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State of the art on video communications

Le Tien Anh Telecom and Management Sud Paris. State of the art on video communications. Agenda. Backgrounds of video communications A bit of history Applications Codecs Video conferencing service and network architectures International standards for the video conferencing service

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State of the art on video communications

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  1. Le Tien Anh Telecom and Management Sud Paris State of the art on video communications

  2. Agenda Backgrounds of video communications A bit of history Applications Codecs Video conferencing service and network architectures International standards for the video conferencing service Network and Service architectures Worldwide market Big boys Start-ups Challenges in Viet Nam Foreign players Home teams Conclusions

  3. A bit of history Fig. 1 : Video communication – a bit of history

  4. Applications Video-phony: Skype®, YIM®, MSN®, Google®… Mobile video calls over 3G networks. Video conference: Business: Conferencing among employees, customers, suppliers, and strategic partners. Governments & Politics: In 2004, 4,000 US Democratic delegates joint video conference, Vietnamese government. Emergencies, Distance learning, distance training, Telemedicine: Patients in military bases or in prisons, Patients in remote areas with the help of visiting nurses. Various desktop videoconferencing applications: Skype®, WengoVisio®, Pornography.

  5. Codecs • Video formats: Table 1 : Main video formats

  6. Codecs • Popular video codecs: • MPEG (ISO): MPEG-1, MPEG-2, MPEG-4, • H series (ITU-T): H.261, H.262, H.264, • Joint Video Team: H.264 = MPEG-4 part 10 or H.264/Advanced Video Coding. • Frames, Group Of Pictures: • I (intra), P (predicted), B (bi-directional) frames and GOP (Group of Pictures) • Size{I} = 4xsize{P}; size{P} = 2xsize{B}, • Frame transmitting order: I P B B P B B P B BIB B • Frame encoding/decoding order: I B B P B B P B B P B B I • GOP length should be selected well. In the DVD standard, GOP length = 15

  7. Codecs • In Nov 2007, Scalable Video Coding (SVC) was added to the H.264/AVC: • Scalability has been supported from MPEG – 2, however it is rarely been used: • Significant loss in coding efficiency, • Large increase in decoder complexity. • Fully compatible with H.264/AVC, • Allowing decoders to process only a subset of the stream to produce scalable outputs, • One encoding / multiple decoding, • Adaptation to a diversity of networks, terminals... • Available scalabilities in SVC: Spatial, Temporal, SNR (Quality), or a composition of them. Fig. 2 : SVC spatial scalability Fig. 3 : SVC scalability

  8. International standards for the video conferencing service Signaling protocols: H.323: ITU-T call signaling and control, multimedia transport and control, and bandwidth control for point-to-point and multi-point conferences, Has been widely implemented by voice and videoconferencing equipment manufacturers, Support video codecs: H.261, H.263 and H.264. SIP (Session Initiation Protocol): IETF signaling protocol, widely used for setting up and tearing down multimedia communication sessions such as voice and video calls over the Internet. Media control and Transport protocols: RTP (Real-time Transport Protocol): Each media stream is transported on a separate RTP connection. RTCP (RTP Control Protocol): Providing periodic reports (statistics, quality of reception, information for synchronizing audio and video streams).

  9. Fig. 4 : Multipoint Control Unit Network and Service architectures • Network architecture: • MCU (Multipoint Control Unit): • Transcoding, • Transrating. • Continous presence: with Multicasting • IP Multicast: • Normally use UDP (1-n), • Unreliable Packet Delivery, • Packet duplication, • Network congestion, • MBone • Application Level Multicast: • Immediate implementation on the Internet, • Not mature enough. Fig. 5 : Naïve unicast/IP/Application Level Multicast

  10. Network and Service architectures • Service architecture: • Voice-activated conference: • Based on the incoming voice energy from participants, the active speaker’s video is sent to all, • “Image pass through” or “stream switching” mode. • Continuous Presence conference: • Displaying two or more participants simultaneously. • Lecture Mode and Round-Robin conference: • The lecturer’s sub-picture is locked, • Students’ sub-pictures operate in a continuous presence mode with voice-activates priority.

  11. Fig. 6 : Cisco’s HD TelePresence Fig. 7 : Polycom TPX HD 306M Fig. 9 : Mobile video phony Fig. 8 : Tandberg 1700 MXP 450 Worldwide market • Big boys: • Cisco® • Polycom® • Tandberg® • Start-ups: • Vidyo®: SVC video conferencing • Dimdim®: webinar over the web • WengoVisio®: Video conference over the web • Mobile video phony: • 3G networks, • Question: who are capable of answering mobile video calls? • Cultural block.

  12. Challenges in Viet Nam Foreign players: Polycom®, Tandberg®… Wining business “telepresence” services. Home teams: Viettel Technologies® (HD Teleconferencing): Vietnamese government Elcom® (eVision): Vietnam Ministry of Defense (Bo Quoc Phong) CMC®, Teleconferencing services: VTI, VTN: 2% revenue, 10 M VND/3 hours. Telemedicine: Viet Duc hospital and VNPT succeeded in tele-operations. Winning room conferencing services, virtual office services.

  13. Challenges in Viet Nam • Challenges: • Lack of equipments: • Hardware codecs must be imported. • System costs, • Lack of network quality (business quality is around 400 kbps), • ADSL speed in Viet Nam is around 200 kbps. • Lack of static IP: • Dynamic (local) IPs are usually assigned, • NAT traversal techniques, • Using leased lines with high renting prices and low usability. • Security: • Governments, military. • Lack of standardization: • Local video conferencing services are using different codecs and signaling protocols, • Difficulties inter-operating with each other and with foreign systems. • Cultural block: • Face-to-face meeting habits.

  14. Conclusions • Video communications is the future of human telecommunications, • Standardization is very important in order to open to the world of multimedia communicators, • Scalable Video Coding is a suitable video codec for a video communication environment with different bandwidths and variable terminal’s computabilities, • Real-time video codec cards are extremely expensive now in Viet Nam, this is a business opportunity for hardware producers and assemblers to make money from a raising video communications industry. • The solution for the expense problem can be “virtual office”.

  15. Q&A • Thank you very much for your attendance!

  16. [1] Video conference: the whole picture. [2] http://www.sipro.com [3] Voice and Video Conferencing fundamentals [4] Scalable Video Coding-Scalable extension of H.264 / AVC-Thompson [5] http://www.mbone.net/ [6] http://esm.cs.cmu.edu/ [7] http://www.mpegla.com [8] http://www.cisco.com [9] http://www.polycom.com/ [10] http://www.tandberg.com/ [11] http://www.elcom.com.vn [12] http://www.vietteltechnologies.com.vn/en/services.html [13] http://www.vidyo.com/Conferencing.html [14]http://chinhphu.vn/portal/page?_pageid=33,128127&_dad=portal&_schema=portal&pers_id=134916&item_id=7818047 References

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