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Wanted - 45 Mile Wireless Broadband?
Slashbaby asks: "I am a net admin for a school division that doesn't have broadband Internet. We are a rural school division, so we don't even have a provider in any of our towns. What I am looking for is a way to get highspeed Internet access into our division through either RF or microwave. There is a city about 45 miles away, (max. distance) that has ISP's that would be willing to sell us bandwidth if we can find a way to get it the 45 miles to the schools."
"What I am looking for is either companies or websites that deal with this kind of technology. I have no idea what to really look for, so any help ideas would be appreciated. Our budget for this project would be ~$125 000 CND ($80 000 USD).
We are currently using Direct PC satellite (which is NOT broadband) Unfortunately, they are dropping us in 2003...they are dropping service for rural communities in order to expand service for government funded projects."
A whole lotta cable :)
Too bad bandwidth through power lines hasn't come out yet. It probably woulda come in handy now.
I heard Iridium phones are going cheap.. How about purchasing the whole smear and having satellite modems ;)
Try a solution based on a form of 802.11, or it's variants. Find a suitably high place in the city to mount a directional antenna on, point it at your school, go about 10 miles, install an 802.11 acces point in some friendly location, add more directional antennas. You'd probably run up to $10k getting the proper communications equipment and such, and you'd need a PC at the first of the hubs to be providing the gateway (*Nix or 2K Server so it won't crash too much) It might work or it might not. There are many communities that are providing 802.11(x) service for their entire city, but I don't think it's ever been taken past a city before.
JKoebel
I suppose you could offer to give residential homes between you and the city free access to your broadband pipeline as long as they set up equipment to act as a wireless relay. You supply/(pay for) the bandwidth and access..and willing participants will set up the equipment.
Your biggest problem will be overcoming the fresnel zone. Most wireless requires radio line of site, which means there can be no obstructions. The fresnel zone is actually the eliptical path that a radio wave takes from one point to the next - for a 45 mile link you would need ungodly clearance between the 2 points. To calculate the fresnel zone and other requirements try going to www.ydi.com and use their online calculators.
If you do, some kind of microwave system might work. If you don't have line of sight (or can arrange for a series of relays), you are probably out of luck.
BTW, whats wrong with two way dish ?
Free Techno/Jazz/DNB/MI Music by guys obsessed with monkeys!
Light travels about 1/100 of an inch in a picosecond, not 45 miles. And microwaves travel just as fast through air as visible light does through fiber.
83chrise.nuf
Have a company sponsor you with cat-5 cabling and cable pipes. Then declare a "Plant A Cable" field day in the entire district, spread the kids out evenly along that 45 mile stretch with shovels and pickaxes, and let them dig! Or you could have a chain-gang-themed masquerade, and have them in striped shirts and fake manacles, with a price to the class with the best costumes.
Or maybe not.
/Janne
Trust the Computer. The Computer is your friend.
I don't know what the law is in Canada about 802.11b wireless ethernet, but people do make line of sight point-to-point 802.11b links with dish antennas on both ends that are as long as 20+ miles. I understand that Linksys WAP11 access point (US$200) can be configured as a repeater, as can some Cisco Aeronet unit that costs US$1k. Of course, when you include the antennas, housing, professional design and installation, the cost of making these repeater stations will go way up, but still nowhere near US$80k.
I'd say Fiber
I don't think optical is even remotely possible, even if the school was located on a flat plain.
Granted, fiber is indeed a superior connection. Lets not forget how cheap fiber is these days.
The communication companies know they can't charge much for the connection and for the physical fiber. In order to make a killing profit they must inflate the costs of installation. These costs are currently so high, that unless you are a huge corporation or university with a high demand and budget, optical is not a possibility.
If the school was in a more urban area, this could have been an option. Once fiber is already installed in a general area, it's relatively cheap (even with the phone company over-charge) to hook up to it.
Seeing how this school is located far away from any urban area, I'd say optical (or any wired connection for that matter) is out of the question.
can't sleep. clowns will eat me.
My school district used to be in the same situation. We used Intellicom's VSAT technology.
http://www.intellicom.net/kids.htm
45 miles is a pretty long haul for RF, given as other posters have remarked, the Fresnel zone, line of sight, and - from what I have been told -- the the curvature of the earth at those distances.
I administer a WWAN for my employer. We use Solectek Skyway wireless Point to Point bridges/routers. These units operate at 11mbps in the 2.4Ghz spectrum. I like these units alot, they are well made (NEMA compliant) and perform very well (~20ms latency on my 90 mile roundtrip network). They do not use 802.11b due to some the inherent problems with that standard. Their WCOPP RF protocol is based on HDLC, and their bandwidth managment is top notch.
Their maximum rated distance is 30 miles. My longest link currently is 18 miles (line of sight) and works great. While you may not be able to dp 45 miles with one link, it might be possible to operate a repeater site off of some radio tower between you and the city. I have 2 such sites, due to line of site concerns.
Good luck!
Too bad there isn't a "+1, this guy's right, you're screwed" for Ask Slashdot posts.
See Reach Out and Touch Someone and some more followups in Cringely/Old Hat. Admittedly, he used 802.11b wireless for less than 10 miles, but maybe you can extend the technology somehow.
One followup which might be of interest is the suggestion to become the broadband supplier for your town: Roll Your Own: Not Only Can You Do Your Own DSL, Here's How to Become a Broadband Tycoon at the Same Time -- if you could do that and get enough 802.11b customers locally (meaning no wires to string), you could justify some up-front costs.
HTH
"A gun is a tool, Marian. No better, no worse than any other tool. An axe, a shovel, or anything." Shane (1953)
but the distance wasn't so far, only 10km. He used telescopes to find a neighbor who was close enough to telco for DSL (Cringely wasn't), then hooked the neighbor up for free and mounted 21dB-gain directional Yagi antennas.
The story's an interesting read.
Big Daddy, Johnny, Burp, Aunt Zelda, Scott, Slurp, Big Momma
Fiber installation typically runs $15K-$90K per fiber mile, if one already has the right of ways.
The fiber itself is cheap; the expensive part is installation which is highly labor intensive, even today. Add in the insurance installers have to have to cover cable cuts made when they run their directional boring machine through someone's cable, and it's obviously not a project you'd want to take on without some kind of co-op with city/regional government.
Sig??? I don't need no stinkin Sig!
Why doesn't the local communities get together and form a co-op? The school system would take the lead on this since they would benefit first but the rest of the members would benefit.
If your system is anything like where I grew up, we had small schools for each of the communities. Why not take a room from each of the schools and turn it into the local pop for the service. If you've got a line of sight from each of the schools or could get access to a point where you could relay it, then you wouldn't have to worry about using T1's to connect each of the locations.
The co-op would sell access to the Internet and since they're the only game in town there's no competition.
The school system would get deep discount since they're providing the space and power. But, setup a non-profit to run it and make them responsible.
Of course they'll be some interesting political hurdles to jump but hey that's what makes life so great.
If you live in Virginia there is a state program to get deep discounts called Virginia Link. They did have some really nice pricing on T1s and installation. James
How about satellite?
I know that ping times are a little crappy, and if you want to do any hosting you'd best forget about it and all, but it's not too bad a solution.
Down here in Australia, we've got a real problem with rural schools. 45 miles is nothing, some face distances of hundereds of miles to the nearest populus. Telstra, our major carrier tend to pitch the satellite option to our rural users quite heavily.
I work for a regional school, and although we aren't far from a small population, we still don't have access to DSL or anything similar, so we use a Sat. connection. It isn't perfect, but it does the job where the kids are concerned. It serves 150 desktops without any real difficulty, and with very little downtime due to the satellite itself (some due to the people running it though).
I'm sure there must be some Sat. options available in other countries (after all our uplink is in the U.S.). You might want to give it a try!
"How much truth can advertising buy?" - iNsuRge - AK47
The high school I used to attend had wireless broadband years ago (well probably 5 or 6 years ago anyway).
A little poking around on the net brought me to this site which explains all the details of the install at my school and the other schools in the board. You might want to check out that site for some ideas anyway.
If your area has cell phone towers, then radio relays can cannect you. (It uses those microwave dishes that are on each cell tower, thus you do not have to set up a single huge dish up high.) I do not know the price, but it has been the way my company has linked remote offices in the mountains. I heard it is pricey for a subscription, but bearable. It is also not too fast, but it will be faster than 56k, and is essentially your network...you set it up, they maintain the dishes. BUT You will also have to deal with telco BS.
I would say try getting T1 if you can
badness 10000
Buy yourself a nice car for $100,000 CDN and a CD burner and offer to drive CD's from the city to your town.
:-)
You will get better range and lower latency than sneaker-net.
- http://www.oreillynet.com/pub/a/wireless/2001/0
5 /0 3/longshot.html
It would be interesting to see if they could pull this off with repeater stations, the only problem being cost for putting up the antenas needed. Not sure how much that would cost, but I'm guessing a lot!Have you considered using multilink ppp over modem connections? Assuming you can get a 56k modem connection in your area, buy 4 modems and get an account with an ISP that supports multilink and always on connections. Cost shouldn't be too bad: 4 lines * $20 + $50 ISP account(???) = $130 a month for approx 200kbps. Cheaper than a T1 and works anywhere with decent analog phone service. Add more modems if you need more bandwidth.
what happened to PCDirect? High-speed down,
modem uplink, maybe twin modem uplink. Should be plenty of bandwidth for a school, unless you're producing amateur video.
Well, when I tested data over Iridium the latency was around 1 second round trip. Pretty good for satellite communications but not what poeple these days are really expecting. Also, the data rate was 2400 baud and the connection was pretty lossy (voice calls were only tolerable on the phones). Iridium is not a solution for something like a wireless lan. Besides, you can't buy airtime on the constellation as an individual anymore (and it's way more expensive than you'd want anyway)
I read the internet for the articles.
Yes, I know: it's 72.4 km
This sig under construction. Please check back later.
I think probably the best chance you have is to set up two or three repeaters in between your school and the city. Someone earlier mentioned that you could go 25 miles, but with a very tall antenna (100 feet is very tall for an amateur project, IMHO). Hops of 10-15 miles would be easier.
Then again, there may already be some tall structures or antennas in your area. If there's a radio or TV broadcast antenna in between the two cities, it might be a good idea to ask them if they would do it. Of course, these folks probably actually talk to the FCC on a moderately regular basis, so they might be somewhat concerned about helping in this way..
Cell phone towers might be good candidates for the several-hop idea..
From here:
Northern Lights School Division No. 69
Project brings the internet to rural school division
Northern Lights School Division defied conventional wisdom to bring the world to the desktop of over 6,700 students and 700 staff in 25 schools. Using Wi-LAN technology the jurisdiction established the world's biggest wireless education system in both geographical area (5,714 square miles) and number of sites. It cost them $650,000.
The project has been recognized for its innovation and successful implementation both within the educational community and the industry. ASBO International awarded project manager Gary Krawchuk the Pinnacle Award for Excellence, making him the first Canadian to receive this prestigious award.
For more information contact Ed Wittchen,
Superintendent, at 1.780.826.3145.
Metamuscle.com - News in the Iro
I've been using a tachyon system for over a year and I find it works just fine for web surfing, email, FTP uploads, etc. May not be good for gaming, but students are supposed to be doing real work :)
Depending on who your RBOC/Telco is, you might want to consider frame relay from them. I used to run a small ISP in Oklahoma, and Southwestern Bell has *no mileage charges* on their frame relay service.
We used Intermedia for our primary pipe, but for redundancy, we got a second pipe from Southwestern Bell Internet Services. 1.5mbps, 64 IP addresses, DNS provided by them if we wanted to use it (which we didn't). They used Williams for their upstream backbone, which performed rather decent. All for only about $500/month, again with no mileage or loop charges.
Most likely Pacific Bell and the former Ameritech have similar pricing since DBC has borged them both.
Longhaul lines aren't that expensive. I highly doubt the line will be more than $1k/mo, which honestly isn't that bad. Yes wireless can be cheaper, but with that you sacirifice a lot of reliability, and honestly with a budget of $80k, $1k/mo doesn't seem that bad considering the startup costs for a land-based lines is basically nil compared to any wireless solution. (Contrary to common belief, pringles cans are not acceptable antennae).
Also you may want to call a couple Tier1 resellers and see if you can get a decent price from them. Very often the Tier1s are able to undercut local providers in situtations like this because their longhaul lines are cheaper than through the local telco.
A quick bit of background.
I am co-owner of a tech engineering company in the mid-west. We specialize in 4 areas, Cisco, Linux, Medical IT and last but not least wireless network design (LAN, WAN and Long Haul).
We had a customer that needed an interum solution (something to last them about 10 months until another means of connectivity came available). It had to be inexpensive, relatively fast, and wireless. We used FHSS gear to accomplish our task (Proxim RangeLAN2 to be exact). Our reasons were many, but I won't go in to that here. I will say forget about 802.11b for this (and for any serious wireless tasks other than LANs). We used two Proxim 7521-05 access points (the XR series as it outputs at 500mW as opposed to the 7520 which outputs at 100mW). As someone alluded to earlier, you have to have Fresnel clearence (ie cooperative geography). You have to know how to do a path survey, and you have to do one methodically at this kind of distance.
Let's assume that for you "task at hand" you can gain Fresnel Clearence and you want to do this. Since you are in Canada, you have to know your output power limitations, here in the US you cannot use high-gain antenna's with the 500mW AP's, unless you attenuate the signal before it reaches the antenna to reduce the output power to legal limits (and in the Carribean where we also do a lot of work, no one gives a rats butt what the law says). Not a problem for this type of thing, as normally the cable length from the ap to the Antenna on top of the tower is sufficient to reduce signal strength. Anyway, a couple of 21dBi or 23dBi parabolics, a couple of AP's (one in master mode, one in station mode), some cable and either your own tower or access to a tower on each end. Keep in mind, you can always use a repeater (passive or active) to clear obstacles in the middle, or to zig-zag as needed. Let's look at some dollar figures.
7521-05s normally retail for about $1,100 bucks. We are currently buying them for $189 from a place that bought out an ISP that went belley up. They are brand new in OEM packaging. Their address is www.imsales.com. So...
$400 for two APs
$800 for two good quality Parabolic Antenna'
$800 for excellent quality cable
$500 for two polyphaser lightening arrestors
Who knows for towers.
You got a long way to go before you reach 80 G's.
Now, the down sides. First, the speeds aren't going to be stupendous. You'll get between 800Kbps and 1Mbps. Still, not bad. The task of path surveying is not for the inexperienced. It requires lots-o-experience and knowhow, but there is certainly someone in your area that can do it (ask the local cell phone company who they use). Finally, antenna aiming is critical.
There are some other technologies that could get you higher speeds at a higher cost, but still unlicensed. Again, if you want to discuss this in more detail, e-mail me (rindeee@yahoo.com)
Anyway, I hope this helps. I will gladly give you more specifics, debate the virtues of various wireless technologies for this aplication, etc via e-mail at rindeee@yahoo.com. Be glad to help you accomplish your task...I think you will find it quite pleasing in the end.
PS. "Catagory 3" 802.11a (there are three classes of 802.11a the third intended for longer distance point to point) may be workable for this, but it's not on the market yet, so I don't know. The 2.4GHz stuff (Proxim RL2) is nice as the lower frequency than 802.11a (which runs at 5.8xGHz) is a bit more resiliant and has much better propegation over long distances.
For more info look at www.proxim.com and go from there.
Netopia has a multiple idsl unit, upto 576Kbps per unit (4x144kbps). Get 3 of these and combine the bandwidth for 1728kbps worth of bandwidth.
$1200 (3x) Netopia R3100-I
$600 (12x) ISDN line
$2500 ISP data charge
Actually, to some it's a viable solution. I know my school used satallite (when it first came out, and after the RF supplier went under). At peak usage it was real pain in the rear, but peak only happened in my experiance 3 or 4 times in a school year.
It also supplied 2 schools. Which, if all labs were being used, you'd be looking at 60 - 75 connections.
And unless downloading is often done, you're not going to have 60 students requesting information at the same time, so the bandwidth that a student has avalaible at a given time is likely enough to do thier work.
This guy is in rural Canada, not downtown LA.
Rural fiber gets plowed in. Two fiber cables cross my land, and I watched both go in. The 'dozers laid cable at the rate of about 1/2 mile per hour and there isn't a manhole every mile, let alone every 1000 feet.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
...is painfully slow and noisy. Until proven otherwise, I'd imagine internet access through power lines would be the same. There's just too much noise from sudden power drains (such as applicances and factory machines) or surges. The power grid was built to carry power, not data, and it is singularly unsuited to the latter role.
I'm the stranger...posting to
Watch those packets fly with http://www.blug.linux.no/rfc1149/
Enjoy!
A strange game. The only winning move is not to play. How about a nice game of chess? - Joshua (Wargames)
Here are some URLs you might find interesting: HPWREN (featured here recently) have a 45mb backbone using western multiplex tsunami kit, and 802.11b access points. They use solar power and batteries to power some backbone nodes.
Some other people using mostly 802.11b kit who will have some information you can use: BAWUG PersonalTelco.net NoCat.net Freenetworks.org
Using 802.11b or similar tech, you should expect each wireless hop to add about 5ms of latency, maybe a little more depending on distance. You can quite easily build a repeater by connecting two bridges together by a X-over cable. You could probably do this with Linksys WAP11 or similar, but over this type of distance you will find it much easier to use something like the high-spec version of Cisco Aironet 350 bridges (the 100mW versions will push the signal a lot further - 25 miles with 24dBi antennas - you can use Cisco's own, alternatives include Superpass (based in Waterloo), HyperLinkTech and others.
Aironet bridges let you set the distance of the link which modifies timing parameters (a slight problem with standard 802.11b over long distances), and their security is better than WEP.
There's plenty of homebrew opportunities for antennas and other related kit, although I guess they're probably of more use to people who don't have a budget to play with (: There's a collection of links on this page with a particular focus on homebrew kit.
Such a system can't exist, except for the military, which has ongodly amounts of spectrum allotted to it.
The bandwidth of a connection is proportional to the data rate of said connection. i.e. high speed data links use more spectrum than slow ones.
As you get higher in frequency, you have more spectrum available.
Problem is, once you pass around 30-50 MHz (depends on time of day and solar conditions...), radio waves go through the ionosphere instead of bouncing off it. In general, the legal limit on bandwidth below 50 MHz is only a few kilohertz. (For example, amateur radio operators are only permitted to use FM at 50 MHz and above due to bandwidth restrictions.)
Now, at VHF, UHF, and even microwave, there is a phenomenon called tropospheric ducting that allows for long-haul non-LOS propagation. Unfortunately, this is dependent on a temperatur inversion in the atmosphere. (i.e. weather dependent) It cannot be relied upon for communications.
retrorocket.o not found, launch anyway?
If I am not mistaken, this guy is Canadian. In Canada, telcos are either:
1) Crown corporations that have no problem spending that kind of money.
2) Regulated private monopolies. They are forced by the CRTC to build the last mile by 20?? anyway, so this shouldn't be a problem.
God save our Queen, and Heaven bless The Maple Leaf Forever!
Try this. Get 1 Watt amplifiers, 24dBi directional antennas, and 50' of LMR400 cabling from Hyperlink Technologies as a kit. Get two kits. Then, get two Orinoco ROR-1000 bridges and Orinoco's 802.11b gold pc cards. You should be able to stretch that distance. We are using the same equipment, but with 15dBi wide angle and omni antennas for a ship to shore connection. We get about 10-15 mi. (we're using lower gain antennas than the 24dBi directionals.) You can check it out here. If you just need a point-to-point solution, using the Hyperlink 24dBi directional / amp kit and Orinoco ROR-1000s may be the way to go.
This was a very interesting article. A couple of sticking points come to mind immediately. I dunno, maybe I'm a pessimist.
- What if the guy with the DSL connection has his phone and/or electric service cut off for some reason?
- What if, aided by his newfound bandwidth, becomes hopelessly addicted to multimedia porn newsgroups and sucks up all the bandwidth?
- What if they guy moves and is a jerk and takes the Airport basestation and other equipment with him? Even though setting up the shared connection is not technically illegal, it might be a pain to press charges in such a case.
load "linux",8,1
You will need a clear fresnel zone of around 300 feet (back of the envelope figures) above the tallest obstruction in the path. So you are probably talking about a 400+ foot tower, or something like a 150 foot tower on a 300 foot hillside (cheaper).
A 45 mile link will be hard to align properly, you will want to hire professionals. Cell phone companies use this kind of gear and go these distances regularly, for their cell-to-cell backhauls.
A lot will depend on where in our country you are. Industry Canada has their Schoolnet Initiative in the past, and I don't know what they have currently, but spend some time at strategis.ic.gc.ca and see what you can dig up. I'm also interested in decent bandwith to rual areas in Canada...where I want to live, I am about 5 kilometers from the closest Cable (ick, Rogers@home!) feed. I don't think that bell has ADSL out there yet. A company is starting to deploy wireless in a number of rual regions around Ottawa, probably using 820.11b, but I haven't investigated them much.
Please make sure and follow up if you find a solution!
ttyl
Farrell
CAN-CON 2019 - Ottawa's only book oriented Science Fiction Convention! October 18-20, Sheraton Hotel, Ottawa, Canada h
Yea, it's so cheap that NBTel has fibre drops to people's doors in New Brunswick.
In order to make a killing profit they must inflate the costs of installation.
Again, this is Canada. The Telcos do not have to make a profit, at least not in Saskatchewan or New Brunswick. Most of them are Crown corporations, they don't even have to break even.
If any of you non-Canadians are wondering what this "Crown" thingie I've been talking about is, it's the government. In Canada the government is "The Crown", as it represents Her Majesty the Queen of Canada, by running the country for her.
.God save our Queen, and Heaven bless The Maple Leaf Forever!
(+2, Informative) ???
WHAT?
In Canada (i'm Canadian, AND work for one of the major telcos)
1) None of the telcos are Crown corporations, sorry.
2) Regulated, yes, monopolies no.
Anyways, what would probably serve you best is a T1. You may be 45 miles from the city, but you likely aren't more than a couple of miles from your remote office. Most of the larger ones are equipped for T1 service.
Point-to-point microwave would be ridiculously expensive, and that leaves you with satellite which is great if you don't mind the lag. If you decide on a satellite connection, get in touch with Telesat, and i'm sure they can hook you up with some more info.
I can't remember but if this was ever true, but it isn't now.
Extreme Networks and Cisco both have long haul GBICs available, and have done for a little while.
I don't have info on the Cisco models available right now (Ciscos website is BIG!), but Extreme have a 1000BaseLX-70, that will do 70 km on singlemode dark fibre. On top if this they do what I could best call a gigabit fibre line driver in the form of a "SummitGbX"[tm]. They claim it will definately do 80 km, and possibly up to 100 km, I have heard one claim that these units managed to reach 120 km. Basically, you hook these up to your 1000BaseSX interfaces at each end, and it does some wibbly-bits to bridge the 80 km or whatever length of fibre :)
I would love to verify all this independently :) but I never even dared ask the prices :/
Of course, all this doesn't really help your cause much... you might be able to find a friendly telco that will blow fibre in for you. Apart from that, your realistic options might not include wireless.
At that range, you will have to go for some sort of microwave transmission, and even then you will probably have problems due to the Fresnel effect, which bends and scatters photons at the earths surface. The maths escapes me at this moment, but to reach 45 miles in one hop you would probably need to have each end nearly 200 foot up in the air in order to clear inconvenient obstacles in between, like buildings and trees (how careless to put them there!). To do it in several smaller hops might be easier, but then you have to rent or buy locations to put your repeater stations on.
Another possible thing to do would be to link all the schools locally to a central point using some easily available method. Microwave links might be suitable here, as well as optical wireless links, T1 leased lines, or whatever you chose. The most usefull central point would be a telco CO, which means that you will only have to rent backhaul bandwidth on the telco's network without having to pay for an expensive tail to anywhere else. Almost all CO's will be served by fibre now, which makes renting a fast connection very much cheaper and easier to provision. As you well know, it is that last mile that makes it expensive.
I wish you good luck :) maybe you'll let us know how it turns out?
btw, I don't have any connection with Cisco or Extreme, I just use their kit in my job
meow! Maria
The BBC have a timely interview here with Bertrand Hartman of Omnired, describing his rollout of internet access to a rural town in Argentina.
Also theres this describing such done by the Peace Corps for Luki, Bulgaria.
Finally, a former Ask /.:Internet Connectivity Options in Mozambique? may be of interest.
troodon.net
If they have enough phonelines to run a school, there is enough copper in the ground to get a t1 there. If there isn't, I believe it's the telco's legal responsibility to plant (copper|fiber) to get something there. A t1 only uses two pair copper, and if you have a phoneline you have two pair copper. You can even do neat stuff like using X amt of your t1 channels as voice lines, so "i don't have any more copper" isn't a very valid argument because you can replace your pots lines with your t1 as well.
I highly suggest you call your telco reseller and/or look to get a new one if they say it can't be done without a really really really good reason on why it can't. The telcos will *always* create reasons on why things can't be done, but if you (actaully theoretically your reseller) keep on pressing them and/or talk to other people (who's heads aren't in their ass), you'll usually find out that it can.
Also, my figures are based on inter-city copper links of longer distance, they certainly apply here.
I hope you are not really an EE student. If you are, try to remember your physics, as you will need it eventually.
The speed of travel of electromagnetic waves of a particular frequency depend on the medium of travel. The fastest it can ever be is in a vacuum, where it is C (the famous constant). Furthermore, there is something called a mode of propagation which effects the speed of a signal in a waveguide (which fiber is).
In air, with a direct (no bounce) link you should get vanishingly close to C, as the relative dielectric constant of air is close to 1. In fiber, you have to know both the relative dielectric constant of the fiber, and the mode of propagation to figure the effective speed of propagation, but it can only go down from C. (I'm not a fiber expert so I don't know which mode of propagation is used or what epsilon is for the fibers).
In typical printed circuit boards, the speed of propagation for inner layers depends on the dielectric constant of the board material. FR4 is a common material type, and it has a nominal dielectric constant of 4 (that's what the 4 in FR4 is for). In spite of this nominal value, the actual value is usually taken to be 4.2 for high-speed signals. And if you are not dealing with high-speed signals, then you probably don't care whether the constant is 4 or 4.2. This means that signals travel at slightly less than half the speed in an FR4 circuit board than they do in air.
I hope you have learned something!
MM
--
By including this sig, the copyright holders of this work or collection unreservedly place it in the public domain.
Do what MMNET, Middle Michigan Network. They got a bunch of the area school districts to band together to build a fiber network. It contains about 300 miles of fiber.
The project worked so well, that they picked up the call to offer the region internet connectivity, through edzone.
It is politically and financially difficult to do, of course. But, Publicly Owned Networks are a good thing... right?
Check into the Tsumami products from Western Multiplex, you will most likely find a solution that will work for you in your price range. http://www.wmux.com/products/index.html
Can't you get a fractional point-to-point T1 from the phone company? They have to bring lines in somehow...
45 miles is nothing when you expect to pay about $1000 per month for a full T1 over 250 miles. I'd guess you can get a fractional T or link to a frame cloud for about $500 per month and about $2000 per point. If your budget is $80,000, that leaves you with $70,000 (in one year) to pay for Internet services from an ISP. You should be able to get internet services for less than $1000 per month. If you're looking at $80,000-$4,000 (for hardware) = $76,000 / $1,500 (per month), you'll be able to have that active for over 50 months (that's over 4 years for those counting).
Skip the huge outlay of money for a technology that will be sketchy at best in bad weather and go for something that works and is proven many, many times over. If you want equipment recommendations, let me know. You can pick up some standard T1 routers (Cisco) with an integrated CSU/DSU off eBay for close to $1000 each. Your ISP may not even require you buy one at their end if they've got space on their T3...
All money estimated in U.S. currency.
Eric
LOAD "SIG",8,1
LOADING...
READY.
RUN
I work with PTP circuits everyday all day long. I know of one guy who is paying well within their budget for a much longer loop.
Currently in the US Worldcomm is waiving setup, they may do so in Canada as well, but I just priced an approx 120 mile T1, and the loop fees were only $670/month with 1 year contract. (Downtown Sac to North Shore Tahoe). The link up at the other end with a major ISP was $500/month.
With a $120,000 budget, even Canadian this should be doable.
Preface: I'm amazed at how poorly Slashdotters read the question. The post is about a 45 mile hop in rural Canada -- this is not the usual suburban nerd's home connection. No FCC, no RBOCs, and no, you can't just trench 45 miles of fiber optics for C$125k. (That's about what one mile of urban trenching costs, or maybe ten miles of rural Ditch-Witch burial.)
This type of application can, I'm sure even in Canada, use licensed point-to-point microwave. This allows lots higher power than 802.11 (forget the "b" which means higher speeds for even shorter distances). Typical rule-of-thumb is that frequencies under 10 GHz can go up to 30 miles (okay, say 45 km) on a single hop, if you can get line of sight. The site in question might need a repeater along the way. The terrain is all-important.
It probably is possible to get some microwave radios on that budget, though a repeater would possibly blow the limit. Harris, for instance, has a good selection, and a free program, Starlink, on their web site, which does path calculations for various radio - antenna combinations. (You can source the radios elsewhere, but Starlink is obviously geared to match Harris' own radios.) These would probably deliver 3 to 45 Mbps, depending on the radio in question. Industry Canada (which regulates spectrum matters) would probably be able to point you in the right direction for licensing and frequency/path coordination.
Shamir presented a paper that nukes WEP from orbit- in fact, there is an exploit program out there making the rounds...
I am not merely a "consumer" or a "taxpayer". I am a Citizen of the State of Texas
Unless you build a lot more around it, you can still play man in the middle attacks, etc. with 802.11... However, for what they're setting up IPSEC would work with it with little issues.
I am not merely a "consumer" or a "taxpayer". I am a Citizen of the State of Texas
I helped setup the wireless system for this school a couple years ago. We used BreezeCom and Tsunami equipment. They have done much more since then. At 45 miles though you will have deal with the curvature of the earth. All wireless/microwave systems require line of site.
We setup relay stations for the sites we couldn't reach by one line of site path. The director of IT at the above mentioned school has a great deal of knowledge in this area. I'm sure he would not mind sharing that information. Good Luck!
Propagation characteristics differ depending on the frequency involved. Energy density will determine whether or not a signal is degraded enough to detect it or not.
Line of sight is not a good rule of thumb for RF propagation- for some things it's a good rule, for others it's only a good determinant of the maximum possible range.
RF is an interesting beast, one in which at one frequency, you're absorbed by the media, in another you're scattered by the same. Sometimes reflection comes into play and the signal bounces all over the place getting where you don't expect it. Sometimes the signal penetrates some media and goes further than you'd normally expect it to. Sometimes the signal hugs the earth and follows it's curvature to some extent (Which is where people get the thinking of line-of-site from- some signals bend some don't.).
Low frequency can be propagated through water and rock. High frequency can't. Low frequency propagates along the curvature of the earth. High frequency propagates along straight lines from the emitter source.
I am not merely a "consumer" or a "taxpayer". I am a Citizen of the State of Texas
Ok, I didn't read all the replies... So, I apologize in advance if this is a repeat. This solotion uses a combination of HAM and Commercial pieces. The commercial part of it is you'll need to license frequencies from the government. The HAM part of it is packet radio. There is a college in Italy that is using this. They have connection speeds ranging from 2Mb to 34Mb. Check out their web site here. The theoretical limit is 155Mb according to the site. If your interested in reading more about packet radio you can check out The Tucson Amateur Packet Radio Club. I'm not sure what is entailed in licensing frequencies from the government. But, it can't be that much trouble.
This just appeared on the BAWUG list, with some info on Canadian regulations for the 2.4GHz band.
My uncle works for Minnesota Power, and electric utility in northern Minnesota. Apparently they're doing a bit of a side business by selling excess capacity in their microwave relay system that is used to control and monitor their grid. They've also started running fiber with their transmission lines that they've installed in the last few years to expand their broadband capability.
science is a religion
I agree with the comment to call Cisco. Your sales rep has many ways to get funding (private and government) for schools. I just saw a memo last week from Cisco for New England Cisco partners to meet with them to discuss the options and strategies to land these types of fundings.
There really are many options from the government to wire schools.
--- RFC 1149 Compliant.
...then you give up the chief advantage of power line internet access: the use of an existing infratstructure, with no modifications or enhancements needed.
I'm the stranger...posting to
thanks
I'm the stranger...posting to
Because it's the easiest to do of all of them (requiring linear time for bitspace used for encryption.).
WEP as a system is weak because of assumptions they made to make it easier to implement.
I am not merely a "consumer" or a "taxpayer". I am a Citizen of the State of Texas