Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Locking the primary (upload) frequency band on a debranded Huawei B525
I recently came across this YouTube video showing how to lock the primary frequency band (EARFCN) on a Huawei pocket modem and found that these commands work on my Huawei B525. 

Update: This requires debranded firmware that enables Telnet connectivity.  With my Three branded Huawei B525, I flashed it with jhowel22's firmware a while back to unlock additional capabilities. Three's firmware blocks Telnet.

Unlike locking to a band #, locking the primary frequency band has the advantage of allowing the router to continue operating in 4G+ mode.  

Windows Telnet needs to be installed (if not already):
  1. Click Start and type "Windows Features".
  2. Click "Turn Windows Features on or off"
  3. Tick "Telnet Client"
  4. Click 'OK' and give it a minute to install Telnet.
To connect to the Huawei's Telnet console:
  1. Press the Windows key + 'R'
  2. In the 'Open:' field, enter: telnet
  3. Click 'OK'.
The following commands are for controlling the primary band lock:

Check the frequency lock status. (^FREQLOCK: 0 = Not locked, ^FREQLOCK: 1 = Lock enabled)

Check the current frequency (EARFCN), which is the forth value in the sequence.

Lock the primary frequency to the ### EARFCN.
atc 'AT^FREQLOCK=1,"03",###'

Remove the frequency lock

Examples for the Irish Three network:
atc 'AT^FREQLOCK=1,"03",6300' - Lock primary to band 20.  
atc 'AT^FREQLOCK=1,"03",1700' - Lock primary to band 3 (main Three 20MHz spectrum). 
atc 'AT^FREQLOCK=1,"03",1275' - Lock primary to band 3 (former O2 15MHz spectrum).
atc 'AT^FREQLOCK=1,"03",525' - Lock primary to band 1 (temporary reallocation of 3G band 1 for 4G during Covid 19)

  • If you try to lock to a primary frequency that is not in use in the area, the router will lose Internet connectivity showing "No Service" until the frequency lock is removed.
  • The Huawei B525 loses the frequency locking after a reboot. 
  • If the router loses connectivity, 4G+ may not work until frequency locking is temporarily disabled.
My usage scenario:
One issue I've been having with Three is random latency spikes with a distant 4G+ mast.  I am outside the range limit of being able to connect to band 3 as the primary band, but can use it for carrier aggregation when connected on band 20.  The problem here is that the B525 intermittently tries switching to band 3 (and failing), causing latency spikes.  While this does not affect most Internet usage such as browsing, downloading or streaming, it is certainly noticeable on latency sensitive connections such as VoIP where the voice intermittently drops out for a second.


By locking my B525 to EARFCN 6300 (band 20), these latency spikes disappear and VoIP calls are no longer interrupted every 20 to 30 seconds.  The only issue I have now doing this is that whenever Three turns the mast off for maintenance (during the night), I need to temporarily turn off and on the frequency lock to re-enable 4G+, otherwise the router operates on band 20 only.

Forum Jump:

Users browsing this thread: 1 Guest(s)