Laser Links

[Simcfc73]

Hi guys,

 

Anyone used Laser links to network buildings before.?? I've seen a base model which does upto 200m for less than £2k which would be way less than getting someone to dig a channel for fibre (if its possible).

 

I've heard horror stories about weather affecting the signal and stuff but theres going to be very little network traffic and most of it will be netowrk camera traffic transmitting back to the server.

[Geoff]

We've used WiFi bridges for a couple of buildings.

[Sirbendy]

I would have thought wifi...54meg a second should be OK..and it's cheap.

[Dos_Box]

Agreed, wi-fi and even directional wi-fi should be hellishly cheaper than the 'cheap' 2K 8O you think you need. 2K, what I could do wirelessly with that!

[free4440273]

while where on this topic, anybody have any views on what wifi models give the best results for this kind of thing. specifically, make and model - belkin, linksys, buffalo?

[Guest]

Yeh WiFi would be a whole lot cheaper, but.... How cool would it be to say your connected to your network via "laaaaaser" lol

[Geoff]

using a couple of 54g buffalo bridges here to link up a portacabin.

[Simcfc73]

Laser links does sound way cooler than WIFI. I may have a look at the new 802.11 ** whatever the standard is with the added range with a nice shiny external antenna. I have some really cheap DLINK wireless which I installed for our boarders to access the internet in their rooms a couple of months ago but they are way too weak to be any good and aren't configurable enough for my liking.

 

My last school had Cisco 340s and 350s which were pretty good but expensive. (25 of them around school ££££££££). you could configure them to the Nth degree but most of the time they had WEP and Sid enabled and the rest just looked after itself.

 

S

[E1uSiV3]

i have 10 Cisco Aironet 1200 APs, over 400 quid a pop but superb coverage, the usual cisco configurability (is that even a word? lol) but for a P2P, probably way too much money, jus a pair of buffalos as Geoff mentioned. Out of interest Geoff, how far is the air gap between the APs and what are the aerial specs?

[Geoff]

Just the standard internal areial. Distance is about 20ft.

[Dos_Box]

I use Buffalo for preferance. I had some D-Link, but they were flaky to say the least. Apparently D-Link have sorted themselves out, but once bitten twice shy etc.

[MkII]

We trialled an infra red 115Mb link over a mile. Was absolutely chronic! Welsh valley - fog? sited through park with protected trees - summer? High winds would blow it out of alignment so muggins would scale the roof of the three storey building it [still] hangs off with a kid leaning out of a window below watching a machine pinging across it whilst I struggled to move the thing.

 

It's still there, doing nothing. The kids think it's a big security camera! Maybe ebay - hmmm

[sahmeepee]

Our LEA (and quite a few others out there, Bradford I think) use microwave dishes (not the pyrex type) to provide broadband. They do 64MBit over a few miles line-of-sight IIRC. Not cheap, however.

 

I reckon microwave sounds almost as cool as laser, but certainly miles cooler than crumby ol' wifi

[artram]

One school I work for recently installed a laser link. It seems to work wel but the lovely children keep kicking a ball at it and mis-align it. The installing company charge £600 to come and re-align it.

 

The school have now had a cage installed around it. I'm sure the little darlings will work out how to throw a blazer over it at some point.

[ChrisH]

Dont go giving them ideas

[ChrisH]

Dont go giving them ideas

[MrLudwig]

We're in a similar situation. Having a new sports hall built at the moment on the other side of a public road, but must have it linked to the main school network (one of the conditions of the grant that’s funding the build). Was originally going to be a simple WIFI connection, but they want to do streaming media among other things which I don't think a 54Mbit link will cope with very well.

 

Had quotes of 10-15K for digging up the road and laying fibre, which is really way more than we can afford.

 

Have looked at laser, but there was on-going servicing costs as well as the initial purchase/installation.

 

The distance is only around 80-100 metres and there is a clear line of sight.

 

Any advice would be of great help.

 

Thanks.

 

MrLudwig

[john]

when you say road, do you mean pubic highway or private school road?

[Ric_]

You could cut down the costs considerably by using overhead cabling rather than digging a hole.

 

This of course assumes that you have plenty of height, you own the land in between and other overhead wires exist. For instance, if there will be a phone line going to the building suing an overhead wire, why spend £10K burrying your fibre?!? It all depends on what your school policy is.

 

Another thought is to see what conduit is being run between buildings - you could steal a bit of space in some

[john]

Ric, those were my thoughts, we use overhead, as well as KMs of duct work under the roads with the fibre in them. So shop around though as you may find using your sparks and yourself makes things cheaper. I was quoted by NYCC £800 for networking an external classroom (duct work in place already, and it was CAT5 not fibre) I did it for the cost of the materials and 2 days overtime, came to about £200 including the overtime bill for me and we had some spare CAT5 at the end of it for the next few projects.

[ChrisH]

You gotta be carefull with over head links and Fiber if its going to get tossed around alot by the wind some breakage may occur. Its worth getting it put in the ground just to see one of those mole machines in action

[john]

Or just do like I have done in the past, - spade, pick axe, and some hard digging, makes life far far cheaper, and saves on the need to go to they gym

[ChrisH]

Or just do like I have done in the past, - spade, pick axe, and some hard digging, makes life far far cheaper, and saves on the need to go to they gym

 

... or make more productive use of the PE departments detentions?

[john]

Or just do like I have done in the past, - spade, pick axe, and some hard digging, makes life far far cheaper, and saves on the need to go to they gym

 

... or make more productive use of the PE departments detentions?

 

Rats, I wish I had thought of that one before! But as I did the work in the holidays it would not have been easy to get the kids to do it, but for future jobs I will remember it.

[MrLudwig]

Thanks for the replies.

 

It's a public highway, not ours. We did get a cheaper quote for going under the road from a local contractor, but the county council won't let them dig up the road unless the staff they use have some sort of 'road digging up' certificate, which will cost them and thus push up the quote considerably!

 

There is a BT conduit under the road, but they won't let us use it. Apparently they did allow others to use their conduits in the past, but had lots of problems with their own cables being damaged so they stopped.

 

So the only options I can see are a WIFI link which will almost certainly be too slow, or laser or microwave links which are more expensive and require ongoing specialist servicing (yet more costs).