Multiple wireless solutions will be the answer …
I agree completely with this study! As I have continued my research into wearable and mobile computing, and the requirements of wireless connectivity, it has become apparent to me that I will want numerous options for speed and mobility. High-speed 802.11b or 802.11a will be what I want in hot spots, and even for quick peer-to-peer networking. When I go roaming in the metro area, I’ll then be willing to use lower-speed cellular technologies. If I really venture out to the edges of the techno-universe … I’ll fall back to satellite …

Public WLANs Essential for 3G: Study. Says public WLAN, 3G operators must cooperate [allNetDevices Wireless News]