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Guru Elite

Re: Client match behavior

Muhtereminair,

How long has this been happening?
Who designed the WLAN?

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Occasional Contributor I

Re: Client match behavior

This has been happening for like two months , after startup.

 

This is a warehouse designed by us. There is a 8 IAP-224 Cluster. Hand terminals are working inside the warehouse. After some time , customer had complained about the latency issue. Handterminals are struggling to send data to server , there is a noticable latency issue from the workers. First we were suspicious about handterminals , made some wifi improvments (Channel sens , roam threshold , scan interval and etc. ) but the problems persist. The problem doesnt occur every moment but sometimes of a day , someplace (randomly) on warehouse. As I said this issue not exact but workers face it sometimes. So I cant prove when we do "x" , "y" happens , but customer faced it several times. And he tells , it occurs especially when roaming.

 

I have opened a case regarding it is a latency issue , and tac had changed some changes. But the problem still arrives. 

Guru Elite

Re: Client match behavior

How high are the access points mounted?

Are they mounted between stacks or in the open?

What antennas are you using?

How far apart are they mounted?

What handhelds are being used?

Are the handhelds using 2.4ghz?

What technology was being used before and how high and how far apart were the access points mounted?  What was the power?

 


*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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Occasional Contributor I

Re: Client match behavior


@cjoseph wrote:

How high are the access points mounted?

 

Like 9-10 meters high 

 

Are they mounted between stacks or in the open?

 

Warehouse have some stacks also half of the warehouse is open.

 

What antennas are you using?

 

Ant-1w is used.First the wrong polarization being use , as they were vertical to the ground make too much interference , then it changed to horizontal to the ground.

 

How far apart are they mounted?

 

There are at least 20 meters between them.

 

What handhelds are being used?

 

Called Dcom

 

Are the handhelds using 2.4ghz?

 

Yes haldhelds are using 2.4 Ghz

 

What technology was being used before and how high and how far apart were the access points mounted?  What was the power?

 

There are 2 engenius APs on the warehouse. One of them is sitting on a table in from of the warehouse other one is lying behind stacks but not that high as now.

 


 

Guru Elite

Re: Client match behavior

Have you done a post installation survey to see how much coverage you are getting with the ant-1ws at 9 to 10 meters?
Have you done a spectrum analysis to see if there is any interference in the warehouse?
What type of goods are there in the warehouse? Paper, Metal or Frozen?

What is the ARM Min and Max power for your access points?
How many ssids are being broadcast?

*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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Occasional Contributor I

Re: Client match behavior

Yes I have done post installation survey and doesnt see any coverage problem / black hole and etc. Have seen -75dbm worst.

 

There are mainly office supplies in the warehouse , so many kinds of goods there are (liquid , paper , metal cans etc.)

 

ARM min 9dbi , max 24dbi , just one SSID is broadcasting.

Guru Elite

Re: Client match behavior

Muhteremonair,

It is entirely possible that you have too much coverage. RF propagates pretty well in open spaces, so you might have to space your access points at every 33 meters in open space to avoid this. You could also first lower the max power to 18.

On your survey you might want to see how many access points you can see on the same channel in an area that has slowness. You could also do a packet capture on a single channel and see if you see traffic from access points that should be far away. That will determine if you have to consider reducing coverage to avoid slowness.

You can also make sure Broadcast Filtering is on "all" to make sure that excess broadcasts on the network are not hurting your performance.

The only thing I did not see you mention is spectrum analysis; interference could be playing a part here.

Everything I mentioned could contribute to the slowness you are seeing...

*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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Occasional Contributor I

Re: Client match behavior

Thank you for your help 

 

Warehouses are hard places to position APs. At 10 Meters high all APs show the other. 

But in this case i think problem is different , my main problem is not slowness because the amount of data sent is very low , only barcode information queried from server that is all. I opened a topic (which I couldnt find now) in airheads forum and also a TAC case.Slowness just result of the issue. Not a constant slowness , ping goes constant at 3-4ms then a suddenly waves to 100+ msecs.Also handhelds are not clever enough to overcome at that situation then boom connection lost. 

 

At last , i put a test controller to the system and convert all them to CAP and it is now significantly better. Will try to reposition some APs to get better results.

Guru Elite

Re: Client match behavior

Sir,

 

If in any given spot, all 8 other access points can be seen, you have to lower the ARM Maximum Transmit power, or choose one or more more access points in open space to turn into an Air Monitor(s).  You might have to do both.

 

Access points can easily be seen at 100 meters in open space.  The problem is that if they can see each other they will pause or slow down the traffic because they can see each other talking.  

 

If you can hold down the keys on the scanner gun and there are pauses, that is another way to determine if you could afford to possibly reduce coverage.

 

If you can put the scanner in "site survey mode" you might be able to see how many access points your scanners can see at any one time to determine what your coverage is.  Some  scanners have limited association tables, and might try to associate with access points that are no longer in range if they can see too many, and that could create an issue while they are roaming.  Some scanners are expecting very, very thin coverage with access points on very high power on 2.4ghz.  

 

If you have other devices that are 5ghz, you can still deploy an  SSID on 5ghz only on all access points and it should work just fine.

 

These are all just individual ideas, and they do not all have to be done; your customer just has to be happy.

 


*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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