I have been testing Quectel EC25-A, EC25-V and EC25-AF modules and find their ability to connect and stay connected in weak signal areas is poor.
I have one other module, a DW5804 (Expedite E371) made by Novatel. The Novatel can connect - and stay connected in areas where the Quectel cannot.
Raspberry pi 3B+, Raspberry pi 4B+ (2GB)
Raspbian - latest
SixFab mini PCIe “hat”
SixFab provided QMI interface software
Quectel EC25-X modules
T-Mobile (USA) SIM card
Antenna - 4G multiband antenna - specs below
- High Gain: This 9 dBi SMA stick antenna can increases the range of your wireless device.
- Dual-band: With high value Dual-band antennas you can get maximum omnidirectional wireless coverage and reliability
- Application: Devices with SMA connector interface, Verizon, AT&T, Sprint, T-Mobile, and all 3G, 4G, LTE,GSM & CDMA cellular services, Wireless Network Router/USB Adapter/PCI PCIe Cards/IP Camera, etc.
Only ONE antenna was used for the tests. The setup was done by the SixFab configuration file, which was written to support the Quectel. NO CHANGE to any software was performed when changing to the Novatel card.
My home is located in an area with relatively poor T-Mobile signal strength. Exactly the same setup was used for both cards.
The Quectel modems will usually not connect. If they do, they do not usually stay connected for more than a few minutes before they lose connection.
The Novatel modem usually DOES connect, and while the PING times (to 184.108.40.206) are over 100mSec, it still does work. And it stays connected.
The Novatel uses a Qualcomm chipset, I don’t know what Quectel is using, but it does not work as well as the Novatel.
I did not try the throughput in strong signal areas. Perhaps there is a difference there. I need > 6Mb/sec up and 5Mb/sec down - guaranteed.