extending the range of 802.11g

I'm playing around with the idea of setting up a neighborhood wan using

802.11g (a free alternative to the Internet). The problem is 802.11g is limited to about 300 feet.

What if everyone in my neighborhood had their own 802.11g router? Would it be possible to somehow link them all together and create one giant network? If so, would it be possible to roam within this network?

How big could such a network be? Could it cover an entire city? Multiple cities?

Has this been tried before?

Your options are limited, Bill.

Do a google search on this group and you will find a lot of information about extending the range of of a wireless system.

Directional outdoor antennas at both ends could work for you and your friend and might be the simplest way. Access point at your house ... eithernet bridge at his.

Willam Lee

Visit this site ( all stoof for Boosting wireless and more )

http://www.hyperl>Actually, Bill, I think you are chasing a dream.

Hi Floyd,

How big of an area would a wireless G router mounted on a 300 foot tower cover?

Off the shelf wireless G routers?

A wireless G router costs less than $100. Each user would buy his/her own.

My goal is to create a city wide free alternative to the internet. Free meaning no connect fees. Each user would be required to buy his/her own router.Eventually it might actually connect to the Internet, but for now I'd be happy with a large intranet.

It would be a hobbyist project. Anyone could get in for the price of the required hardware.

Is this doable? Could it be done at prices that hobbyists would be willing to pay?

Hi William,

What if I want my whole neighborhood to participate? Let's say that just about everyone has their own 802.11g router (probably mounted on their roof). Can they somehow form a large network? Would I need more hardware than just the roiuters?

Once set up, would it be possible to roam around the neighborhood with a laptop?

Actually, Bill, I think you are chasing a dream. (some of our best inventions were thought up by dreamers)

If you are planning to hook up the city to the internet for free what connection are you going to use? Are you going to lease a T1 connection to supply the internet service to your network? Dont think of using the cable company until you talk to them first. They might have some ideas of their own about that.

Getting a signal out to cover a large area may be possable with a tall antenna and a few watts of power but the person at the other end must use enough power to get back to the your access point. Inceasing the RF power would certinaly bring you under the control of the F.C.C. and no doubt require a license of some sort.

From what you have posted I think you need to read up more on wireless networks and how they work. Placing a wireless router on every rooftop is not a workable option. Even if you placed a wireless access point at every intersection in the city and tied them all togather to a central location I doubt it would work like you would want it to.

William Lee

Dumb idea. Putting a power amplifier on an access point creates an "alligator". That's an animal with a big mouth and small ears. It can talk (and interfere) at a much larger range than it can hear. Tropos Networks 1watt mesh network radios are a good example of an alligator. The problem is that the amplifier doesn't really improve the receiver sensitivity. If the access point is listening to a bunch of low power laptop transmitters, the range will be no more with 1 watts belching from the access point, as with a power level equal to the 35mw laptops, so the range will be symmetrical. In my never humble opinion, power amplifiers are a great way to create interference and nothing else.

Yep. There are SBC (single board computahs) available that are designed for building "mesh networks". The basic idea is that each "node" on the network is also a repeater. Eventually, the packets arrive at the router that connects into the internet. This saves the cost of having each node have its own connection back to the internet. The problem is that it's a spectrum hog, suffers from bottleneck issues, and relys heavily on a supremely complex routing algorithm. Performance also sucks because each simplex node (that can only transmit or receive one at time) cut the available bandwidth in half.

The problem is that mesh networks do not scale very well at each extreme. If there are a insufficiently small number of nodes, then traffic may hit a dead end or go nowhere. If there are too many nodes, then the bulk of the air time will be spent forwarding packets in circles that eventually arrive, but rather slowly. There will also be far too many collisions. Nodes with two or possibly three radios that can do full duplex are a BIG improvement, but cost more.

Actually radios and infrastructer are only a small part of the problem. Managing the system, maintenance, security, customer support, enforcement, billing, interference mitigation, aluminium hat RF exposure nuts, and the inevitable government "assistance", will all be needed. Hardware also gets obsolete fast, so plan on replacing literally everything every 5 years or so.

Yep, sorta. Metricom, Rooftop Networks (Nokia), and a bunch of others. Horror stories and why they bombed if you want details.

(Motorola) Plenty of others.

So much for the technical and on to the political. I'm the chair personality, keeper of the faith, and bill collector for our neighborhood association, road committee, defunct cable co-op, and fiber/wireless network. In the past 30+ years I've lived in the neighborhood, I've had to deal with all manner of neighborhood cooperative efforts. Most fail. I would rather deal with the government bureaucracy from hell than with some of the stupidity I've encountered dealing with the neighbors and the fiber/wireless system. I've literally paid for almost all the hardware myself and they treat it like I run a public utility. If you value your sanity, I strongly suggest you develop a paying business model and forget about being nice. Otherwise, I hope you enjoy getting phone calls at 2AM asking if the internet is up.

"Bootstrap Bill" wrote in news:juVne.16111$qJ3.11105@trnddc05:

On a smaller scale to your vision, have a look at this:

If your German is not too good, look at the diagram and photos.

It's relatively easy to set up point-to-multipoint bridges like this. They do not suffer from the same complexities as mesh networks, but there is of course a bandwidth hit since the devices are single radio and cannot receive and transmit concurrently.

Hope this helps

Avast ye maties. T'is a landlubber amongst us. A good formula to remember is that the optical horizon is roughly: range = sqrt (2 * height) range = statute miles height = ft range = sqrt (2 * 300) = 24 miles.

Coverage area = Pi * r^2 = 3.14 * 24^2 = 1809 sq miles

Actually, the radio horizon is somewhat furthur than the optical horizon, but NLOS (non line of sight) propogation at 2.4GHz is in my opinion a crap shoot.

Your radio horizon will also be extended if you include the height of the client radio antenna: range = sqrt (2 * tower_ht) + sqrt (2 * client_ht) range = statute miles tower_ht = ft client_ht = ft For a 20ft high client antenna: range = sqrt (2 * 300) + sqrt (2 * 20) range = 24.5 + 6.3 = 30.8 miles

For extra entertainment value, drive around your area with Netstumbler and estimate how many access points per square mile you find. Double the number as about half are either not broadcasting their SSID or cannot easily be heard from the road. Using my latest Netstumbler maps, for Santa Cruz City, I'll guess a density of about 200 access points per square mile. Therefore, if you deploy in an urban area, you're looking at the interference caused by about 6,000 access points. You can get similar results by simply taking a laptop and decent antenna (panel or biquad) to the top of a tall office building and running Netstumbler. My record is 190 access points in downtown San Jose.

You do not want to know what it would cost to build and install a 300 ft communications tower. The Peoples Republic of Santa Cruz County has an ordinance limiting towers to 52ft above average terrain and about 15 ft for rooftops. Your local politics may vary.

It crashed in tests over Hawaii. That was also 1998. At the time, I was maintaining a web page for alternatives to DSL and cable modems for the San Francisco Bay area.

is really old so don't expect all the links to work. I've kept the page up beause it's become somewhat of a historical record of all the great dot bomb type of ideas for providing last mile service. Near the bottom is the science fiction section which includes the airplane flying donuts in the sky, the teathered balloon repeater, and a few of the many LEO and MEO satellite based financial disasters.

Ham radio field day is coming up in a few weeks. My grand plan is to construct an inflateable tower. In theory, just pump it full of air and up it goes.

(5.3MB) Photos and damage report next month.

It's difficult to justify even sharing the bandwidth when DSL at

1500/384kbits/sec now costs $15/month.

Who needs a tower?

Of course, it would cost far more than any group of hobbyists could afford to pay.

Hi Jeff,

Your Idea about an inflatible tower is a good one,

a few field day's back (1988 or 1989 ) we had a 4sq inflatible vertical setup for 160 and 8 meters with 8 weather ballons in Humboldt countty.. Helium was to expensive ,, so we had a buddy that had a tank of hydrogen,,,

worked good until sunday morning,, we head a 'pop' and on of the ballons broke, caught fire and we a a 'hot' vertical for 160

No problems, the ballon was out before it landed, but what a trip,, the verticals worked great..

Bob Smith NA6T Fort Bragg, California

I've been told by everyone involved that it either won't work, or is useless if it does. That's a sure sign of a great idea and also my secondary motivation to prove them wrong.

I saved enough vinyl from an old water bed to make a fair size tube. However, I can't seem to make a decent seal. Everything leaks.

So, I went to commerical tubing: |

| 6 mil tube isn't really thick or strong enough, but I figure a tripod type of arrangement should get me up to about 30-50ft. At

3cu-ft/min, my air compressor will take 20 minutes to pressurize to 2 atmospheres, so I'm currently looking into blowers and compressed air bottles. I wanna try to raise a small yagi, but it most likely will end up mooring an inverted-V.

There is a practical reason for all this as I wanna sell "emergency" tower kits.

Nice work and great way to start a forest fire. Almost every year, someone brings a balloon of some sorts to field day. Those are the years when the wind is blowing, and the humidity is low enough to produce really impressive sparks from the long wire. Every time, someone's antenna tuner is sacrificed to the cause. The 160 meter vertical magically became horizontal when the wind blew. This year, nobody is going to bring a balloon, so I guess we won't have any wind. Therefore, my inflatable tower might actually fly...err... work.

Barry ===== Home page

Most home users don't need wireless.

Once upon a time, I did some work with Metricom. They were into doing the same thing. Users were expected to roam around the city with their laptops (and later PDA's) while connected via (900MHz) wireless. At one point, I inquired about the sales of replacement batteries for the Ricochet radios. The NiMH batteries would last about 1-2 years. It was evident that the battery sales were ridiculously low for the number of units deployed. The implication hit me immediately that these devices were not being used for roaming around, disconnected from the wired world, but rather as an AC powered desktop modem replacements to provide a full time internet connection. So much for the un-tethered world.

The same thing happened with pocket calculators in the late 1960's. Everyone predicted that calculators were going to be used for all kinds of amazing things. My favorite is adding up your purchases at the supermarket. I haven't seen anyone use a calculator in the market for several years.

Another was the original concept of the laptop by companies like Grid. Prior portables were "luggables" and too heavy to be considered truly portable. Grid and Gavilan made the first laptops that could be effectively transported. The advertising literature showed a business executive (the only person that could afford the overpriced laptops of the day) with the laptop on the hood of his luxury automobile on a job site in the middle of nowhere. It was a grand picture of how portable computing was going to revolutionize management. When I asked real executives what they thought of the image, they informed me that they had flunkeys to do their computing for them, and didn't want to be bothered dealing with such mundane tasks as crunching numbers. So much for portable computing.

Lots of other dumb wireless marketing examples on request.

So, if you have some illusions of supplying wireless connectivity to the GUM (great unwashed masses), I strongly suggest you find a problem worth solving with wireless, and then see if your solution fits the problem and can justify the expense. Someone has to pay for the system.

Thanks for the info. I was about to give up.

One problem. It isn't wireless.

With my network (if it works as I hope it does), you'd be able to roam anywhere in the city with your palm pilot and make free voip calls to anyone else on the network.

Well a number of area in Australia already do this ( similar anyway) , google brismesh or Sydneymesh .. have fun.