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.
(Longer bars indicate better performance)
(Longer bars indicate better performance)
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.