SECN Firmware for AR750M Device - SECN and VT-RACHEL

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T Gillett

May 28, 2018, 5:21:49 AM5/28/18
to village-telco-dev
For those interested in small dual band routers, we have recently posted test SECN firmware for the GL-iNet AR750M dual band device.

The device is based on the QCA9531 SoC ( and QCA9887 (

It can support various combinations of AP and Mesh connections across the 2GHz and 5GHz bands, and so it may be suitable for simple mesh networks eg where it is desirable to run the mesh network on a separate band to the APs as a backbone network.

The 5G (1T1R, 20dBm) radio has a uFL antenna connector on the board, so it is possible connect an external antenna.
The 2G (2T2R, 23dBm) radio has two antennas built in to the main PCB and can operate in MIMO mode.

SECN Firmware
The default SECN firmware configuration runs an Access Point on 2GHz and a Mesh on 5GHz, bridged on the LAN network side, as for other SECN devices.

A Mesh WAN mode configuration is also available, so you can set up for example a 5GHz mesh backbone network for nodes that provide local individual AP networks on 2GHz for wifi client access.

Mesh and Access Points can be configured to operated on either or both 2GHz and 5GHz radios.

The test firmware is available here:

The default SECN-VT-RACHEL firmware runs as a simple router with an Access Point on 2GHz with the Ethernet WAN port active.
After connecting to the AP, the digital library content can be accessed at:  http://vtrachel  or http://vtrachel/rachel
The administration page can be accessed at:  http://vtrachel/admin

The default configuration also runs a "Public" (guest) Access Point which allows access to the library content but not the WAN.

A "WAN Mesh" mode is available, and this configuration runs a Mesh on 5GHz, bridged on the WAN side of the router.
This configuration allows automatic sharing of an upstream network connection (eg to an Internet modem/router) between multiple devices.

If the Ethernet WAN port of one device is connected to the Internet, then the connection will be shared to all other devices via the 5G mesh.
This can be used as a simple way to provide classroom routers serving digital library content, and sharing an Internet connection.

If you are interested in using this device, please test and report any issues.


T Gillett

Jul 31, 2018, 10:10:25 PM7/31/18
to village-telco-dev
Hi All

I had the opportunity to do some open range testing on the AR750M device looking at the range of the 5GHz radio used in a mesh and I have attached some test results.

I used the SECN 5 Alpha 3 firmware for the AR750M, with default parameters TxPower for 5GHz set to 20dBm, and used just the built-in antenna which is a small pcb antenna, probably with a gain of 3dB or thereabouts. The radios are a simple single antenna design with no MIMO capability.

The devices were configured with AP running on the 2.4GHz radio and Mesh running on the 5GHz radio.
Having two radios allows the devices to use the full resources of each radio separately for the AP and Mesh functions.

The tests were run over two test ranges, 300 metres and 1100 metres in open farming country with a clear line of site between two AR750M devices located 3 metres above ground.

The attached screenshots show the SECN Status screen for each device as well as a map shot showing the range.

As you can see in the results, the received signal strength is around -75 / -80 dBm in the 300m / 1km tests.

The antenna gain pattern for these antennas is unknown, but in simple orientation tests they did not exhibit any particular directional gain.

These results indicate that the devices are likely to perform quite well in simple campus networks over distances of a few hundred metres.


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