Ask an Expert: For Mobile Video Telephony in the US, Should I Use SIP or 3G-324M?

By Tsahi Levent-Levi

Categories: Ask an Expert

September 2nd, 2008

[Ask an Expert is a new service in RADVISION's Blogs. In this service, you ask questions, and we do our best to answer them here on one of our blogs. If you have any question to ask, feel free to contact one of the bloggers through our About pages]

Last week a Product Manager from a large company who provides services to service providers approached me with the following:

I am very interested in Mobile Video-telephony services. Specifically the protocol currently used for Mobile Video-telephony in North America. With regards to your article published in May 26, 2008, in which you’ve written that the 3G-324M protocol is not supported in USA, would it mean that Mobile Video in USA can be done only using SIP protocol or are there other alternatives?

Straight to the point

Today, if you are a mobile operator or a large contact center, 3G-324M is the only way to effectively deploy mobile video telephony.

Why 3G-324M?

• 3G-324M exists in most 3G handsets on the market. There’s no need to install anything additional.
• Operators around Europe and Asia have the service enabled on their networks and have roaming agreements in place - you can dial a video call from a mobile phone in Israel to a mobile phone in Taiwan, and it works (been there, done that - more than once).

Why not SIP?

• SIP requires additional installation on most handsets. The user will probably also need to download a client, and most SIP clients for mobile handsets today don’t support video at all.
• Mobile operators don’t support SIP clients, so it’s harder to service such applications.
• There are additional barriers for using SIP for mobile networks. Remember that adding video to it makes it even harder.

What goes on in the US?

• 3G-324M works on WCDMA and TD-SCDMA (the Chinese 3G flavor). CMDA2000 (theoretically) supports 3G-324M, but that has never been deployed. The US has WCDMA networks - AT&T and T-Mobile have them deployed.

BUT US operators don’t enable video calls on their networks AND don’t sell 3G phones with front facing cameras.
In fact, even when a certain model has two cameras (front facing and back facing) in Europe, the US equivalent will have only the back facing one in the US. This makes it quite hard to do video calls, and requires some “out of the box” design a-la Gizmodo.

Where are we headed?

• If you are thinking of deploying a mobile service that requires video telephony, you will need to focus on Europe and Asia - the US is out of the game at this point in time.
• Had Apple made the bet on video telephony using SIP, it would have changed the landscape, but that didn’t happen.
• Mobile Video Telephony today IS 3G-324M. It will take time for SIP to replace it, although that will surely happen. And when it does, it will be with its IMS “flavor”.