They're a nice visual indicator, but each device manufacturer uses their own formulas for coming up with what determines 1 bar versus 4 bars (or dots).
And usually, bars have nothing to do with how fast your connection will be because there's a lot going on behind the scenes that can affect your data performance whether you are connecting to a Wi-Fi network, cable, satellite or cellular internet data source.
To truly optimize your connectivity, you need to learn how to measure your real-world performance to know if your efforts are having an impact.
And the best quantitative measurement of this is the download and upload speeds you are actually getting, which often have no direct relation to bars or dots.
Included In This Guide:
- Setting Up to Speed Test
- Speed Testing Services
- Understanding Speed Test Results
- Speed Testing Tips & Tricks
- dB Signal Strength vs Bars
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Setting Up to Speed Test
Data speeds & consistency is what really matters when considering a mobile internet connection.
Testing can be a bit tricky, as you really need to isolate as many factors as you can.
For instance, multiple Wi-Fi transmitting devices in the same area can cause congestion and slow speeds down. Multiple cellular devices within range of a booster's interior antenna can divide up the enhanced signal. The distance between devices when connected over Wi-Fi can also make a huge impact.
It's best to test each component individually, with as many devices as possible around you turned off or in airplane mode.
Then, run speed tests with and without your various signal enhancing options - such as boosters or antennas. Remember to also take a baseline reading for each device without any signal enhancing so you can tell if your antennas or boosters are having any impact.
We generally recommend running 3-5 tests for each combination and looking at the average results. Anomalies can happen, and the speed testing servers themselves can impact the results.
Here's an example of the testing data we collect, in this case comparing different cellular boosters with AT&T and Verizon hotspot devices:
Our members have access to our extensive field testing data for various devices we're constantly experimenting with in our Field Testing Lab.
Speed Testing Services
To test your upload and download speeds, use one of the many free speed testing services out there. These services allow you to send a chunk of data to their servers and they measure how long it takes.
There are numerous speed testing services and apps but these are the ones we regularly use:
- Ookla Speedtest (www.speedtest.net)
- Ookla Speedtest App (www.speedtest.net/mobile/) - For iPhone, iPad, Android, and Windows phones.
- DSLReports Speed Test (www.dslreports.com/speedtest)
- Speed Of Me (www.SpeedOf.Me)
- Netflix's Fast.Com (www.fast.com) - Uses video files for testing, so a great way to check to see if your carrier is throttling video streaming when compared to other speed test services.
A Note About Crowdsourced Apps: There are several crowdsourced signal apps out there - Sensorly, Rootmetrics, Open Signal - that include a speedtest service as well.
Please don't use these apps for *testing* your signal enhancing efforts. The results of these speedtests get recorded in a central database for sharing about your current location with others. Adding in your experimental data with boosters & antennas will skew the results for everyone.
You should only report speeds to these crowdsourced resources using your baseline readings - unenhanced - without boosters & antennas. That's the data these apps are looking to record, so that other users know what to expect. Remember, not everyone travels with boosters and antennas.
Run the app on your phone, tablet or computer.
If you are testing the signal enhancement and performance of a mobile hotspot or cellular embedded router (not the phone's cellular connection itself), then connect via Wi-Fi directly to that source from your testing device.
Do keep in mind that the distance between your device and the Wi-Fi source can have an impact on speeds too - so keep this consistent during your testing.
Understanding Speed Testing Results
You will typically get some of these results from most speed test apps:
Latency (aka Ping)
This is the time in milliseconds it takes for a request from your computer to reach the speed-test server and to return, like the ping of a ship’s sonar. The higher the number, the slower the speed.
Latencies under 100ms are good, under 50ms are great, and ping times over 500ms (half a second!) begin to feel painful.
Unusually high latencies are often a sign of an unreliable connection - indicating that the cellular tower is needing to resend data multiple times to get through successfully.
This measurement is particularly important for online gaming, but any interactive task can begin to suffer from higher latencies. For general surfing, it will be noticeable as that blank pause when you first request a new website.
Jitter is an indication of how much the connection latency varies moment-to-moment. The higher the number, the worse it is.
Some apps report a percentage of “packet loss.” Think of this as letters lost in the mail. Substantial and persistent packet loss on a connection means the connection is unreliable, and web pages may not reliably load (for instance, you may be noticing images not loading and displaying a little 'Red X' instead).
Reported in either kilobits per second (Kbps) or megabits (equivalent to 1000 kilobits) per second (Mbps). This is a measurement of the maximum speed that data is able to flow to you from the speed-testing server.
Here are some benchmarks:
- Over 20Mbps will feel awesome for all web surfing and a required minimum for 4K HD video streaming.
- Speeds over 5Mbps give a solid surfing experience and are suitable for most HD (720-1080p) video streaming.
- Speeds under 1Mbps start to make the modern internet feel slow but usable - and even low res video (360-420p) streaming may still be possible.
- Speeds under 500Kbps can get downright painful for anything more than the basics.
Download speeds have a particularly large impact on streaming audio and video. If the speeds aren’t able to keep up with the resolution you’ve selected, you will experience stuttering, pauses and long buffering delays. And of course, the slower the speeds the longer it will take to download large files.
Modern LTE devices are capable of real-world speeds over 100Mbps when the conditions are right - but as long as you are getting at least 5Mbps you shouldn't stress too much about optimizing for more unless you have some big downloads or 4K video.
The opposite of download speed, the upload speed tells you how fast data is able to get from your device to the speed-test server. Upload speeds are almost always substantially lower than download speeds. For many typical internet tasks, upload speeds don’t have a huge impact.
But, upload speeds are critical for two-way video chatting, video broadcasts and uploading large files like photos, videos or cloud-synced backups.
- Speeds over 500Kbps are the bare minimum for low-resolution video chat.
- Speeds over 1.5Mbps should deliver smoother video chat results at higher resolutions.
- Anything higher will be awesome
TIP: If you see upload speeds faster than download speeds, that may be an indication that the cell tower is congested since there is usually more download demand on a tower than upload demand.
Speed Test Tips & Tricks
Speed tests work by sending a large chunk of data from your device to a server on the internet, and measuring how long it takes. Each app has their own set of servers used, and the servers themselves can impact the results based on their current load and their distance from your current location.
This can cause speed test results to have variability which may not have anything to do with your current signal conditions. And an individual speed test is just a snapshot of the current conditions - and not always an indicator of how your connection will be later in the day when weather moves in or your local tower or Wi-Fi hotspot becomes overloaded.
To get a sense for the actual health of your connection you can run several speed tests over the course of the day. Doing this can help you get a better sense of what average speeds you are actually achieving.
Most speed-testing sites and apps have a way to change the test server, letting you select a different server to communicate with and test against. Trying different servers can help you rule out whether strange results are isolated or not.
Make sure that your speed tests are using the same server when comparing them! An overloaded server can make one connection test out slower than another, when in fact it might actually be faster.
And finally - keep an eye on your data usage. Excessive speed testing can burn through your monthly data caps rapidly if you are not careful because they are sending large bits of data to run the tests.
dB Signal Strength vs Bars
More bars is generally good thing - but very few people realize that different phones and operating systems calculate how many signal bars to display very differently.
This means that comparing "bars", unless you are on the same phone and same carrier, is actually a very poor way to compare coverage and signal quality between different devices.
The bars your phone or hotspot is displaying sometimes do not even directly correspond to the actual signal strength - in addition to raw signal strength, the phone may be measuring network congestion and other variables to calculate how many bars to display.
This can make it harder to measure the impact a cellular booster is having - boosting the signal strength might not register as "more bars" if the phone is focusing on network congestion.
In general - the iPhone puts more weight on network congestion when calculating how many bars (or - "dots" as of iOS 7) to display, and Android focuses more on raw signal strength.
Understanding Raw Signal Strength
To get a sense of the real signal strength being received - it is a good idea to learn how to look up the raw received signal strength on your mobile devices, which is measured in decibels (dB), instead of relying on counting bars.
The decibel is a logarithmic scale - every change by 10 represents a 10x change in received signal power. Wireless signal strength will be recorded as a negative number, and the numerically lower the number, the weaker the actual signal.
- -50dBm would be considered an awesome signal.
- -60dBm is 10x weaker, but still great.
- -70dBm is 100x weaker.
- -80dBm is 1,000x weaker.
- -90dBm is 10,000 weaker.
- -100dBm is 100,000x weaker - and is when you are likely to start seeing a serious impact.
- -110dBm is a million times weaker than -50dBm, and is usually barely usable.
- And by the time you would see -120dBm the device has probably already given up and switched to "No Service".
Lots of things can impact signal strength, but distance from the tower or access point is a primary influence.
For a great video demonstration of how bars reflect signal strength on both iPhone and Android, look here: http://vimeo.com/59084995
Hotspots & Routers
Most dedicated data devices have readings given in dB - usually found within their dashboards. The location of the readings will vary by device - but if you poke around in information tabs and advanced diagnostics you'll usually find this information.
iPhone: Field Test Mode
This mode is enabled by going to the dial pad, and dialing: *3001#12345#*
You can click on the "Serving Cell Info" to find the "Freq Band Indicator" to look up what LTE band you are connected to.
Most of the rest of the information you will find in Field Test Mode is useless to anyone but a cellular engineer - but you can't hurt your iPhone, so feel free to look around.
Apple has removed most of the useful information (like dBs) from these screens since iOS 9. We have not yet found a solution to looking this information up.
For Android devices, this seems to work on most phones:
Go to Settings -> About Phone -> Status.
The 'Signal Notification' app for Android is also an option without going through the Settings menu - and there are plenty of other signal status apps that will give you access to raw signal strength and even more wireless diagnostic information.
Carrier Aggregation Notes
Carrier aggregation is a technology supported by LTE-Advanced modems to combine multiple frequency bands together to enable vastly faster speeds.
When Carrier Aggregation is enabled, one band is the primary band for both upload and download connections, and one or two other bands are added into the connection to turbo-charge the download speed.
But for some reason device makers and the networks make it very hard to tell when carrier aggregation is active.
Usually the only easy way to even guess that Carrier Aggregation is engaged is to run a speed test side-by-side with a device that has CA support tested against something that does not.
The iPhone Field Test Mode does reveal a bit of info though:
Go into field test mode by dialing: *3001#12345#*
Selecting "Serving Cell Info" gives you the primary LTE Band next to "Freq Band Indicator" if you're lucky. You may need to quit and restart Field Test Mode several times before you see a sensible value here.
Back at the top level, selecting "Connected mode LTE Intra-frequency Meas" will let you know if CA is enabled. Look for "E-ARFCN" at the bottom of this page.
If it's 0, you're not CA. If it says 1, then you are in 2x CA mode, and if it says 2 you are in 3x CA mode.
The iPhone Field Test Mode though is often unreliable.
There are some Android apps that attempt to calculate the LTE bands in use too.
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