[dsushant]

The mobile industry body GSMA's Rich Communications Services (RCS) initiative seems relevant in this context.

"joyn services enable customers to chat and enrich messaging or voice calls by exchanging images or video simultaneously during calls, in a private and secure manner, with any member of their contact list that has joyn, regardless of the user’s network or mobile device. Additional services such as voice over IP (VoIP) or IP-video call will be introduced in the near future. These services may be used on both the operators’ mobile networks and on Wi-Fi networks." (Source: http://www.gsma.com/newsroom/spanish-mobile-operators-launch...)

http://www.gsma.com/futurecommunications/rcs/ http://www.joynus.com