teach me how to find tower info/location using Router details

[ericj205]

New to the forum and DIY cellular modems/routers. I purchased a refurb teknikal 9500VA (WE-826-T w/ Quectel EC25 running GoldenOrb_2019-03-10) and configured it for use with the ATT $35 unlimited data SIM. I have the device working. Now I want to optimize it for my application and also learn how to locate the best tower/bands.

My first question, mainly out of curiosity (I'm a mech engineer). Is can someone explain to me how to find the cell tower that my device is connected to currently and see it visibly on a map?

Second question is what steps should I take next to determine if that is the best tower/band to be working off of and how to re-configure my device to take advantage of the best possible signal/bandwidth?

2019-12-13_18-26-06.png

Thanks in advance for your help!

-EJ

[rramse]

Okay, I'll just get you started on this long, complicated process. First of all, your Network (HSPA) and cell ID (41663) indicate a non-LTE (slow 3g) connection. Probably because you are too far away to get an LTE signal. Before you do anything go here: https://opencellid.org/#zoom=15&lat=34. ... =-86.91392 and type in your MCC=310 MNC=410 LAC=22981 into the search bar and hit enter. Verify that your cell Location Area Code indicates Hartselle, Alabama. The 3g cell tower id is not in thier database. Now go here: https://www.cellmapper.net/map?MCC=310& ... ours=false and search for the nearest LTE tower. How far is the closest known tower? This is just the first step.

Your Quectel EC25 modem is just a catagory 4, so it will only use one band, so there is not much optimizing you can do.

[ericj205]

Thanks for your help!

I did the search on opencell and confirmed that based on 310/410/22981 that the tower is located in Hartselle, AL. The strange thing is that is ~18 miles away from the modem. That is not possible is it? Plus the modem is showing 100% signal strength?

The coordinates for my neighborhood are:
Huntsville, AL 35824
34.636179, -86.726933

When I use the cellmapper site and 310/410/4GLTE I find the following towers (my router location is at the tip of the red arrow)

What should I do next?

310_410_4GLTE.png

[rramse]

Okay, good. The 22981 LAC is just a general area code, not a precise locator. Obviously you know where you are; I was just demonstrating how to find the tower from just the modem connection details.

Your first question was how to find the tower and see it on a map. I hope you can see now that the modem is connected to cell NB ID 4166 sector 3, on band 5, frequency 887 MHz, located somewhere on the corner of Martin Rd SW and Zierdt Rd.
https://www.cellmapper.net/map?MCC=310& ... urs=false#

The red dots on the map indicate approximate (calculated) locations of cells. The green dots indicate verified exact locations of cells. If you can't physically see the tower then using an AT&T phone with the cellmapper app installed will eventually triangulate the location.

The next question you asked was which tower/band was best to be working off of. So from the given data you want to be connected to the LTE 224043 tower because it offers better bands. Currently the longer range lower frequency tower is taking over so your next step is to disable 3G connections (use LTE only) on your modem and see if you can connect.

[ericj205]

So when I logged into the router this evening, it appears it has switched towers. Also the Ookla speedtest results are significantly better. (from 12M down/1M up -to- 40M down/15M up on average):

Tower Connection 12_15_19.png

Based on this new info, I created a satellite view using cellmapper info, google maps and local knowledge of actual tower location:

ATT Cell Tower Map_Lake Forest.png

I assume the current tower (224166) is just as good as the tower you mentioned (224043)? Is there a way to lock the modem to a specific tower?

For your recommendation on configuring modem to only use 4G LTE I assume I make the change via the router interface here by changing the cellular mode from "Automatic" to "4G Only"?

Cellular Mode Auto.png

Cellular Mode 4G.png

[JimHelms]

I know of no way to lock a modem to a particular tower.

You should be able to lock the modem to LTE only with the following AT Command:

Code: Select all

AT+QCFG="nwscanmode",3,1

[BillA]

Just like phones, a modem's firmware is programmed to always search out the best possible signal based on the received RSRP and RSRQ signals. Unless it's a buggy firmware, there's really no need to lock it to any particular band. Due to environmental and tower changes in the signal, it's actually best to leave it on default automatic band selection.
If you ready need to, you can lock it to a specific band using AT commands such as
AT+QCFG="band",2e0,20000000000000000,0 - to lock it to band 66
You will need to consult the Quectel's "EC25 AT Commands Manual" (available on their website) to learn how to calculate the proper band parameters to send to the modem.
Try not to play around with random numbers, because your can really lock the signal out completely, then you'll have to factory reset the modem to get back to normal again. I would recommend finding the best LTE signal spot in your home, and just leaving the router there to let it do its thing.

[ericj205]

That makes sense. I will leave the bands alone. I just selected 4G only, that is acceptable is it not unless I move it to a location where 4G is non existent?

[BillA]

That makes sense. I will leave the bands alone. I just selected 4G only, that is acceptable is it not unless I move it to a location where 4G is non existent?

Yes that should be fine, but for heaven's sake don't suffer with 3G speeds (lol). You'd be surprised how much difference even a few feet of your router's placement (especially placing it at the highest point in your home) or the adjustment of your antenna's angles can have on your signal. If needed, purchase a nice directional antenna from The Wireless Haven, which should be able to hit a tower as far away as 10km in a line of sight.

[LoveMeSomeCALTE]

If needed, purchase a nice directional antenna from The Wireless Haven, which should be able to hit a tower as far away as 10km in a line of sight.

I am interested in a directional antenna but I feel I should figure out the orientation of my local towers before I go ahead with a purchase.

[BillA]

I am interested in a directional antenna but I feel I should figure out the orientation of my local towers before I go ahead with a purchase.

The most important factor is having a clear line of sight (LOS), otherwise the signal get's attenuated by trees, hills, structures, and gets bounced around degrading the signal especially if the tower is miles away. You could use one of those online cell-tower mapping sites, through I've found that they are often inaccurate due to crowd sourced data and changes in network management/topology. The most effective method I've found so far, is turning the directional antenna in a 360 degree circle (disregarding where the towers are shown on the map) in 10 degree increments while checking the signal strength/quality at each step, and often times you can find a better signal/speed via this method. Your mileage may vary.
Try the The Wireless Haven store first, if they're out I would recommend a Proxicast or better yet a Poynting brand directional antenna. You need to spend between a 100-200 bucks to get a high quality, high directional flat panel antenna.

[mickmorley]

Adding information to help others find towers using Cradlepoint CBA850LP6.

I found the at!lteinfo? command dumps the tower information needed to use https://opencellid.org/. You can take the MCC and MNC from here and use the LAC and Cell ID from the Connection Status page

Code: Select all

at!lteinfo?

!LTEINFO:
Serving:   EARFCN MCC MNC   TAC      CID Bd D U SNR PCI  RSRQ   RSRP   RSSI RXLV
         6225 234  30 11340 00805C0D 20 2 2   4 346 -11.0  -86.1  -60.8  35

IntraFreq:                                          PCI  RSRQ   RSRP   RSSI RXLV
                                                346 -11.0  -86.1  -60.8  35
                                                347 -16.7  -93.5  -67.9  35
                                                417 -15.2  -93.9  -69.7  35
                                                133 -13.4  -93.5  -71.1  35

InterFreq: EARFCN ThresholdLow ThresholdHi Priority PCI  RSRQ   RSRP   RSSI RXLV

WCDMA:     UARFCN ThreshL ThreshH Prio PSC   RSCP  ECN0 RXLV