USB vs WiFi – Tethering 4G Broadband to a Laptop via Android Phones

A lot of UK people have tried tethering their Smartphone’s mobile broadband (4G, 5G) connection to a laptop by using the ‘Wi-Fi Hotspot‘ feature, but not everybody is aware that you can do the same thing by using a wired USB-C cable. As a bit of fun we decided to find out if tethering via a wired link is any better than a wireless one.

In theory the idea of essentially turning your Smartphone into a wired broadband router, albeit of the most basic type (in terms of settings/control), might seem a bit odd to those who prefer the familiarity of a WiFi hotspot. But there are some good reasons why you might prefer to carry an extra cable around, instead of relying on the increasingly congested radio waves.

One obvious advantage is security, since you no longer need to broadcast a WiFi hotspot and hastily created password to your vicinity. On top of that a wired USB link will often help to charge your phone at the same time as it’s being used for data connectivity, although this will suck juice from your laptop’s battery. Finally, if you’re working in an area with lots of WiFi networks then avoiding that congestion could boost your speeds.

We should add that Android devices have supported connectivity via wired networks for years (particularly since v6 “Marshmallow” in 2015), but experiences do tend to vary between different Smartphones. However, this should improve further with Android v11, which allows such devices to serve as the host network as well – ‘Ethernet tethering‘ (we don’t have the v11 update yet and so haven’t been able to test this).

Conducting the USB-C Tethering Test

For the purpose of this test we made use of a Microsoft Surface Pro 7 computer (a tablet / laptop hybrid). As for the Smartphone, we used a OnePlus 7T Pro running Android v10. We also picked Three UK for the test as in this area they appeared to deliver the most consistent performance, but such things will vary from place to place.

Before getting started we ran multiple tests using WiFi in order to try and establish what the rough baseline performance expectation should be for a normal WiFi based Tethering experience. We also continued to run these tests in-between our wired benchmarks, which helped to confirm that the mobile network, speed and signal quality were all still operating close to the established baseline.

All of the testing was conducted at the same indoor location and with the devices positioned directly next to one another. We opted to use Ookla’s speedtest.net service for the testing (picking the same remote server each time) and have displayed the resultant speeds as a typical range below (intended to reflect the inherently wide variations of mobile performance).

Approximately 50 tests were conducted over a two hour period on day one, including 25 via a WiFi Hotspot and 25 via USB, which occurred between 10am and 11am. We repeated this all again on day two, albeit between 1pm and 2pm. Prior to this we also conducted an additional 30 tests (each day) in order to try and establish a reasonable baseline of performance using the WiFi Hotspot.

Signal strength via 4G was very good, although in this location we were only able to connect via Band 1 (2100MHz). 

DAY 1 – Baseline Speeds via WiFi Tethering

Download Range: 26Mbps to 47Mbps

Upload Range: 8Mbps to 13Mbps

Ping (Latency): 40ms to 59ms

DAY 2 – Baseline Speeds via WiFi Tethering

Download Range: 48Mbps to 58Mbps

Upload Range: 6Mbps to 8Mbps

Ping (Latency): 34ms to 40ms

At this point we switched off the OnePlus’s WiFi Hotspot and connected a USB-C to USB-C cable made by Nimaso. You can also do this a different way by purchasing a USB-C to RJ45 Ethernet (LAN) adapter cable (ideally with Android v11 installed), which might work better if you’re using a device that doesn’t have a USB-C port or support tethering via USB (we didn’t try this ourselves). As for the phone itself..

On the OnePlus 7T Pro phone we found the option for ‘USB tethering‘ (this was greyed out until we connected the cable) under ‘Settings > Wi-Fi & Internet > Hotspot & tethering‘ – upon enabling this it was a simple matter of connecting the cable and waiting a few moments for the network to be recognised. The fact that you don’t need to set a password for this makes it very simple to connect.

DAY 1 – Speeds via Wired USB-C Link

Download Range: 22Mbps to 52Mbps

Upload Range: 10Mbps to 11Mbps

Ping (Latency): 24ms to 29ms

DAY 2 – Speeds via Wired USB-C Link

Download Range: 53Mbps to 80Mbps

Upload Range: 6Mbps to 9Mbps

Ping (Latency): 33ms to 35ms

Overall on DAY 1 we got the impression that, if you ignore the natural variations in mobile performance, both the WiFi and USB Tethered links seemed similarly capable in terms of achievable speeds. Nevertheless, the USB link did deliver a consistently better and more stable latency time, which is good if you’re a fan of fast paced multiplayer games. The difference in latency was instantly noticeable when swapping between USB and WiFi.

Strangely, we also found that upload speeds seemed to be more stable via USB too, but the difference wasn’t big enough to confirm and we remain unsure of why it held so steady. On DAY 2 we found that downloads via USB were more stable than via WiFi, while uploads were virtually identical but the latency times between WiFi and USB were much closer than on DAY 1.

At the end of the day a Smartphone created WiFi hotspot, thanks to modern advances in chipsets and antenna design, seemed to deliver similar performance to that of USB tethering. Despite this it does appear as if using a wired link from your mobile phone may bring a very slight benefit to latency, and security, provided you don’t mind lugging around the extra cable.

One issue with our testing is that we weren’t even close to maxing out the capabilities of either the WiFi or USB links on these devices (they were all limited by the 4G service) and one of those may eventually hit a physical performance ceiling. In the future it might be interesting to re-run this test with a modern 5G phone and mobile setup at ultrafast speeds.

Finally, we should highlight that the Apple iPhone can also do tethering via WiFi, Bluetooth or USB, but we weren’t able to test that (it also seemed to need iTunes to be installed) – in any case we suspect the results would be similar. Just for fun we also attempted to conduct the same test by tethering via both Bluetooth, but we struggled to get either working in a stable way and the setup was quite fiddly (the laptop struggled to recognise it).

iPhone Personal Hotspot Settings (Under ‘Mobile Data’)