Scan and Lock Cellular networks on a SarOS router

This article will describe how to scan for cellular networks via GUI or CLI on a SarOS router (WR11,WR21,WR31,WR44) and lock to a particular cellular network.

Please note: While the router will scan for networks, the cellular connection will be terminated. This process should be done with local access to the router.

GUI (Graphic User Interface):

- Open a web browser window to the IP address of the router.
- Navigate to Management-Network Status>Interfaces>Mobile
- Click on the Scan for Networks button*

*Please note: In certain cases, the scan will fail and report "no networks found". When this occur, it will be needed to force the router to disconnect and then execute the scan.
1) Navigate to Configuration-Network>Interfaces>Advanced>PPP 1>Advanced
2) Uncheck "Enable "Always On" mode for this interface"
3) Apply
4) Navigate to Management-Connections>PPP Connections>PPP 1
5) Click on Drop Link
6) Go back to the previous steps and Try to scan again.
Ensure to re-configure the "Always On" mode before saving any configuration!

When the scan is finished, a table will appear at the bottom of the page like this:



To lock the device to a specific cellular network, simply click on the "Lock" button.
You will be required to save configuration and reboot before it takes effect.
Please refer to the previous note before saving configuration

To revert this change at a later time, simply click on the "Unlock networks" button.

CLI (Command Line Interface):

- Open a TELNET, SSH or SERIAL connection to the router
- Issue the following command: modemstat s

- The following should appear:
​modemstat s
Scanning for networks
OK
- Wait a few minutes and issue modemstat ?
- A table showing the networks should now be visible at the bottom of the module information:
Networks Detected:
Status         LongName       Short Name     Numeric        Technology
Current        Orange F                      20801          LTE
Available      Orange F                      20801          UMTS
Available      F 16                          20816          LTE
Available      Orange F                      20801          GSM
Forbidden      F SFR                         20810          LTE
Forbidden      F-Bouygues Telecom               20820          GSM
Forbidden      F-Bouygues Telecom               20820          LTE
Forbidden      F-Bouygues Telecom               20820          UMTS
Forbidden      F SFR                         20810          GSM
Forbidden      Free                          20815          UMTS

*Please note: In certain cases, the scan will fail and report "no networks found". When this occur, it will be needed to force the router to disconnect and then execute the scan.
1) Disable the "Always On" mode by issueing: ppp 1 autoassert 0
2) Drop PPP by issueing: ppp 1 deact_rq
3) Proceed to scan the network again
4) When the list of network appears as expected, revert back these changes by issueing: ppp 1 autoassert 1


- To lock to a network,  note the "numeric" value of the desired network.
- Issue the following command where xxxxx is the "numeric" value previously recorded:

modemcc 0 net_str "+COPS=1,2,xxxxx" 

- Save configuration by issueing: config 0 saveall
- Reboot the router: reboot

To revert this change at a later time:
- Issue: modemcc 0 net_str !
- Save configuration: config 0 saveall
- Reboot

Last updated: Sep 08, 2020

Filed Under

Cellular/Transport

Recently Viewed

No recently viewed articles

Did you find this article helpful?