I tested my internet connection using the built-in speed test on my iPhone. The upload speed was 14.9 Mbps, but the download speed was only 0.37 Mbps. I'm using a Huawei B315s-607 modem and have already forgotten and rejoined the Wi‑Fi network, but that didn't help. What could cause download performance to be this much worse than upload, and what troubleshooting steps should I try?
3 Answers
The B315s-607 is an LTE modem rather than a 5G device, so its performance depends heavily on local tower coverage and congestion. Download traffic may be saturated by other users even when upload capacity is available. Restart the modem to force it to establish a fresh connection, then test again at different times of day.
That kind of imbalance can happen with a weak or congested cellular connection. Check that both external antennas are connected properly and aren’t aimed in exactly the same direction. It’s also worth checking the modem’s signal and network statistics, then contacting your provider if the signal looks poor or the problem continues.
Try testing with another device and, if possible, over Ethernet or right beside the modem. That helps determine whether the issue is the cellular connection or the Wi‑Fi link. If every device gets roughly 0.37 Mbps download, the likely causes are tower congestion, weak signal, or an account/provider issue rather than the phone’s saved Wi‑Fi settings.
I didn’t realize upload and download could differ that dramatically, so I’ll check the antennas and signal information.