Pictures of the Future    Spring 2006

Television for Travelers

The DVB-H standard has big potential, including simultaneous transmission of TV programs to large numbers of viewers. Siemens is a driving force in DVB-H and is field testing it in the Czech Republic.

Numerous pilot tests all over the world have shown that it is technically possible to use the new digital DVB-H (Digital Video Broadcasting for Handhelds) television standard to broadcast TV shows to cell phones. The service is expected to create many promising new applications. DVB-H equipment from Siemens is being used, for example, by mobile communications provider T-Mobile for an interactive mobile TV project in the Czech Republic. Since October 2005, this project has been making it possible for a group of cell phone users to watch TV while on the go.

To enable the users to receive TV broadcasts, they were given cell phone prototypes with built-in DVB-H chips. The phones are manufactured by BenQ, a Taiwanese company that acquired Siemens' mobile phone division. "Not only can cell phone users watch the online news broadcaster CT-24 around the clock, they can also view highlights of the popular reality show VyVolení,"says Stefan Schneiders, who is responsible for business development of Mobile Broadcasts at Siemens Communications. "We will follow up this project by conducting further field tests in cooperation with mobile communications companies throughout Europe."

Around two years ago, the DVB-T terrestrial digital video broadcasting standard was adapted for mobile use as DVB-H and standardized worldwide. DVB-H can be transmitted along with DVB-T on the same frequency band, but national media authorities haven't yet allocated frequencies to providers who want to offer mobile TV. The new standard is a power-saving variant of DVB-T optimized for mobile reception of broadcasts on devices with displays of up to 20 cm. DVB-H uses the "time-slicing"process, in which the various programs and services are transmitted consecutively on one channel in small time slots. The cell phone only receives data in the time slot assigned for the service selected.

The receiver thus only needs energy when data packets are actually being received. Siemens has developed a solution that automatically adjusts the picture to the size of displays found in small terminals and cell phones. For users trying to watch soccer games, for example, the ball would otherwise appear as a tiny dot. Between the signal receiver and the terminal is an interface that records the soccer match. It zooms onto the ball when the entire field is shown and sends the enlarged picture to the viewer's display.

The main advantage of DVB-H compared to other transmission processes is that while only a dozen participants can simultaneously receive streaming services (i.e. videos) in a UMTS mobile transmission cell, a DVB-H transmitter can, like normal TV, broadcast to a large number of viewers. As a result, more than 20 TV and radio programs can be broadcast on a single channel. In addition, the mobile radio connection to the terminals creates a feedback channel to the transmitter. This allows viewers to interact with the program by, for example, voting for their favorite star in a TV show or participating in live competitions. The new technology is a prime example of how radio and TV markets are converging with the telecommunications sector.

Siemens has been taking part in one of the first DVB-H pilot tests in Germany since 2004. "We were one of the founding members of the Broadcast Mobile project in Berlin,"says Schneiders, "Our goal was to test in advance the complex interaction between the infrastructure, the mobile phone manufacturers and the content providers."In 2003, Berlin became the first state in Germany to switch to the terrestrial digital TV standard (DVB-T) and approve a frequency for testing DVB-H.

Since then, Schneiders and his team have been optimizing DVB-H technology to ensure that the infrastructure interacts well with the systems from the broadcasting companies and the mobile communications providers. "Besides offering the Electronic Program Guide, our test system manages the content and checks to see if users are authorized to access certain programs,"says Schneiders. "In addition, it also takes care of invoicing viewers' access to the content."

Feedback Channel. The Siemens test system was presented live in February at the world's largest telecommunications fair—the 3GSM World Congress in Barcelona—as well as at the CeBIT trade show in March. There, visitors not only had an opportunity to use various terminals, such as cell phones and PDAs, to watch TV, but also to answer quiz questions or take part in competitions. But, according to Schneiders, DVB-H still poses many challenges that need to be overcome. These include the question of who will own cell phone TV programs—the broadcasters or the providers of mobile phone services? There is also the question of which frequencies can be freed up for this service worldwide, and how promising business models for cell phone TV should be organized.

Because of these issues, Schneiders thinks it will still be some time before cell phone TV is ready for the mass market. "We will be conducting 'friendly user tests' with several hundred terminals during the 2006 World Cup,"he says. According to Schneiders, the breakthrough for mobile television will come in 2007. "DVB-H will be used on a large scale in 2008 during the European Cup in Austria and Switzerland, and for the Olympic Games in Beijing a short time later,"he says. Until then, only a few users will be viewing live sports on their cell phones—not counting video clips of the most exciting goals, of course. These are already being transmitted via other standards, such as UMTS.
                                                                                                           Nikola Wohllaib