Kerlink LoRaWan Wirnet iFemtoCell review

LPWA networks needs antennas and gateway to receive the device communication and transfer them to a network kernel. You can take a look to my post on the LPWA network architecture for more details.

In the LoRaWan ecosystem we call the first part of this network architecture a gateway. There are different kind of gateway : The network operator gateway with a big and efficient antenna, capable to support external weather like the Kerlink IoT Station and some low costs solution you can deploy at home or within a building (indoor) to cover a local device fleet.

The Kerlink Wirenet iFemtoCell device is a such type of gateway. this post will review how to get start with it and what we can expect in term of coverage.


The Kerlink Wirenet iFemtoCell is a white peace of plastic looking really cheap but made to be unobtrusive. As usual the delivered documentation is light as nothing and once you plug it to power you see green lights but you are like a chicken with a knife. That’s for the first feeling you have once the box opened.

In term of hardware the solution is really nice : inexpensive price and the same performance as the IoT stations.

The documentation is accessible one the Kerlink wiki ( where you need to have a login & password. So the first step once you open the box is to find a kerlink contact and request an access to the documentation, this will take a while and waste your time.

Getting start

The first time you need to connect it on you LAN to make the initial configuration. The device is configured to get an IP from a DHCP so you have to find the device IP from you router. The device name is like klk-wifc_XXXXXX where XXXXXX is the end of the device id as written on the back of the device.

Once done you can reach the administration page and jump back instantaneously about 20 years back on the first days of Internet. You may also note that this page requesting for your Wifi credential is not secured. back in the 1990th I said.

You may register the MAC address of the gateway in your DHCP to ensure the IP used by the station will be fixed.

Update the firmware

From your LAN or WLAN you can access the gateway using ssh. You can loggin as root with using as password pdmk-XXXXXX where XXXXXX is the end of the device id written on the back as BoardID.

My device version was 2.4.x and the first step was to upgrade the firmware to 3.1.3. The wiki explains how to do it and you should refer to it to avoid failure. Basically this step is simple : you transfer the .ipk file to the station in directory /user/.updates, flag a sw update using kerosd -u command and reboot to execute the upgrade.

You can check the version with the following command

cat /tmp/sys_startup_status.json | grep sw_version

The other way to manage upgrade is to use an USB storage to push the firmware. This way you can upgrade device deployed where you network access are restricted. Before going this way it is recommended to change the default password protecting the usb installation.

At this time you jump from the 90s to the 21th century ! wahooo !

Hard point to find in the wiki, the default login/pass is admin/admin…

Once logged you will not have a lot more setting than IP settings & WLAN settings. You can’t change the default password from the web interface, this point could be improved.

Add a packet forwarder

Kerlink station are not really ready for use. We could expect a such thing from a small device like the Wirenet iFemtoCell but in another hand we are also expecting to use the kernel network of our choice and packet forwarder is usually related to this. In my opinion a such device may have some of the main network kernel provider installed as default and configurable through the WebUi. May be for later versions with a market more mature.

To connect to TheThingsNetwork, the packet forwarder you can use is the Semtech packet forwarder. It is installed the same way as a new firmware.

Then you need to modify the /user/spf/etc/global_conf.json file

"gateway_conf": { 
 "gateway_ID": "7276FF00390300A0", 
 "server_address": "", 
 "serv_port_up": 1700, 
 "serv_port_down": 1700, 
 "keepalive_interval": 10, 
 "stat_interval": 30, 
 "push_timeout_ms": 100, 
 "forward_crc_valid": true, 
 "forward_crc_error": false, 
 "forward_crc_disabled": true 

The gateway ID to be set is located in the local_conf.json file. Once done, reboot the gateway.

Now you can create the gateway in the TTN console selecting a legacy packet forwarder. (note : the TTN will propose you different server & port but you need to use the one above)

At this point it work, the gateway is up & running on TheThingsNetwork.



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