Mobile VoIP !!!!

Mobile VoIP or 'Mobile Voice over Internet Protocol' is the application of voice over IP technology to mobile handsets.

Mobile VoIP requires a mobile handset that supports, at minimum, high speed IP communications. Most commonly this is using Voice over WiFi or VoWiFi, but the same protocols (typically SIP or jabber) can be used over any broadband IP-capable wireless network connection such as the various 3G standards, EVDO rev A (which is synchronously high speed - both high speed up and down), HSDPA or potentially WiMax.

Mobile VoIP will require a compromise between economy and mobility. For example, Voice over WiFi offers free service but is only available within the coverage area of the WiFi Access Point. High speed services from mobile operators using EVDO rev A or HSPDA with probably have better audio quality and capabilities for metropolitan-wide coverage including fast handoffs from mobile base station to another, yet it will cost more than the typical WiFi-based VoIP service.

Technologies

There are three main technologies used for mobile VoIP:

UMA - The Unlicensed Mobile Access Generic Access Network, designed to allow VoIP to run over the GSM cellular backbone SIP - The standard used by most VoIP services, and now being implemented on mobile handsets Skype Protocol - a proprietary modified version of Jabber