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Video calling is happening:

• 28% of Skype calls are video calls
• Asus just released a Skype videophone
• Quanta plans an ooVoo videophone
• Vidtel launched a video telephony service

And there are a lot of others who are either interested or currently developing and preparing to launch video services.

In the past several years, mobile operators around the world had the opportunity of launching a video service on their own, using a technology called 3G-324M. But somehow, this service is not used too much.

The main reason can be attributed to the quality of experience in these video calls. But what makes this experience poor?

Camera and Image Post Processing

When you call from your mobile phone you’re on the road. Usually, in an area with poor lighting, or below florescent lighting.

My own experience with using the phone’s camera for still images - the results are mediocre at best - and that at the best possible environments. So what can be expected of the same camera operating in real time video telephony calls in extreme environments?

To improve the quality of experience, cameras of mobile phones should be improves - especially their image post processing capabilities.

Bandwidth

3G-324M uses 64kbps channel. Into this extremely thin pipe, audio and video need to be squeezed. This means around 12 frames per second at QCIF resolution. Just to compare - high definition needs above 1mbps for video alone - that’s 16 times more than what you get for your phone.

Without more bandwidth to go around, the video quality cannot be improved above a certain level of “poor”.

CPU

Handsets today utilize almost all of their processing power just to encode and decode the video during video calls. Once we get more bandwidth - there will be a need for better CPUs to increase the resolution, frame rate and quality.

At least on this front, I can say that the newest application chips coming from all chipset vendors who are targeting mobile handsets are capable for the task.

What’s Next?

While mobile video telephony isn’t that good today in terms of quality, by changing the imaging on the handsets, this can be improved. Bandwidth can’t be fixed - at least until the 3GPP decides to increase the pipes - something that probably won’t happen.

When will we see a real change? When IP will be used instead - probably in conjunction with the migration to IMS and the promise of higher bandwidths. It must be as simple as 3G-324M is today in terms of usability to succeed though.