Typically a coverage map will indicate the area within which the user can expect to obtain good reception of the service in question using standard equipment under normal operating conditions. Additionally, the map may also separately denote supplementary service areas where good reception may be obtained but other stations may be stronger, or where reception may variable but the service may still be usable.
The field strength that the marked service boundary on a coverage map represents will be defined by whoever produces the map, but typical examples are as follows:
For MF / Mediumwave, the BBC defines the daytime service area boundary as a minimum field strength of 2 mV/m. At night, the service area of mediumwave services can be drastically reduced by co-channel interference from distant stations.
Often coverage maps show general coverage for large regions and therefore any boundary indicated should not be interpreted as a rigid limit. The quality of reception can be very different at places only short distances apart, and this phenomenon is more apparent as the transmission frequency increases. Inevitably small pockets of poor reception may exist within the main service area that cannot be shown on the map due to scale issues. Furthermore, the use of sensitive equipment, high gain antennas, or simply being located on high ground can yield good signal strengths well outside the indicated area.
Often companies will construct low power satellite stations to fill in bad reception areas that become apparent once the high power transmitter's coverage map has identified where the network is deficient.
US Patent Issued to Cisco Technology on July 19 for "Radio Frequency Coverage Map Generation in Wireless Networks" (California Inventors)
Jul 24, 2011; ALEXANDRIA, Va., July 24 -- United States Patent no. 7,983,667, issued on July 19, was assigned to Cisco Technology Inc. (San...
Wipo Publishes Patent of Philip Orlik, Jianlin Guo, Yukimasa Nagai and Mitsubishi Electric for "Method for Generating a Coverage Map for a Wireless Network" (American, Japanese Inventors)
Oct 05, 2013; GENEVA, Oct. 5 -- Publication No. WO/2013/146100 was published on Oct. 3.Title of the invention: "METHOD FOR GENERATING A...
Publication No. WO/2009/138562 Published on Nov. 19, Assigned to Nokia for Network Coverage Map Preparation, Exhibiting System, Method (American Inventor)
Nov 20, 2009; GENEVA, Nov. 21 -- Gabor Bajko, United States of America, has developed a system and method for preparing and exhibiting a...