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On Tue, 21 Jan 2014, Rob Beard wrote:
Rob Beard <rob@xxxxxxxxxxxxxxx> wrote:Sadly homepages aren't an option, both buildings are on separate electrical supplies.Home pages? Lol I mean home plugs.However my Bing Fu kicked in and I found some interesting kit that does Ethernet over 75ohm coax. Using RG59 cable it can reach up to 300 metres at 100Mbit which would be ideal. Turns out it's actually for replacing analogue CCTV cameras with IP cameras. It's about 200 quid for the adaptors and about another 90 quid for the cable. RobThis got me thinking about Fibre again. Does anyone know what rural projects like B4RN up in Lancashire use?
Fibre.You can do about 80Km with not too expensive kit, but the distances you want are fairly trivial.
There are wireless solutions though, as well as free-space-optics. I'd avoid the FSO solutions though - they're not too good in heavy rain and fog... Wireless too - but look for kit with a proper outdoor unit that takes Ethernet to the unit (ie. avoid the ones that run co-ax to the antennae - you lose too much db that way)
Just down the road in Newton Abbot is a company who make full duplex Gb links that run at 60GHz, but they're probably a bit costly for your needs... (distance limit is about 1Km, so would work well though)
You can do it with Wi-Fi too - but the "trick" here is to get a system that allows you to use horizontal polarisation - that'll give you an extra 20db separation from the usual verticals that the consumer kit uses, so you can re-use the same channels - however Wi-Fi is half duplex. Actually, most wireless bridge solutions are half duplex as the cost of the filters, etc. is relatively high - however for simple video streaming you probably won't notice it, but also assume that the data rate they quote is the symbol rate - actual bit rate will be half that at best.
I'm not sure how the co-ax solution is working - unless it's pretending to be a store & forward switch at each end.
The distance limit on Ethernet is due many factors - the most limiting one AIUI is the Ethernet frame collision detection time for half duplex Ethernet and the "power" of the driving side.
You could stick Ethernet switches every 100m ... If you have power.However do be aware with co-ax/Ethernet/cabling solutions - even when buried, lightning can still pose a risk - go with fibre if you possibly can.
If you don't have an Ethernet switch with fibre ports then you can use something like a pair of these:
http://www.broadbandbuyer.co.uk/Shop/ShopDetail.asp?ProductID=12876one at each end and just plug the copper side into the switch at each end and run duplex fibre. You may have to do the termination yourself though, or just buy a Km of it ready terminated....
Gordon -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/listfaq