User guide

Building Your Canopy Network March 2005
Through Software Release 6.1
Issue 1 Page 127 of 425
Canopy System User Guide
15 AVOIDING HAZARDS
Use simple precautions to protect staff and equipment. Hazards include exposure to RF
waves, lightning strikes, and power surges. This section specifically recommends actions
to abate these hazards.
15.1 PREVENTING OVEREXPOSURE TO RF ENERGY
To protect from overexposure to RF energy, install Canopy radios so as to provide and
maintain the minimum separation distances from all persons shown in Table 33.
Table 33: Exposure separation distances
Canopy module Minimum separation distance from all persons
Antenna of 900-MHz AP or SM 60 cm 24 in
2.4-, 5.2-, 5.4-, or 5.7-GHz radio
with no reflector
20 cm 8 in
2.4-, 5.2-, 5.4-, or 5.7-GHz radio
with a reflector
1.5 m 60 in (5 ft)
At these and greater separation distances, the power density from the RF field is below
generally-accepted limits for the general population.
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NOTE:
These are conservative distances that include compliance margins. In
the case of the reflector, the distance is even more conservative
because the equation used models the reflector as a point source and
ignores its physical dimensions.
15.1.1 Details of Calculations for Separation Distances and Power Compliance
Margins
Limits and guidelines for RF exposure come from:
◦ US FCC limits for the general population. See the FCC web site at
http://www.fcc.gov
, and the policies, guidelines, and requirements in Part 1 of
Title 47 of the Code of Federal Regulations, as well as the guidelines and
suggestions for evaluating compliance in FCC OET Bulletin 65.
◦ Health Canada limits for the general population. See the Health Canada web site
at
http://www.hc-sc.gc.ca/rpb
and Safety Code 6.
◦ ICNIRP (International Commission on Non-Ionizing Radiation Protection)
guidelines for the general public. See the ICNIRP web site at
http://www.icnirp.de/ and Guidelines for Limiting Exposure to Time-Varying
Electric, Magnetic, and Electromagnetic Fields.