to provide broadband access to schools, hospitals, and businesses. These networks could be seen as complemen- tary to other cellular-based networks and could be employed in either a fixed, por- table, or fully mobile setting, depending on the application. 3G Deployment Issues A main barrier to 3G is that there is a lot of competition in this arena, with many different standards being advocated. Also, there is already an installed base of 2G Chapter 14 Wireless WANs and 2.5G networks, and companies want to protect their investment there. A num- ber of important issues, including the following, have yet to be fully resolved: Problems providing seamless handoff between 2G and 3G networks- Although there are dual-mode and triple-mode phones coming into the market, handoff troubles are still common. There are problems with hand- offs from UMTS to GSM, with connections being dropped or handoffs being possible only in one direction (from UMTS to GSM), with the handset returning to UMTS mode only after the user hangs up, even if UMTS cover- age returns. There is also the issue of initially poor coverage due to the time it takes to build a network. Service delivery problems-There are large issues from a service delivery perspective. For example, in order to support true 3G VOD features, a base station needs to be set up every 1,000 yards to 1 mile (1 to 1.5 km). As you can imagine, although this may be economically feasible in urban areas, it is much more difficult to justify in less populated areas, such as suburbs or rural environments. The complexity of W-CDMA-Not many knowledgeable engineers have substantial experience in W-CDMA. Because 3G standards are still evolv- ing, 3G is a moving target to some extent. The fact that speeds are lower than promised creates concern and is one of the reasons that many have opted for 2.5G rather than moving forward with the brand-new infrastruc- ture required by 3G. The availability and cost of 3G devices-Large operators have an easier time ordering and receiving the limited number 