How they work: “How Mobile Phone TV works”

Have you heard of the “Mobile Phone TV” concept? This can be said to be a situation whereby a mobile phone owner uses a phone to watch TV broadcasts; unlike the embedded Radio Receiver, this uses TV signals integrated within the mobile phones’ own network. Extensive mobile television has been a long time coming. TV-enabled cell phones have been available in Korea as early as 2002. In that first embodiment, the TV signals were transmitted over a standard cellular network, meaning per-minute watching fees and enormous phone bills. In 2003, Samsung and Vodafone introduced phones in Korea and Japan that received local analog TV broadcasts for free. But the video was jerky, and it drained the phone battery. The real “mobile TV revolution” is only beginning, as telecom companies together with the manufacturers release high-quality, DTV enabled phones and concurrently design the broadcast networks to distribute the corresponding content. Basically, the TV phone is rather simple: It’s a cell phone that acts as a TV receiver. Cell phones pick up radio signals all the time, it’s in the case of TV phones, they have the ability to receive radio signals in the TV allocated frequency bands in addition to the bands allocated for cell-phone voice and data. For example, a TV phone in the USA might tune in to the 2110-to-2170-MHz band for a conversation and the 54-to-60-MHz band to pick up TV channel 2. Similar to the traditional TV, the TV phone has the equipment to take out the audio and video content from radio signals and process them to display a TV programme on the screen. This is not as complicated as it sounds, but just intended to deliver TV signals within a mobile framework though it poses some challenges. One thing is for certain, streaming video requires high speed broadcast. Previously the “2G” GSM networks provided data delivery speeds of 10 to 14 kilobits per second (Kbps), and “2.5G” networks offered 30 to 100 Kbps. At 10 Kbps, a TV show is nothing but a mere slide show; and at 100 Kbps, it’s pretty jerky. There’s also the bandwidth issue. Television data takes up a lot more space than voice data, and delivering live TV to thousands of cell phones simultaneously can slow a network so considerably. That means, receiving, processing and displaying video content requires battery power, high network speeds; many cell phones don’t have much of that. Technological advancement are beginning to make TV phones a viable lreality. Basing on theFast “3G” and the “3G plus” networks (which provide broadband Internet access to cell phones and other mobile devices) provide data-transfer rates of 144 Kbps to 2 megabits per second (Mbps). 3G multicasting technology saves bandwidth by allowing multiple subscribers to access a single broadcast stream (as opposed to unicasting, which is a one-to-one transmission). And companies are implementing power-saving transmission techniques like time slicing, which transmits data in spaced intervals so the receiver can turn off in between transmissions. Much as one may subscribe to a TV service plan right now (such as MobTV, Sprint TV or Smart Video) if you have the right phone, the standards for mobile TV broadcast and delivery methods are still in their early years. (to be continued) eddie@afrowebs.com