This map was prepared by Strategis Group, Inc., for use by B-system cellular carriers in the U.S. and Canada, and generally depicts the service area boundaries of B-system service carriers in each of the 50 States and Canada. Because an area is shaded does not necessarily mean that there is complete cellular coverage; in fact, there are "no coverage" areas (including areas too small to depict) within the shaded areas. Wireless service is a radio technology that is subject to transmission limitations caused by service area limitations (such as cell site availability), customer equipment or its installation, as well as weather, atmospheric, magnetic, environmental, topographic and other like conditions. In addition, service may be temporarily limited or suspended due to system capacity limitations or system repairs or modifications.