Project Fi: Signal Icons and What They All Mean

With the introduction of Project Fi, and the rapdid proliferation of its users, there have been many inquiries surround the signal icons and what they all mean.  This post aims at becoming the definitive guide to these signals and is designed to hopefully provide as much clarity as possible. The goal of this document is to be so simple, that even my mother would understand what is happening with her device and data should she see any of these indicators.

About Mobile Networks

Before we dive into the specific indicators that are seen on Project Fi, it is important to have a basic primer about mobile networks and how they relate to Project Fi.  Over the years, we’ve seen a lot of networks come and go, technologies appear and fade.  Here are the technologies available to each network…

Network Type	T-Mobile	Sprint
4G	LTE	LTE
3G	*HSPA (H) GSM (3G)	EVDO(3G)
2G	EDGE (E)	1XRTT

4G - Newest and fastest network.  Has the capability (but not on our devices yet) for HD voice, calling and data usage at the same time (for most 4G networks, except Sprint Spark), and better capacity for more users with more bandwidth.  You can do anything on this network you could on your home computer, assuming you have a good strong connection.

3G+ - HSPA is a higher grade 3G network (in fact, AT&T called it 4G before LTE existed because of its better data speeds).  The network is only used by T-Mobile.  Great quality fallback if LTE isn’t available

3G - 3G networks are a more widespread fallback.  They provide adequate data speeds for email and messaging, but not for streaming videos.  You will not be able to talk and send data over CDMA on Sprint, but you can on T-Mobile.  

2G - If you need to call someone, this network will do.  But if you want message or load something over data, don’t bother.  It isn’t going happen. T-Mobile has the largest left over EDGE network and is supposedly swapping it out for LTE in all markets by mid/late this year.  You most likely won’t see this unless you’re traveling in rural areas.

Project Fi Indicators

Now that you have a decent understanding on they types of networks that potentially exist while using Project Fi, we can review the different connection indicators you may see in your notification shade. These inidcators help tell users what level of connectivity they are currently experiencing, including cellular, wifi and data connectivity (both mobile and WiFi).

Indicator	Explanation	Uses Mobile Data?	Has Internet?
	You have a good wifi connection. Your phone will be able to send data through your wifi connection,  but can also send and receive texts through your cellular connection.  If your wifi connection becomes too weak, it will switch to cellular for everything (but then you’d have no WiFi signal)	NO	YES
	There are some connectivity problems with your wifi connection, and you may not be able to get internet (or Google is down)	NO	MAYBE/NO
	You have a 2G/3G/4G data connection	YES	YES
	There are connectivity problems with getting onto the 2G/3G/4G tower.  You may not be able to load pages, and you may not be able to place or receive phone calls or texts	YES*	MAYBE/NO
	If you are connecting to a Wi-Fi router while already connected to Fi, then while the connection is happening you will continue to use data.  When the “LTE”, “H” or “3G” goes away, you will no longer be using data If you are already connected to Wi-Fi and a ! appears, then no data will be used, but you may not have internet.  Check on the status of your router and ISP.	YES NO	YES MAYBE/NO
	Your Wi-Fi connection is good, but your phone can’t authenticate on the Fi network.  Texts and phone calls will be handled through Wi-Fi until the authentication issue is resolved	NO	YES
	Your Wi-Fi network and Fi network are having connectivity/authentication issues	YES*	MAYBE/NO
	Indicates, WiFi assistant is active. This feature helps protect you by securing your connection to high quality networks approved by Google.	N/A	N/A

Hopefully this document helps you understand what is going on with your Fi Phone connections.

Thanks so much to +Ziggy Dziegman, +Dencil Smith, +Aleksandar Škodrić and +Techno Bill for helping me complete this document