New Case Study: Delivering the connectivity in Shipyards


Guest Mike

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I've been reading the case study and have some questions:

1. Why use the  XL CARRIER CLASS 2.4 GHz on each deck? Is it used as AP antenna for client's devices to connect? This is a directional antenna, that looks to me a bad choice in any building like environment. Especial since its a shielded type of antenna. A better choice to me would have been a ceiling fit omni directional or something like StationBox InSpot housing.

A typical ship superstructure is internally also divided by metal bulkheads (= walls) that are highly reflective and non penetrable. Hence in my opinion a multi path multy antenna AP, preferably 4x4 with beam forming would be a much better choice. The signals can then enter cabins and other spaces through doors etc. 

2. Although on the outside the horns are used to pickup the signal from distant AP I hope these ships are not regularly moved to another part of the quay. If so you need to re-align the ship unit each time again. But this is not a common practise I know (the moving of the ship).

3. Since it seems this is a temporarily situation for ships occasionally berthing at the dock it means the horns are to be moved and used again on the next ship each time again? I happen to have to move a horn once after two months and at the second attempt to tighten the screws one of the bolts 'locked' by the destruction of the tread. The alu bolts already corroded. I had to replace it.... This is in a very arid hot climate miles away from any salty sea air...... The guy using these horns in this environment better greases the bolts otherwise he need regular replacements... (The materials of the bolts are a weak point in the furthermore splendid design! :-) )

4. How is the network distributed from the CPE-Netmetal to the netmetals on each deck? He must be using a switch or router with many Ethernet ports. One for each device? 

5. The cables, do they run over the decks? On the bulkheads? Walls? How to enter the accommodation superstructure? Usually a ship's superstructure is made watertight, so unless doors/window are left open cables have no simple way to enter. To run and fit and later remove the cables seem a lot of work to me each time again. And then most cables don't like to be moved a lot. Or they tend to be a hazard if loose and trip people. I know, I'll tell you!

6. How is the power supply of all the devices arranged? You need a set of 110/220V and maybe even other type of voltage power supplies that also need to fit the different socket types that are to be found on ships... Ships have as many standards as there are on the world and probably even more.....

 

I have one suggestion that might proof to be workable; 

Have the CPE unit fit on the bow mast of the ship. Also fit a second directional (Just enough to cover the whole superstructure from there.) Another 30 degree horn could be perfect) These units in the mast are well out of the path of most workers and can be fit with short cables and one power supply only. No more risks of somebody tripping over a loose cable or braking the cable and only one socket needed to fit ship's (or yard's) power supply.

Then on each deck, behind a cabin's- or recreation room's- or the brige's- window place an indoor dualband (5Ghz for CPE and 2,4Ghz for AP) device.

If this device is placed direct behind the window it will pickup the outdoor 5Ghz signal and on the interior now distribute a 2,4Ghz signal in that cabin/bridge/deck (if there are not metal bulkheads blocking it). No need to run cable to each indoor AP. And most rooms/spaces have wall sockets available so it won't be hard to find one for the 'window-'unit. And if the signal from one such device is not penetrating the whole deck, just fit another one behind another window..... 

To me this looks a much cheaper, more manageable solution also less vulnerable (no loose cables = security item!) to incidents or accidents. No extra router needed (one of the Netmetals in the fore mast can do all the client's authentication, limiting and routing etc.) since all deck AP's are wireless connected to the one AP. The indoor CPE-AP units can be much cheaper too. So cheap that you can leave them as a bonus to the crew! (And where to hang the big XL's? A rb hAP-ac with its 2x triple chain radios is a perfect high capacity unit that presents the deck with some Ethernet ports too!) And we don't have to use any cables!

 

Regarding the 5Ghz signal penetrating the glass of the superstructure; 

When the outdoor AP is in the foremast, it will hit the glass of the superstructure under an almost 90 degree angle. I think the signal passes that without too many losses. If the AP would be located at the side (on the quay for instance! Even less work!) then I am not sure. It could be that when the signals hits the (thick!) window glass under a smaller then 45 degree angle it might get reflected..  The bottom line is I can pick up outdoor signals inside my house with a device better behind a window then behind a wall and in fact years ago we've had 5Ghz ubnt nanostations with a special vacuum nap device to fit it on the inside of the window picking signals from an AP a kilometre away..... it worked fine.

I've been working on ships 25 years of my life and now for 15 years am a wireless network operator with RF as my main field of interest. Probably from the days as radio licensed officer with basic background educations on the behaviour of radio wave propagation.....

If my suggestions are appreciated by the operator he can send me a pm rudy@marucom.es if he'd like to discuss any other aspects. I even have an idea to avoid the need of the foremast CPE-AP setup to save even more costs and hassle.

Nice article though!

 

 

 

Edited by wirelessrudy
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There is no only way to solve a problem.

We tested many ways, many equipment... and then we solve the deployment.

1. Yes XL CARRIERCLASS is used as AP and is the best solution, the signal is OUTSIDE the decks and send the signal inside. All de ceiling or indoor solution requires to put one cord throw the sealed doors. With our solution all the AP are outside and no need to pass cords across the sealed doors. The RF signal with de XL CARRIERCLASS is EXCELENT and is capable to reach 2 decks with one AP.

2. Wrong, the ships moves, not a long distance 50-100m, this is the reason to use the horns with 30º. Horns are capable to reach the signal in that case without need of repositioning or move the PtP horn.

3. Only one netmetal in PtP, the another are Mikrotik inside XL CARRIERCLASS and all the solution is conected with a POE switch, only 1 in the ship.

4. All equipment is in good state, you need to protect and not damage the bolts in the second tight.... use the correct tools and the needed force.

5. All the solution is linked from outside the indoors, this is the best solution to avoid sealed doors, distribution inside, meters of cords... We can mount and umount all the solution in less than 1 hour. The other providers and solutions requires to deploy too much cords, ceilings, meters of cords... TIME IS MONEY, and de RF singnal is below our solution.

6. Ships has 110v or 220v. Use the correct conversor to our standart in spain who is 220v

All your alternatives can be possible, test it and improve it, but we are proud to say we make a working one....

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