Mobile VoIP requires a mobile handset that supports, at minimum, high speed IP communications. Most commonly this is using Voice over Wi-Fi 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 Wi-Fi offers free service but is only available within the coverage area of the Wi-Fi Access Point. High speed services from mobile operators using 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 Wi-Fi based VoIP service.
Mobile VoIP will become an important service in the coming years as device manufacturers exploit more powerful processors and less costly memory to meet the users' needs for ever-more power in your pocket. Smartphone in mid-2006 are capable of sending and receiving email, browse the web and in some cases watch TV.
The challenge for the mobile operator industry is to deliver the benefits and innovations of IP without losing control of the network service. Users like the Internet to be free and high speed without extra charges for visiting specific sites versus other sites. Delivering mobile VoIP is a service that challenges the most valuable service in the telecommunications industry – Voice. The opportunities, threatens and pace of innovation in the global communications industry.