Which Mobile VoIP to Choose?

Updated: August 20, 2012

Question: Which mobile VoIP client will end up the winner? Answer: What do you mean by mobile VoIP client? Is it software that lets you make VoIP calls via your cellular data service? That lets you make wifi calls using your dual mode handset? That lets you initiate cellular calls that end up being delivered over the Internet? Or some or all of the above? You see the problem. At present, mobile VoIP is more a marketing term than a specific service or technology.

The purest form of mobile VoIP travels over IP links all the way to the handset. Usually this requires a 3G-speed cellular data service (and a cellular carrier that doesn't prohibit it). It also requires a soft client that works on the particular handset in question, which at present limits the number of phones you can use. Two obvious examples are Fring and Skype Mobile; Raketu plans to come out this month with a mobile client that will work at less than 3G data speeds. Either way, your choices are limited.

Those clients also support VoIP calls made through wifi hotspots using dual mode cellular/wifi handsets. Other clients for such handsets similarly support VoIP calls over wifi, but not over cellular data networks. In that case, all calls made out of hotspot range have to travel over the cellular voice network. Whether that qualifies as true mobile VoIP is again a matter of definition. Truphone is a high-profile example of this approach.

The possible combinations of software, service models and transport methods are almost limitless. Some services, for example, use clients running on handsets, and VoIP switching, but mainly transport their calls over the PSTN. Others do without the client, but deliver their calls over the Internet. No two contenders take exactly the same approach.

ISkoot is one that uses client software on the handset along with VoIP transport, specifically by delivering mobile calls to Skype . The client reaches out over your cellular data network to set up calls, and connects you to the Skype network via a local call from your phone using your cellular air time. You pay for SkypeOut and SkypeIn services as you would if using them from your PC. For now, iSkoot isn't charging for connecting you to Skype. (It also has a Fring-like dual mode product in beta.)

Mino Wireless also uses client software to set up calls, though you can use your handset's Web browser to go to its site and get the same result. Mino's service initiates calls to your cellphone and to the number you're trying to reach, then connects them in the middle. It uses a combination of conventional telecom carriers and IP infrastructure to carry the calls great distances at low prices.

GrandCentral Mobile, by contrast, is mainly an alternate method of accessing the main GrandCentral service. That service provides the Web-based call management features and flexibility of VoIP, but all calls start and end on the public wire line or wireless networks. The mobile version merely lets you access key features through a handset, and it requires no client software. You simply use your handset's browser to log on to the GrandCentral mobile site. Once there, you can see your voice messages listed, click to listen and call, change your forwarding number and the like, all through your phone's tiny keypad and LCD screen.

Companies such as Jajah, Rebtel, Eqo and others each mix the various ingredients in different ways. So to return to the question of which mobile VoIP will prevail in the future, the answer becomes clear: It will be the one that lets you make cheap mobile calls, with all the flexibility and convenience that VoIP offers, without having to know any of the details you've just read.