AP 1552E: Put their antennas in different places

[rfuentes15]

Hi Guys

I have an AP Cisco 1552E mounted on a mining truck (CAT 797F) in a mesh wireless network. I´d like to know if i can place each antenna in diferent places of the truck with 3 LMR400 cables (e.g.: one in the left side, one in the middle and the third one, in the right side),... because when a i place the AP with its 3 antennas in a corner, the coverage is blocked by the truck structure. I know that im gonna lose signal but im looking for a "functional" solution. Do i have to respect a distance between the antennas? I attached an image for a better understanding.

Thank you!

[George Stefanick]

1550 as a client sounds expensive and labor intensive .. Why not go with a 1300 bridge in wgb mode or a 819 .. ? As for antennas placed in different directions with a 1550, it's not recommended. The antennas should be spaced properly for optimal performance. However seeing that all new bridges / clients are 8o2.11n you have limited options. It best to test ..

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[George Stefanick]

Btw what mine do you work for ? I have a close friend who designs wifi in mines around the world. I just returned from Peru. I was assisting him on a training project ..

Do you use modular ?

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[rfuentes15]

I dont work for a mine. We integrate Caterpillar technology in different mines in Chile.

The problem with WGB is that solution can not transport multicast traffic in different Vlans, but the native vlan (the one associated to SSID) and much of the customers want a multiservice network to transport sistems that use multicast/broadcast traffic.

The mesh network is not a problem at all. The challenge is in the clients (trucks) where the coverage is blocked in a big % cause of the structure.

However we integrate CAT technology, that is our core business.. but we need a good network to support it

[Scott Fella]

I don't really think that would work, but it might be something that you should test and see if it does.  The issue is with the diversity and the antenna separation.  That is where you can run into issues.

Thanks,

Scott

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[George Stefanick]

On these trucks due to their size and having to cover both sides diversity isn't in play..

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[Scott Fella]

Interesting. So the solution should work. I would just think that the antennas would hear the other AP since it has to be a MAP and loose connection to the parent RAP.

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[George Stefanick]

Mining is a world of its own and how they operate on wifi in the pits. I just spoke to Bruce. He has years of experince and can add valuable input. He also has 2 mines in Chile that he designed on Cisco 1524s.

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[Scott Fella]

Yeah I bet... I just know that mesh sometimes takes a while before joining a parent again if you loose connection to the parent.

Thanks,

Scott

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[George Stefanick]

I dont know that I would install a MESH ap on a truck. Thats asking for challenges.

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[bruce-frederick · Accepted solution]

The convergence time on the Mesh makes sensitive applications (Modular, DSS, matrikon, etc…) we use the 1310 as a WGB (the limitation is no dot1q and encryption on the 1310). We run a flat network right now. We have not seen a major driving need to add multiply VLANs on the mobile fleet. However, we are now shifting to the 819 Mobile Router. The results have been very good. We are doing multiple VLAN and most importantly the mobile station command works good on the 819. As for the antennas, we only use two antennas, one on each of the mirrors. This allows for better vision when the truck in against a high wall and the shovel is loading it.

[rfuentes15]

Very good input Bruce. Definitely mining is a world apart.

Cisco engineers have recomended us the isr819 as well, but they dont mention the use of an AP with a different configuration (as antennas placed in different directions). For obvious reasons they are based on the "best practices installation", but much of the times, these are not practical solutions for mining.

Glad to know that the solution with the isr819 and 2 of its 3 antennas have worked fine. Im gonna test it.

Are you using the 819 as wgb? Regard to the Cisco technical documentation, WGB permit multicast traffic just in the native vlan, wich is not a problem at all, but when you have a fleet with 500 vehicles with at least 2 systems on board (Fleet system, Proximity Awareness system and so on) that use multicast/broadcast traffic, it could be a serious issue to have a flat network.

[bruce-frederick]

We are currently running systems with over 200 units in the mobile fleet at our largest mine. Running Matrikon, Seeing machines, Modular dispatch, Trimble, IBIS, Centurion and several other systems. We have not seen traffic on the mesh caused by the broadcasts in a flat network cause the network have issues. YET!!!! We do see our Mesh networks growing and have the same concerns but they have not been founded in the three + years we have been running the Mesh with 1524SB radios.

BTY: we have also tested the 819 connecting to the mesh on 802.11g and then rebroadcasting a local SSID on the 802.11a. This could be an asset to our survey crews so they can drive a light duty vehicle in an area that they can get a connection with the 819 (the handhelds don’t have enough power to reach far). They could then broadcast a different SSID around their truck to download map updates.