This article is sponsored by the Java Community Process.
Digital broadcasting has recently emerged to bring live television to cell phones, PDAs, and other mobile devices. Such broadcasts carry not only video and audio, but also metadata, and even software applications, in a digital broadcast stream. The new JSR 272, Mobile Broadcast Service API for Handheld Terminals, aims to define a common Java API to control and access digital broadcast content from mobile devices.
Tough luck: You just missed the final episode of your favorite TV show. Perhaps you were stuck in traffic, on the train, or in a boardroom meeting. While the JCP can't bring you back The Donald , it can help you find consolation in a recent JSR that aims to bring live TV programs to a cell phone in your pocket. OK, you have to be a nerd to find consolation in that, but read on, because this new JSR has implications not just for how we watch TV programs, but also for an entirely new category of handheld applications.
JSR 272, the Mobile Broadcast Service API for Handheld Terminals  aims to define a common API layer for interacting with broadcast services, such as digital television, from a mobile device. While mobile telecoms operators already offer streaming video services through third-generation cellular networks, the one-to-many broadcasts, or mobicasts, addressed by this JSR don't use the cell phone network, and are received instead via a special digital broadcast tuner resident on a cell phone, PDA, or some other gadget.
Over half of the respondents to a 2003 European survey said they'd be willing to pay 10 Euros a month to watch TV on their cell phones. Considering that digital broadcast decoder chips are expected to cost around $10, mobicasting may turn into a very large business.
"I don't expect mobile digital TV to replace your existing TV set. It's a completely different experience, " comments Antti Rantalahti, a JSR 272 expert group lead, and Senior Research Engineer at Nokia's Multimedia Research Laboratory. Rantalahti catches up on soccer games via his mobile handset, thanks to a digital broadcast trial under way in the Finnish capital. "But that's not something you watch actively [on a small device], because you can hardly see the ball. But news works on a small TV as well as on a large one." Still, Rantalahti sees new kinds of programming developed specifically for mobile devices.
Digital broadcasts not only deliver video and voice, but may also include data files and entire applications. For instance, the broadcast of a talent show or political debate may include a software application to facilitate voting by the viewers. "That back-channel capability, and the ability to deploy applications alongside a TV program, make digital broadcasts an exciting new territory for developers," says Ivan Wong, a Distinguished Member of the Technical Staff at Motorola's Mobile Device Business, and JSR 272 co-lead.
Mobile devices must contend with restrictions not shared by your stationary TV set: battery power limitations and environments where reception with a small built-in antenna proves difficult. Addressing those constraints, DVB-H (Digital Video Broadcasting - Handhelds) adapts the emerging DVB standard to mobile devices . Pilot projects with DVB-H are under way in Pittsburgh, and in 2003 Finnish Mobile TV became the first venture to explicitly focus on mobicasting. In addition to DVB-H, two additional standards—the Digital Multimedia Broadcast (DMB)  and MediaFLO —address the needs of handheld devices in receiving digital broadcasts.
With that many standards (See Sidebar), JSR 272 aims to provide an API that abstracts out the transport layer, and gives developers high level access to digital broadcasts, according to Wong. JSR 272 will define both the management of interactive services received via digital broadcast, and the management of applications contained in the broadcast stream. Along with Motorola, the JSR 272 initial expert group includes Nokia, Vodafone, and Siemens.
"On one level, you will be able to control access to digital channels, search and discover services, switch between channels, receive and consume services, and purchase and subscribe to services," says Wong. An interesting aspect of the API is to access metadata associated with a service. "You will be able to access programming information, [interact with] electronic service guides, and write software to find programs suitable for kids, for instance," adds Wong. Metadata for a TV program may also include a URL to the program's Web site. An application on the mobile device could present the contents of that URL to the user for further details on a TV program.
The second important feature of JSR 272 will be the ability to manage applications downloaded as part of a broadcast stream. JSR 272 will provide some form of application lifecycle management, possibly building on the well-established midlets paradigm, and will also manage security for the downloaded applications.
Wong and his expert group members envision an ecosystem of mobile media applications, not unlike the ecosystem for midlets. That ecosystem will likely consists of broadcasters offering digital programming, data carriers providing the connections for back-channel data transmissions, software vendors, content providers, device manufacturers, advertisers, and end users. "There will be carriers who will purchase software, and broadcasters will be able to work with those carriers [to enable those applications to work in tandem with a broadcast]," says Wong.
Since JSR 272 was only recently accepted into the JCP, it is still in its preliminary stages. "[At this stage], we are anticipating and trying to help create a new market for mobile broadcast applications, " says Wong. "[We are] waiting for an inflection point to occur in the market, and are working on this JSR in preparation for that. If that happens, [mobile broadcast services] may bring in a lot of revenue, both for data services, and also for advertising," said Wong. "Digital broadcasting is another trend for mobile devices that developers should be aware of."
"It ususally takes between one and one-and-a-half years to produce a standard through the JCP. You might be able to purchase devices with this API sometime around 2007," adds Nokia's Rantalahti.
With the ability to watch The Apprentice on your cell phone, who said TV was just for couch potatoes?
 "The Donald" refers to Donald Trump, hero of a popular TV show, The Apprentice, broadcast on
NBC in the US.
 The home page for JSR 272, Mobile Broadcast Service API for Handheld Terminals:
 Digital Video Broadcasting (DVB); Transmission System for Handheld Terminals (DVB-H) (EN 302 304 v1.1.1 ETSI, November 2004):
 Digital Multimedia Broadcast (DMB) is a proprietary South Korean standard derived from the Digital Audio Broadcast (DAB) standard:
 MediaFLO is a proprietary standard from QUALCOMM:
 Advanced Television Systems Committee (ATSC):
 Java TV is an API for interactive television services:
Frank Sommers is a Senior Editor with Artima Developer. He also serves as chief
editor of the Web zine ClusterComputing.org, the IEEE Technical Committee on Scalable
Computing's newsletter, and is an elected member of the Jini Community's Technical
Advisory Committee. Prior to joining Artima, Frank wrote the Jiniology and Web
services columns for JavaWorld.
Sidebar: Many Standards, One Java API
In some parts of the world, you can already tune into digital broadcasts from your living room TV set. In parts of North America and South Korea, for instance, the Advanced Television Systems Committee (ATSC) consortium  offers HDTV broadcasts suitable for stationary antenna reception. In Japan, the Integrated Services Digital Broadcasting (ISDB-T) standard offers audio, video, and multimedia not only to HDTV-enabled TVs, but also to mobile devices.
The Digital Video Broadcast Terrestrial (DVB-T) standard should be familiar to Java developers from Java TV , Sun's Java-centric API to interact with digital broadcasts based on that standard. Parts of Europe and Asia have adopted DVB-T to digitally beam standard-definition programming to capably equipped TV sets. In Singapore and Taiwan, DVB-T provides digital TV in public transportation, as well as in cars and high-speed trains. And DVB-T will soon enable HDTV broadcasts in Australia as well.
This article is sponsored by the Java Community Process.