of available devices than do smaller operators, which affects their ability to market a diverse line of devices to go along with the new and more expensive service. Poor battery life and overweight devices-When using the new 3G termi- nals for high-speed data communications or videoconferencing, a user can easily drain the battery after 15 minutes of a session. The size and weight of the devices is increased to accommodate a screen that has enough pixels to make an image worth looking at, and the need for more battery power to sustain high-speed data and videoconferencing adds to the weight. Of course, these devices generate more heat as well. As a result, there are also some additional health risks associated with 3G handsets: They emit even more power than their 2G counterparts. Dual-radio handsets-those that could cross between TDMA and CDMA-are not readily available, nor are handsets that can work across all the variations of CDMA. Beyond 3G The cost and ability of gaining new sites-We've been building cellular networks since the 1980s, but finding a proper site and getting the agree- ment to place a base station may be limited in larger cities. The fact that car- riers aren't spending as quickly as they used to is delaying rollouts as well. Other barriers are differences in frequency allocations, proper assessment of the demand in terms of voice versus data versus video, and the cost and coverage associated with 3G versus what already exists and seems to be adequately accom- modating medium-speed data. One of the biggest problems for 3G is a lack of sig- nificant consumer demand (which, in some cases, is a result of the reluctance of carriers, especially those in the United States, to envision services that people will pay for). In addition, Wi-Fi wireless LANs and WiMax wireless MANs, given what they can do for data, create some competition for 3G; Chapter 15 discusses these types of networks in detail. Beyond 3G While we are in the throes of finally seeing 3G networks deployed, there is already a buzz abou