see Yoo (2004b). Networks in Telecommunications Profit SR Figure 11.1. Short-run and long-run equilibrium under monopolistic competition. volume. Indeed, it is conceivable that network diversity might make it possible for three different last-mile networks to coexist: one optimized for traditional Internet applications such as e-mail and Web site access, another incorporating security features to facilitate e-commerce and to guard against viruses and other hostile aspects of Internet life, and a third that prioritizes packets in the manner needed to facilitate time-sensitive applications such as streaming media and VoIP. Network diversity allows greater experimentation with different ways to take advantage of technological differences. Consider, for example, the fact that wireless telephone networks in the U.S. have employed incompatible standards. The initial standard, known as time division multiple access ("TDMA"), is being replaced by global system for mobile communications ("GSM") and code division multiple access ("CDMA") without inconveniencing consumers to a significant degree. In some cases wireless carriers are using different transmission protocols for voice and data communication in order to utilize the characteristics of the transmission medium to meet the different technical demands of each application (Yoo 2007b). The experience with wireless telephony highlights the economic benefits that can flow from competition among standards. Had the United States followed Europe's example and adopted a uniform standard for second-generation wireless telephony, it would have precluded the realization of the benefits associated with CDMA, which supports a broader range of data services, makes more efficient use of spectrum, and provides the most straightforward migration path to the next generation of wireless technologies (Gandal et al. 2003; Weiser 2003a). The Regulation of Broadband Networks and the Internet Entering into exclusivity arrangements with respect to content represents another possible means for