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."

Comments

Fresnel Zone

[Jason Straight]

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.

Range Reality Check

[zobo]

Here is an article called "Range Reality Check" that looks at the range from a purely physical perspective. The conclusion drawn by the author, one of the NoCat folks, is that

"...your antennas would have to be at least 104 feet above the surrounding terrain, separated by 25 miles, pointed directly at the ground 12.5 miles away, with no intervening ground clutter."

So, in theory the original poster could achieve a range of ~50 miles with a repeater station (PC with two 802.11b cards) at the midpoint, 4 high-gain directional antennas, etc.

802.11b point-to-point

[Adam J. Richter]

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.

Cringely did this w/802.11b & Directional Yagi

[schmaltz]

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.

Two way Satellite

[certsoft]

Have you tried www.tachyon.com? They have a number of different plans depending on the bandwidth you require. $80000 would support this type of system for many years.

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 :)

Re:You already have the answer

[OmegaDan]

ok, so, buy 5 dishes and a load balancer. that should be what, 250 - 500$ a month ? your school probably spends more on toilet paper

home networking through power lines...

[ColGraff]

...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.