Poor uplink tests and high ping times...

The ping times to this SM are very high… and they time out often… does this sound like interference at the customers location? There are a few people in this general area having similar problems. REbooted SM but did little to help.

Stats for LUID: 7 Test Duration: 2 Pkt Length: 1522
Downlink RATE: 1082624 bps
Uplink RATE: 49152 bps
Downlink Efficiency: 100 Percent
Max Downlink Index: 100
Actual Downlink Index: 100
Expected Frag Count: 4229
Actual Frag Count: 4229
Uplink Efficiency: 5 Percent
Max Uplink Index: 100
Actual Uplink Index: 5
Expected Frag Count: 192
Actual Frag Count: 3622

No sounds like a problem at the ap. If the interfearance was at the sm the downlink efficiency would suffer.

I may be wrong here, but I did a Link test at both ends and the uplink was still poor on both tests… First from Sm to AP, then from Ap (luid select, link test) to SM.

I’ll try it again and see.

I’m suprised you were able to complete a link test with only 5% uplink. What is the distance from the ap? have you tried a screen dish or reflector? Do you have your ap’s on different color codes.
I had a simular problem when I first started we used the same color code on all the ap’s we found that if a cyclone went down the sm would register to a different ap even if it was on the back side.

Our AP’s are on opposite sides of the water-tower. When going to “AP EVAL DATA” the SM can only see the 1 AP it connects to. I just spoke with a customer who appears to be down (intermappe) however, I had her log into the SM and she said it was registered. I cannot ping the SM however. I think I have seen this problem in other posts.

Distance is around 8 miles. Using a 13 dbi Yagi. 900SMC

Seeing the AP and even registering to it is no guarantee it will work.

If the AP is on the opposite side of the water tower it’s not likely that you are going to be able to make it work.

Now if you can raise the AP so it’s above the top of the tower, then you will be in good shape.

I think you have it wrong… we are not trying to connect a “southern” customer to the NORTH facing AP. I hate 900 sometimes… the signal just seems to fade out during certain times.

The two link tests you mentioned are the same. Uplink means uplink from the sm to ap no matter what end you test from ap or sm. Your problem is at the ap. The reciever of the ap has interfearence. The transmit signal from the sm is having trouble getting to the ap. Put the ap in sm mode then enable the spectrum analyzer under expanded stats. Look at the status page of the sm. What is the rx level in db not rssi. For 900 i do not leave any customers with anything worse then a -77. What is the jitter? This is the signal the sm is recieving from the ap. Now go to the ap under sessions what is the rx level for that sm? what is the jitter? this is signal the ap recieves from the sm. On the spectrum analyzer look at the freq you have the ap set to, what is it? You want the recieve level on the sessions page of the ap for that sm to be 10 db better then what you see on the spectrum.

Compare the rx level of the ap and sm they should be relatively the same give or take a few db. If they are 10db or more apart like a -80 at one end and a -70 at the other and their isn’t interfearence at the -80 end of the link then you probably have a bad transmitter at the -70 end of the link. I have had several transmitter’s go bad but i have yet to see a bad reciever.

I may have gone overboard on that but maby it will help some. if not you someone else.

From my experiance the 900 has more problems with multipath then the other canopy. You said you were mounted on a water tank. Is it a elivated tank or does it sit on the ground? Where is your ap in relation to the tank part? How far away? If it is an elivated tank and you are mounted on the side This could be your problem also. The signals could be bouncing off the tank and cousing self interfearence.

The only reason i am singling out the ap is that you said several customers have this problem. Hope this helps.

OK - I missed the part about 2AP’s.

Is the 8 mile customer on the same AP as your .53 mile customer?

Also, does your 8 mile customer have LOS? If there are trees in the path you are not going to burn through even with a 13dB yagi at 8 miles.

You will see drastic improvements if you lower the power on any links on any SM’s in your system that are over -65dB to fall within -65 and -75.

Also, try playing with the transmit frame spreading. Our 5.7’s and 2.4’s require it to be on, but the 900’s fall apart when it’s on. Also make sure you have the same number of control slots on both AP’s.

Is the 8 mile customer on the same AP as your .53 mile customer?
Yes. There are 5-6 SM’s that will NOT stay connected and they vary in geographics/location.

Also, does your 8 mile customer have LOS? If there are trees in the path you are not going to burn through even with a 13dB yagi at 8 miles.

NO LOS. Many of our customers go through trees and it worked for the longest time. Now these select few start acting up. Maybe the noise floor raised?

You will see drastic improvements if you lower the power on any links on any SM’s in your system that are over -65dB to fall within -65 and -75.

I am currently lowering the DBM’s on the SMs that are not in this range. The nearest customer had a 49 dbm signal.

The North and South antennas have the same settings. All of the north customers are fine.

I had not heard of the power issue and tried it. On one radio that had three customers in the -50s, I saw some 3-4 mile NLOS 900Mhz links improve from -84db to -79db. Great tip!!

I lowered our closest 900 customer to 9 dbm and by logging into the AP and selecting AP EVAL DATA I notice their power lever went from the high 40’s to 50’s… Should I lower it some more?

Just a little fooling around, I found than under 8dbm gain the units would start getting a little punky. This on a client with -42 when I started. :shock:

How about max distance settings? I know we’ve discussed this before but right now I have my 2 900’s at 30 miles each. Even though our farthest customer is 12 miles. I am tempted to raise it to 40 just to see if those 4-5 customers with bad links will connect!

This really sucks b/c I am the one having to talk to these customers, and there really isnt anybody else besides “the boss” that knows this stuff and he won’t help. “Call tech support”. :roll:

Im tempted to ask any of you to take a look via Remote Desktop!

The range is set on the AP. Won’t help you to set it any higher if the AP can’t see the SM. My experience is that the SMs almost always can see the AP at a much higher power level than vs. vs.


RSSI Out of Range 6946

Anybody have an answer to why this keep climbing?

This my not be relavent to your problem, are you running a cmm? do you know if another wireless provider or company (office to office)moved into your area?

cmm micro. The only other 900 that we know of is our own site that we put up 15 miles to the west of this site. Perhaps that site raised the noise floor ?

are your systems connected via backhauls? I’m still not clear do you have a cmm micro?
I was told a rule of thumb set the max mileage in your ap 1 to 2 miles past your furtherest sm, no more

Yes we are using a cmm-micro at all 3 of our sites. We have 42 customers on this south facing AP. Most of them are going through trees, which right now are leave’less. These sm’s range from .5 miles to 12 miles. When I tried lowering the max distance to 20 miles, 5-10 SM’s failed to connect within 5 minutes! Those that did connect had over 20 reregs right off the bat. Raised it to 30 and they all connected with no more than 5 re-regs.