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Watching the Games on our mobiles

by Jim Slater

I guess that by 2012 it won’t be just a vision that I can leave my home in the West of England early in the morning to travel by train to the games site in East London, carrying with me a mobile phone that will not only enable me to stay in touch with home and office throughout the day, to take photos of the events as they happen, sending these back to the office with explanatory notes, but that will also let me watch colour television pictures of the news as I travel on the train and see other events happening in real time at other venues as I sit in the London athletics stadium. In between the athletics I will be able to watch the sailing at Weymouth, the swimming events in the nearby aquatic centre, beach volleyball in Horse Guards Parade, football at Wembley, and gymnastics in the Millennium Dome.

Venues for Olympic events

For this vision of mobile television to turn to reality, however, a great deal of further work needs to be done, and it is only the remarkable track record of our commercially competing mobile phone companies in making things work that can lead us to have any confidence that everything will be in place to enable a viable mobile television system which is rugged and reliable and available everywhere in just four years time.

There is no shortage of commercial ideas and plans, and more potential technical methods of providing mobile television exist than anyone could reasonably hope for. If technologies and standards are reckoned to be ‘a good thing’, then we certainly have plenty of them, but this very plenitude may not in fact be universally beneficial. Before we get involved in competing broadcast standards and their multiplicity of abbreviations and acronyms like DVB-H, MediaFLO and DMB let us have a look at the basics of the various ways in which television pictures and sound can be carried to your mobile phone.

What does Mobile TV mean?

Mobile TV means video and audio content that's either ‘streamed’ or ‘broadcast’ direct to your mobile phone. It is distinct from a video-phone service or from systems that download and save pictures and sound onto your phone for later viewing, which could be called mobile video.

Broadcasting versus Streaming

It is important that we understand the key differences between streaming and broadcasting. Most of us will understand that broadcasting (even if, confusingly, it is a stream of digital data that we are broadcasting) is a process that sends data from one source to many receivers, and we are familiar with the concept of the huge transmitter mast at Crystal Palace radiating TV signals that can be received by many millions of people in Greater London and beyond. Other masts around the country effectively duplicate the process, so that virtually the whole population can receive television by picking up the broadcast signals on a modest aerial.

Diagram to show how video and audio streaming workStreaming over a mobile telephone service network is quite different – it is a one-to-one data transfer process, and many of us will be familiar with the idea of using our home computer to call up a video clip from a remote server via the internet. The use of the widely known Internet Protocol (IP) makes it simple and straightforward to call up a continuous ‘stream’ of data that represents the picture from the distant server on which it is stored, which our computer puts together bit by bit to generate a picture and its accompanying sound on our computer screen and speakers.

Users quickly learn that if we have a high-bandwidth internet connection the data flows smoothly and the pictures and sound are excellent, but if the bandwidth is restricted, either because we are using an old-fashioned telephone line and modem rather than a broadband link, or even because the internet can’t cope with the vast amounts of data that it is being required to transmit at times of peak usage, delays in receiving the data mean that the pictures break up and the sound stutters, completely ruining the experience. For any mobile TV service, then, we are going to have to consider any potential bandwidth limitations.

Carrying mobile data

Early mobile phone services were designed to carry digitised audio telephone calls in the most efficient way, and therefore the systems needed to carry only modest quantities of data, but as the need for carrying other forms of information such as emails, still picture files and then eventually video files, became apparent, it was realised that newer generations of mobile phone systems would be needed to cope with the higher data rates that would be required. Enhancements to the current second-generation mobile phone system allow data to be transferred at up to 384kbits per second under favourable conditions, but there is currently a move to the so-called third-generation or ‘3G’ systems - a generic term covering a range of future wireless network technologies, which will eventually allow for much higher rates. 2Mbit/s should be possible and typical on a regular basis, but there are also longer term plans for HSPA systems (High Speed Packet Access) able to deliver speeds up to 14.4Mbit/s on the downlink and 5.8Mbit/s on the uplink. 3G combines high-speed mobile access with Internet Protocol (IP) based services, which will allow for fast mobile connection to the World Wide Web as well as streamed mobile television.

Mobile TV over the cellular networks

Since a network of ‘broadcast’ transmitters suitable for mobile TV covering the country doesn’t yet exist, whereas most of the population is well served by second-generation mobile phone services with 3G available in highly populated areas and along the main transport arteries, it is not surprising that apart from a few broadcast experiments, the only existing mobile TV services are operated by mobile phone companies streaming the data over their 3G networks.

3G phoneAlthough data rates are limited, careful compression of the pictures by the operators means that acceptable pictures on displays of around two inches square and 320 x 320 pixels can be achieved at data rates of between 80kbit/s and 250kbit/s, within the capabilities of current 3G phone systems. Korea and Japan are miles ahead, and the existing Korean 3G network is used to stream live TV and make broadband services available on mobiles.

In the UK, the main 3G phone operators offer mobile TV or, perhaps more accurately, video services using data streaming, and they work, but there is one big snag. The same datastreams that are used to carry mobile phone calls are also being used for internet access and for TV pictures, but the TV pictures require vastly more data than the phone calls. Since it is common for mobile phone companies to charge for the amount of data that is downloaded, and since there is currently little competition in this field, watching streamed TV on your mobile can be horrendously expensive. The newspapers carry tales of people going on holiday in Europe and finding on their return that they have been charged hundreds of pounds for downloading data over their mobile phone services, and even in countries like Korea where mobile TV over their 3G networks is well established, the costs can be very high – a recent example claimed that it cost about $50 to watch TV for under an hour. Cost, it seems, will be an important factor in determining whether mobile TV will be successful.

Cost isn’t the only problem with mobile TV over data circuits – after all, we might expect that competition could eventually drive down the amounts which customers are charged. Probably even more important is that streamed television forms of mobile TV are actually ‘unicasting’, and not technically broadcasting, since each programme access requires a data link to be set up from the programme provider’s server to the ‘computer’ in your hand-held mobile unit. While 3G networks can support streaming video to a few users, every new viewer requires the phone company to provide more server space and uses more of the network bandwidth - the required network capacity in UMTS is proportional to the number of users. So it can be both technically and commercially difficult to provide high-quality mobile TV pictures to large numbers of subscribers simultaneously over a 3G telephone network. 3G mobile phone networks use the Universal Mobile Telecommunications System (UMTS) for what are effectively point-to-point services, with typical data rates between 30 kbit/s and 384 kbit/s. It is also important to note that the maximum total data rate shared by the users of one network cell is around 2 Mbit/s, and that a typical total data rate for mixed traffic (phone, data, TV) is around 0.9 Mbit/s to 1.25 Mbit/s per UMTS cell.

Just as you thought that you were starting to understand the clear distinctions between streaming and broadcasting, let me tell you that UMTS can also offer a broadcast mode (Multimedia Broadcast / Multicast Service - MBMS) and a fast point-to-point data channel (HSDPA – with a downlink data rate of 3.9 Mbit/s), and whereas, as we have seen, the required network capacity in UMTS is proportional to the number of users, the required network capacity for MBMS instead becomes proportional to the number of services. MBMS effectively offers a one-way point-to-multipoint service, optimising the capacity available in a network cell via multicasting and broadcasting. But there are significant problems for the network operator to consider, since the introduction of MBMS takes up a large amount of network capacity and if care isn’t taken there won’t be enough left for the main commercial business of carrying mobile phone calls.

3G services paired frequency bands

UMTS operators were awarded groups of paired frequency bands for the 3G services, with uplinks in the 1920-1980 MHz band, and downlinks in the 2110-2170 MHz band. They also gained ‘unpaired’ frequency bands in the ranges 1900-1920 MHz and 2010-2025 MHz, which could be used for ‘broadcast’ TV data without affecting the mobile phone channel usage. One system planning to use these channels is TDtv, which has shown that using very low cost base stations up to 14 300kbps TV data channels can be delivered inexpensively in 5MHz of unpaired spectrum, and the mobile operator is in full control of what is ‘broadcast’.

Mobile TV via ‘broadcast’ channels

So although it is perfectly possible for mobile phone service providers to sell mobile TV services based on data streaming, there is a growing acceptance that the future of mobile TV lies with the broadcasting model rather than unicasting data. Broadcasting effectively means that an almost unlimited number of users can pick up the signals and watch digital content without competing for limited bandwidth resources.

Various ways of broadcasting multimedia or mobile TV via broadcast networks exist and have been the subject of trials and rollout in different parts of the world. These include Digital Multimedia Broadcasting (DMB), via satellite or terrestrial transmitters, DVB-T, the existing fixed terrestrial broadcasting service used in Europe and elsewhere – we know it as Freeview, but ruggedized to improve mobile performance, DVB-H, the H being for ‘handheld’, a specially developed variant of DVB-T for mobile applications, (ISDB-T) and MediaFlo™. Other systems (DVB-SSP) and DXB will be available soon.

3G phone in useDigital Multimedia Broadcasting (DMB)

DMB is based on the existing DAB (Digital Audio Broadcasting) system (Eureka 147), and is already operational in Korea and Germany, with China suggesting it will adopt a variant. BT carried out trials using the DAB spectrum to distribute TV and radio channels with Virgin Mobile phone subscribers who were able to watch Sky News, Sky Sports News, a music video channel and listen to 50 radio channels. Virgin's service used a standard called DAB-IP, sharing the network with DAB digital radio. DAB-IP used an Enhanced Packet Mode, standardized by the WorldDAB Forum, which enables video and other services that are more sensitive to errors than the usual DAB audio services to be carried with appropriate degrees of ruggedness. Unlike some other DAB-based mobile TV standards, DAB-IP can share multiplex capacity with DAB digital audio services, enabling operators to use any existing spare capacity on DAB networks to start offering mobile TV without waiting for new spectrum to become available.

The prototype handsets used for the trial were modified versions of an existing smartphone but the handset subsequently being developed is a fully functioning 2.5G mobile phone which includes an integrated DAB receiver, so users can enjoy broadcast digital TV and DAB digital radio services. The trial was very successful, but there are currently no plans to extend the service.

Terrestrial DMB signals are transmitted in the VHF band III, which maximises coverage with a relatively small number of transmitter sites, or in the L-Band (1452 to 1492 MHz), sharing the frequencies used by Digital Audio Broadcasting, DAB and using the same infrastructure. In the UK not more than 20% of the DAB capacity can be used for mobile TV. The channel bandwidth is about 1.7 MHz and just over 1 Mbit/s can be carried on each channel. DMB is standardised by ETSI, and handsets are readily available. Something under 90% of the UK population can currently receive DAB transmissions.

Development of other DAB-based systems is taking place, with DXB/eDAB using convolutional coding, statistical multiplexing and interleaving data within the existing DAB transmissions in order to make the best possible use of the available bandwidth. It is being designed to minimise power consumption, and switching delays.

FLO (Forward Link Only)

Another ‘broadcast to mobile’ technology, FLO (Forward Link Only) was designed specifically by Qualcomm for the efficient and economical distribution of multimedia content to millions of wireless subscribers simultaneously, lowering costs and allowing consumers to “surf” channels of content on the same mobile handsets they use for traditional cellular voice and data services. FLO technology claims to offer better performance for mobility and spectral efficiency with minimal power consumption, and is already in use in the USA using UHF channel 55. A typical FLO system can offer multiple live TV channels plus full access to internet services and interactive services. The TV services are received on handheld mobiles via the Flo transmitter network, and control and interactivity takes place via the normal 3G mobile communications system using completely different frequency bands from the TV transmissions. The transport mechanism for the distribution of this content to the FLO transmitter may be via satellite, fibre, etc, and wide area content, local content and non-real time content, received by a content server, typically via an IP link, are combined together into FLO packets, converted to FLO waveforms and transmitted via FLO Transmitters. Pictures are quarter-VGA. Typically, 32 TV programmes can be transmitted within a standard 8MHz wide UHF channel.

Diagram of a FLO network

Transmissions take place via a Single Frequency Network, using layered modulation, with the FLO data stream divided into a base layer that all users can decode, and an enhancement layer that is decoded in areas where a higher Signal to Noise Ratio (SNR) is available. The majority of user devices will be able to receive both layers of the signal to deliver 30 fps video quality, but layered modulation allows for graceful degradation of service and the ability to receive in locations or at speeds that could not otherwise have reception. Effectively, Qualcomm has taken elements of other digital broadcasting technologies, including OFDM, QAM, QPSK, SFN and various transcoding and compression techniques and developed a system with optimised parameters specifically suited to delivering TV pictures to a handheld unit. Qualcomm claim that a FLO network can provide better coverage and higher quality services than other multimedia services.

Interestingly, in May this year Qualcomm bid for and was awarded a chunk of UK spectrum in the 1452-1492 MHz range by Ofcom. It paid £8.334 million to use of the band, but hasn’t yet said what it will do with it, apart from bringing “a variety of innovative wireless technologies to the UK market.” The rumours suggest that Qualcomm will import its mobile TV service MediaFLO into the UK using this bandwidth, and it is known that last year, Qualcomm tested MediaFLO services with BSkyB, further stoking the rumours as to what will happen. Actually having the spectrum available NOW could be a huge advantage over other potential mobile TV services, including DVB-H, which we will discuss next, since there is unlikely to be sufficient spectrum available for this until the digital switchover is complete in 2012.

Handheld Digital Video Broadcasting (DVB-H)

Technically based on the existing DVB-T terrestrial digital systems, carried on UHF in the UK and on both VHF and UHF in Europe, the DVB-T transmitter infrastructure can be used for DVB-H at the same time, although modifications at the transmitters will be needed and more spectrum will be required to carry the extra programmes. Bit rates of 5-9 Mbit/s can be achieved in a standard 8 MHz multiplex channel, allowing for between 14 and 20 handheld TV programmes. The DVB-H ETSI-Standard has been agreed and handsets have been developed. DVB-H handsets will also provide normal mobile phone facilities via GSM, GPRS, and UMTS systems. DVB-T transmission will cover over 98% of the UK population once the full digital switchover has taken place by 2012, with the Crystal palace transmitter due to switch to its high-power digital signals in April 2012, well in time for me to be able to watch handheld pictures for the Games.

Internet tabletIn Oxford in 2006 the mobile phone company O2 and broadcast transmission company Arqiva ran an early six-month, 16-channel mobile television trial using DVB-H involving 375 customers, but although the services were liked by those taking part, there is no spectrum yet available to carry the broadcasts regularly, and much more work remains to be done before a commercial business plan for such services can be developed.

For the trial Arqiva built a single-frequency network of eight DVB-H transmitters on UHF channel 31, under a special test and development licence obtained from Ofcom. The pictures, at a resolution of 392 x 320 pixels, were displayed on a Nokia 7710 handset using an active screen size of about 5 x 4cm. The handsets were fitted with a slim DVB-H receiver panel on the back. For the trial pictures were displayed at 12.5 frames per second, but more advanced coding could provide better pictures at 25 frames per second for future services.

Coverage within the Oxford ring road provided reliable reception at street level outdoors, indoors and inside moving vehicles. There was an Electronic Service Guide to provide the information necessary for the handset to find the service and for the user to choose what to watch. The trials showed that the DVB-H platform can be optimized for multichannel TV delivery in a mobile environment, with robust performance and low battery consumption.

Interestingly, there is also a version DVB-SH, which delivers content and data to mobile phones via satellite, using terrestrial gap filling transmitters to provide the missing coverage whenever a line of sight to the satellite can’t be found. This complements the existing DVB-H standard.

Engineering challenges of handheld reception

Although people don’t really think about it, digital TV in the home has been designed to work with a high-gain aerial mounted at chimney height and able to take as much electrical power as needed from the mains. Viewers of any mobile TV service are going to expect similar standards of reception, but there are huge problems of getting decent reception while you are on the move as well as in getting adequate working time from a tiny mobile phone battery. We now have good screen technologies available but current mobile TV screens use a lot of power relative to other mobile phone circuitry, and the screen and speakers obviously need to be on whenever programmes are being watched.

You would expect that the TV receiving circuitry would also have to be switched on throughout the programme, but engineers have developed a technique called time-slicing which means that at least the receiver is not on all the time, although the screen and speakers obviously need to be. Time-slicing allows the mobile’s battery last a lot longer. The programme being received is transmitted in short bursts of data, and between those bursts the receiving circuitry can be shut down. As far as the user is concerned it looks like as though the programme is being received constantly, but in fact the circuitry is in a stand-by state for the majority of the time. As the programme data is received in short, high-speed bursts, the data is buffered for a few seconds before it appears on the screen, and the buffering means that the mobile TV can also cope with short breaks in reception, so you don’t lose the picture if you momentarily pass under a bridge or are screened from the transmissions by a building. The built-in antennas for mobile TV reception and mobile phone reception on several different bands also represent major challenges for designers, but the various trials have shown that rugged and reliable reception is possible with the various different systems.

Standards

With the plethora of potential systems available, it is difficult to predict what will happen, but the European commissioner for information, media and society has stressed the importance of Europe having a single standard, and the EC has recently thrown its weight behind DVB-H, although the proponents of other systems aren’t giving up without a fight, and are arguing that their systems can work now, whilst frequencies for full DVB-H coverage aren’t likely to be available before 2012. I was interested to see that TV information for the 2008 Olympics in China was shown in subways and on buses, and that handsets which could use both China's 3G standard, TD-SCDMA, and the home grown China Multimedia Mobile Broadcasting (CMMB) standard (also known as S-TIMI or satellite terrestrial interactive multi-service infrastructure), were distributed to some visitors and officials. The mobile TV service definitely worked, but it is unclear as to whether the satellite component was actually used. Seven TV channels could be received, including CCTV and the Olympics Channel, with a clear picture and excellent signal.

What about the viewers – will mobile TV be accessible?

There is still a great deal of work to be done before a sound business case is developed for mobile TV, which, although undoubtedly attractive to many people, will need to be low-cost before it takes off widely. There are also lots of unanswered questions about the best type of programming for watching on a tiny handheld display – will we want to watch normal programmes, or will specially developed short ‘snippets’ be more popular it commuters who might not want to watch a complete half-hour programme whilst standing on a busy train.

More than that, though, and bringing the focus sharply to today’s topics, what needs to be done to make the mobile TV programmes and data truly accessible to all viewers? We need to apply a dose of common sense, of course, in that it obviously won’t be easy for a visually-impaired viewer to see much detail on a two-inch screen, but many ‘normally’ sighted people are likely to find this difficult too, if great care isn’t taken to make the displays as clear as possible, with sufficient brightness to watch pictures in reasonably bright outdoor conditions. New light-emitting display technologies may well prove better than reflective LCDs, and already some mobile phones are using OLEDs. The real problem is that unless we use seminars like today’s to highlight the potential problems, no one will even give a thought to the difficulties that users might encounter. As an example of the ‘nobody thought about it’ scenario, let me tell you of a recent encounter with South West Trains about the ticket machine on my local unmanned station. When it rains the touch screen doesn’t work, as the water confuses it. When the sun is bright, you can’t read the screen. I wrote, politely, suggesting a change of position for the machine, and their answer astounded me.

“ I am sorry that you have had difficulty using our ticket vending machine in sunlight and when it is raining. We are aware that this can be a problem and unfortunately this is a feature of this kind of technology. ....There is little that can practically be done to improve the luminance of the screens in direct sunlight. We have looked at the option of fitting an anti-glare cover, however, this resulted in the system being very difficult to use. We did carefully plan where to place the ticket vending machines....I am sorry that you are unhappy with the positioning of the machine you used. Please be assured that your comments have been logged and thank you for your feedback.”

So let us take an ‘in advance’ look at how mobile TV needs to be accessible, and let us highlight to designers and manufacturers of the equipment and systems just what it is we need.

Mobile phone with internet accessScreens – we already mentioned that these need to be of sufficient resolution to make the pictures as clear as possible, and with easily adjustable brightness to cope with different viewing conditions indoors and out. Many digital cameras have a ‘zoom’ facility on their LCD displays which allows you to examine a small portion of the image in detail – this same facility should be incorporated in mobile phone TVs to help everybody, not just those with impaired vision.

Subtitles – it has taken around 30 years to get UK terrestrial TV to a situation where subtitles are available on most TV programmes. We need to act now in order to get mobile TV providers to ensure that ways are found of incorporating these as an integral part of their mobile services. It may not be easy, and you certainly can’t use the existing subtitling systems, since the characters would be too small when displayed on a two-inch screen for anyone to read. Maybe one answer would be to provide perhaps a half-inch deep ribbon across the bottom of the TV picture which could carry a stream of large Tiresias characters showing the subtitles when required. Digital broadcasters already carry such ribbons on their news pages, so the technology is there, we just need to get mobile TV developers to realise that the service is needed and to incorporate it.

Signing for the hard of hearing – This again could be difficult, since a tiny screen would mean that an inset picture of a signer might be too small to be useful. The presentation of the signer on the display screen needs to be of sufficient size and resolution to show all movements of the full upper trunk together with arms, hands and fingers, shoulder, neck and all relevant facial movements and expressions. All important gestures that convey meaning through sign language must be easily and accurately recognised.  I can’t see immediately how this could be achieved on a tiny screen – perhaps half of the screen could be reserved for the signer and half for the picture. Already on terrestrial digital TV the visual image is sometimes reduced by perhaps 25 per cent in order to have a larger area to display the interpreter, so research work needs to be done on these much smaller mobile TV screens to see just what can be usefully achieved.

Audio Description - Audio description is a spoken description of the visual aspects of a television scene, inserted in the gaps in the dialogue to help visually impaired people more fully understand what is happening on the screen. It has been introduced to a wide range of TV programmes in recent years and proved extremely popular and useful. Audio description will need an extra audio channel to be superimposed on the standard mobile TV audio. It requires only a modest amount of data (especially since GSM quality mobile phone sound would probably suffice) compared to the data being used to provide the TV services, but once again we need mobile TV developers to appreciate the need and to build AD into the system right from the start. If the levels of the AD could be adjusted by the viewer and the service easily switched on and off, then so much the better – it is important that we let the developers know our requirements as early as possible, so that ways can be found of incorporating them in the new mobile services. Since mobile phone TVs always incorporate the possibility of two-way communication, it might be possible for a future service to receive subtitling, signing or Audio Description via Internet Protocol data services independently of the broadcast programmes but synchronised with them.

Clean Audio - Many people with a hearing impairment have problems in understanding speech when there is background sound on a television programme, and other normally hearing people can find background sound distracting. One possibility for a future access service would be to provide a 'clean audio' channel which provides the speech without any background music or other sounds. This, like audio description, will require an additional audio channel, and a modest amount of data capacity reserved for its transmission. With digital television programmes, the cost of providing such an extra audio channel is modest, and the extra production costs are small compared to the number of people who would be helped by such a facility. It would be good if mobile TV could incorporate this facility from the start.

Hearing aid compatibility – Many hearing aid users find that they can hear phone conversations much better if they use a phone with a built-in inductive coupler, with their hearing aid set to the 'T' (telecoil) setting. Although I haven’t come across a mobile phone with a ‘T’ setting, most standard phones and some DECT portable phones incorporate inductive couplers, so phones with an inductive coupler are not necessarily expensive. It might be good to ensure that users of mobile TV phones could buy one with a built-in inductive coupler, since listening to good quality audio becomes even more important if you are listening to a half-hour TV programme than when on a short phone call.

Speech input – No, I haven’t gone into the realms of cloud cuckoo land, and we are looking to the future in this seminar, so let us consider making speech recognition as a requirement for mobile TV phones. There are already mobile units which respond to ‘dial’ commands and to users’ spoken number inputs, so let’s make it a user requirement and insist that mobile TVs can be controlled by the user’s voice, since this would provide many benefits for viewers with a wide range of disabilities. It would be of particular help to people with motor disabilities that make it difficult to select and press the correct button. Using speech as a means of selecting channels or interactive TV options would also help a much wider range of people who might not consider themselves as ‘disabled’, such as elderly people with arthritis.

Speech output: Again, this isn’t an impractical suggestion – the lady in my car’s sat-nav has no difficulty in nagging me for mile after mile with a range of different instructions, so the technology obviously exists for a mobile TV to read out its electronic programme guide or on-screen information and instructions in audio form when required. This would be invaluable to those who find reading small print difficult. There is at least one set top box that provides this facility, and it would be useful if mobile phone TVs could incorporate it from the start.

Other uses

Once you have this new generation mobile phone that allows you to watching television, you will be able, if those planning the future facilities now will get on with it, to use the same mobile phone for a whole range of new facilities. ‘Push to talk’ on your mobile phone, known as PTT or PoC or Push to Talk over Cellular is a feature that allows you to use your mobile like a walkie-talkie. It connects directly to your friends, either individuals or as a group, almost instantly, and often without the usual mobile call charges, making it simpler for those with disabilities to keep in touch with the group with which they might have travelled without having to make several calls to coordinate everyone – finding your mates isn’t always easy if you cannot see. Push-to-talk calls are half duplex communications — while one person speaks, the other(s) listen. Currently, PTT service is supported only between parties on the same mobile service, and users on different networks can’t talk to each other. Technical advances may well bring interconnectivity of PTT traffic between different networks in the near future.

Internet tablet with real-time updatesWith a bit of forward planning the same phone could be used to bring a whole range of text and video-based services to those sitting in the stadium. Lists of medal-winners and the league tables could be made available constantly, and video and audio clips of the various medal-winning performances at the many different Olympic sites could be available at the touch of a button, allowing spectators to know what is happening elsewhere and to feel that they are really taking part in the games, ‘chatting’ to their friends, and thoroughly enjoying the atmosphere of really being there.

User Requirements – let’s start NOW

Most TV access services have had to be added to existing TV transmissions, which has often meant that there were technical difficulties and problems involved in modifying existing services. In contrast, we are now at a unique time in the development of a new mobile TV services, in that everything is still flexible since no irrevocable major business or technical decisions have yet been taken, and we certainly don’t yet have services that have been widely rolled out.

Before these services start in earnest it is important that the telecoms regulatory bodies ensure that an agreed list of user requirements is drawn up, in consultation with groups representing disabled people, and that those companies intending to provide mobile TV services are persuaded, compelled if necessary to incorporate the additional features that are needed to make mobile TV services truly accessible to all. Time is short, as competing manufacturers and service providers thrash out their business plans for new mobile TV services, so let us seize the opportunity and start now in working with the regulator to draw up a comprehensive list of user requirements to ensure that Mobile TV, when it comes, can be used by everyone. Then, when we sit in the Olympic park in 2012 we will know that as a result of this seminar in 2008, we will all be making use of the world’s best and most accessible mobile TV services.

 

 



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