When Samsung Electronics said last year that it was developing a cell phone capable of receiving satellite TV broadcasts it seemed almost too futuristic to be true.

Rather than requiring a large dish antenna or set-top box receiver, the phone would be able to receive TV and radio signals broadcast from a satellite with nothing more than the built-in antenna and hardware. Progress in digital electronics, which helped miniaturized the components needed, and a broadcasting platform that delivers a powerful signal at frequencies close to those in use by 3G phones were crucial in making the phone possible, but how well does it work in a crowded city like Seoul?

To answer that question I took Samsung's SCH-B250 cell phone out around Seoul on Thursday last week. The phone is the latest model from Samsung to support the satellite DMB (Digital Multimedia Broadcasting) service offered by TU Media. Subscribers can receive 11 video channels and 26 audio channels that encompass a wide range of entertainment including news, music, drama and business TV channels and all sorts of music options. The service launched earlier this year and has about 200,000 subscribers.

A big problem for TU Media in setting up the service was how to get around potential reception difficulties that would face mobile satellite users, particularly in the city. Tall buildings could easily block the signal, leading to a frustrating experience where the signal would keep cutting out, so the company built a network of terrestrial transmitters to fill in the coverage gaps. The stations, so-called gap fillers, have even been built into the subway network so you're likely to get a good signal in most parts of the city.

That's certainly the experience I found with the Samsung phone. For several hours I walked around central Seoul with the phone tuned in to one of the video channels. It worked flawlessly in the street, didn't show any glitches when I sat down to lunch in a coffee shop, and kept in tune with the TV channel as I descended into the subway. Even on subway trains between stations, deep under the city streets, the gap fillers provided a strong-enough signal that I could continue watching TV without interruption -- much to the interest of fellow passengers.

I experienced glitches only twice during the test, which lasted about three hours in total. For a couple of seconds at two moments while riding the train the picture briefly froze and the audio disappeared, but it came back quickly.

The quality of the picture is also good. It's QVGA resolution (320 pixels by 240 pixels) and the screen on the phone is nice and sharp so even the smallest characters could be read with ease.

Operating the DMB function was easy. The clamshell form-factor phone has a display that can swivel through 90 degrees, so you just open the phone and twist the screen to the left so that it's vertical and the satellite broadcasting software starts. There's also a dedicated button, marked "TU," that will do the same thing when the display is vertical.

I didn't test the many other features of the handset, which include a 2-megapixel camera, video recording and MP3 player.

I should say a word about the physical size of the phone. All of this technology doesn't come small and the phone was quite a thick package. The specs have it as 95 millimeters by 48mm by 28.5mm thick and it weighs 144 grams, which is certainly on the heavy side for a cell phone today. The good news is that the B250 is Samsung's smallest satellite DMB phone yet.

All in all, the satellite service is very impressive and the gap filler network does its job well. Reception might be more hit-and-miss outside the major cities, where gap fillers don't exist and the phone has only the satellite signal to depend on. For such instances where weak signals are a problem the SCH-B250 has a socket for an external antenna.

The phone is available now in South Korea for about US$700. It will not work overseas as the TU Media signal covers only South Korea.