05-13-2013 06:32 AM
Rail road industry has an idea to use mobile device in train for their passengers. My question is Aruba AP can be installed inside train and get wireless from leaky cable bedside the rail road?
Do you have any reference to use in train or car?
The thing is, Aruba AP is usually placed in fixed place. If it is located in train or car, can it provide stable wireless circumstance during movement?
AP in train will roam if the train moves from AP to AP which are connecting by leaky cable along the rail way but clients don’t roam because they always access to the Aruba AP inside the train.
Or it is better for clients to access wireless to leaky cable directly without having AP in train?
05-13-2013 10:17 AM
Leaky coax is not appropriate for this application for a number of reasons.
- At 5GHz, the signal decays very quickly even with directional leaky coax (e.g. slots only on one side). If you look at cable manufacturer data sheets, the loss is on the order of 25dB per 100m for expensive high quality cable. and over 30dB per 100m for cheap cable. so you need LOTS more APs with this approach than using standard antennas.
- The cable will not work if it is buried. Ground / soil absorption in 5GHz is extremely high.
- So you need to hang it from poles. And it's very heavy. Many tracks don't have any type of poles along side.
The strategy we usually use here is to mount APs at on poles with separations on the order of 500m to several KM depending on the rail speed, track geometry, above/below ground and other factors. We use standard outdoor dual-pol antennas to connect with the trains.
Do you have a specific project you are bidding? If so I can hook you up with your local Aruba account team for more support.
05-15-2013 02:25 AM
Thanks for your prudential information.
I understand that leaky cable solution has some risk.
We have a project, but it is initial stage so we need to take a look how it proeeds more.