The early Wi-Fi standards that opened the world's eyes to wire-free networking are now holding back the newer, faster protocols that followed in their wake, Cisco Systems said. The IEEE 802.11 standard, now available in numerous versions with speeds up to 6.9Gbps and growing, still requires devices and access points to be compatible with technologies that date to the late 1990s. But those older standards -- the once-popular 802.11b and an even slower spec from 1997 -- aren't nearly as efficient as most Wi-Fi being sold today.