pjhtech ToolsLock an LTE modem to a measured EARFCN/PCI pair using the command for its exact modem family below. If a lock fails after reboot, check the persistence column: most of these locks are volatile, while R11e-LTE6 retains its lock.
Match the command family
| Documented device/modem | Family | Persistence / limit |
|---|---|---|
| R11e-LTE | AT*Cell | Lost on reboot or modem reset |
| R11e-LTE6 | AT*Cell | Persists; primary carrier lock, CA can use other bands |
| R11e-4G | AT%CLCMD in modem-init | Apply while modem is non-operating; saved init reissues lock |
| Chateau LTE12 / LTE18; LHG LTE18; ATL LTE18 | AT+QNWLOCK common/4g | Lost on reboot or modem reset; network can redirect |
| Chateau 5G / 5G R16 / 5G R17 ax; ATL 5G R16 | AT+QNWLOCK common/4g | LTE anchor/primary lock; not an NSA NR-cell lock |
Match the listed modem family; QNWLOCK support cannot be inferred from the chipset vendor alone.
First collect a real candidate
/interface/lte/print detail
/interface/lte/monitor lte1 once
/interface/lte/cell-monitor lte1Run cell-monitor only when supported, and stop it with Ctrl+C after the sample. Record the serving operator, EARFCN and PCI. EARFCN selects the LTE channel; PCI selects the physical cell on it. PCI is reused, so the pair is not a worldwide tower identifier. The examples below use a hypothetical observed B3 EARFCN 1650 and PCI 120; substitute values actually measured at your site.
R11e-LTE and R11e-LTE6
/interface/lte/at-chat lte1 input="AT*Cell=2,3,,1650,120"Mode 2 selects cell locking; network mode 3 means LTE in this AT command. The empty band field is intentional. R11e-LTE6 applies the lock to the primary carrier; additional CA bands can remain in use unless separately restricted.
/interface/lte/at-chat lte1 input="AT*Cell=0"Confirm the resulting serving cell with monitor. R11e-LTE loses its lock on reset; R11e-LTE6 retains it.
R11e-4G: startup configuration is different
/interface/lte/set lte1 modem-init="AT%CLCMD=1,1,1650,120,"The final empty PLMN field is permitted by the manual. Alternatively use the intended operator’s MCC+MNC with the documented quoting. Save the previous modem-init string first: set replaces it. The modem must be non-operating when the initialization command runs. After saving modem-init, run /system/reboot from local access in a maintenance window and confirm the prompt; the whole router and its traffic restart. The saved command runs during modem startup. Then use /interface/lte/monitor lte1 once to check the serving cell.
To return to automatic selection, restore the recorded modem-init string with /interface/lte/set lte1 modem-init="<previous-init-string>". If the previous value was empty, use /interface/lte/set lte1 modem-init="". Then run /system/reboot and confirm locally; this restarts the router and clears the volatile lock without reapplying it. The manual defines AT%CLCMD mode 0 as disabling the lock; query syntax is modem-specific. A lock reissued by modem-init can survive router restarts even though the modem clears its volatile state.
Documented QNWLOCK LTE devices
/interface/lte/at-chat lte1 input="AT+QNWLOCK=\"common/4g\",1,1650,120"The 1 after common/4g means one EARFCN/PCI pair. Query the lock with the next command; use the final command to remove it.
/interface/lte/at-chat lte1 input="AT+QNWLOCK=\"common/4g\""/interface/lte/at-chat lte1 input="AT+QNWLOCK=\"common/4g\",0"These QNWLOCK locks are volatile. Reboot or modem reset clears them. The manual also warns that the network can redirect or hand over the modem to a different cell despite the lock.
Retest aggregation and rollback
Run /interface/lte/monitor lte1 once during a transfer to confirm the serving cell and CA bands. If the selected cell is worse, remove the lock with the command for that modem family and restore any band restrictions changed for the test.