How to force GX450 Active Frequency Band to LTE BAND 4 only?

I’m helping a client out, and what they are looking for is to force a GX450 connecting to Verizon’s network to only communicate on LTE Band 4 (i.e. it doesn’t ever attempt to communicate on LTE Band 13). Is this possible given the current settings and AT commands? If not, let this post serve as a feature request to Sierra Wireless for a firmware update.

This is requested as the speeds they are getting on LTE Band 13 as per fast.com (and other speed testing websites) are, at best, 2-4 Mbps (worst is 400 Kbps). However, with LTE Band 4 they get, at best, 5-12 Mbps (worst is 2-4 Mbps where various web pages won’t load). With a midrange cell phone they get as a best case 23 Mbps down, 5 Mbps up but that’s because Verizon lets cell phones burst, while non-phone devices are throttled as per:
verizonwireless.com/news/LTE/Overview.html

Also, when connecting to LTE Band 13 the signal isn’t as good:
Signal Strength (RSSI) -98
LTE Signal Strength (RSRP) -112
LTE Signal Quality (RSRQ) -20
LTE Signal Interference (SINR) -6.6

But with LTE Band 4:
Signal Strength (RSSI) -77
LTE Signal Strength (RSRP) -112
LTE Signal Quality (RSRQ) -17
LTE Signal Interference (SINR) -3.4

The device connects to LTE Band 4 less than 20% of the time (based on tens of times the device is restarted and the LTE Band it is found to communicate on).

GUI Settings

In WAN/Cellular settings:

  • RX Diversity Enable
  • Network Roaming Preference Home Only
  • Current Radio Module Band North America 4G
  • Setting for Band North America 4G
  • Bandwidth Throttle Disable
  • NOTE: a potential bug in ALEOS 4.7.0 has been identified where even though Bandwidth Throttle is disabled in the GUI, the settings queried via AT commands still affected speeds. Hence, one would want to set the following in addition via SSH:
    ATDOWNBAND=0
    AT
    DOWNBURST=512000
    ATUPBAND=0
    AT
    UPBURST=512000

In LAN > DHCP/Addressing settings:

  • MTU Source Auto (This is because when manually set, the device would have frequent difficulties obtaining an IP address. Instead, they would just set the MTU to 1326 on an ethernet connected router as they would get 2-3 times better speed test results then either the default 1500, or Verizon’s DHCP set 1428).

In Services > Low Power:

  • Low Power Mode Disabled

In Location > Global Settings:

  • Location Service Disabled

No other exotic, or esoteric configurations set (RSR, DMNR, Dynamic DNS, VLANs, VRRP, VPN, port forwarding, port filtering, etc).

As a side note, SSH via GNOME 3.18.3 Terminal in Ubuntu 16.04 worked a handful occasions consecutively. However, every time after logging in, it just sits at OK as per below and doesn’t register inputs. I’ve tried other terminals in Ubuntu, and same problem. GNOME Terminal wasn’t updated immediately prior, during, or after it was working. I’m not ready to call this a potential bug with Sierra Wireless, but given the potential bandwidth bug noted above, I’m leaning that way:
ssh USERNAME@X.X.X.X -p X
USERNAME@X.X.X.X’s password:
OK

Antennas:

  1. Cellular: Superbat 5dbi 700-2600Mhz 4G LTE Omni Directional Antenna with SMA Male Connector
  2. Rx Diversity: One shipped by default

ALEOS Software Version: 4.7.0
ALEOS Build number: 027
Radio Module Type: MC7354
Radio Module Identifier: VZW
Radio Firmware Version: SWI9X15C_05.05.58.01 r27044 carmd-fwbuild1 2015/03/05 00:02:40

Please note, if you are considering replying to this post with any of the following suggestions, please don’t waste either of our time doing so:

  • Contact Sierra Wireless Technical Support, a Channel Partner, or an ISP.
  • Buy a different device model or another manufacturer’s device. If you know for a fact that another device/manufacturer does this precisely (not guessing, “I think so…”, “I believe…”, etc.) then please go ahead and name it, along with documentation that precisely specifies how to do it.
  • Buy new antennas. This is already happening.
  • Move it next to a window or different window. Already done.

I’m resurrecting an old question. Is it possible to lock the LTE band to 4? I have two modems in different locations of the same small town, both banging on the same cell tower. There is only one cell tower for this area.

Modem 1: Signal strengths are OK enough. Uses Band 13. Pings are < 100 ms. Internet works decent enough for my needs.

Modem 2: Signal strengths are excellent. Using Band 13. Pings are > 500 ms. Internet is in practice unusable.

Identical modems (GX450). Sometimes I’ve seen modem 2 flop over to band 4. When it does the signal strengths are markedly worse, but Internet works well. I want to lock modem 2 to Band 4. Is this possible?

Hi @Gary.Hodges
Unfortunately, I have checked all the Configuration User Guide and there’s no way to lock modem to LTE band 4 only.
Thanks,

Thank you for looking into this question.

Thought I’d follow-up with how I left things. In summary I was able to get the modem to lock on to Band 4 by changing the antenna, which meant putting everything back the way it was before I arrived.

I went on a work trip to try and improve site coms at two field research stations located in the Rocky Mountains. At the first station I was able to improve coms with the installation of: Poynting PY-M-WS2-06W-M5 omni antenna https://usatcorp.com/shop/poynting-omni-600-cellular-antenna/.

At the second station I had been using a single Wilson 314411 directional antenna https://www.wilsonsignalbooster.com/wilson-314411-wide-band-directional-antenna-with-n-female-connector.html. This station has had the better coms of the two, but it still wasn’t great. I planned to install a Poynting PY-P-PS200-09W-16 directional antenna in hopes of improving our service https://usatcorp.com/shop/poynting-xpol-2-4g-lte-mimo-antenna/. The Poynting antenna provided excellent signal strength, and always locked on to Band 13. The latency was horrible though, and establishing connections in or out was almost impossible. [MANY BORING TROUBLESHOOTING DETAILS OMITTED]. In the end I went back to the single Wilson antenna, restarted the modem, it locked on to Band 4 with markedly worse signal strengths than the Poynting, but latency dropped a lot and connections in and out actually work.

I did not have another Poynting Omni to try at the second station. Another research group is located at this same location and they are having pretty much the same connectivity issues. They are using a Digi modem with the same Wilson antenna, but their set-up never locks on to Band 4, and instead stays on Band 13. For both of us when on Band 13 nighttime connections are much improved, but daytime goes to poo.

This was a really confusing trip.