Local Tower Upgrades (Verizon)

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xdavidx
Posts: 267
Joined: Tue May 28, 2019 4:04 pm

Re: Local Tower Upgrades (Verizon)

Post by xdavidx » Mon Jul 08, 2019 5:42 pm

Maybe just try a few times to see if it gets in there?

swwifty
Posts: 463
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Local Tower Upgrades (Verizon)

Post by swwifty » Mon Jul 08, 2019 7:37 pm

OK, I got it figured out, below is an update on that flashing issue, and the testing I did.

When I first attempt to flash the modem, I got a error similar to the following (as seen on this link: https://github.com/danielewood/sierra-w ... QMI-SDK.md)
mbim open respons type error -2147480831
Error in modem crash state checking!error code = 103
Exiting Application!!!
The document suggests adding the "--dmreset" flag to avoid this error. I read the documentation for Linux flashing tool "fwdwl-litehostx86_64", but it was still unclear. Regardless, it helped me bypass that error.

I then ran the same command again a second time. When I put the modem back into my PI and started GoldenOrb, I saw the image status as shown in my previous reply. I then realized one of two things.

1. I noticed the .zip file was still in the folder containing the firmware and the log file showed it trying to read that in.
2. I hadn't removed the "--dmreset" flag on the second flash.

I tried removing the zip, and removing the --dmreset flag and then it properly flashed the modem. It hung for a few minutes stating it was flashing the modem, then I ran it again and it said the firmware was already up to date. I suspect that --dmreset flag prevented me from actually flashing the firmware and only ended up doing the PRI version.


Anyways, onto the good stuff.

I took the modem outside with the PI and only the 3dbi omnis to test. Strangely enough the RSSI and RSRP values look correct now, but it doesn't show the band names anymore! :x So now its kind of difficult to know which bands i'm connected to without locking. Screenshot below.
Screenshot from 2019-07-08 19-35-59.png
Screenshot from 2019-07-08 19-35-59.png (64.53 KiB) Viewed 925 times
Speed tests were around 60mb down / 20mb up.

At this point, I decided to slap it really quickly into my outdoor setup to see if the performance was any better. Screenshot of the status in my outdoor setup.
Screen Shot 2019-07-08 at 7.51.11 PM.png
Screen Shot 2019-07-08 at 7.51.11 PM.png (68.38 KiB) Viewed 925 times
Speed tests surprisingly didn't look much better.
Screen Shot 2019-07-08 at 7.48.31 PM.png
Screen Shot 2019-07-08 at 7.48.31 PM.png (54.97 KiB) Viewed 925 times
In conclusion, I think a few things are going on here.

1. I don't think Verizon is aggregating more than 30mhz of bandwith to my modem, regardless of how many carriers it has. I noticed on the EM7565 that when I was doing a speed test, CA was only active on one of the SCC carriers not both. Not sure why thats the case, but it appears to be so.

2. The EM7565 is picking band 2 as primary, but the MC7455 is picking B4 as primary. Best I can tell is, there actually might be two different carriers in Band 66 but I'm not sure cause it seems that the 7455 refers to parts of band 66 as band 4, and the 7565 refers to Band 4 and Band 66 only as band 66.

3. I thought this might be max performance i was going to see. I drove to the tower with my Samsung S8 which has a Cat 16 LTE modem and couldn't get much more than 70mbps down only 500ft away with clear line of sight. I tried from a different location too with clear LOS and same thing. Granted, this is with crappy cell phone antennas, but still. I would think up close if it was aggregating three bands, I could easily get over 100mbps.

4. The only last thing I can think to try is to test more with the EM7565 and lock to Band 4 + Band 66 and see what happens.

If I had a SDR that went above 2ghz it would be pretty easily to figure out what the bands are and their widths.

xdavidx
Posts: 267
Joined: Tue May 28, 2019 4:04 pm

Re: Local Tower Upgrades (Verizon)

Post by xdavidx » Mon Jul 08, 2019 8:17 pm

Oh yeah, I forgot about the Band 4/Band 66 thing. It will show up only as 66 on a Band 66 capable modem, I believe.

I did some digging and I don't believe Band 66 can be the primary band for carrier aggregation when there are other bands present. The exception would be Band 70 and 71. So that's why it is putting Band 2 first. Not sure if CA combinations are to blame for why it is only activating 2 out of the 3 carriers. Hard to know without knowing what those bands are.

You did have Band 66 with 10 MHz and 20 MHz as secondary and tertiary with the old image, so probably a pretty good bet those are what you are seeing as 2 and 3 now. It didn't show which chunks of 66 they were though. What about running LTEINFO while a speed test is running? That should show the EARFCN and you can convert that into the band number, as well as know which section of the band it is.

Difficult to know max speed with only a few tests, since congestion could be limiting it. However, if you don't believe there are many people around there using the tower, then maybe that's all you can get. Middle of night test might help with that.

I am guessing (only guessing) that if you lock Band 4 and Band 66, you'll get Band 66 as primary and either another chunk of Band 66 as an active secondary carrier, or just Band 66 as primary and no other active secondary/tertiary carriers, if there isn't more than one chunk of Band 66, or if Verizon isn't set up for that combo.

I wonder if the Verizon firmware image for the modem would show the CA band numbers?

xdavidx
Posts: 267
Joined: Tue May 28, 2019 4:04 pm

Re: Local Tower Upgrades (Verizon)

Post by xdavidx » Mon Jul 08, 2019 8:19 pm

Another test would be to allow all bands except Band 2. This would show you if there are other bands on there that it might give you if you can't get Band 2.

swwifty
Posts: 463
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Local Tower Upgrades (Verizon)

Post by swwifty » Mon Jul 08, 2019 9:27 pm

Good ideas. I'll do some more testing and report back here, before I decide to just stick with the 7455.

swwifty
Posts: 463
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Local Tower Upgrades (Verizon)

Post by swwifty » Tue Jul 16, 2019 9:21 pm

OK, so I got around to finally doing some more testing with the EM7565 and Verizon. The results are quite interesting. Below are the results, but I've been able to determine for sure what bands are on the tower now. Please use below as the reference throughput this post.

Band 13 (750mhz / 10mhz wide)
Band 5 ( 850mhz / 5mhz wide)
Band 2 (1980mhz / 10mhz wide)
Band 4 (2120mhz / 20mhz wide)
Band 66 (2165mhz / 10mhz wide)

I started off testing in my office with just my upgraded 3dbi omni antennas attached to the modem. Please note too that the latest version of the firmware for the EM7565 has all the band names jacked up for some reason.
Screen Shot 2019-07-15 at 9.37.28 AM.png
Screen Shot 2019-07-15 at 9.37.28 AM.png (72.59 KiB) Viewed 814 times
Notice B2 was primary while band 4 and band 66 were assigned as CA.

I also took a screenshot while doing a speed test and all secondary carriers were active. I don't have a screenshot of the speed test but it was about 70mbps down with about 25mbps up.
Screen Shot 2019-07-15 at 9.52.35 AM.png
The screenshot above was outside on my deck with some extra 9dbi yagi antennas hooked up. I had tried outside on the deck with just the omnis with the same results. I thought maybe the higher gain antennas would give me a different band order, but it didn't. Also note during this screenshot I was doing a speed test and in this case only ONE of the secondary carriers was active. That speed test got me about 65mbps down with 25mbps up.
Screen Shot 2019-07-15 at 10.11.49 AM.png
Screen Shot 2019-07-15 at 10.11.49 AM.png (70.12 KiB) Viewed 814 times
I then put the EM7565 in my outdoor setup, and tried some more tests. As you can see same carrier configuration, and I could only get one carrier active while doing a speed test. Speed test was about the same at 65mbps down / 25 up.

So this is where it gets interesting. For some reason, I thought maybe I should try the modem in QMI mode rather than MBIM. I had seen some threads about latency issues in MBIM mode that were improved with QMI, so I thought what the heck, let me give it a shot.
Screen Shot 2019-07-15 at 6.06.28 PM.png
Screen Shot 2019-07-15 at 6.06.28 PM.png (56.72 KiB) Viewed 814 times
And bam! Suddenly now the modem selected Band 4 (even though it says Band 66) as primary with Band 2 and Band 66 as secondary carriers. I have literally no idea why QMI mode caused this to happen, but I did notice that I didn't get an IPv6 address while in QMI mode as well.
Screen Shot 2019-07-16 at 11.19.25 AM.png
Speed test while in QMI mode. I also saw on speedtest.com about 70mbps down and 45mbps up. The interesting thing here is that the MC7455 that I normally use, selects Band 4 as primary too, but band 5 as the secondary carrier (remember 7455 only supports 2 carriers while the EM7565 supports 3).

So in conclusion there's a few things.

1. In my case, the EM7565 doesn't seem to make much of a difference in performance for me, because I'm not getting aggregation of all three bands. I don't know if this is unique to this tower, or if how Verizon just setups their different bands. I did test this modem with AT&T sim, and it did aggregate all three of their bands together (B12,B2, and B30).

2. I really feel like I should be getting better download speeds. My AT&T sim on my outdoor setup can get 75mbps down on B12 and B2 and that tower is 5 miles away NLOS, and only has a SINR of 10mbps! I suspect this tower must be over loaded even though it was just upgraded, because when I was in downtown Atlanta standing near some Verizon small cells with the exact same bands, I was able to get 290mbps down and about 60mbps up on my Samsung S8. I even drove right next to the tower with my phone and couldn't get more than 80mbps down, so the tower is either totally limited or highly congested already.

Anyways, just thought I'd post that to share my experiences. Really interesting, kind of disappointed, but the upload is probably worth the extra expense of using Verizon over AT&T. My current upload with AT&T is only about 3-5mbps because B2 is primary and the tower is so far away.

It'll be quite interesting to see what happens when all the leaves fall off.

xdavidx
Posts: 267
Joined: Tue May 28, 2019 4:04 pm

Re: Local Tower Upgrades (Verizon)

Post by xdavidx » Wed Jul 17, 2019 12:46 am

swwifty wrote:
Tue Jul 16, 2019 9:21 pm
Band 13 (750mhz / 10mhz wide)
Band 5 ( 850mhz / 5mhz wide)
Band 2 (1980mhz / 10mhz wide)
Band 4 (2120mhz / 20mhz wide)
Band 66 (2165mhz / 10mhz wide)
You've got quite the smorgasbord to play with there. :D
swwifty wrote:
Tue Jul 16, 2019 9:21 pm
Also note during this screenshot I was doing a speed test and in this case only ONE of the secondary carriers was active. That speed test got me about 65mbps down with 25mbps up.
Interesting that they took away one band. Maybe just timing? When they take mine away, it comes and goes, with it being gone more during the day and present more at night. Maybe the better signal strength did it too -- they figured you had all you should have with the 2 bands. :D
swwifty wrote:
Tue Jul 16, 2019 9:21 pm
So this is where it gets interesting. For some reason, I thought maybe I should try the modem in QMI mode rather than MBIM. I had seen some threads about latency issues in MBIM mode that were improved with QMI, so I thought what the heck, let me give it a shot.

And bam! Suddenly now the modem selected Band 4 (even though it says Band 66) as primary with Band 2 and Band 66 as secondary carriers. I have literally no idea why QMI mode caused this to happen, but I did notice that I didn't get an IPv6 address while in QMI mode as well.
You're on a different CID. I'm guessing that was the reason instead of USB composition in the modem, but anything is possible.
swwifty wrote:
Tue Jul 16, 2019 9:21 pm
1. In my case, the EM7565 doesn't seem to make much of a difference in performance for me, because I'm not getting aggregation of all three bands. I don't know if this is unique to this tower, or if how Verizon just setups their different bands. I did test this modem with AT&T sim, and it did aggregate all three of their bands together (B12,B2, and B30).
I'm starting to get the idea that Verizon is more stingy about CA, based on your results and what others have posted.
swwifty wrote:
Tue Jul 16, 2019 9:21 pm
2. I really feel like I should be getting better download speeds. My AT&T sim on my outdoor setup can get 75mbps down on B12 and B2 and that tower is 5 miles away NLOS, and only has a SINR of 10mbps! I suspect this tower must be over loaded even though it was just upgraded, because when I was in downtown Atlanta standing near some Verizon small cells with the exact same bands, I was able to get 290mbps down and about 60mbps up on my Samsung S8. I even drove right next to the tower with my phone and couldn't get more than 80mbps down, so the tower is either totally limited or highly congested already.
Maybe they have so many more towers in the city (so they can leave it wide open), or the city towers have more advanced equipment (more MIMO, higher modulation, etc.). *Or*, in the city, they worry less about people using them for home internet service, and in the open spaces, they are trying to limit what any one person can get.
swwifty wrote:
Tue Jul 16, 2019 9:21 pm
Anyways, just thought I'd post that to share my experiences.
Thanks. It's really valuable to have these types of tests for others to compare against.
swwifty wrote:
Tue Jul 16, 2019 9:21 pm
Really interesting, kind of disappointed, but the upload is probably worth the extra expense of using Verizon over AT&T. My current upload with AT&T is only about 3-5mbps because B2 is primary and the tower is so far away.

It'll be quite interesting to see what happens when all the leaves fall off.
Sucks to have to pick between upload and download, but I agree. I could, in theory, point my antennas at hill behind me and get very good daytime speeds with the reflected signal from a given tower. The uploads will be single digits though. Or, I can get slightly slower download speeds during the day from another tower and get really good upload speeds.

I still haven't given up on pointing directly at the tower that I can get good speeds from by pointing at the hill. But with my current setup, there are too many competing towers in that direction causing problems. I also have a theory that there might be some obstacles between me and the tower, so pointing directly at it doesn't work as well, but the signals are able to collect and rebound in a narrower beam off that hill. Very weird no matter how it is happening. Still mulling over a grid antenna to laser connect to the tower of my choice.

Yeah, if your verizon tower is very close, then maybe the foliage won't make as big of a difference vs that further away AT&T tower.

swwifty
Posts: 463
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Local Tower Upgrades (Verizon)

Post by swwifty » Wed Jul 17, 2019 10:08 am

xdavidx wrote:
Wed Jul 17, 2019 12:46 am
You've got quite the smorgasbord to play with there. :D


Interesting that they took away one band. Maybe just timing? When they take mine away, it comes and goes, with it being gone more during the day and present more at night. Maybe the better signal strength did it too -- they figured you had all you should have with the 2 bands. :D


You're on a different CID. I'm guessing that was the reason instead of USB composition in the modem, but anything is possible.


I'm starting to get the idea that Verizon is more stingy about CA, based on your results and what others have posted.


Maybe they have so many more towers in the city (so they can leave it wide open), or the city towers have more advanced equipment (more MIMO, higher modulation, etc.). *Or*, in the city, they worry less about people using them for home internet service, and in the open spaces, they are trying to limit what any one person can get.


Thanks. It's really valuable to have these types of tests for others to compare against.


Sucks to have to pick between upload and download, but I agree. I could, in theory, point my antennas at hill behind me and get very good daytime speeds with the reflected signal from a given tower. The uploads will be single digits though. Or, I can get slightly slower download speeds during the day from another tower and get really good upload speeds.

I still haven't given up on pointing directly at the tower that I can get good speeds from by pointing at the hill. But with my current setup, there are too many competing towers in that direction causing problems. I also have a theory that there might be some obstacles between me and the tower, so pointing directly at it doesn't work as well, but the signals are able to collect and rebound in a narrower beam off that hill. Very weird no matter how it is happening. Still mulling over a grid antenna to laser connect to the tower of my choice.

Yeah, if your verizon tower is very close, then maybe the foliage won't make as big of a difference vs that further away AT&T tower.
It might be just a timing thing, but really hard to confirm that unless I logged data about the modem all the time and could graph it somehow.

I suspect the antennas in cities are much better. They are moving towards active antennas that do beamforming in the cities, and I'm sure rural areas are mostly still on passive antennas and will be the last to get updated. That being said, it's possible this tower has active antennas now, cause I tend to see my SINR bounce between 15-30. I can't tell if thats during receiving data or not.

It's clear to me that the upload speed indicates the tower can hear my modem very well. With the EM7565 I was getting 40mhz of aggregated bandwith which I would think could easily do over 100mbps.

swwifty
Posts: 463
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Local Tower Upgrades (Verizon)

Post by swwifty » Wed Jul 17, 2019 1:51 pm

Forgot to add I scheduled a cronjob at 3am to run a speed test with the speedtest-cli tool, just to rule out any possible congested. This is the results:

Wed 17 Jul 03:00:01 EDT 2019
Retrieving speedtest.net configuration...
Testing from Verizon Wireless (174.218.132.14)...
Retrieving speedtest.net server list...
Selecting best server based on ping...
Hosted by QTS Data Centers (Suwanee, GA) [22.38 km]: 46.476 ms
Testing download speed................................................................................
Download: 66.30 Mbit/s
Testing upload speed................................................................................................
Upload: 38.20 Mbit/s

So it seems the tower is probably not all that congested, i'm just rate limited.

xdavidx
Posts: 267
Joined: Tue May 28, 2019 4:04 pm

Re: Local Tower Upgrades (Verizon)

Post by xdavidx » Wed Jul 17, 2019 3:10 pm

swwifty wrote:
Wed Jul 17, 2019 10:08 am
It might be just a timing thing, but really hard to confirm that unless I logged data about the modem all the time and could graph it somehow.
This might help with that: https://testmy.net/auto It won't show you how many bands you have, but you could possible tell, indirectly, based on speed.

swwifty wrote:
Wed Jul 17, 2019 10:08 am
That being said, it's possible this tower has active antennas now, cause I tend to see my SINR bounce between 15-30. I can't tell if thats during receiving data or not.
Can you check the SINR during a speed test and without a speed test to see if that's the case?
swwifty wrote:
Wed Jul 17, 2019 10:08 am
It's clear to me that the upload speed indicates the tower can hear my modem very well. With the EM7565 I was getting 40mhz of aggregated bandwith which I would think could easily do over 100mbps.
I was able to get over 100 Mbps when close to an AT&T tower on 40MHz of bandwidth (20+10+10), and I'm sure there was some congestion due to variability. I was even able to get up to a peak of about 145 Mbps on 30 MHz (15+10+5) on another tower that same day.

I wish these things had a command to see the modulation rate. There is a chance there is an unpublished command, but I haven't found it yet.

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