Using iPlayer, the BBC is currently streaming 100Tbyte of programming a day over the internet: a far cry from the single channel black and white broadcast days of Watch with Mother in 1952.

When BBC antennas began television transmissions from Alexandra Palace in 1936, only a few hundred viewers in the immediate vicinity could see the broadcasts. By 1939, transmissions could reach almost 40,000 television screens. Aside from the plug being briefly pulled during World War II to prevent German fighter pilots from using the vhf broadcasts as radio beacons, the BBC has remained at the forefront of programme transmissions ever since. More than 73 years on, BBC's iPlayer service is watched by millions of viewers and its success recently resulted in the formation of a video on demand (VoD) service, tentatively called the 'Kangaroo project'. This collaboration between BBC Worldwide, ITV and Channel 4 was intended to provide a revolutionary way to view programmes online and to allow users to browse a massive back catalogue of programmes. However, the plans came to an abrupt standstill when the Office of Fair Trading deemed the project unfair to competition and warned of a risk that the platform could become too powerful. The BBC's on demand tv service BBC iPlayer – created by the BBC's Future Media and Technology Division in partnership with Red Bee Media and Siemens – was launched officially on Christmas Day 2007. The three companies took on separate responsibilities to ensure the service was as robust as possible. Red Bee was responsible for the content, transcoding and quality control via an automated workflow system enabling programmes to be repurposed for the BBC iPlayer. This involved intense metadata tagging to allow users to search for programmes, as well as pointing towards related online content. Siemens took responsibility for the delivery technical infrastructure, applying the digital rights licence and for distributing media to end users via a peer to peer network. Siemen's Kontiki broadband delivery service software allowed users to install the iPlayer application on their pc and download and store programmes. Consultations between the BBC and its consultants enabled the development team to build a platform from which accessibility features, such as the display settings options, could be built. Once viewers have accessed BBC iPlayer and have downloaded a programme, they have up to 30 days to watch it. Once seen, the file automatically deletes itself. Recently, simulcast streaming has been added, allowing viewers to watch tv live in addition to the on demand catchup services. On average, the BBC estimates that iPlayer receives 300million play requests per day. Anthony Rose, controller of the BBC's vision and online media group, said the motivation behind iPlayer was to develop a consumer proposition with the ability to satisfy end users in an age where the public seeks entertainment from the internet rather than the tv set. But what does the public really want? "They do not care about codecs and metadata taxonomy," believed Rose. "They want to find content that interests them. We did not want the iPlayer to become a regular video sharing site like YouTube, nor a music store like iTunes, where people would need to sort through thousands of programmes to find one of interest. This is a different use case. The reason why people like to come to the iPlayer site is because it allows them to find a particular programme that they missed on tv or radio." When iPlayer was launched, the home page had just six featured programmes – all chosen by the BBC's marketing team. "The first home page design was essentially 'the BBC chooses what you watch'," explained Rose. "Then we added a 'most popular' zone on the home page – this was about what other viewers (rather than the BBC) recommended that you should watch. And then we added a 'just in' feature, for those items that had just arrived, and 'the last chance' feature, for items that would soon disappear. Finally, we added a 'more like this' option as a sort of recommendation system (similar to that used by Amazon). These content selection mechanisms proved to be extremely useful and popular among iPlayer users." Rose explained the iPlayer contains four layers: the iPlayer destination portal site, what everyone sees; the embedded media player, a Flash player used for media playout in iPlayer and across the BBC site; media production, to create content that can be used by the Flash player and invisible to most people; and a media distribution system. Not surprisingly, the vast amount of users means the BBC's bandwidth bill is not insignificant. With 100Tbyte of streaming traffic per day, how exactly is the enormous amount of usage handled? Rose revealed: "The iPlayer uses content distribution networks that operate at a global scale and specialise in delivering large amounts of data. The BBC servers, positioned close to the edge of the internet, cache the iPlayer content so it looks like a very large distributed server farm." Having the servers at the edge, noted Rose, minimises the amount of network that the content has to traverse before reaching the end users. "This is beneficial because networks can become congested, so the less network, the better the experience." Despite the amount of traffic, Rose says the cost of bandwidth is falling rapidly, creating competition between the content delivery networks. Nevertheless, Rose warned that tv set top boxes with integrated iPlayers could result in bandwidth requirements 10 times this amount. He noted: "The question is, what is the best solution for this problem? Should we make this new box with peer to peer or shall we build an edge caching solution in conjunction with other broadcasters and ISPs? We do not know the answer, but we need to build an agile layer from the content delivery formats, the Digital Rights Management and the download manager, so that we can flexibly glue in different propositions at short notice as needed." The increase in network load caused by iPlayer traffic recently resulted in ISPs filing complaints with telecom regulators, although Rose suggested the press largely exaggerated the situation. "The reality is that about 7% of peak UK internet usage is due to the iPlayer," he insisted. "So the iPlayer is only a small fraction of the overall traffic and will certainly not cause internet failure." The latest innovation, BBC HD, is a free to air high definition channel, available on both satellite and cable. The new format is comprised of a wide array of programmes from across other BBC channels and, according to the organisation, provides up to five times more detail than standard definition television. Alongside the introduction of high definition programmes on BBC iPlayer, higher quality streams are also available within a new resizable media player. The new media player allows users to select a large playback window size in which users can view streams almost twice as powerful as the previous high quality format. The original format is now the default setting for the smaller playback video window. Danielle Nagler, head of BBC HD, explained that new adaptive bitrate technology can detect the amount of bandwidth available automatically and switch streaming options accordingly. She observed: "It's great that we've been able to bring the BBC HD channel to the BBC iPlayer family. For some people, this will be their first experience of high definition viewing, allowing them to see and hear programmes that they love from the BBC in the very best quality possible." Additional features include a new internet speed diagnostics page and the BBC iPlayer Desktop, a cross platform manager which allows Windows, Mac and Linux users to download BBC programmes, including those in high definition. Nagler added: "In the last month, we've extended the channel hours to nine per day, refreshed the look, enhanced the range of programmes and now our HD content will be available whenever and wherever audiences want it. We're seeing huge demand for HD content and I'm confident this will help ensure it is as accessible as possible." Rose agreed the new format marked a significant milestone in boosting video quality over BBC iPlayer. "The new adaptive bitrate technology and speed diagnostics page help optimise the viewing experience," he asserted, "while the resizable window gives users flexibility to switch between different quality streams, hopefully leading to a more satisfying experience overall." With the Kangaroo Project quashed indefinitely by the UK's Competition Commission, the BBC's plan to introduce VoD may have been usurped by a US company called Hulu. The NBC and News Corp founded service has been holding a number of talks with broadcasters in a bid to establish a UK version of its successful US platform. And it could be a serious contender, with Walt Disney having bought a 30% stake in the business. Hulu's service currently offers US users an enormous range of VoD, but the company has actively been working on HD programmes too. Within its HD Gallery, users can view programmes streamed at 1280 x 720 resolution as Flash video files. The files are encoded using an On2 Flash VP6 codec and supported on Flash Player 8.0 – installed on more than 98% of computers in the US. Hulu currently supports four different streams including 480, 700 and 1000kbit/s and 2.5Mbit/s. While talks are still ongoing, NBCU International president Peter Smith warned that this could be a long, drawn out process. "The UK is more complicated than anywhere else to have this dialogue at the moment," Smith noted. "We just had the Kangaroo dialogue … and a whole set of political issues which make conversation slow." Nevertheless, regulators are clearly keen to keep the UK VoD market competitive and, if a deal is struck, Hulu's platform could emerge as a major commercial rival to the BBC's iPlayer. Meanwhile, the BBC is currently investigating plans to share its iPlayer technology with UK broadcast rivals. Following the axing of the Kangaroo Project, this would help cut costs for its commercial rivals, but would also mean the iPlayer plan could become a state owned monopoly. And there is one final issue, of which both the BBC and Hulu must be aware. Under British law, copyright for tv series lasts just 50 years from the date of publication. As a result of this, programmes such as Watch With Mother are appearing on alternate internet sites, regardless of the BBC or Hulu's efforts.