From videoconferencing to telepresence

The technology of videotelephony made its debut in 1964 at the New York World’s Fair in the United States, when AT&T tested its Picturephone service on members of the public. However, attempts to create a commercial market for videotelephony services have not been very successful. This is partly as a result of high costs and lack of bandwidth, poor picture quality, and because of consumer resistance to interacting on camera.

It was not until the early 1980s that integrated services digital networks (ISDN) standards allowed digital signals, such as compressed video and audio, to be transmitted over long distances. This allowed the equipment market for videoconference products to begin expanding. Videotelephony has since developed in two different directions: at the personal level and for business use.

For individual consumers, many personal computers come equipped with webcams to transmit images, and mobile phones have cameras. Generally speaking, these represent applications rather than services, and the level of commercialization is based mainly on sales of equipment and bandwidth rather than minutes of use. But, with the phenomenal success of user-recorded short videos on such Internet sites as YouTube, and with the rapid increase in broadband speeds, wider use of real-time video is expected to follow.

For business users, videoconferencing has been growing as a means of encouraging collaborative work among offices spread around the globe and as a substitute for travel, but needs a boost in quality to see real progress. As an ITU Technology Watch Briefing Report puts it, “after the laborious setup of cameras and microphones, you seem to spend more time worrying about technical problems than talking about the topic at hand, with repeated loss of connection. As frustration grows, and attention wanders, it is difficult to avoid the feeling that you should have arranged a face-to-face meeting instead.”

Making the virtual experience more real

Cisco

A business meeting uses a telepresence studio

The good news is that advances in network technologies, conference hardware and software should provide users with a more real experience of “being there without going there”. This could be achieved with “telepresence”, the name given to new, high-performance, studio-based videoconferencing. In a telepresence studio, the aim is to give users the illusion of sitting on the opposite side of a remote party’s conference table. High-definition (HD) video images and audio are transmitted via a packet-based next-generation network (NGN), connecting multiple conference rooms around the world, and covering thousands of kilometres with almost zero latency. Telepresence systems are already available, and vendors see the technology as a potential billion-dollar market.

With telepresence, participants may now appear life-size on large HD plasma or LCD displays of one metre and above. ITU standards for high-definition television (HDTV) have been essential in supporting this, especially Recommendation BT.709 of the Radiocommunication Sector (ITU–R). With the HDTV standard, live video resolutions can go up to 1080p at 30 frames per second, where “1080” represents the number of lines of vertical resolution and “p” the progressive, non-interlaced mode of scanning. The 1080p high-definition video means that every expression and gesture is now clearly visible, whether you are meeting across town or across time zones. Future technologies will be based upon Recommendations from ITU–R and from the Telecommunication Standardization Sector (ITU–T) on large-screen digital imagery (LSDI). They will define how images can be delivered that are up to four times the quality of standard HDTV.

The photograph above shows a typical telepresence conference. It features three plasma screens (each of 165 cm), and a specially designed table that gives the illusion of seats for twelve people in the same room. Multiple HD cameras can be deployed closely above the screens, although ideally, cameras should be embedded in the screens themselves to simulate true eye contact among participants. In telepresence, spatial, CD-quality audio is directed to the conversation partner, simulating the acoustics of face-to-face talks.

Software now focuses on usability, simplicity and interoperability, allowing the user to easily set up conferences between two or more offices. Presentations and documents can be shared and made available on an additional display, improving collaboration and interactivity.

The demand for telepresence

Demand for telepresence exists in such areas as distance education, telemedicine and entertainment. However, its main market lies in the business sector, where it can be used for not only meetings, but also remote interviewing for recruitment, for example, technical consultations, or virtual “face-to-face” customer support. Nowadays, the environmental benefits of videoconferencing are also increasingly emphasized. A significant reduction in carbon dioxide emissions can be achieved, compared with flying participants to a central conference venue (see article climate change).

A question of bandwidth and networks

Transmitting video and audio in HD quality demands high-bandwidth connections. To achieve a life-like experience, transmission delays must be negligible for the human eye and ear. Bandwidth requirements for 1080p conferences are specified as 15 Mbit/s. In relative terms, telepresence requires around 150 times more bandwidth than traditional voice conference calls.

Demand for bandwidth is rocketing. According to ITU’s annual survey of broadband services and prices, by the end of 2006, two-thirds of the world total of Internet subscribers had broadband access, or some 280 million people in 166 countries. Furthermore, available bandwidth has been increasing by 66 per cent per year, while the median price has been falling by 41 per cent per year since 2003. This makes high performance videoconferencing more available and affordable.

However, as well as more bandwidth, providing the telepresence experience could also require dedicated networks. The guaranteed availability of bandwidth on demand is essential, as rescheduling meetings due to network unavailability is not an acceptable option for businesses or remote surgery, for instance. Before starting a session, participants should be able to reserve bandwidth (via call admission control). Telepresence traffic should be detected automatically by network operators and be given high priority in return for a higher price, as well as comply with strict service-level agreements to safeguard quality of service. It is also essential to ensure end-to-end security, so as to protect networks from denial-of-service attacks or unauthorized access.

Standardization work at ITU

Telepresence has implications for ITU as a potential user organization, and in its leading work in developing global standards in the field of information and communication technologies (ICT).

ITU–T, for example, is experimenting with ways to facilitate remote participation in its meetings, especially from developing countries. A first trial was carried out in November 2007 with a link between ITU’s headquarters in Geneva and its Cairo Regional Office. Such remote collaboration tools, which can include additive video transmission, require only a conventional Internet connection.

In contrast, telepresence requirements cannot be met on today’s public Internet, but are implicit in the specifications for next-generation networks (NGN), which are a major focus of ITU–T work. The deployment of NGN in a new era of multimedia communications will bring with it a need to consider updating or replacing the current multimedia protocols, such as H.323 (developed in ITU–T Study Group 16) and the session initiation protocol (SIP) developed by the Internet Engineering Task Force SIP Working Group. Interoperability is a key requirement of telepresence to ensure broad connectivity with traditional and emerging video environments. Today, most of the available products support both H.323 and SIP.

A workshop held in May 2006, jointly by ITU–T and the International Multimedia Telecommunications Consortium (IMTC), identified strong and weak points in both protocols, and proposed that H.323 and SIP should be migrated into a new generation of multimedia protocols, called H.325 or advanced multimedia systems (AMS), that take account of special aspects of security, flexibility and quality of service.

Work on AMS also addresses the current lack of multimedia support for mobile systems. Standards require low complexity codices for mobile use, and must focus on low power consumption as well as interoperability among devices and different systems. Today’s standards for video compression, such as ITU–T H.264, are appropriate for high-motion video content. But in order to obtain quality beyond HD, existing standards have to be enhanced in matters of resolution, frame rate, colour accuracy and efficiency.

Market players

Members of ITU that are actively involved in standardization activities include telepresence vendors, such as Cisco, HP, Polycom and Tandberg, and network service providers such as NTT and Verizon. New providers with different service models are expected to emerge.

Cisco expects its solutions to generate USD 1 billion annually in revenue from hardware sales by 2013. Its research suggests that network services from the full range of providers will represent a USD-4-billion opportunity by 2010.

Developing countries can benefit

For developing countries, the success of videoconferencing in general, and telepresence in particular, is tightly linked to the deployment of NGN infrastructure and the higher bandwidth required for high-performance services. If more powerful networks are made available, many benefits could result.

For example, ICT vendors and service providers with global operations could establish branches and research centres in emerging economies, and use telepresence to collaborate with head office or other research units. Already, universities and institutions of higher education in developing countries have been cooperating with universities in developed ones to share knowledge via distance learning and to make it available in remote regions. Telepresence will help to enhance the degree of interactivity and collaboration between students and educators.

In addition to communication in high definition, personal video communication on mobile devices will also play a major role in developing countries, once the infrastructure is provided. This is because it is likely to be more affordable and more available, given the important and growing role of mobile communications in developing countries.