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T-Mobile Sonic 4G Mobile HotSpot review: T-Mobile Sonic 4G Mobile HotSpot

T-Mobile Sonic 4G Mobile HotSpot

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
6 min read

The T-Mobile Sonic 4G Mobile HotSpot is just slightly larger than the previous version, the T-Mobile 4G Mobile Hotspot ZTE MF61 . To make up for this, it supports T-Mobile's faster 4G data speeds of up to 42.2Mbps down and 5.76Mbps up, which was first introduced with T-Mobile's Rocket 3.0 4G Laptop Stick .


T-Mobile Sonic 4G Mobile HotSpot

The Good

The compact and good-looking <b>T-Mobile Sonic 4G Mobile HotSpot</b> offers mobile Internet access for up to five Wi-Fi clients via T-Mobile's 4G and 3G networks. The device has long battery life, works as a tethered modem, features an SD card slot, and supports text messaging.

The Bad

The T-Mobile Sonic 4G Mobile HotSpot data speeds could use some improvement, comparatively. Its included limited data plans are rather expensive, and the router's connection speed is throttled when the monthly data caps are reached.

The Bottom Line

Well-designed and reliable, the T-Mobile Sonic 4G Mobile HotSpot makes a very good travel companion.

This doesn't mean the router necessarily offers better cellular data speeds at all times, however. In fact, in our testing around the San Francisco Bay Area, the Sonic was, on average, actually slightly slower than the ZTE MF61. But the truth is that the speed of a cellular connection varies a great deal from one location to another, and we find the Sonic's performance, though not as stellar as we wanted it to be, acceptable. It's fast enough for basically any Internet applications.

Similar to other T-Mobile mobile access devices, the Sonic offers concurrent Internet access for up to five Wi-Fi devices and comes with limited data plans; when the caps are reached, the device's connection speed will be significantly throttled for the rest of the month. All things considered, at $100 (after discounts, rebates, and with a two-year contract), the T-Mobile Sonic 4G Mobile HotSpot will make a very good investment for those who travel frequently. If you're looking for a 4G device that comes with a more affordable and unlimited data plan, we'd also recommend that you check out the Apollo from Clear .

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Design, ease of use, and features
The T-Mobile Sonic 4G Mobile HotSpot has a candy bar design, with a sleek casing that measures just 4.02 by 2.2 by 0.61 inches. It's also very light at just 3.88 ounces. On one side, the devices has a power button that you need to press and hold for a few seconds to turn it on or off, and a WPS button, which allows you to add wireless clients to its Wi-Fi network.

The device has a tiny OLED display on the top that manages to show all important information, including a battery gauge, cellular connection status/signal strength, and the number of connected Wi-Fi clients. The display turns itself off after a few seconds but will come up immediately with a quick press on the power button.

The bottom of the device can slide open to reveal the 2,200mAh battery. The device ran for 7 to 9 hours during our testing, depending on how heavily we were using the Internet. That's actually one of the best battery life scores we've seen among mobile routers of this size, thanks to the router's smart standby mode that puts the router to sleep when there's no connection and immediately brings it back on when there's a data request. In our trials, the router's battery can actually last for days when used sporadically. With other mobile hot spots we've seen, you have to manually bring it out of standby mode by pressing on the power button before you can use it again.

Near the battery are the SIM slot and a microSD slot that can host a card (not included) of up to 32GB. At one end, the router has a Micro-USB port that both charges the device (a cord is included) and allows you to connect it to either a PC or Mac, so it can be used as a tethered modem. When connected to a computer, the router also charges the battery and acts as a card reader.

When the battery bay is opened, you'll also find a label with the device's default wireless network and the encryption key printed on it. With this information, all you need to do is turn the router on, connect Wi-Fi clients to the default network, and you're set. As long as you're within T-Mobile's coverage, you're connected to the Internet.

The router's Wi-Fi network's settings, as well as other settings can be change via its Web interface. To access this, from a connected computer, juts point the browser to the router's default IP address, which is The default password to log in is admin.

The Sonic's Web interface also enables users to send/receive text messages and manage the microSD card. You can choose to make the card work in the USB mode (when the router is connected to a computer) only or in WebShare mode, which allows any connected clients to access data stored on it via a browser. This is actually a great feature, which worked well in our trials, for those who want to share data while on the go.

Data plans and performance
We tried the T-Mobile Sonic 4G Mobile HotSpot around the San Francisco Bay Area, and similar to the Rocket 3.0 Laptop Stick modem, it didn't offer anywhere close to 42Mbps download speeds. This doesn't mean the mobile router doesn't offer that speed in your area, however, since mobile cellular data speeds tends to vary a great deal from one place to another.

In the end, on average, we found that the Sonic offered about 3,000Kbps up and 1,200Kbps down, which are not slow speeds but much lower than other mobile hot-spot devices we've seen. The Clear Spot 4G+ Apollo, for example, offered around 9,200Kbps up and 3,300Kbps down when we tested it.

Nonetheless, the Sonic's data speeds are fast enough for any Internet applications. In fact it could blow through 10GB of data in just about 4 to 5 hours. That 10GB, by the way, is also the data cap for the top plan that T-Mobile includes with the Sonic, which costs around $80/month. There are also two other data plans with monthly caps of 5GB and 2GB that cost $50 and $40, respectively.

While limited data plans are standard for most carriers, it's disappointing that the Sonic has no option for an unlimited data plan. For this reason, maybe it's a good thing that the Sonic isn't as fast as T-Mobile claims, or else you would go trough the allowance in a heartbeat.

The good news is, in case you indeed use up the monthly data amount, you can still use the device without having to pay more. The only catch is that it will work much slower for the rest of the month. In a way, the Sonic offers a somewhat semi-unlimited data plan.

The T-Mobile Sonic 4G Mobile HotSpot supports Wireless-N standard, which is much faster than the 802.11g that other mobile hot spots offer. In our trials, it offers very good range (for a device of its size) and decent speeds for the local Wi-Fi clients. And support for a microSD card makes the router a very good solution for those who want to share data on the go. Note that you'll have to turn the "AP Isolation" setting to off using the Web interface for the connected Wi-Fi clients to see/talk one another.

The router gets a little warm when being used, however, so don't leave it inside our pocket or purse.

CNET's Cellular Internet speed (in Kbps)
(Longer bars indicate better performance)
Clear 4G+ Appolo
Clear 4G+ USB Modem (4G)
T-Mobile Rocket 3.0 (4G)
T-Mobile Sonic 4G Mobile HotSpot
Sprint MiFi 2200 (3G)

Despite the relatively slow data speeds and the lack of an unlimited data plan, the T-Mobile Sonic 4G Mobile HotSpot's great design, reliability, long battery life, and nifty features make it a very good mobile Internet solution. It would be an excellent one if its data plans were more affordable.


T-Mobile Sonic 4G Mobile HotSpot

Score Breakdown

Design 8Features 8Performance 7