Mobile VoIP Software Roundup - Pei Zheng's Mobile Computing Blog - Site Home

Skype has beta version for Windows Mobile Smartphone. It allows you to choose either WiFi or GPRS to connect. Skype Moile runs good with my home 802.11b wireless LAN. If you want to get more information about how Skype is encroaching the business world, see this Business 2.0 story.

The following are some other mobile VoIP client software. Most offer free calls between accounts, and low rate between mobile and/or landline calls. Some observations:

There are more Symbian based mobile VoIP clients than Windows Mobile ones.
Interestingly, all these companies are in Europe or US; no one from Asia.
Technologies behind mobile VoIP are SIP or UMA (Unlicensed Mobile Access aka Generic Access Network), designed to allow VoIP to run over the GSM cellular backbone.
Few can do seamless handoff between WiFi and cellular.
The idea of Peer-to-Peer has been used by some mobile VoIP software (including Skype) to improve system availability and bandwidth efficiency.

Here is the list:

Barablu:
From the company's website: "Our big thing for 2007 will be a brand new version of barablu that can switch seamlessly between GSM and Wi-Fi, connecting you in the most cost-effective way without dropping your call, or losing quality. " This is a feature not available on other mobile VoIP clients. Barablu supports a wide variety of devices, including Windows Mobile (assuming .Net CF 2.0 is installed).

Truphone:
Now Truphone only works on some Nokia cell phones. Windows Mobile version is in development.

Jajah:
Use your phone to make Internet based calls.
Free for Jajah users calling within and between US, Canada, China, Hong Kong, and some other countries and regions.
No download needed. Just enter your phone number and destination number on the web page.
For mobile: user can access their mobile site mobile.jajah.com from a cell phone and make calls.
There is a plug-in for Symbian.

Raketu:
Free call to mobile and landlines to US, China, and some other countries (may change after the promotion ends May 2007).
Desktop application only.

Fring:
Peer-to-Peer based mobile VoIP client for some Symbian phones. Calls are free between Fring users, Skype users, and Google Talk users.

iSkoot:
This is NOT a Skype killer - in fact, it is a Skype certified mobile client for Symbian and Palm phones.