Wi-Fi now rules the roost, according to a new research report concluding that wireless technology has gained a slight edge over Ethernet cables in home networks. The survey, by research firms Parks Associates, found that 52 percent of U.S. households with a home network were using wireless technology, compared with 50 percent for Ethernet and about 5 percent for power line networking via electrical wires. The numbers don’t add up to 100 because some homes use a combination of technologies.