WASHINGTON, DC.- Until recently, visitors to
Smithsonian museums on the National Mall in Washington, D.C., faced an
unexpected challenge: they could not use their cell phones unless they were near
a window or door. The solid construction of the Smithsonian’s historic
buildings made it nearly impossible for cell phone signals to penetrate the
walls. The 100-year-old National Museum of Natural History, for example, has
granite-faced walls that are nearly three feet thick.