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

Page  2 Agenda 1.Backgrounds of video communications  A bit of history  Applications  Codecs 2.Video conferencing service and network architectures  International standards for the video conferencing service  Network and Service architectures 3.Worldwide market  Big boys  Start-ups 4.Challenges in Viet Nam  Foreign players  Home teams 5.Conclusions

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

Page  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.

Page  5 Codecs  Video formats : FormatTotal Aspect RatioSize SQCIF (Sub QCIF)16:11128x96 QCIF (Quarter CIF)4:3176x144 CIF (Common Intermediate Format)4:3352x288 4CIF4:3704x576 16CIF4:31408x1152 SD (Standard Definition)4:3704x480 HD (High Definition)16:91280x720 (i or p) Table 1 : Main video formats

Page  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 B I B 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

Page  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 scalabilityFig. 3 : SVC scalability

Page  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 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).

Page  9 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. 4 : Multipoint Control Unit Fig. 5 : Naïve unicast/IP/Application Level Multicast

Page  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.

Page  11 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. Fig. 6 : Cisco’s HD TelePresence Fig. 7 : Polycom TPX HD 306M Fig. 8 : Tandberg 1700 MXP 450Fig. 9 : Mobile video phony

Page  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.

Page  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.

Page  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”.

Page  15 Q&A Thank you very much for your attendance!

References [1] Video conference: the whole picture. [2] [3] Voice and Video Conferencing fundamentals [4] Scalable Video Coding-Scalable extension of H.264 / AVC-Thompson [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] d=