More on Project Fi Wi-Fi Calling

One of the benefits of being a Project Fi subscriber is the ability to place and receive calls over Wi-Fi.  Wi-Fi call is nothing new and Google certainly wasn’t the first with this minute savings feature.  But what Google has done with Project Fi is make it seamless – so much so that unless you look at your phone during a call, you may not even know you are using Wi-Fi for that conversation. Even better, if you start a call on Wi-Fi and your signal drops (or you leave the building), your call is handed over to the cellular network so you can keep talking.

I mentioned Wi-Fi calling in my review of Project Fi, which you can read at this link.  Earlier this week I also posted an overview of how Open Wi-Fi works on the service which would be a good read too as it is somewhat foundational to this article.

How Does Project Fi Determine When to Place a Call on Wi-Fi

At it’s core, Fi is always looking for Least Cost Routing (LCR).  This is a common term used in Unified Communications & Collaboration and what it means is that your Nexus device will always be looking for the lowest cost way to make a solid, reliable call.  To do this, a lot of things are taken into consideration.  What is the quality of your cellular signal?  What is the quality of your Wi-Fi signal?  How stable are these connections?  Taking all of this into consideration, when you start a call, Fi uses this information to determine which path to use that will meet the least cost criteria but also provide you the best quality of call.  So, for example, if both Wi-Fi and Cellular are available but the quality of the wireless connection is spotty, Fi will use the cellular path to make the call.

You may be asking yourself, “Why bother with Wi-Fi calls if the minutes on Project Fi are free?”.  That’s a great point but think about it from a call quality perspective, not just a cost perspective. If you are in an area where the cellular coverage is weak at best but you happen to be in a coffee shop with outstanding Wi-Fi, why not leverage that for a call?  That’s somewhat how Fi looks at the world of getting your call completed.  From the cost perspective, even though the minutes on Fi are free to you, they are not free to Google.  Any time they can off load a call to free Wi-Fi, it benefits them but ultimately us as users as well as it allows Google to keep costs low and thus our monthly subscriptions low.

How To Know if Your Call is Going Over Wi-Fi

Determining if a call you have made is going over Wi-Fi is straightforward and found in the Phone app on your Nexus device.  Using the app, place a call to someone.  If you are connected to Wi-Fi and that signal is strong enough to support a call, you will see a Wi-Fi signal icon (the same one you see in the Status bar) in the Phone app along with the name of the wireless network you are connected to for that call.  If you see a regular phone icon, then your call has gone over cellular.

As a sidebar to this conversation, Project Fi can also send text messages via Wi-Fi too but you will need to be using Google Hangouts to get this benefit.

Let’s say you have a call that you started on Wi-Fi but you are leaving your office or home.  On most Wi-Fi calling solutions like Hangouts or Skype, you have to disconnect the call and place the call back to the person.  That is not the case with Project Fi.  Calls are seamlessly handed in from Wi-Fi to the cellular network without you as a user having to do anything.  Doing this is an engineering feat and extremely difficult which is partially while I think we haven’t seen Fi released for other device manufactures.

As a general rule, here in the United States, Wi-Fi calls are going to be free.  There are a few calls to specific special numbers that could cost .01 Cent per minute but those are pretty rare.  Internationally however, that’s a different story.  You can expect a charge for calls made over Wi-Fi internationally even if you are calling them from the US – but at a much cheaper rate.  For example, if I want to call Mexico mobile number from the US, that call on Wi-Fi or Hangouts will cost me .05 Cents per minutes.  That is .23 Cents lower than what most carriers will charge for the call.  You can get a complete rundown of all of the charges from Google at this link.

What About 911 Calls

Project Fi can and does route calls to 911 (emergency services here in the US for those reading from abroad) over Wi-Fi and supports Enhanced 911 (E911) services which will give the operator your name and approximate location.  Not all 911 offices support E911 yet and there is the risk that they will not know where you are located and you may have to provide that information to the operator.  Worst case, the service will use your service address on your Project Fi account as the place to send responders.

Obviously this is less than ideal and it isn’t all Google’s fault.  The 911 systems here in the US are not exactly stellar in many locations and even placing a 911 call from a cellular phone is problematic. The systems are catching up as land line usage continues to fall at a precipitous rate but there are gaps so be aware.  It would be great if Google could recognize a call is being placed to 911 and force it over cellular, even if that cellular signal is weak.

You can read more about Project Fi’s 911 functionality here but the bottom line is know that their are limitations.


Wi-Fi calling is a big benefit to Project Fi and it allows you to make calls in places where you have great Wi-Fi but not-so-great cellular signal.  The best part is, you don’t really have to do anything.  It just works behind the scenes and gets you connected for your call using one of the channels.

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