Changes

==Introduction==

==Overview==

All mobile carrier cells are assigned a unique ID, which is broadcasted to all connected devices. It is usually irrelevant information for the end user, as cell switching on mobile phones and routers has become very good. But sometimes in remote areas, it is beneficial to lock the LTE router to a single cell, as automatic mode may choose a cell with fewer or slower bands, as it only really looks for the best signal. For now, only devices with Quectel modems support this feature.

All mobile carrier cells are assigned a unique ID, which is broadcasted to all connected devices. It is usually irrelevant information for the end user, as cell switching on mobile phones and routers has become very good. But sometimes in remote areas, it is beneficial to lock the LTE router to a single cell, as automatic mode may choose a cell with fewer or slower bands, as it only really looks for the best signal. For now, only devices with Quectel modems support this feature.

==Determining the modem manufacturer==

==Finding the modem manufacturer==

In your [[RUTX_Routers]] WebUI, go to "Status" -> "System" page. Under the "Modem" section, you'll see the "Model" row. If the model starts with EG, RG, EC, and '''not SLM''', this feature should work. However to make sure it's supported, command '''''gsmctl -A 'AT+QNWLOCK=?'''''' should not return '''ERROR''', when ran via [[Command_Line_Interfaces_RutOS#SSH|SSH]] or [[Command_Line_Interfaces_RutOS#CLI_.28WebUI.29|CLI]]. The response should look something like this:

In your [[RUTX_Routers]] WebUI, go to "Status" -> "System" page. Under the "Modem" section, you'll see the "Model" row. If the model starts with EG, RG, EC, and '''not SLM''', this feature should work. However to make sure it's supported, command '''''gsmctl -A 'AT+QNWLOCK=?'''''' should not return '''ERROR''', when ran via [[Command_Line_Interfaces_RutOS#SSH|SSH]] or [[Command_Line_Interfaces_RutOS#CLI_.28WebUI.29|CLI]]. The response should look something like this:<br>

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_checking_compatibility_v1.PNG|border|class=tlt-border]]

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_checking_compatibility_v2.PNG|border|class=tlt-border]]

==When to use cell locking?==

==When to use cell locking==

Let's say you're setting up RUTX14, which supports up to 3CA (Carrier aggregation) and you have two cell towers within a similar distance. Let's say Cell A transmits on bands 1, 7, and 20, while Cell B transmits on bands 3 and 20.

Let's say you're setting up RUTX14, which supports up to 3CA (Carrier aggregation) and you have two cell towers within a similar distance. Let's say Cell A transmits on bands 1, 7, and 20, while Cell B transmits on bands 3 and 20.

Since the signal from Cell B is a little stronger, the router will connect to single band 3 on Cell B as it does not support B3+B20 CA. This means much lower speeds and reduced throughput.

Since the signal from Cell B is a little stronger, the router will connect to single band 3 on Cell B as it does not support B3+B20 CA. This means much lower speeds and reduced throughput.

* '''It is not recommended to perform these actions while the device is connected remotely as if it loses connection, it will not be recoverable!'''

* '''It is not recommended to perform these actions while the device is connected remotely as if it loses connection, it will not be recoverable!'''

===Setting the router to LTE-only mode===

===Configuring LTE-only mode===

----

----

To start, we'll set the router to LTE-only mode, by using the command:<br>

To start, we'll set the router to LTE-only mode, by using the command:<br>

This may cause the router to lose connection for a few seconds, so before continuing to the next step, please make sure the router is connected to the network.

This may cause the router to lose connection for a few seconds, so before continuing to the next step, please make sure the router is connected to the network.

===Checking the current and neighboring cells===

===Finding the serving cell details===

----

----

To know if our changes had any effect, we'll check the current cell we're connected to, by using a command:

To know if our changes had any effect, we'll check the current cell we're connected to, by using a command:

The output should look something like this:

The output should look something like this:

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_serving_cell_v1.PNG|border|class=tlt-border]]

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_serving_cell_v2.PNG|border|class=tlt-border]]

We're mostly interested only in the highlighted parts:

We're mostly interested only in the highlighted parts:

* '''139B15''' - currently serving cell ID in hexadecimal form. This ID is unique to each cell. It is only used as a reference point in this configuration.<br>

* '''139B15''' - currently serving cell ID in hexadecimal form. This ID is unique to each cell. It is only used as a reference point in this configuration.<br>

* '''459''' - PCID/PCI or Physical Cell Identity. PCI is necessary for a modem to communicate with a cell tower. This is one of the variables we will use when setting up cell locking.<br>

* '''459''' - PCI or Physical Cell Identity. PCI is necessary for a modem to communicate with a cell tower. This is one of the variables we will use when setting up cell locking.<br>

* '''1850''' - LTE EARFCN stands for E-UTRA Absolute Radio Frequency Channel Number. EARFCN is used to determine the channel frequency, but it will not be important to us in this configuration. This will be the second variable when setting up cell locking.<br>

* '''1850''' - LTE EARFCN stands for E-UTRA Absolute Radio Frequency Channel Number. EARFCN is used to determine the channel frequency, but it will not be important to us in this configuration. This will be the second variable when setting up cell locking.<br>

 

To check the neighboring cells, that we can connect to, this command should be used:<br>

To check the neighboring cells, that we can connect to, this command should be used:<br>

'''''gsmctl -A 'AT+QENG="NEIGHBOURCELL"''''''<br>

'''''gsmctl -A 'AT+QENG="NEIGHBOURCELL"''''''<br>

And the output should look like this:

And the output should look like this:<br>

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_neighbour_cells_v1.PNG|border|class=tlt-border]]<br>

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_neighbour_cells_v2.PNG|border|class=tlt-border]]<br>

Here's an explanation of the first line for each value:<br>

Here's an explanation of the first line for each value:<br>

* '''LTE''' - network generation;

* '''LTE''' - network generation;

* '''1850''' - EARFCN value;

* '''1850''' - EARFCN value;

* '''459''' - PCI;

* '''459''' - PCI;

* '''-3''' - RSRQ (dB);

* '''-6''' - RSRQ (dB);

* '''-70''' - RSRP (dBm);

* '''-71''' - RSRP (dBm);

* '''-47''' - Signal Strength - RSSI (dBm).

* '''-45''' - Signal Strength - RSSI (dBm).

The explanation for the last 3 measurements can be found on our [[Mobile_Signal_Strength_Recommendations|Mobile signal strength recommendations]] page.

The explanation for the last 3 measurements can be found on our [[Mobile_Signal_Strength_Recommendations|Mobile signal strength recommendations]] page.

===Locking to a selected cell===

===Locking to a selected cell===

Once we pick out the cell that we prefer, we can execute this command, with <EARFCN> and <PCID> replaced with desired variables from the previous commands (< and > are not needed):<br>

Once we pick out the cell that we prefer, we can execute this command, with <EARFCN> and <PCID> replaced with desired variables from the previous commands (< and > are not needed):<br>

'''''gsmctl -A 'AT+QNWLOCK="common/lte",2,<EARFCN>,<PCID>''''''<br>

'''''gsmctl -A 'AT+QNWLOCK="common/lte",2,<EARFCN>,<PCI>''''''<br>

Output from the command should be OK, if it's not, please double-check the spelling.

Output from the command should be '''OK''', if it's not, please double-check the spelling.

==Verifying the cell change==

==Verifying the change==

To verify that the cell change occurred, let again run the command '''''gsmctl -A 'AT+QENG="SERVINGCELL"''''''<br>

To verify that the cell change occurred, let again run the command '''''gsmctl -A 'AT+QENG="SERVINGCELL"''''''<br>

The output values for PCI and EARFCN should now match the ones used in the previous command. If not, please double check, that you have not set the same cell as the router was connected to before.

The output values for PCI and EARFCN should now match the ones used in the previous command. If not, please double check, that you have not set the same cell as the router was connected to before.

Cell ID and signal strength values can also be checked by going to ''Status -> Network -> Mobile'' in the router's WebUI:

Cell ID and signal strength values can also be checked by going to ''Status -> Network -> Mobile'' in the router's WebUI:

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_verification_v1.PNG|border|class=tlt-border]]<br>

[[File:Networking_Quectel_configuration_locking_cellids_on_devices_with_quectel_modems_verification_v1.PNG|border|class=tlt-border]]<br>

Please keep in mind that Cell ID is displayed in its decimal form on WebUI.

''Please keep in mind that Cell ID is displayed in its decimal form on WebUI.''

==Reverting to an automatic cell selection==

==Reverting to an automatic cell selection==