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Sprint MiFi 4082 3G/4G Mobile Hotspot review: Sprint MiFi 4082 3G/4G Mobile Hotspot

Sprint MiFi 4082 3G/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
7 min read

Having reviewed Sprint's MiFi 2200 mobile router , we were excited to take on the MiFi 4082 3G/4G Mobile Hotspot. For the most part, this new mobile router delivers. However, it didn't impress us as much as the MiFi 2200 did when it was new, thanks to the MiFi 4082's lower-than-expected 4G speed and some connection issues with a few mobile devices.


Sprint MiFi 4082 3G/4G Mobile Hotspot

The Good

The <b>Sprint MiFi 4082 3G/4G Mobile Hotspot</b> is good looking, compact, easy to use, and features wireless N. The device comes with an affordable unlimited 4G data plan, includes GPS and network storage functionality, and has decent battery life.

The Bad

The Sprint MiFi 4082 3G/4G Mobile Hotspot sporadically doesn't work well with certain Wi-Fi mobile devices and can support only five wireless clients at the most. The device runs hot at times and its 4G connection is comparatively slow.

The Bottom Line

For mobile users who travel within good Sprint 4G coverage areas--especially those traveling with laptops-- the Sprint MiFi 4082 3G/4G Mobile Hotspot makes a good companion.

To make up for this, the MiFi 4082 costs just $80 (with a two-year contract) and comes with a single data plan of $50 month that offers unlimited data usage for the 4G connection. The router also supports wireless N, has a GPS, an external antenna port, and a nifty network storage function that works surprisingly well for a device of its size.

If you're looking for a mobile hot spot for a small group of five or less users, the MiFi 4082 3G/4G Mobile Hotspot will make a decent investment.

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Sprint's MiFi 4082 3G/4G Mobile Hotspot is slightly thicker and shorter than the MiFi 2200, and is one of the tiniest mobile routers on the market. It's compact enough to be tucked away in the glove compartment of a car or even your pocket.

Along with the power button on top (which you must press and hold for a few seconds to turn the device on and off), the MiFi 4082 has a small LCD screen that uses a backlight technology similar to that of Amazon's Kindle. The LCD shows the status of the Wi-Fi network, the battery life, and the GPS signal. We like the design of this LCD; it is just bright enough to show the information in any lighting condition without being glaring.

The little LED light on the side of the router, however, is less subtle. This bright light shows which network the router is connected to--green for 3G and blue for 4G. It turns to red when there's something wrong with the device. Near this light, you'll find a Wi-Fi Protected Setup (WPS) button, a Micro-USB port, and a MicroSD slot. The USB port is used with the included USB cable to charge the router by plugging it into a computer or wall socket (with an included power adapter). The MicroSD slot is to host a MicroSD card (not included) for the router's network storage function.

The router comes with a removable battery that can be accessed from its bottom. Here, you'll also find a small slot to connect an external antenna (not included.)

There's virtually no setup required with the MiFi 4082 3G/4G Mobile Hotspot. The device comes preconfigured with the wireless network SSID (the network's name) and the encryption key both printed on a label. All you have to do is turn it on, get the wireless clients connected manually or via the WPS feature and--assuming that you are in a Sprint coverage area (ideally a 4G network coverage area)--you're all set. The router can support up to five clients at a time; that's pretty limited but is similar to what you get with the MiFi 2200. In our trials, the router took about 20 seconds to boot up and connect to the Internet and to wireless clients.

For a device so tiny, we were impressed by the amount of features the MiFi 4082 has to offer. It's the first mobile router that has built-in network storage functionality via the MicroSD slot. This slot can hold a MicroSD card of up to 32GB, though most cards are within the 2GB-to-8GB range. While these capacities seem small, they are large enough to store thousands of pages of document or hundreds of photo, enough to be a viable storage solution for a small mobile group.

To enable this storage feature, you just need to access the router's Web interface from one of the connected computers by pointing a Web browser to its default IP address, which is Once enabled, the MicroSD card is shared as a folder that can be accessed from any connected computer--just like with a NAS server. You can further restrict access by making a password for this share. We tried this feature with a 2GB MicroSD card and it worked surprisingly well.

Apart from managing the network storage feature, the Web interface also allows for customizing the router's settings and other features, including the GPS so you can access local services such as weather. You can also change other basic settings, like the name of the wireless network, the encryption key, the amount of supported wireless clients, and so on.

For security, the MiFi 4082 features both WEP and WPA encryption. It also gives the option to filter wireless clients via their MAC address. This is convenient when using handheld devices, such as VoIP phones, because you don't want to have to fiddle with typing in the encryption key.

When plugged into a computer, apart from changing its battery, the router can also work as a 4G/3G modem, a feature also known as tethering. The software driver is stored on the router itself and will run automatically the first time the device is plugged in. Subsequently, each time the router is plugged in, the computer will immediately gain access to the cellular Internet, as though it were plugged into a network port via a CAT5 cable. There's no dialing software to fiddle with. In our trials, the MiFi 4082 could work as a modem and as a wireless router simultaneously, with the tethered computer being in the same local network with the wireless clients. This means they can share resources such as files or printers. This is actually a very nice feature that eliminates the need to carry the router's power adapter along with you when you are out and about. On top of that, the tethered computer does not count toward the total five wireless clients in our trials.

The MiFi 4082 3G/4G Mobile Hotspot works both as a 4G and as a 3G router, with the latter serving as the backup in areas where 4G is not available. Note that while the use of 4G is unlimited, Sprint caps the 3G portion with just 5GB and you'll need to pay 5 cents per MB extra once this allowance is reached. This is similar to how the data structure works with the Clear 4G+ modem .

The MiFi 4082 3G/4G Mobile Hotspot was very fast in our trials when compared with previous 3G mobile routers. However, when compared with other 4G cellular devices, such as the Clear 4G+ or Verizon's VL600 LTE USB Modem, it wasn't as fast as we expected.

In our trials in the San Francisco Bay Area, the MiFi 4082's download speed fluctuated between 0.9Mbps and 3.5Mbps, with 2.5Mbps being the most consistent speed. In comparison, the Clear 4G+'s range of download speed was from 5Mbps to 12Mbps. Though not as fast as we expected, 2.5Mbps is still a very fast connection, comparable to most broadband connections at home, and it allows for hi-def streaming. For uploading, the MiFi 4082 was more stable at around .9Mbps.

Note that these download and upload speeds could vary a great deal from one city to another and the numbers mentioned here only represent the experience for those who live in the Bay Area.

What's more consistent, however, is the MiFi 4082's performance as a wireless router. Despite its tiny size, the MiFi 4082 did well at 16.8Mbps and was able to handle long distances up to 100 feet away. Obviously, these were not even close to the speeds of regular wireless N routers but for a mobile router, this is fast enough for most common file sharing tasks, including accessing the MiFi 4082's network storage.

In our trials, Sprint's MiFi 4082 3G/4G Mobile Hotspot offered slightly more than 4 hours of battery life when used continuously with 4G signal, which is a comparatively long battery life but is still not long enough. It would be ideal if the router could offer 10 hours or more. For now, however, this is about the longest battery life of mobile routers on the market.

For the most part, the Sprint MiFi 4082 3G/4G Mobile Hotspot router worked well, but we did notice a couple of odd things the cause of which we couldn't pinpoint. First, the router didn't seem to work very well with some mobile devices, such as the iPhone 4. In our trials, when getting out of standby, the phone would more often than not lose the connection to the router and couldn't get an IP address. The only way to fix this was to remove the network from the phone and add it again. This, however, happened less with other devices, such as laptops, and almost never with Android-based devices. The second issue was that sometimes the router ran hot and would drain the battery really fast. To fix this we would have to repower it. None of these issues happened all the time, however, but they occurred often enough to be noticed.

Nonetheless, overall we liked the MiFi 4082. We wished its 4G speeds were faster and that the router was more stable with all wireless devices, and we hope those issues will be fixed via a firmware update.

Cellular Internet speed (Kbps)
(Longer bars indicate better performance)
Sprint MiFi 4082 3G/4G Mobile Hotspot (4G)
Verizon MiFi 2200 (3G)

CNET Labs 2.4Ghz Wireless-N Performance Score (in Mbps)
(Longer bars indicate better performance)
Linksys WRT320N
Sprint MiFi 4082 3G/4G Mobile Hotspot

The MiFi 4082 3G/4G Mobile Hotspot, though not perfect, makes a great mobile router for those who travel in small groups and within Sprint's 4G coverage area.


Sprint MiFi 4082 3G/4G Mobile Hotspot

Score Breakdown

Design 7Features 8Performance 7