The Difference Between Mobile Video Telephony and Video Share

By Tsahi Levent-Levi

Categories: Clients, Technology

October 13th, 2008

Today, there are two standardized real-time video communication technologies that are available on commercial mobile handsets: video telephony and video sharing. From questions I receive once in a while from people, it seems like the differences between the two are not that obvious.

What is Mobile Video Telephony?

Mobile Video Telephony is a circuit switched based technology that uses 3G-324M for bidirectional video calls. It is available on a large (and growing) number of handsets.

The way you use it is by pressing a number (or selecting a contact from your address book), and opt to dial a video call instead of a regular voice call.

The call takes up more network resources, and you get a stable connection of 64 kbps in each direction for the call.

What is Video Sharing?

Video Sharing is a packet switched based technology (IP),that uses IMS SIP for sharing a unidirectional video stream. It is available on a small number of handset model and on numerous networks around the world.

The way you use it is by dialing a normal voice call, and then, opting to send video to the other end at some point into the call. The video is sent in parallel to the voice, with no synchronization with it whatsoever. It can be stopped at any point in time during the call and reopened later on (from either side of the call).

As this is an IP based solution, the bandwidth available for the video may vary, depending on network conditions.

So What’s the Difference?

To tell you the truth - they are totally different. And not only from the point of view of technology - the use cases for each are different.

The main things to remember are:

• Video Sharing CANNOT be used for video calling. The video is NOT bidirectional.
• Video Telephony CANNOT be added on top of a voice call. You need to select to dial a video call without knowing if the other participant wants/can accept video calls.

Next time you decide to add video to a mobile handset, start by asking yourself what use cases you want to cover and then choose either video telephony or video sharing (or both).