Even as high-definition televisions are eclipsing entire walls in homes, tiny screens are proliferating on cell phones, pocket PCs and portable media players. The telecommunications industry has long considered supplying video to nomadic subscribers its next big opportunity after voice calls and text messaging, so wireless carriers have been upgrading their systems to third-generation, high-speed networks for that purpose. But thanks to new transmission standards, another industry plans to enter the field, one with much more experience in video delivery: digital TV (DTV) broadcasters.

Currently the market for mobile video seems largely untapped, as consumers have yet to become enamored with existing systems. Forrester Research, a technology and market research firm, found that only 1 to 3 percent of people surveyed in 2006 said they would care to access video on a handheld device. The chief reason is cost. Verizon Wireless subscribers, for example, pay an additional $15 per month for its so-called V Cast service. Moreover, a quality-of-service issue plagues conventional cellular systems because video hogs bandwidth: frame rates drop when too many callers are on at once. This problem has forced cellular providers to build higher-power transmitters and to use additional frequencies.