My Ultimate LTE router using a Raspberry pi 4B

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poodad
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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by poodad » Mon Oct 19, 2020 8:21 am


poodad
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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by poodad » Mon Oct 19, 2020 8:31 am

SliverGT wrote:
Sun Oct 18, 2020 8:27 pm
Nice work, do you have a better picture of how your mast is attached to the roof?
I made the telescoping post from two pieces of metal tubing from Home Depot that fit one inside the other almost perfectly. One was a section of electrical conduit and the other a chain link fence top rail section.

I drilled a 1 1/8" hole in the top of the ridge vent which was exactly the same diameter of the outside pole.

The bottom of the pole rests in a "cup" made from a small bit of 2X4 with a 1 1/8" hole drilled 90% through. This is screwed to the attic floor. I made a locking collar that attaches to this block of wood and when tightened, prevents the pole from rotating.

poodad
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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by poodad » Mon Oct 19, 2020 8:36 am

R1250GSA wrote:
Sun Oct 18, 2020 3:59 pm
OUTSTANDING!
Well played Dr. Frankenstein.

What are the speeds now that the smoke has settled?
Which carrier?
Any lessons learned from your modem choice, the Sierra CAT-12?

Yes, I would like to see your Perl scripts.
Right now, I'm testing with a business class AT&T SIM using the i2gold APN. Speeds are good (12Mb/3Mb), but latency is terrible at around 1s. I guess I'm hitting AT&T routers on the moon or something.

Learnings:

1. The Raspberry Pi 4 is not ready for prime time as a router. If it weren't for for some guru named Wulfy23 who is building a top-notch community build of OpenWRT for the RPi4, I'd have been stuck. The stock daily snapshots for the RPi4 suck.

2. The EM7565 seems like a top notch LTE modem. I'm seeing a bit of weirdness with AT commands, but everything seems to be working. I'll know more when I start trying band locking.

3. I need to play around with QMI vs MBIM. I've heard rumors the QMI works better for Qualcom based devices.

4. The EM7565 gets HOT when under load. My modem temp shot up to 65 degrees C while testing. It may get a heatsink

5. Grafana is awesome stuff!

R1250GSA
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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by R1250GSA » Mon Oct 19, 2020 9:28 am

I do not see any grounding of your roof setup.
It looks like a very juicy lightning rod.

poodad
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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by poodad » Mon Oct 19, 2020 7:26 pm

R1250GSA wrote:
Mon Oct 19, 2020 9:28 am
I do not see any grounding of your roof setup.
It looks like a very juicy lightning rod.
I have a couple of VERY tall trees close to the house and the antenna should fall within the cone of protection of those trees. However, I am going to add a ground just to be safe, just haven't done it yet.

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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by poodad » Wed Oct 21, 2020 10:27 am

Update: I've been testing some more. When left to defaults, the modem will do carrier aggregation with band 66 and some other band which escapes me at the moment. I do remember that the secondary band was one of the 700-800Mhz bands. This resulted in download speeds of around 16Mb, but upload speeds of only 1Mb. The modem temp went to 65 degrees. Testing using RDP into a terminal server resulted in a not great experience.

I'm about 5 miles from the tower (I think - the cell ID I'm seeing doesn't seem to exist on any of the locator web sites), and I have heavy amounts of trees and a hill obscuring the path. When using CA with B66 as the primary, my RSSI was around -90dB which I'd expect given that B66 is 1.7Ghz.

I tried band locking to the couple of low frequency bands this tower supports, and B5 seemed best. RSSI in the low to mid -70dB range. Downloads dropped to 10Mb, but uploads jumped to 6Mb. Overall experience was better. RDP was markedly better.

Now, I need to find a provider to replace the testing SIM I'm using. Nomad used to be a good choice, but they've recently gotten a terrible reputation of disrupted service and continuing to charge credit cards after canceling. They are expensive now to boot.

Visible seems to be a popular choice, as does the AT&T post paid tablet plan. Both of these require some extra hoops to jump through, but I guess I'll do whatever it takes.

lordrylen
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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by lordrylen » Sat Feb 20, 2021 3:32 pm

poodad wrote:
Wed Oct 21, 2020 10:27 am
Update: I've been testing some more. When left to defaults, the modem will do carrier aggregation with band 66 and some other band which escapes me at the moment. I do remember that the secondary band was one of the 700-800Mhz bands. This resulted in download speeds of around 16Mb, but upload speeds of only 1Mb. The modem temp went to 65 degrees. Testing using RDP into a terminal server resulted in a not great experience.

I'm about 5 miles from the tower (I think - the cell ID I'm seeing doesn't seem to exist on any of the locator web sites), and I have heavy amounts of trees and a hill obscuring the path. When using CA with B66 as the primary, my RSSI was around -90dB which I'd expect given that B66 is 1.7Ghz.

I tried band locking to the couple of low frequency bands this tower supports, and B5 seemed best. RSSI in the low to mid -70dB range. Downloads dropped to 10Mb, but uploads jumped to 6Mb. Overall experience was better. RDP was markedly better.

Now, I need to find a provider to replace the testing SIM I'm using. Nomad used to be a good choice, but they've recently gotten a terrible reputation of disrupted service and continuing to charge credit cards after canceling. They are expensive now to boot.

Visible seems to be a popular choice, as does the AT&T post paid tablet plan. Both of these require some extra hoops to jump through, but I guess I'll do whatever it takes.
How do you send AT commands to your modem? I cannot get socat to work properly.

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Didneywhorl
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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by Didneywhorl » Mon Mar 22, 2021 2:19 pm

lordrylen wrote:
Sat Feb 20, 2021 3:32 pm
How do you send AT commands to your modem? I cannot get socat to work properly.
try adding picocom, simplest for me. That or minicom

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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by lenn0x » Tue Mar 30, 2021 8:00 pm

Great Project!
I'm looking to do something similar with an EM160R-GL, LTEFIX 4x4 MIMO antenna, and now a raspberry pi4. I tried to use a B1300 but kept running into power delivery issues. Dairyman recently released a Goldenorb Build for the Pi4.

http://www.aturnofthenut.com/upload/Ras ... -03-23.zip

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Re: My Ultimate LTE router using a Raspberry pi 4B

Post by techdeisel » Thu Sep 02, 2021 8:57 am

poodad wrote:
Sun Oct 18, 2020 11:46 am
It's alive! Frankenrouter (as I've come to call it) is put together and installed.

IMG_5604.JPG

Inside is the Raspberry Pi 4B, the USB3 M.2 enclosure with a Sierra Wireless 7565. Also notice the heat management system. I drilled some tiny holes in the bottom of the case (you can see the inlet holes on the left), I took a 1 1/4" sink drain tailpiece, cut it to length, hot glued a small fan on top, then hot glued that over the holes on the bottom right. The fan pulls hot air from the top of the case and pushes down the tube and out the bottom. Not optimal, but it appears to work since the RPI4 temps are the same with the case open and closed. The fan is powered from the 5V GPIO pin on the RPI.

IMG_5605.JPG

Here's a shot of my Grafana dashboard. I've got perl scripts that queries the Raspberry Pi 4 temperature and fan speed and the modem stats and writes them to an InfluxDB database. You can see that the modem starts heating up pretty dramatically when it is under load.

grafana1.jpg

Next move is to remove the top of the USB enclosure case for improved airflow. I may add a heatsink to the modem.

BTW, if anyone wants the perl scripts, let me know.
Hello thanks for all your test and documentation, wondering if there's a specific guide, you followed maybe you could point me that direction or a little help setting it up ? The granfa and stat portion, I have everything else licked

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