Face to face

The cost of video conferencing have come down. Now quality is an issue.

Face to face

Video conferencing units have come a long way since the clumsy, expensive, ISDN bound units of the 90s. Video conferencing is no longer just for the boardroom.

The ubiquity of IP (Internet Protocol) has played a huge part in helping to reduce the cost of video conferencing. Widespread IP has made bandwidth far more affordable. Cheaper equipment has made it more common. 

With the onset on unified communications, video conferencing is set to play an even greater role in day to day office life as it becomes integrated into business applications. For instance, when Keith from head office sends over a the monthly forecast spreadsheets to Clare in the Coventry office, a system can automatically video conference the two together.

With businesses looking to reduce their carbon footprint and scrutinise the time and cost of corporate travel, and with the growing trend of teleworking, video desktop conferencing is becoming a major part of the communications mix.

And the cost of bringing video conferencing to the desktop? You can buy a decent webcam for less than the cost of a decent meal.

However, ensuring quality can sometimes be problematic.

Clear vision

Video conferencing compression has improved in leaps and bounds. Codecs have evolved, using less bandwidth and producing higher resolution pictures. It is still important to remember that all compression technologies must make the trade off between resolution and bandwidth. It's a case of choosing a system that gives a fit-for-purpose fix given the network capabilities, end equipment and the user's tolerance of picture quality.

While the visual aspect is often a focus, it is important to remember that audio is also a crucial factor. In fact, while many users will tolerate a small amount of corruption on screen, the same cannot be said for audio where stuttered speech greatly affects the quality of a video conference. As conferencing invariably involves real time conversation, distortion, echo and latency greatly impact the user's experience.

Users may be more forgiving in a home environment; in a business setting, they need to have a consistently good experience or they won't use it at all.

Engineers refer to quality of service (QoS) as a gauge on how well a video conferencing facility performs. Unfortunately, QoS only checks the health of the network and doesn't take into account how the end-users will perceive the experience. For this reason, it makes more sense to talk about quality of experience (QoE).

Quality of experience

QoE is notoriously tricky to evaluate. On top of the plethora of problems that can occur across the network, each end device that a video conference participant is using must be taken into account, as well as the individual codecs and the unified communications system that is in use. Add to this the users individual environment and perspective and the picture looks very complicated indeed. For instance, those assessing the environment will need to consider a number of factors: Are participants placing the handsfree mic in the correct place? What are the acoustics in the participant's environment?

In the past, companies would ask individual users to rate their experience. That's all very well for a small group, but that approach does not scale for a network operator, manufacturer or business user.

What's required is a technology that can predict all of these factors accurately. Once all the accurate data is to hand, then it is possible to build the tools that can discover what is going on in the network in a meaningful way.

Currently, the most accurate way of assessing the QoE is by using perceptual measurement derived from software algorithms which give a mean opinion score (MOS). Software is now available which can evaluate MOS through to the end point, including analysis in real-time, allowing a report on actual quality delivered. It can also immediately indicate the likely cause of the service issue.

This kind of analysis 'aims the gun' for the communications engineer tasked with fixing any problems with a video conferencing network and helps them understand what is needed and when. For instance, if diagnosis reveals that the system requires a network upgrade, this cannot necessarily be tackled automatically. However, if the issue is that a user does not have their headset positioned correctly, then it's only a ten second job. 

Substituting unified communications and video conferencing for long distance business travel and commuting is sensible for businesses to streamline their processes as well as minimise impact of business on the planet.

So, with a multitude of variables to get right, it is essential that the tools are in place to accurately assess any problems and resolve these in the most efficient manner. After all, as users are comparing video conferencing with real life experience, they are bound to be demanding. 

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