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Re: Settings for MSM466 with External MIMO Antenna - MSM760 Mobility Controller

 
Lrod78
Occasional Advisor

Settings for MSM466 with External MIMO Antenna - MSM760 Mobility Controller

Hey folks, need a little help with this one.  

 

Just installed 20 MSM466 AP's with 1 HP MIMO Antenna(J9169A) and need a little guidance on configuring the radio settings on the MSM760 controller.  (Btw, the antenna was connected to the 2.4ghz radio by the installers)

 

Basically the AP's and Antenna's are setup in a warehouse.  Each AP is setup at the end of the ailse with the atenna faced down towards the end.  The next AP is setup on the next ailse over but on the opposite end.   

 

I've read the documentation for the antenna's and the AP's but would like to get some advice and best practices.   The only items that will connect to the wireless network are motorola/symbol barcode scan guns. 

 

So far,  because of channel interference, I've manually set the channels of the AP's  1,6,11,1,6,11, on the 2.4ghz radio(which is radio 2).  Everything else is pretty much default at the moment.  

 

I believe I need to adjust the antenna gain and lower the transmit power, but when I did that, we ran into a lot of issues with dead spots and guns not able to connect. 

 

So at this point, any advice, tips and guidance is welcomed. 

4 REPLIES 4
tschaps
Valued Contributor

Re: Settings for MSM466 with External MIMO Antenna - MSM760 Mobility Controller

...

I believe I need to adjust the antenna gain and lower the transmit power, but when I did that, we ran into a lot of issues with dead spots and guns not able to connect. 

...


You have not described any issues you're having at the default settings, only if you adjust the gain and transmit power. What issues are you having?

 

Also, you are not using the 5 Ghz band, no antenna connected, so you have that radio disabled, right?

Lrod78
Occasional Advisor

Re: Settings for MSM466 with External MIMO Antenna - MSM760 Mobility Controller

Doh, you're absolutely right.  In the process of trying to give as much info as possible, i forgot to explain what the problem was.  

 

Users with the scan guns are reporting connections issues and when they do connect, it's low signal strength or very high latency.  

 

To answer your question, the radio without the antenna is disabled.  

 

The AP's were set to defaul settings but we were still having issues.  So I figured I may need to adjust a few settings, but wasns't quite sure which ones and to what.  Was hoping to see if anyone had any advice or best practices they follow. 

tschaps
Valued Contributor

Re: Settings for MSM466 with External MIMO Antenna - MSM760 Mobility Controller

It sounds like you've got the channel selection set to minimize interference. If I understand the layout, the nearest any AP is to another on the same channel is three aisles down and on the opposite side of the warehouse. 

A couple thoughts:

-- My first inclination is to suspect that the scanners are "hanging on" to a weaker AP as the workers move through the warehouse rather than hopping from AP to AP. If you have a good database of the device MAC addresses, you can ask users to stop right where they are when having trouble and phone you with the scanner number so you can look up which AP they are connected to see if its one of the nearest or if its "hanging on." You probably won't need many reports to check before confirming or ruling out this theory, as long as they do not move from the spot when they are having the trouble. 2nd best option, if they do not have mobile phones or walkie talkies in the warehouse, is to set the scanner down right where they are and go call you. Ideally, give them a "case #" to write on a post-it or piece of masking tape to show exactly where they were, and bring out a laptop or other wi-fi scanner to see what the wireless landscape is at the point they are losing connection.

-- how many VSC's? Just one, or different ones for different aisles?

-- I would also like to understand how this implementation was designed: by some engineers who did a proper site survey to look for sources of interference and map out how signals are reflected, etc., or if this was designed based on what has worked in other warehouses?

-- You've probably already done this, but verify that the scanners won't work in 5 Ghz and see if there are any firmware updates for them. Also check, if you haven't, if the scanner vendor has any recommendations for the wifi, such as data rate, encryption methods, visible vs. invisible SSIDs, etc.

-- Depending on what the warehouse racks and shelves are made of and what is being warehoused on them, you could have a LOT of interference from reflected signals. 

Z273
Frequent Advisor

Re: Settings for MSM466 with External MIMO Antenna - MSM760 Mobility Controller

Hi,

 

On MSM466, leave the antgain whatever value it was.

Put max power.

 

The antenna spec is here, for 2.4 gain is 8dbi, the antenna pattern is of a patch antenna, thus directional but not highly directional, more of a sector directional.

http://h20565.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c02697118

 

On page 4 of the antenna spec, you can see the antenna pattern/beam to help you figure out the direction where you want the signal to be hot.

 

You can inspect how the scanner and AP interact by looking at the data rate used by them, you can go into the wireless page client and click on the mac of the client, you will see the wifi tx rx rate, usually it gives a hint on how well they see each others.

 

Cheers.