Not sure what's going on...

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Twoods196
Posts: 7
Joined: Sat Jan 19, 2019 12:11 pm

Not sure what's going on...

Post by Twoods196 » Sat Feb 23, 2019 3:18 pm

Hello all, so I got my 2 directional antennas mounted to the pole in a mimo configuration. I used cellmapper to locate b41 towers around me and found 2-3 around me. So I programmed all the Sprint bands in so I could manually lock b41. Otherwise it connects to B25.(MC7445)

So inside of my debug information how many RSSI signals should I have with 2 antennas? When connected to B25 I see 2 RSSI strengths but when I connect to B41 I would see 4 RSSI signals but 2 of them would dissappear every few seconds. Tried reaiming and everything but my signal in signal info would be around 45-50% and if I tried to go to a website it would try to load the site and then timeout.

I get around 6-8mbps down with B25 and the 2 RSSI signals. That's with around 70% signal in the signal info. Should there be more RSSI showing up like they do temporary on B41? If so where should I start to figure out what's going on? Thanks.

swwifty
Posts: 502
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Not sure what's going on...

Post by swwifty » Tue Feb 26, 2019 9:43 am

you mind showing some screenshots of what you're seeing?

Also, can you describe your hardware setup? You mentioned a MC7455, but what kind of device is that mounted in?

Twoods196
Posts: 7
Joined: Sat Jan 19, 2019 12:11 pm

Re: Not sure what's going on...

Post by Twoods196 » Thu Feb 28, 2019 10:51 am

Thanks for the response. Let me fill you in on what ive done since that post. ALOT of Research! It never occured to me that a double pane window could reduce signal sooooo much. I have a 2 story house and in one of the attics there is a window that is at the very top of the house. I figured this one would be a good spot to do my testing get everything configured and then move it outside to its final resting place.

With that said, I did research on how much loss you can get from a window(especially double pane, and even more so ones with gas between them. Just incase someone else reads this you can loose up to 13dbi from a double pane window.

So this morning I decided to open the window facing B41 and lock it to that band to test. Low and behold:

Code: Select all

HAN?
!UMTSCHAN: NOT IMPLEMENTED
OK
AT!GSTATUS?
!GSTATUS: 
Current Time:  705		Temperature: 49
Reset Counter: 1		Mode:        ONLINE         
System mode:   LTE        	PS state:    Attached     
LTE band:      B41    		LTE bw:      20 MHz  
LTE Rx chan:   40978		LTE Tx chan: 40978
LTE CA state:  INACTIVE    		LTE Scell band:B41    
LTE Scell bw:20 MHz  		LTE Scell chan:41374
EMM state:     Registered     	Normal Service 
RRC state:     RRC Connected  
IMS reg state: No Srv  		
PCC RxM RSSI:  -88		RSRP (dBm):  -119
PCC RxD RSSI:  -87		RSRP (dBm):  -126
SCC RxM RSSI:  -99		RSRP (dBm):  -121
SCC RxD RSSI:  -100		RSRP (dBm):  -126
Tx Power:      0		TAC:         280B (10251)
RSRQ (dB):     -10.4		Cell ID:     05151833 (85268531)
SINR (dB):      3.8
OK
AT!PCTEMP?
Temp state: Normal
Temperature: 49.00 C
OK
Speed test shows 10mbps down.

This was just me point it in the general direction and trying. I havent fined tunned it or anything. Ive also learned that the extra RSSI values is when your acheiveing Carrier Aggregation.

Now to my current question, With B25 and the window down I was getting 10mbps down and around 4-5mbps up.

Would I be better off opening the window pointing towards the B25 Tower? As it seems if I was getting 10mbps down with the window up I should in theory get much more with it up. or Should I fine tune the B41 and see what speeds I can get from it.

A Concern of mine has been that I bought 50ft of Altelix N Male to N Male 400 Series Coaxial Cable Assembly 50 Feet for each antenna. Now knowing the loss that occurs over that 50ft and the pigtails. Should I try to get shorter lengths of actual LMR400? Mount my router as close to the antennas so that I dont loose as much signal? Even then 50ft was overkill and im gonna have to order new cable anyways so I figured I might as well get actual LMR400 with NMale to rp-sma to remove any loss obtained using a pigtail.

Once I have this all figured out, Im going to be mounting the antennas outside on the roof of my house so I have 2 options. Waterproof the router combo(we826 with MC7455) so that I can mount it to the pole the antennas are on. Making the cable length very short. Or should I install the router combo in the attic near the locations of the antenna with around 15ft of LMR400. I know LMR200 should suffice for that distance but I want to make this the best it can possibly be.

An lastly what is a good mounting system for these antennas, like which pole did you use and the best system to be able and adjust its azimuth while still mounted would be great. Looking at some RF Topographic maps I generate from my house to the antenna shows a 1 degree to be best. As stated I want the best setup possible. Cost does not matter, as I work from home quite often for the Department of Defense doing computer programming.(We basically make a video game that trains cybersecurity people how to defend against different attacks and also offensive missions, you can learn more about it at www.projectares.com were currently not available for the public but that will changing soon as we are in the works of moving everything from vmware to Azure Cloud and offering subscriptions. Its pretty awesome training platform/video game. So if your interested in CyberSecurity I highly recommend checking it out! Also if you would like more information let me know an I will be glad to show you more.) Back to the matter at hand, im connecting to Virtual Machines daily and also we stream our tv 100%. So I need to the best I can get.

So to recap, right now my we826 with mc7455 has r00ter firmware on it and its just setting on the floor with 2 pigtails that connect to the NMale Cable, then runs to my two 15dbi Directional wideband antennas purchased it from ltefix. Configured in MIMO with a heavy duty curtain rod and this is setting at my window with the antennas pointed towards B41.

So if you were doing this setup, what changes would you make to the current system. Which Cables? Best roof mounting hardware that allows me to adjust it and installing the router/modem outside closer to the antennas or use 15ft of cable to run to the cables inside. Until I get all the equipment, should I move the antennas back to the B25 and open that window. As I was getting 10mbps before with the window. Im thinking until I get my setup to mount outside, so move it over there, open the window and would prob get close to the max throughput that B25 can provide. Opinions?

Thanks for all the help, without this place none of this would have been possible!

swwifty
Posts: 502
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Not sure what's going on...

Post by swwifty » Thu Feb 28, 2019 8:12 pm

I'm going to try and answer all your questions in a logical order below. If you haven't seen already, I'd recommend reviewing my post on my setup, and this other thread on my single antenna review thread (contains a lot of other info than just on the antennas).

https://ltehacks.com/viewtopic.php?f=37&t=123
https://ltehacks.com/viewtopic.php?f=24&t=103

The comments on the double pane window are pretty hilarious, because I ran into a similar issue. I have a couple Ubiquiti Nanostations (Model: NSM2) that I use to connect my Mom's house to mine for Internet access. When I first set them up, I had to put the one on my house, just in the window of my office with a suction cup mount. I was able to connect them, but they seemed to be performing very poorly. Long story short, I discovered that the mesh screen on the outside window to keep out bugs was pure metal, and basically acting as a faraday cage. After I removed it, I picked up somewhere between 15-20dbm in signal strength!

Your signal stats look pretty decent, but they are also pretty weak as well on B41. This is expected, especially if you are far away cause B41 is at 2500mhz frequency which is less than ideal for penetration in non-line of sight. The good thing is, you have CA (as you discovered) and the bandwidth of both bands is 20mhz, which is as wide as you can get in LTE. Your SINR (Signal to Noise Ratio + Interference) isn't terrible, but could be better. Ideally, you want a stronger RSRP signal, and highest SINR value you can get.

There's no way we can till you which band you should try and use. You'll need to experiment with various bands, with the window down to give you the proper information. I can tell you though, that most of the time, it's less than ideal to lock to a specific band. You could try locking to B25, then B41, then unlocked, and see what things look like.

I'm not sure what you mean by azimuth adjustment for your pole mount? Normally you adjust all of that with the mount that the antenna uses.

I would mount your router/modem as close as possible to the antennas. If you search for a coaxial cable loss calculator, you'll see that the higher in frequency you go, the more signal loss there is. Which means, you will need higher quality cables to lose less signal strength. IMO, it's just better to not have long coaxial cables period (plus they are crazy expensive for good quality LMR400), and mount the router/modem as close as possible.

It's cool that you work remotely for the DOD doing Cybersecurity. I bet we have a lot in common in the tech industry. I work remotely as a Systems Engineer.

Can you share the signal stats from your various band tests? That will help me provide input.

Twoods196
Posts: 7
Joined: Sat Jan 19, 2019 12:11 pm

Re: Not sure what's going on...

Post by Twoods196 » Sat Mar 02, 2019 7:00 pm

Thanks for the response! Yeh I'm prob gonna waterproof the router/modem and mount it on the pole with the Antennas. The reason I locked it to band 41 is there is also a B26 between me and the B41 tower and it will just connect to the B26 tower which barely loads a webpage. I will post my other signals when I get back to my PC but since I'm getting signals just from my window WITH the mesh still on just the window open and 50ft of cable on both Antennas I believe once I get it permanently mounted outside and shorten the cable length dramatically I think I can get a better SINR and a stronger RSRP.

Regarding the azimuth yes it is adjusted on the antenna bracket but with me just having it inside on a pole and not stationary adjusting it now doesn't do me much good as I can just lean it back etc which is not very reliable.

I was talking to a guy that builds antennas and helped work on Sprints(clearwire) wimax when it was wimax. He suggested trying spatial diversity. So I might give that a try. He also gave me the distances apart from each Antenna for the spatial diversity. If I have good results I'll post all the info back here.

I have not seen your review of different antennas but will go And check that out now. Thanks for all the help!

swwifty
Posts: 502
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Not sure what's going on...

Post by swwifty » Sun Mar 03, 2019 2:16 pm

Twoods196 wrote:
Sat Mar 02, 2019 7:00 pm
Thanks for the response! Yeh I'm prob gonna waterproof the router/modem and mount it on the pole with the Antennas. The reason I locked it to band 41 is there is also a B26 between me and the B41 tower and it will just connect to the B26 tower which barely loads a webpage. I will post my other signals when I get back to my PC but since I'm getting signals just from my window WITH the mesh still on just the window open and 50ft of cable on both Antennas I believe once I get it permanently mounted outside and shorten the cable length dramatically I think I can get a better SINR and a stronger RSRP.

Regarding the azimuth yes it is adjusted on the antenna bracket but with me just having it inside on a pole and not stationary adjusting it now doesn't do me much good as I can just lean it back etc which is not very reliable.

I was talking to a guy that builds antennas and helped work on Sprints(clearwire) wimax when it was wimax. He suggested trying spatial diversity. So I might give that a try. He also gave me the distances apart from each Antenna for the spatial diversity. If I have good results I'll post all the info back here.

I have not seen your review of different antennas but will go And check that out now. Thanks for all the help!
The fact that you already have two antennas does give you spatial diversity. LTE is designed to work with 2 antennas on the mobile side (although I can work with just one, but not recommended) If the guy you were talking to was referring space between them, then I can see playing around with that, could make a difference. You can read all about my woes with antenna spacing and multipath fading, in my thread on my setup on the forums here.

https://en.wikipedia.org/wiki/Antenna_diversity

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