrolled(General Public and Controlled(Occupational Maximum
Permissible Exposure (MPE).
Prepared by: SAI Communications
260 Cedar Hill Street
Marlborough, MA 01752
508-573-5407
Date of Report: June 7, 2011
Table 0fContents
Introduction.................................. ...................................................... .......................................................3
RFExposure Prediction Method.............. .......... ............................. ......................................................3
CaseSummary....................... ......................................... ............................................... .....................4
RIFDesign Specifications....................................... ..................... ........... ...............................................4
FCCGuidelines.......................-........................... ....... ..... ...................... ...... .....................S
FCCRF ExposureLimits........ ......................................... .............................................. ........................6
CalculationResults~~~.— .............................. ............. ............................................... .......................7
StatementnfCertification........................................... .................................... ......... ...............................8
Introduction
SAI Communications has conducted this theoretical analysis for AT&T, to ensure that the
proposed radio facility complies with Federal Communications Commission (FCC) regulations.
This report will show that, through the use of FCC suggested prediction methods, the radio
facility in question will be in compliance with all appropriate Federal regulations in regards to
Radio Frequency (RF) Exposure.
RF Exposure Prediction Method
Power Density is calculated in accordance with FCC OET Bulletin 65 formula (7):
2.56 * 1.64 a ERP,.ei
S = z
4*n*R
R
V _�.
Va ICalculation Point
Vp
H J
Ground Level
Where:
S = Power Density
ERP,ei= Effective Radiated Power relative to antenna pattern
R = Radial distance =V—H2 + Vz
H = Horizontal distance from antenna
V =Vertical distance from antenna = Va—Vb
Va =Antenna height above ground
Vb = Calculation height above ground = 6ft
Page 3 --
Case Summary
The proposed radio facility will have a radiation center of 88ft located at the following
geographic coordinates:
Latitude: 42.70776111
Longitude: -71.1143
See sketch below for specific property location.
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R
c
a y
0 �
p r
q � v
MA 3469-AWE-912006007 STEVENS ESTATE
ay F
0{
9 ^l.
Y b .
p J +fid `A MAao�ol
RF Design Specifications
AT&T Mobility is planning to install 1 panel antenna per sector, for LTE Technology, with
azimuths of 70-190-310 for alpha-beta-gamma sectors. Table below shows the technical data
used for the calculation.
GSM1900 UMTS850 I UMTS1900 LTE700 LTE2100
Antenna Type: Kathrein Kathrein Kathrein
800-10121 800-10121 800-10766
Antenna Gain(dBd) 14.35 11.35 14.35 13.75 15.65
Rad Center, AGL(ft) 88 88 88 88 88
ERP(d8m) 55.35 56.35 59.35 58.75 60.65
No of Radios 3 1 2 1 1
— — Page 4
FCC Guidelines
Table 1. MPE Limits for General Population/ Uncontrolled Exposure
Magnetic
Electric Field Power Averaging Time for
Frequency Range Strength Density �Ej2, IHI2 , or S
(MHz) (V/m) LStField
rAl gth (mW<cm2) (Minutes)
0.3 - 1.34 614 1.63 100 * 30
1.34-30 824/f 2.19/f180/fZ * 30
30-300 27.5 0.073 0.2 30
300- 1500 — ff1500 30
1500— 100,000 1.0 30
f=frequency in MHz ` = Plane wave equivalent ower density
General populationluncontrolled exposures apply in situations in which the general public may be
exposed, or in which persons that are exposed as a consequence of their employment may not be fully
aware of the potential for exposure or can't exercise control over their exposure.
Table 2.MPE Limits for Occupational/Controlled Exposure
Power Averaging Time
Frequency Range Electric Field Magnetic Field z z
(MHz) Strength (V/m) Strength (A/m) Densit z for JET , �H� or
mW/cm S Minutes
0.3-3.0 614 1.63 (100 * 6
3.0-30 F 1842/f 4.89/f I900/f2)* 6
30-300 61.4 0.163 11 1.0 6
300—1500 11 11--noo 6
1500— 100,000 00L 5.0 6
f=frequency in MHz ' = Plane wave equivalent power density
OCCOpational/controlled limits apply in situations in which persons are exposed as a consequence of their
employment provided those persons are fully aware of the potential for exposure and can exercise control
over their exposure. Limits for occupational/controlled exposure also apply in situations when an
individual is transient through a location where such occupational/controlled limits apply provided he or
she is made aware of the potential for exposure.
Page 5
FCC RF Exposure Limits
FCC MPE LIMITS (mW/cm')
EXPOSURE ENVIRONMENT AT&T FREQUENCY BANDS
`..�.,�"" Cellular PCS
General Public Uncontrolled 0.59 1.0
Occupational Controlled 2.93 5.0
1,000
—OccupationaliControlletl Exposure
-----General PopulatieniUncontrolled Exposure
100 --- ----
E \
E \
\
10 --- %{ --- — ---
N \
d {
O \
6 \
\ '
0
0 1 10 100 1,000 10,000 100,000
Frequency, MHz
Maximum Permissible Exposures. OccupationallControlled and General
Population/Uncontrolled MPE's are functions of frequency.
Page 6
Calculation Results (6ft AGL)
The following charts show the graphical representation of the calculated AT&T contribution on
power density levels and % MPE at 6ft above ground, as horizontal distance from antenna
increases. The calculations take into account the vertical pattern of the antennas and represent
the immediate direction of each sector azimuth within the antenna horizontal beamwidth. The
calculations also assume line of site to the antennas and the result will be lower if measured
indoor due to in-building penetration loss.
Power Density and %MPE
10 I A
1
E
v —
3
E 0.001 ---- -- —GsMtsoo
3
W —UMTs850
00001 —UMTs1900
L
N —LTE700
m
O —LTE21
0.00001 - 00
f
0
c i
a
1E-C --
1 10 100 1000 10000
Horizontal Distance from Antenna,ft
1000.0000%
1000000r -
IPeak(Une ntrolled/General
Public),36. 0875f,0 3782%
10.0000% - -- - -'
LU Peak(Controlled/omuq� onal),
1 36.50875ft,0.0756/
1.0000% -- --
o i —Unconimlled
—Controlled
R
F 0.1000% i _Llmit
peak
00100% --
00010% --
0.0001%
1 Ito l mo loon
10000
Horizontal Distance from Antenna,ft
— Page 7
Statement of Certification
I certify to the best of my knowledge that the statements contained in this report are true and
accurate. The theoretical computations contained are based on FCC recommended methods,
with industry standard assumptions&formulas, and complies with FCC mandated Maximum
Permissible RF Exposure requirements.
A comprehensive field survey was not performed prior to the generation of this report. If
questions arise regarding the calculations herein, SAI Communications recommends that a
comprehensive field survey be performed to resolve any disputes.
June 7, 2011
Sanket Y Joshi Date
SAI Communications
Page 8