llite DTV-In the satellite TV market, DTV is mainly used to multiplex large numbers of channels, including pay TV, onto the available bandwidth. Because satellite operators have much more bandwidth available to them, they often can compete very effectively with terrestrial DTV providers in terms of both number of channels and picture quality. Cable DTV-For cable TV providers, the main advantage of replacing their analog systems with digital cable was initially the ability to offer users more channels and better picture quality. Of course, in today's era of convergence and service bundles, a digital two-way system is absolutely required to sup- port the emerging modern services such as VoIP, IPTV, VOD, and interactive HDTV. In addition, an expanding range of set-top boxes and middleware software also makes many new features possible. Depending on the choices an operator makes in hardware and software, features such as TV guides, program reminders, content censorship, interactive Web-style content viewing, gaming, voting, and on-demand services such as VOD can add significantly more value and ultimately revenues. IP television (IPTV)-The Internet is starting to be adapted for use with DTV deployments as part of triple play. When combined with advances in new compression standards, such as MPEG-4 H.264 or WM9, and in the picture quality supported by HDTV, IPTV represents a big step forward as a new approach to distributing television programming. (IPTV is discussed in Chapter 9, "IP Services.") Telcos of all sorts, far and wide, are helping to lead the way into the video space. Many are using new IP-based technologies, while others are tapping older, Multimedia Networking Requirements but known and reliable, techniques such as radio frequency (RF) broadcasting to deliver a full-service menu of high-definition programming, VOD, DVR, music channels, interactive gaming, and more. Combined with voice and data services, telco TV is expected to become serious business. Some analysts suggest that telcos' success will hinge