Google Hangouts | Technical service details | Consumer forum

As you may have seen elsewhere, Google recently added an internet calling feature to the Hangouts app for Android in the form of the Hangouts Dialer add-on app for Hangouts version 2.3. Surprisingly the dialing feature was already available months earlier integrated into the iOS Hangouts app. It lets you make calls for free to any number in the U.S. or Canada, and for 1 cent per minute to most other countries (calls to cell phones in caller-pay countries costs extra of course, for example +5 cents per minute to a cell phone in Brazil). Free SMS is also supported, as is MMS (but photos on outgoing MMS are in the form of a web link rather than embedded). Credit has to be added to your Google account for pay calls - there's no connection to your cellular carrier account. But you don't need any credit for free calls or SMS.

If you have a Google Voice number, you can connect it to your Hangouts account and have incoming calls ring the app on your phone (GV is free, but only U.S. numbers available at present, usual workarounds for Canadians to obtain one). Incoming calls are free, and you get free Google voicemail with speech-to-text email transcription. It's fairly well integrated on the phone, looking like just a slightly different alternative to your phone's regular dialing, answering, messaging and notification features. You can also call/SMS from the PC app. Not sure if you need a GV number for SMS/MMS support in Hangouts. SMS to/from Canadian numbers works fine and very quickly. International SMS outside USA/Canada is not supported at this time.

In my tests the data usage for voice calls is about 0.9 Mbytes per minute, both on WiFi and HSPA+. Others report variable results depending on the quality of the mobile connection. The app probably steps down in quality and bps if the connection is slower. Video calling to/from other Hangouts users is also supported, but I haven't tested it.

A quick calculation shows that this equates to a calling rate of about 9 cents per minute on Speakout data at the rate of $0.10 per Mbyte. No extra cost for calling long distance in Canada or USA. + 1 cent for calling international. That compares well to Speakout's standard voice rate of $0.25/minute for local calls and +20 cents/minute for Canada/USA long-distance and more for international, although of course you can get reduced rates if you pay $2 extra for the Global Long Distance add-on and dial through their local gateway numbers.

In terms of calling and messaging cost, it's a significant saving if you pay for a data add-on anyway. Even if you talked a lot and it pushed your data usage over the included monthly amount, overage continues at the exact same rate of 10 cents per Mbyte, so it's not like you're losing anything.

Quality is another matter. It's generally excellent on WiFi, but with slightly more delay than a regular cellular call. More variable on HSPA+. Probably ok for personal calls.