This series of maps show the pattern of power density in relation to the Safety Code 6 limits for selected areas of Ottawa. The data was acquired from a newly developed system which is capable of reading both power density from the base station and position information from GPS satellites, simultaneously.
Base stations are used to link cellular phone conversations from cell phone to cell phone or to a central office (to reach a land line). They are composed of several channels, which have individual transmitters emitting radiofrequency signals in various patterns. In the city, they only cover a short range and must be located near the areas of demand.
In Canada, Safety Code 6 specifies power density limits of 6 Watts per square meter for the analog band (824-894 MHz) and 10 Watts per square meter for PCS (digital)(1850-1975 MHz).
In response to the controversy and public concerns over the siting of cell phone towers, such as has happened in the City of Toronto, a need has arisen for mapping the power density levels from these towers in areas of concern.
Here are some selected areas in the city of Ottawa which have been surveyed and power density maps produced. In all cases the equipment has been mounted on the roof of a vehicle and measurements taken while driving the streets. Thus all power densities were measured approximately at head height.
One should note that the power density is a random quantity in that it fluctuates with time in a random fashion (when measured at a specific point). This is because the power density received by an instrument is actually the sum of a large number of rays of electromagnetic energy. They all originate from the base station but undergoe different propagation paths (ie. bouncing off of buildings or passing through trees) to get to the receiver. These different paths are in themselves randomly fluctuating, hence when all the rays arrive at the receiver, their sum can undergo destructive or constructive interference in a random fashion. In addition to this factor, for some technologies like analog cellular, the total power transmitted by the base station depends on the number of cell phone calls being processed.
For these reasons, two power density maps of the same location will never be exactly the same. You can see this with a couple of the maps we produced in Orleans from surveys of the same location but on different days.
1.Barrhaven: Two base stations in this area, one located near Fallowfield and Larkin Rds. and the other at Greenbank and Longfield Rds.
2. Bells Corners: A base station is located near Moodie and Robertson Rd. close to a trailer park.(As if the people in the trailer park don't already have enough to worry about with tornadoes, now they've got radiation as well.)
3.Viewmount: The area bordered by Meadowlands Dr., Merivale Rd, Woodroffe Ave. and Norice Rd./Viewmount Dr. This is also a largely residential area. The power densities measured in this area were very low except near the Meadowlands/Merivale intersection.
4.City View and Fisher Heights: The area bordered by Baseline Rd., Fisher Ave., Meadowlands Dr. and Merivale Rd. This is a largely residential area with some commercial zoning to the west. There were no base stations observed in this area.
5. Mooney's Bay Area: Near Riverside Rd and Mooney's Bay (Ottawa South). This area was chosen because of a base station mounted on the roof of an apartment building on Norberry Crescent.
6.Ottawa: Riverside Dr. from Industrial Rd. to Bank St. This is a residential area with some high rise apartments. Interestingly, a number of base station antennae are mounted on the side of the Riverside Hospital and on its roof. It's ironic that they won't let you use a cell phone inside some hospitals, yet this hospital has allowed a base station to be built on top of it! (Survey time: November 2002, 5:20pm. Driving distance: 5 min). Innes Rd. from Blair Rd. (in Gloucester) to Riverside Rd. (Ottawa), a commuting route through a mostly industrial area, with a few residential neighbourhoods.(Driving distance: 10min. Survey time: November 2002 5:10pm.)
Riverside Rd. from Industrial Rd. to Bank St. Power Density Maps
Innes Rd. from Blair Rd. to St-Laurent Blvd. Power Density Maps
7.Gloucester: Innes Rd. from Page Rd. (in Orleans) to Blair Rd. (Gloucester), a commuting route through mostly residential areas, with a few retail stores.(Orleans, 25 min east of Ottawa to Gloucester, 20 min east of Ottawa. Driving distance: 10min. Survey time: November 2002 5:00pm.)
Gloucester Power Density Maps
8.Chateau Neuf (Orleans): A residential area (subdivision of Orleans), located near an analog base station. The surveyed area is bordered by: Innes Rd., Belcourt Street, and Jeanne D'Arc Street. The tower is located near the intersection of Innes Rd. and Belcourt Rd, in close proximity to a water tower. Across the street resides an Esso gas station. (Orleans, 25 min east of Ottawa. October Survey time: 2:00pm. November Survey time: 4:00pm.)
Chateau Neuf Power Density Maps
Chateau Neuf Survey Photos
9.Cumberland: A residential area, located near a PCS base station. The surveyed area is bordered by: Tenth Line Rd, Charlemagne Cr., Orchardview St., and Innes Rd. The tower is located on the roof of a fire station located near the intersection of Tenth Line Rd. and Charlemagne Cr.(Cumberland, 30 min east of Ottawa. Survey time: 2:20pm). A second survey was performed in November, at 4:30pm.
Cumberland Power Density Maps
Cumberland Survey Photos
10.Dunning Rd and Innes Rd: (Cumberland) A rural area, located near an analog base station sitting at the top of a hill. This tower is located near the intersection of Innes Rd. and Dunning Rd. Data was collected on both roads, in proximity of the tower. The highest data points were collected near the bottom of the hill. (Cumberland, 40 min east of Ottawa. Survey time: 2:45pm). PCS measurements were not taken since there were no PCS antennae visible on this tower.
Dunning Rd and Innes Rd Power Density Maps
Dunning Rd and Innes Rd Survey Photos
Additional peak hour power density plots will be added soon. Please note that cellular phones still work at levels millions of times lower than SC6.
