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That is very interesting. Good to hear from someone with real experience of this. I suppose that the system comes into its own when there is no alternative. Developing world countries often have sparse infrastructure. note: the VoIP bandwidth depends very much on the codec used. But that is in the hands of the user. Dave Berkeley On Friday 30 January 2009 13:19:36 Gordon Henderson wrote: > On Fri, 30 Jan 2009, Simon Waters wrote: > > Tom Potts wrote: > >> Dependence on telcos will result in all sorts of ill thought out > >> stupidity - there are moves afoot to sideline P2P 'in case someone uses > >> it for downloading music that only costs 10* the price the musician gets > >> for it to keep the parasitic music industry going and no other reason' > >> OK so we can run everything over port80 using tunnelling but > >> belts,braces and pringles aerials .... I can see 54Meg point 2 point > >> connections costing <£100 for 10km reach... > > > > Speaking as someone who helped build 10Km wifi links, we did it for > > cheap, but it wasn't easy. And cheap is a relative term - antennas and > > decent cables/connectors cost money - fortunately our radio guy had all > > that already. > > > > 54Mbps may be the spec on the devices, but over long distances WiFi > > can't do that (nor can WiMax do its 70Mbps over distance). Some Intel > > wifi devices use to let you tweak the algorithms for transmission, and > > we got significantly better than 56Kbps out of the links, enough to call > > it broadband and connect a few cottages. > > > > I think you are stuck with licensed radio links for most performance > > networking - like - urm - the telecoms companies do. > > I was once heavilly involved with rural broadband projects in the South > west - Buckfastleigh in Devon and Penwith+somewhere else in Cornwall. > Google might tell you something about the Buckfastleigh Broadband project > however, I doubt you'll find much about 1st Broadband who ran the > commercial side of it. > > Basically it failled. It cost too much and the punters weren't willing to > pay and BT were chasing us and enabling the exchanges way before their > target dates... 1st Broadband went bust twice and I eventually took it > over myself with the help of an RDA grant to keep the Buckfastleigh side > going (had 50 'customers' here) before BT enabled the exchange. > > It cost a lot because we did it properly - we used decent (for the time) > outdoor kit, all at rooftop level, to guarantee line of sight - paid > farmers, etc. to host base stations - relied on the goodwill of others to > host other repeater nodes. It was costing us upward of £250 for each > install by the time we took into account the cost of the hardware, the > cost of the person to go up the ladder and fit it (we used local sky > installers as they had insurance and tools), consumables, etc. > > We made it work, but it was expensive, and it took just one P2P user to > kill an entire segment of the network. > > VoIP over Wi-Fi isn't reliable either - sure, you can make it work at > home, but all it takes is one PC to get/put a big file and it'll kill a > conversation. There are more expensive access points now with traffic > management though - but it's still not perfect. VoIP is inherently full > duplex and Wi-Fi is half duplex. VoIP sends 50 packets of 160 bytes per > second each way. Some of the cheaper access points take the same time to > do a link turn-around as a single packet. > > Our longest link was 17.5Km from Marldon masts to a farm on Dartmoor. That > was using a pair of 2' dishes and 5.8GHz kit. The longest Wi-Fi link was > about 10Km - pure line of sight with a high gain onmi at the base station > and an 18db grid antennae at the client end. > > Buckfastleigh was described at the time like living in an egg box... > Trying to get line of sight was hard at times - then the town council > whinged that were were interfering with their CCTV system.... > > >>> When I see churches in rural areas, I see a big communications tower > >>> (you can hide a wifi antenna very easily) > > > > Urm since wifi is predominantly line of site - you can't really hide > > them. Although I know this guy who can make very stylish antennas for > > you, and know which guttering has the best microwave properties if you > > prefer the weatherproofed look. > > > > One church let us stick a satellite dish antenna on their tower for > > demonstration purposes, but I'm guessing that we wouldn't have got > > planning permission for a permanent fixture. > > We approacked some churches. They all said no. Buckfast Abbey did help us, > but only because we gave them a nice feed for free. > > > What I never realised was that many prominent hill tops have regular UK > > power sockets on top of them, to plug in all the radio gear. The radio > > hams have been here (there) before. So often it is just a case of asking > > whoever is paying the electricity bill. > > Good luck to anyone who tries this - again. I really don't think it's > worthwhile persuing anymore - yes, I know there are still some communities > outside the rach of BT, and for them it may work - as long as there is a > genuine commitment from the subscribers, but general-purpose? Forget it. > > Or maybe I'm just too cynical over it all - I did dedicate a lot of my > time and efforts to this and after my experiences, I won't ever do it > again! > > Gordon -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html