Wanted - 45 Mile Wireless Broadband? 409
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."
Large DSL pipes? (Score:1)
Re:Large DSL pipes? (Score:2)
There really are many options from the government to wire schools.
Just buy... (Score:2, Funny)
Too bad bandwidth through power lines hasn't come out yet. It probably woulda come in handy now.
home networking through power lines... (Score:3, Interesting)
Re:home networking through power lines... (Score:2)
The power grid was built to carry power, not data, and it is singularly unsuited to the latter role
On the other hand, a couple of strands of fiber could fit on high tension runs with nary a bit of difference. The only complication would be that you'd need to send two crews out for repairs - one for power, one for fiber splices.
Yes, of course, but... (Score:2)
thank you (Score:2)
Not power lines, power companies (Score:3, Informative)
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.
hmmmm, good luck (Score:1, Informative)
Re:hmmmm, good luck (Score:2, Informative)
Too bad there isn't a "+1, this guy's right, you're screwed" for Ask Slashdot posts.
Re:hmmmm, good luck (Score:2, Informative)
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.
Re:hmmmm, good luck (Score:3, 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.
What about.. (Score:5, Funny)
Re:Satellite Internet can be ok (Score:2)
802.11(b) (Score:5, Informative)
JKoebel
Re:802.11(b) (Score:4, Informative)
Re:802.11(b) (Score:4, Insightful)
WEP keys easily breakable... (Score:2)
No, but it's the most damaging... (Score:2)
WEP as a system is weak because of assumptions they made to make it easier to implement.
IPSEC only a partial solution... (Score:2)
Re:802.11(b) (Score:4, Insightful)
Re:802.11(b) (Score:2)
802.11 at legal limits
8 802.11 line-of-sight pairs using bridges, high gain dishes, etc. runs at least $5K a pair bare bones (including your cabling, nema boxes, etc.), not including the tower, site acquisition, price of installation, etc. factoring those items in, you might double or triple the equipment number. let's say no less than $10K per site x 8 = $80K.
while we're just slightly over the $75K budget, we've constructed a sloppy network that has 8 fail points and terminates into a city - very likely a noisy zone for 2.4 GHz (most are nearly unusable for this sort of link with any level of quality). and you're probably getting at best a 1 Mbps link.
a better solution is two 35-mile engineered links using licensed 6 GHz gear (and if need be, use a 5.8 GHz link from the city tower to the ISP's facility). this will mean two 6 GHz links and 1 5.8 GHz link: $32K + $32K + $10K = $74K total (factoring less sites and less labor included). we make the budget and have 10 Mbps of thruput, though we need to have someone competent (aka "rf professional") do the link since we're dealing with licensed frequencies, permitting, towers, etc. try hunting thru your wireless isp players, since some of us like working with schools and occasionally work at a serious discount to make things happen for them.
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.
Wow... and that deserves a '5' score? Sorry... 802.11 point-to-point has been done for several years in these parts, and we're usually behind the times regionally. Would I rely upon it? No... not unless I was in BFE running a link between two farms with nothing 2.4 GHz nearby. Or did you mean 2.4 has never been out of the city? Huh? I run it on my 50-acre farm and walk around with my ipaq all over the place. The poster sounds like he/she's never been off of Manhatten in his/her life!
*scoove*
Try sharing your bandwidth (Score:2, Interesting)
Re:Try sharing your bandwidth (Score:2)
The problem with this system is that you end up trusting everyone in the city to supply your internet access.
Actually it's not so bad at all. You lease out a part of their basement and build a room (or just use a wire cage or enclosure) and lock the damn thing. Pay a little up ahead and get a separate disconnect and of course run a UPS on the power feed. The idea is to be independent other than the physical quarters.
Fresnel Zone (Score:5, Interesting)
Re:Fresnel Zone (Score:2)
Re:Fresnel Zone (Score:2)
Depends on the frequency you're talking about... (Score:4, Informative)
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.
Do you have line of sight? (Score:2, Informative)
You already have the answer (Score:5, Insightful)
BTW, whats wrong with two way dish ?
Re:You already have the answer (Score:3, Insightful)
Re:You already have the answer (Score:3, Interesting)
Re:You already have the answer (Score:2)
Re:You already have the answer (Score:2, Interesting)
Re:You already have the answer (Score:2, Interesting)
Fiber (Score:1)
Re:Fiber (Score:2, Informative)
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.
Re:Fiber (Score:2, Informative)
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.
Re:Fiber (and other suggestions) (Score:2, Informative)
I can't remember but if this was ever true, but it isn't now.
Extreme Networks [extremenetworks.com] and Cisco [cisco.com] 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 [extremenetworks.com]"[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 [google.com], 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
Range Reality Check (Score:5, Interesting)
Field day (Score:5, Funny)
Or maybe not.
/Janne
Re:Field day (Score:2)
Re:Field day (Score:2, Interesting)
but in another aspect, when a local elementry school went fibre optic, the armed forces came in and did it for the experience. perhaps this is something you can look in to?
and in a much more uprofesional method, whats the range on dry lines?
Re:Field day (Score:3, Informative)
Re:Field day (Score:5, Funny)
Re:Field day (Score:2)
Re:Field day (Score:3, Insightful)
I agree that fiber would be the only way, and you mights still need powered repeaters along the way, but you may be able to power these with solar arrays at the spot.
Metric! (Score:2, Informative)
Yes, I know: it's 72.4 km
Re:Metric! (Score:2, Informative)
Actually it is 72420 meters, but that's assuming the distance is 45.000 miles. If the distance is said to be 45 miles, it means there is an absolute error of 0.5 miles, or a relative error of 1%. After conversion, the relative error is still 1%, which corresponds to an absolute error of 0.7 km. As a consequence, it is misleading to give any digits after the decimal point (when expressed in km).
I should even have said 72 km instead of 72.4, but saying 72.420 km or 72420 m is implying a much better precision than we really have.
To express it in meters, we have to use scientific notation: 72E3 m.
Or we can state the error explicitly: (72000 +/- 700) m
802.11b point-to-point (Score:5, Interesting)
Satellite (Score:4, Informative)
http://www.intellicom.net/kids.htm
Re:Satellite (Score:2)
A suggestion (Score:5, Informative)
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 [solectek.com] 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!
Cringely did something like this (Score:2, Informative)
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 [pbs.org] -- 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
Cringely did this w/802.11b & Directional Yagi (Score:4, Interesting)
The story's an interesting read [pbs.org].
Re:Cringely did this w/802.11b & Directional Y (Score:2)
- 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.
Form a co-op (Score:5, Insightful)
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 [valink.org]. They did have some really nice pricing on T1s and installation. James
Satellite? (Score:4, Informative)
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!
My high school had a wireless broadband network. (Score:4, Insightful)
A little poking around on the net brought me to this site [packetworks.net] 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.
Relay's (Score:2, Interesting)
I would say try getting T1 if you can
Porsche-net (Score:2, Funny)
:-)
You will get better range and lower latency than sneaker-net.
Long shot 802.11 (Score:3, Informative)
- 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!multilink ppp (Score:5, Informative)
Re:multilink ppp (Score:3, Insightful)
Considering a rate of 7 cents a minute for 4 lines on from 7am to 4pm, you're looking at about $151 a day in long distance bills.
I'm sure he could get a T1 or some other service that would not only blow it away in quality, but also in price.
Re:multilink ppp (Score:3, Insightful)
On a typical 56K modem you get between 4.5 and 6 K a second (that's Kbps). So with 4 modems, you'd get somewhere between 18 and 30 Kbps. Not really fantastic bandwidth for even one computer, much less splitting up amoung 40 or 50.
Add to that the fact that your upload stream would be 28.8 X 4, or about 10-15 K a second, and you have a picture of why this wouldn't work. $130 a month for 30K max down and 15K max up is no bargain, and not sutable for splitting into a school network.
~Z
Re:multilink ppp (Score:2)
satellite (Score:2)
modem uplink, maybe twin modem uplink. Should be plenty of bandwidth for a school, unless you're producing amateur video.
several hops (Score:2)
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..
A school district that did something similar (Score:5, Informative)
From here [asba.ab.ca]:
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.
Two way Satellite (Score:3, Interesting)
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 :)
Consider Frame Relay (Score:5, Informative)
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.
Re:Consider Frame Relay (Score:2)
Many people are suggesting exotic ideas like making 802.11 antennae out of pringles cans and such, but I can almost assure you that's going to be a bad idea. When something catastrophic happens, ie, rain, or wind, it's going to be your (now wet from rain) ass going out there trying to adjust your pringles can so that it points the right direction again. And your (this time dry) ass will also be on the line as your administrators ask why their email goes down everytime it rains or gets windy. I'm assuming that at your job you have better things to do than this.
Most LECs (or if you're lucky you can find a longhaul carrier that'll do it) have very decent turnaround times on fixing circuits when they go down (which btw is also very rare with t1s and/or framerelay).
Frankly i'm amazed your ISP isn't helping you more with this. They have a LEC reseller that can easily price this out these land-based options for you, if they won't do this for you it's time to find another ISP. Also you might want to look at buying directly from the Tier1s, often they'll be able to undercut a local/regional ISP just because of their longhaul ties and unusual POPs so they can save large amounts of money on linecharge.
We've done 58 miles... (Score:5, Informative)
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.
Re:We've done 58 miles... (Score:2)
Would the restriction on power output be calculated on a per antenna or a per installation basis?
576K idsl (Score:2)
$1200 (3x) Netopia R3100-I [netopia.com]
$600 (12x) ISDN line
$2500 ISP data charge
Use your 'bird' (Score:3, Funny)
Enjoy!
I don't see why not! (Score:3, Informative)
Here are some URLs you might find interesting: HPWREN [ucsd.edu] (featured here recently) have a 45mb backbone using western multiplex tsunami [wmux.com] kit, and 802.11b [nocat.net] 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 [bawug.org] PersonalTelco.net [personaltelco.net] NoCat.net [nocat.net] Freenetworks.org [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 [cisco.com] (the 100mW versions will push the signal a lot further - 25 miles with 24dBi antennas - you can use Cisco's own, alternatives include Superpass [superpass.com] (based in Waterloo), HyperLinkTech [hyperlinktech.com] 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 [spacehopper.org] with a particular focus on homebrew kit.
You might want to investigate this... (Score:2, Informative)
Re:You might want to investigate this... (Score:2)
Since the signal travels at light speed, every mile of round trip equals ~10.7 microseconds. After about 28 miles the round trip delay becomes higher than the ACK timeout value, and the 802.11 protocol stops working, no matter how much you have amplified the signal. This limit is the same for 802.11 and 802.11b, and will be even worse for 802.11a which has shorter ACK timeout values. Of course, if your product allows tuning of the ACK timeout value, you could theoretically stretch the limit.
Another point to remember is that using 1W transmitters on standard 802.11 products probably violates your country's regulations.
45Mbit licensed or unlicensed gear (Score:4, Informative)
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.
Talk to Industry Canada! (Score:2)
Please make sure and follow up if you find a solution!
ttyl
Farrell
Omnired,the Peace Corps and /. (Score:2, Informative)
The BBC [bbc.co.uk] have a timely interview here [bbc.co.uk] with Bertrand Hartman of Omnired [omnired.com.ar], describing his rollout of internet access to a rural town in Argentina.
Also theres this [bbc.co.uk] describing such done by the Peace Corps for Luki, Bulgaria.
Finally, a former Ask /.:Internet Connectivity Options in Mozambique? [slashdot.org] may be of interest.
Fiber's the way to go (Score:2, Informative)
The project worked so well, that they picked up the call to offer the region internet connectivity, through edzone [edzone.org].
It is politically and financially difficult to do, of course. But, Publicly Owned Networks are a good thing... right?
I am trying to do almost exactly the same thing (Score:2, Informative)
Um, why wireless? (Score:3, Informative)
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
Why Wireless? (Score:2, Informative)
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.
Microwave is the way to go (Score:5, Informative)
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.
www.pcs.k12.va.us (Score:2, Informative)
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!
HAM/Commercial Solution (Score:2, Informative)
Canadian regs for 2.4GHz (Score:2, Informative)
-1, Troll? (Score:3, Informative)
Re:-1, Troll? (Score:2)
Re:-1, Troll? (Score:2)
Re:My $.02 (Score:4, Insightful)
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.
Re:My $.02 (Score:2, Informative)
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.
.Re:My $.02 (Score:2, Informative)
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
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Re:Maybe I'm missing something... (Score:2)
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.
Re:Maybe I'm missing something... (Score:2)
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.
Re:Why not just use two-way satellite?? (Score:2, Informative)
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.
Um, no... (Score:2)
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.