T-Mobile Sonic 4G mobile hotspot review

One possible solution is to add a mobile hotspot to connect a range of devices under a single wireless plan. T-Mobile’s Sonic 4G Mobile Hotspot can connect up to 5 devices concurrently all sharing a single 4G HSPA+ 42 high speed connection, if available in your area.

T-Mobile Sonic 4G Mobile Hotspot T-Mobile Sonic 4G Mobile Hotspot

2012 was a boom year for mobile devices with many vendors introducing new tablets, e-readers, Wi-Fi enabled cameras, and various other Wi-Fi enabled devices. Users face the challenge of connecting all these devices while on the go without going broke activating individual wireless plans for each device. Some carriers offer discounts for adding additional devices but that solution may not work for some devices which are Wi-Fi only.

While some high-end smartphones are capable of functioning as a mobile hotspot, carriers often disable the function unless you pay an additional charge. Even when enabled, some plans limit how many devices you can connect concurrently. One possible solution is to add a mobile hotspot to connect a range of devices under a single wireless plan. T-Mobile’s Sonic 4G Mobile Hotspot can connect up to 5 devices concurrently all sharing a single 4G HSPA+ 42 high-speed connection, if available in your area.


The device is small measuring just 4.02 x 2.2 x 0.61 inches, lightweight at 3.88 oz, and simple to use with an on/off and WPS button on the right and an antenna port on the left. It features a small OLED black and white display showing signal strength, battery life, connection type, number of devices connected, network status, and SMS message. I found the display to be too small for my taste. Internally, the device contains a micro SD card slot allowing sharing of files. It can even be used as a USB stick if you’re in a pinch. The 2,200 mAh battery can run the device for 4.5 hours with up to 150 hours of standby power.

4G speed and coverage

It’s always difficult to review network coverage because every user’s experience will differ. The best thing users can do is to check what their individual coverage is for the areas they plan to travel. T-Mobile claims to reach more than 220 million Americans with their 4G coverage but that is little consolation if you are in a dead spot with no service or slow service. On the bright side, the Sonic 4G Mobile Hotspot is compatible with international carriers so you can use it overseas. In my very limited testing, the speed was generally good, on par with AT&T’s 4G LTE speeds. Where it faltered was coverage. Moving just a half mile away resulted in no service at all. Obviously, your results will vary. The chart below shows various speed test results using tools from Speedtest.net. The first section shows results using just the T-Mobile Lumia 810. The second section shows results from the Sonic 4G Mobile Hotspot with an iPad , laptop, and Samsung Note connect via Wi-Fi. As you can see, the speeds can vary greatly in the same location without ever-moving the hotspot. It’s interesting to note that all the devices share a single connection so flooding the device with one connection will cause all other connections to slow down. This is quite evident in the third section where a laptop was used to monopolize the device bandwidth causing the second device’s speed to drop considerably. In practices, this is probably not going to be an issue since users are unlikely to do continuous downloads over a long period of time with the hotspot. Web browsing traffic tends to be in burst so it will be fully capable of handling the traffic.

Unlimited but limited

There is no data cap but your speed will be severely reduced if you go over your preset data limits which range from 2, 5, and 10 GB per month depending on plan.


For some odd reason, the pricing of this device from T-Mobile vary greatly. I have seen prices range from free to $100 for the exact same device. Currently, the gray version is $25 while the black version is $100. My recommendation is to call them and negotiate a free device. They are in the business of selling service and the device is just a means to an end. The plan prices are $40, $50, and $80 respectively. Over the course of the two-year contract term, your out-of-pocket will be $960, $1,200, and $1,920 respectively excluding taxes and fees. An existing T-Mobile customer I know was offered the device for $30/month so it can’t hurt to ask if you are already a T-Mobile customer.


With many tablet batteries running into the 10+ hour range, the 4.5 hours on the hotspot may be the weakest link in the chain. Doubling the battery life would certainly make this device more usable. During testing, we did have to reset the device once because despite it reporting a good connection, no data was being transferred. On multiple occasion, the device crashed after heavy use requiring a reset. The real question is T-Mobile’s coverage and speed and whether it is suitable for you. If you are an existing T-Mobile customer, you already know the answer. New customers will have to evaluate similar offerings from AT&T, Sprint, Verizon, and Virgin to see what works best for them.

The speed results below will be updated as we test other locations.


San Bruno Town Center
Lumia 810 KiloBytes/sec Megabits/sec
#1 392 3.06
#2 1568 12.25
#3 1568 12.25
#4 784 6.125
#5 1568 12.25
Sonic 4G Mobile HotSpot
#1 iPad 801 Down/32 Up 6.26 Down/.25 Up
#2 iPad 550 Down/97 Up 4.30 Down/.76 Up
#3 iPad 321 Down/41 Up 2.51 Down/.32 Up
#4 iPad 563 Down/106 Up 4.4 Down/.83 Up
#1 Samsung Note 928 Down/93 Up 7.25 Down/.73 Up
#2 Samsung Note 583 Down/158 Up 4.56 Down/1.24 Up
#3 Samsung Note 852 Down/161 Up 6.6 Down/1.26 Up
#1 Laptop 937 Down/48.6 Up 7.32 Down/.38 Up
#2 Laptop 1265 Down/147 Up 9.88 Down/1.15 Up
Concurrent connection test
# 1 Concurrent Samsung Note 201 Down/83 Up 1.57 Down/.65 Up
# 2 Concurrent Samsung Note 237 Down/42 Up 1.85 Down/.33 Up
# 3 Concurrent Samsung Note 37 Down/5 Up .29 Down/.04 Up
# 4 Concurrent Samsung Note 91 Down/37 .71 Down/.29 Up
San Francisco Test KiloBytes/sec Megabits/sec
Near City College 6.74 Down/163 Up 5.27 Down/1.27 Up
Near City College 1,583 Down/160 Up 12.37 Down/1.25 Up
Monterey Heights 106 Down/12 Up .83 Down/.09 Up
Clement/18th Ave 821 Down/166 Up 6.41 Down/1.30 Up
Clement/18th Ave 24 Down/46 Up .19 Down/.36 Up
Golden Gate Park 210 Down/9 Up 1.64 Down/.07 Up
Mission/20th 853 Down/111 Up 6.66 Down/.87 Up
Mission/14th 501 Down/175 Up 3.91 Down/1.37 Up
Van Ness/Market 2,368 Down/142 Up 18.15 Down/1.11 Up
Van Ness/Market 1,676 Down/195 Up 13.09 Down/1.52 Up
Mission/9th 69 Down/115 .54 Down/.90 Up
Mission/5th 33 Down/166 Up .26 Down/1.30 Up
Moscone Convention Center 691 Down/78 Up 5.40 Down/.61 Up
Columbus/Broadway 1,225 Down/118 Up 9.57 Down/.92 Up
Columbus/Broadway 1,280 Down/128 Up 10.03 Down/1 Up
Pacific Ave/Stockton 1,379 Down/150 Up 10.77 Down/1.17 Up


Check out the slide show on the next page for a visual representation of T-Mobile’s speed in San Francisco.