2024-11-03T22:36:00+09:00

MF89U 4G LTE USB dongle: does a cheap, flimsy modem actually work?

I tested an inexpensive Chinese-made 4G LTE Wi-Fi USB dongle bought on Amazon for about ¥4,000. Better-known USB models such as Pixela cost over ¥10,000, so I tried this cheaper option, hoping its supported LTE bands would be sufficient.

Note: This article was first published more than a year ago.

Mobile router and USB dongle models, supported bands, and firmware change with carrier and manufacturer updates. Check the latest specification sheet before buying.

APN, IPv6, and SIM-lock behavior depend on the service plan. The configuration examples use the carrier available at the time.

Signal quality and speed depend heavily on location. Treat these measurements as examples rather than guaranteed performance.

I wanted to keep the LTE connection for a remotely controlled RC car as cheap as possible, so I looked for an inexpensive SIM-based mobile device. An ideal mobile router would cost tens of thousands of yen, which felt rather expensive.

A model with an Ethernet connector would be ideal, but I settled for USB. Wi-Fi is undesirable here: because this is for remote control, I need a wired connection.

I therefore tested whether this cheap, flimsy Chinese-made 4G LTE Wi-Fi USB dongle from Amazon actually worked. Better-known USB dongles from manufacturers such as Pixela cost over ¥10,000, which I did not want to spend.

If the LTE bands match the network, it should provide some sort of connection. The dongle I bought cost about ¥4,000. Similar-looking devices start at ¥2,000, but I ended up choosing the more expensive one because it listed a broader set of bands: B1, B3, B5, B7, B8, B20, B28, B38, B40, and B41.

Search Amazon for the Acogedor 4G LTE USB modem (MF89U in this article) (Ad)

The ¥2,000 version might be much the same. Still, those one- and two-star reviews made me nervous about buying it.

Specifications of the Chinese-made 4G LTE Wi-Fi USB dongle

Item type: 4G LTE USB; material: ABS; model: MF89U; power: direct USB power; card slot: micro SIM; LTE bands: B1/B3/B5/B7/B8/B20/B28/B38/B40/B41; maximum download rate: 150 Mbps; sharing: up to 8 users; Wi-Fi: 802.11 b/g/n; antennas: built-in 1×2.4G, 4G 2T2R; transmission rates: 11b at 1/2/5.5/11 Mbps, 11g at 6/9/12/18/24/36/48/54 Mbps, 11n up to 150 Mbps; frequency: 2.4–2.4835 GHz; encryption: WPA PSK, WPA2 PSK, WPA/WPA2; mobile network: LTE Cat 4; dimensions: approximately 97×33×10 mm / 3.8×1.3×0.4 inches. To use it, slide off the rear cover and insert the SIM card.

A dubious bulk prepaid SIM: 10 GB, 180 days, domestic data on the NTT Docomo LTE network

I bought a prepaid SIM on Yahoo Shopping: 10 GB, valid for 180 days, domestic data only, using the NTT Docomo LTE network. It cost about ¥2,000. This SIM also felt rather dubious, with a terrible manual to follow during setup. It worked in a smartphone too.

The dongle is made of extremely thin plastic, and there is not much inside. I inserted the SIM into its rather fragile slot.

The plastic was so flimsy that the cover would no longer close after I opened it once. Never mind.

Connect it to the PC over USB. You can access the dongle at 192.168.0.1. Use HTTP, not HTTPS. The login is admin/admin.

The settings interface was surprisingly well designed, and it connected without any manual APN configuration. Automatic setup: excellent!

Once the connection was working, the red light turned green. It is nice to see the connection status at a glance.

I tested the connection speed and got roughly 5–10 Mbps, about what I expected. Uploading was stronger than downloading, which is actually helpful for sending video from the RC car. Latency was 26 ms, which is not bad.

It is only 10 GB, but getting up to 180 days of service for ¥2,000 through a SIM dongle seems reasonable. I cannot tell whether the slow speed came from the device or the SIM. The SIM also delivered only around 10 Mbps in my phone, so it may be the limiting factor. The dongle probably is not particularly fast either.

The RC car uses about 1 Mbps. An hour at 1 Mbps is roughly 500 MB, or about 0.42 GB, of data. With 10 GB, I should get around 20 hours of communication. Each RC car test only lasts a few tens of minutes, so that should cover several experiments over about three months. A reasonably inexpensive result, perhaps?