Widespread mobile telly has been a long time coming . television - enabledcell phoneshave been available in Korea since 2002 . In that first embodiment , the TV signals were transmit over a standard cellular net , meaning per - moment look on fees and unbelievable phone bills . In 2003 , Samsung and Vodafone introduced phones in Korea and Japan that receive local analogTVbroadcasts for free . But the video was choppy , and it drained the phonebattery .
The veridical " mobile TV rotation " is only beginning , as telecommunication company give up high - tone , DTV - enable phones and at the same time race to build up the broadcast networks to surrender the corresponding content . In this clause , we ’ll find out what types of mobile television set are in the works and take a face at some of the phones that find the signaling .
The basic idea of the telly phone is middling simple : It ’s acell phonethat acts as a television set receiver . If you ’ve readHow Television body of work , you know that TV signaling are justradiosignals . Cell speech sound pick up radio signal all the clip – it ’s what they do . In the case of television set headphone , they have the ability to receive radio signals in the TV - allocated frequency bands in addition to the band allocated for cell - sound part data . For instance , a TV phone in the United States might tune up in to the 2110 - to-2170 - MHz band for a conversation and the 54 - to-60 - MHz band to pick up television line 2 .
Just like your home TV , a TV phone has the equipment to pull out the audio and picture content from radio sign and process them to display a telecasting show on its sieve .
The concept is not earth - shattering , but surrender TV signal within a mobile theoretical account poses some challenge . For one thing , teem TV requiresfast transmitting speed . late " 2 gravitational constant " GSM networks ply data - livery speeds of 10 to 14 kbit per second ( Kbps ) , and " 2.5 one thousand " connection offered 30 to 100 Kbps . At 10 Kbps , a idiot box show is really a slide show ; and at 100 Kbps , it ’s pretty jerky . There ’s also thebandwidthissue . Television data bring up a destiny more space than interpreter data , and deliver live idiot box to thousands of cell phone simultaneously can slow a web to a crawl . Finally , receiving , processing and displaying telecasting content requiresbattery powerfulness , and cell phones do n’t have much juice to dispense with .
While you may sign to a TV service program right now ( such asMobiTV , Sprint TVorSmartVideo ) if you have the proper sound , the standards for mobile telecasting programme and delivery method are still in their infancy . In the next section , we ’ll take a look at the primary method of mobile TV distribution .
goggle box phones are the path of the future , but click here see howtelephoneshave evolved over time.
Mobile TV Broadcasts
There are a lot of broadcast and rescue methods in use or in development . you could broadcast live tv set to cell headphone via satellite , sublunary towers orWiFinetworks . Here ’s a looking at at the basic techniques involve in each approach .
WiFi/WiMAX
This broadcast method acting streams live TV signals via the Internet . A Web - enabledsmartphonewith data capability can pick up the stream from any WiFi hot spot orWiMAXcoverage area .
Sling Media’sSlingboxuses this glide path with a thin wrench . Instead of send the TV signals straight off from the content supplier , the Slingbox hardware " placeshifts " the idiot box signals deliver to your rest home TV , well out them via your home Internet connector to a mobile receiver like a Web - enabled cellular telephone sound orlaptop .
Terrestrial
Land - based broadcasting method send out analog or digital TV signaling over the air from terrene theme Stations of the Cross . A phone with a TV aerial and an analog or digital television tuner ( receiver ) can pick up the signal .
There are a bunch of mobile - TV version that utilize land broadcast , include analog programme TV , digital program TV and 3G - mesh broadcasting . Standards like T - DMB ( Terrestrial Digital Multimedia Broadcast ) , MBMS ( Multimedia Broadcast and Multicast Services ) , MediaFLO ( a proprietary Qualcomm technology ) and DVB - H all utilize aspects of 3 G technology .
DVB - H , or Digital Video Broadcasting - Handheld , is an version of the DVB - tellurian standard used to circularise over - the - airDTVto homes in Europe . DVB - H usesorthogonal frequency division multiplexing(OFDM ) to make effective utilization of useable bandwidth . OFDM permit providers broadcast more than one signaling in one bandwidth space and circularise data point streams over multiple channels . It may vocalize like a jumble of data , but the system tone dissimilar sign at unlike frequencies so the recipient can figure out which it ’s supposed to listen to and which it should ignore and can put together related signals coming from different channels . In the DVB - H setup , a content provider send live telecasting and audio stream through an encoder ( it ’s typically H.264 encryption for video and AAC for audio recording ) , and the encoder forwards them to a 3 G streaming server . The server air the data to multiple programme towers that surrender the content to the coverage areas . The organization uses the previously mentionedtime slicingtechnique to cut back force requirements . The typical maximal transfer pace for a DVB - H system is15 Mbps .
Satellite
Some standards rely on satellite broadcast medium to deliver live TV to cell earpiece . They can pass around from planet to phone , from planet to base station to phone or expend both methods simultaneously .
WiFi broadcasting is in use everywhere , and the S - DMB inspection and repair has been up and running in Korea since mid-2005 . DVB - H had its first commercial launching in June 2006 in Italy and is currently in trial around the macrocosm . In the next subdivision , we ’ll check out some of the mobile phone phones that are compatible with mobile - television system .
Mobile TV Reception
When it comes to receiving TV signals , you ’re dealing with aTV tuner , which is a type of radio telephone receiver . There are both analogue and digital tuners , and it ’s the same engineering that ’s in a stationary TV set .
The basic premiss underlying a TV radio set is that content providers transmit television signal in certain radio set - frequency set for certain canal . Just like an AM / FM radio tuner , the TV tuner listens to a specific oftenness to pick up theradio wavestransmitted to the aerial for a specific channel . It then extract the telecasting and audio signals from those radio wave .
To turn those signals into a TV show , the tuner sends them to an audio / telecasting ( A / quintuplet ) CPU , which decode and reformats the data so the electronics in the video display can create a moving picture out of it . ( SeeHow Television Works , How DTV WorksandHow Graphics Cards Workfor complete information on this physical process . )
One analog - tv set phone on the market place is the Toshiba V401T. It picks up the same signal a hare - pinna TV pluck up , entail watching telecasting on this speech sound does n’t be anything . The V401 T has a built - in parallel TV radio receiver and antenna , an A / V CPU and a 2.2 - inch , 320x240 - picture element QVGA presentation . It can generate 30 frames per moment , which is received telly motion , and you could watch out up to one hr of video on a single assault and battery charge . speech sound that incur analogue TV typically do n’t offer as much viewing clip as digital receiver partly because it takes more world power to digitalize the analog signals for the earpiece ’s digital display .
With the Nokia N92 , you could view up to four minute per charge . The N92 is a DVB - enthalpy receiver due for button by mid-2006 . Under the hood is a TV feeler and DVB - H radio receiver – fundamentally a digital TV tuner that listens to the radio bands between 470 and 702 MHz . The phone ’s audio / video processor displays 30 frame per second gear on a 2.8 - inch QVGA screen with 16 million colour . One of the coolest feature of speech of Nokia ’s DVB - H headphone is the swivel covert , which you’re able to correct for portrait or landscape painting television - see modes . There ’s also an " Electronic Service Guide " that displays TV programming , among other things , and you could register up to 30 hour of idiot box on the earphone for late playback .
The latest planet - telecasting phone on the grocery store is the Samsung SCH - B250 ( only in Korea as of March 2006 ) . It has a built - in S - DMB receiver with antenna and a Hawai’i - Ra QVGA screen . The silver screen is oriented horizontally and swivels for switching between portrait and landscape fashion while the phone is still vertical . It has a picture - out jack for sending S - DMB content to an external video display , and you’re able to watch up to three hours of TV on a full charge .
The current availability of mobile - TV handset is pretty limited because the content - livery system are n’t deploy on a peck scale of measurement . But that ’s probable to switch within the next six to 18 months , and with increased capacity bringing will come increased functionality on the receiving end .
The Future of Mobile Entertainment
In early 2006 , LG unveiled the V9000 headphone , a metric ton - DMB receiver with the added bonus of virtualsurround sound . LG ’s prototype SB130 is an S - DMB phone that can intermit live TV like aDVR , recording up to an hour of programming using its onboard memory . Features like DVR functionality and fence in sound period to the possibleness that video - enable cell phones will become increasingly focussed on providing a hearty wake experience , rather of just something to look at on the commuter train train .
Along this melodic line , as mobile - TV content becomes more readily available , we ’ll almost definitely see larger screens on idiot box phones . Some analyst are even prognosticate multiple phone displays – one for cellular telephone - headphone and vane subroutine and one dedicated to streaming video . If the engineering science is to gain a real foothold , and if gamy - terminal lineament likeHDTVreception are to be feasible selection , battery life will have to increase . High - remainder TV phones will also offer advertizer a whole new subject platform . Companies are already spill the beans about embedding Web link in mobile - television programming so users can get across their way to a ware in the centre of a show . This would probably necessitate the dual - display characteristic in purchase order to be effectual .
Even show so much hope and industry enthusiasm , mobile TV has some obstacle to overwhelm both on the gadget side and the content side . To deliver the types and cooking stove of contentedness that consumers really want , mobile - goggle box providers will have to licence scheduling from the major goggle box networks . The licensing fees will in all probability stop up raising the price of any television subscription service . Content providers will also facedigital rights management(DRM ) way out in delivering licensed content to substance abuser . They ’ll have to formulate DRM schemes that limit what users can do with the copyright TV programming that ’s delivered to their cell phones . And if the uproar surrounding DTV , DVD , CD and MP3 DRM schema is any index , it could get haired . Still , you never know – maybe everybody will just get along when it comes to mobile television set .
For more information on TV phones and related matter , check out the links on the next page .
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