The Importance of Quality VoIP for Web Conferencing and Collaboration Jan Linden, Vice president of Engineering Global IP Sound, Inc.

Web Conferencing Market Overview Conferencing and Collaboration Primarily an Enterprise Play –According to a recent survey by Interactive Media Strategies, more than 80% of survey respondents reported the deployment of Web conferencing technology within their organizations (December, 2005) Consumer Market could see substantial growth –Increasing popularity of IM puts conferencing capabilities on the desktop and at an estimated quarter of a billion users’ fingertips –The continued adoption of VoIP in consumer applications will accelerate conferencing capabilities – Skype claims over 225 million downloads, 54 million members, Google, AOL, and Yahoo many million users too Quality will be the main driver of mainstream acceptance

The Benefits of Collaboration Office –Increased Productivity –Increased Team Cohesion and Interaction Home –Stay in touch with friends and family members –Brings the office to you Lowering of Cultural Barriers –Europeans and North Americans are more comfortable doing business via teleconference –In the Asia/Pacific region, face to face meetings are preferred –High quality video conferencing could be a way to bridge the gap between cultures

VoIP as an Enabler VoIP is no longer a niche market that only delivers a voice conversation VoIP can exceed PSTN voice quality Now voice can be combined with video and data traffic to provide feature rich applications VoIP will be the centerpiece that enables new, high quality conferencing and collaboration applications Voice is essential to communication –Video conferencing without high quality voice is useless –Explaining complex, real time collaboration via IM is difficult and slow

The Importance of Quality "Videoconferencing is breaking the shackles of its earlier image as a unreliable and expensive technology, thanks to advancements in video and audio quality and IP-based videoconferencing," S.V. Purushothaman, Frost & Sullivan However, there is still room for improvement as IP networks present unique obstacles to quality –Packet loss and network jitter can severely affect call quality –Long delays unacceptable in conferencing –Poor audio codecs can result in unclear conversations –Poor video codecs will give fuzzy and jerky pictures –Bandwidth restrictions and poor video and audio synchronization can also result in a poor user experience –The traditional problems of echo and background noise are magnified in conferencing situations

Quality Aspects Attention to detail –A chain is only as strong as its weakest link Choice of codec(s) Robustness against network degradation Sampling rate (narrowband 8 kHz vs. wideband 16 kHz) Implementation issues –PCs are NOT designed for real-time communications Auxiliary components (e.g. AGC, VAD, AEC) Firewall and NAT traversal has to be efficient and not introduce extra delay Low latency –One of the most important and complex aspects

Handling of Network Degradation Typical problematic scenarios: –Internet applications –Wireless –VPN Packet loss concealment –Smooth concealment necessary Network jitter –Jitter buffer necessary to ensure continuous playout –Trade-off between delay and quality

Device Related Issues PCs tough environments for real-time communications Operating system –Non-real-time OS –Support for multitasking? –Delay and jitter Audio hardware and drivers –Delay –Quality (frequency response and noise levels) –Sampling frequency support –Hands free support Clock drift –Hard to detect and compensate for Application and UI Voice Processing Call Setup SoundcardNetwork Interface

Overcoming Quality Issues A quickly adapting jitter buffer is essential in order to handle delay and jitter High quality packet loss concealment necessary High quality audio codecs provide a clear conversation, that can be better than PSTN quality –Wideband codecs (16 kHz sampling frequency) allows for richer sound presentation –This is especially important when trying to understand and distinguish between multiple people speaking in a conferencing situation High quality video codecs enable clear, consistent pictures that enhance the user experience Audio and video synchronization further add to the real to life feel Highly adaptive echo cancellation technology is vital in environments which include usage of hands free devices

Solutions to the Quality Problem Voice and video (when applicable) processing needs to include the following key features to provide high quality voice and video collaboration: Highly efficient jitter buffer and error concealment module High quality and robust audio codecs Close integration of high quality video codecs Support for standard audio and video codecs Acoustic echo cancellation technology Accurate lip synchronization Efficient bandwidth control (trade-off between audio and video quality) Video codec adaptation to network conditions Freedom in video quality setting (codecs/frame rate/image size) Voice and video recording

Conclusion  Web conferencing and collaboration have the ability to improve life both at home and at the office  VoIP adds a crucial element that is necessary for fully integrated and functional applications  Quality is the main determinant for adoption and acceptance of this emerging technology  By overcoming the obstacles that IP networks present to web-based conferencing, there is no limit to the innovation and development of new and exciting applications