Wireless Network: 1/2 mile wide?

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zacdl

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I'm basically looking to connect a few buildings together- the furthest of which is 1/2 mile away from where I am looking to put the central access point.

I'll have a T-1 connection coming in- plenty of bandwidth. So ideally I want a wireless solution that can deliver good throughput to all buildings (About 5 of them).

I know the traditional home APs are normally 300'... which won't work here at all.
So what are my options for an AP? I was hoping to use an 802.11x standard- so all these remote locations can just get a standard wireless card to use.

My only thought problem is how I will be getting the signal BACK to the AP for upstream communications... I would think the cards in the 5 buildings can't be your regular old Staples/Walmart cards...

I realize the AP may need to be industrial, more powerful than a home AP.
If at all possible I would like to keep the cards as your regular 802.11x.
 
Not to mess with your setup or anything, but have you thought about reconfiguring how this is all going to work?

Your goal is to connect buildings together. So why not just connect the buildings together with dedicated bridges?

Then install a more traditional AP inside the buildings on a different channel - and those are the AP's to which the users connect.

This would eliminate the upstream problem.

3COM makes an amazing 802.11g "Outdoor Wireless Building-to-building bridge" - thats self contained and has its own moderate gain antenna. All you need is a CAT5 to the roof and a pole to mount it up to. Power is run over the ethernet cable via a supplied adaptor. You put every AP into the same "WDS link" - and then plug the other end of the CAT 5 into your building switch, which would also have your indoors AP's.
 
Seems OK, but there is no way I could get this to work with a high powered central AP, and regular devices everywhere else?
 
zacdl said:
Seems OK, but there is no way I could get this to work with a high powered central AP, and regular devices everywhere else?
Click to expand...

Sure you can do that. It's called WiMax. Let me know how those prices hit you.
 
You can link point to point in two steps

Connect the two building with high gain parabolics, like 20-30db antennas, then distro out with smaller antennas.
 
Here is one suggestion:

***D-Link DWL-2100AP for all 5 buildings and the Main Building.
.....At the Main Building, specify the Mode to be WDS with AP
.....Set your SSID accordingly
.... Note that, for now, this mode will restrict you to WEP until a newer firmware comes out (which should)
.....You will manually enter the MAC addresses for each client AP into the table.
..... Set up a small (2 or 3 foot) all-weather dipole antenna, mounted on the roof.
...... Add one 1-watt antenna amplifier in between the root AP and the dipole.

****At each client building
.......Set each client AP to use WDS
.......you can use either a dipole or a small dish,
.......no need for an amplifier.

you will also need extension antenna cables for each ap to get them mounted.
however, this setup should be able to take care of you quite reasonably, provided you dont have a ton of stuff in the way of line of sight.

i have this set up at a forest preserve out in my area, and i could pick up signal from the root ap, with a 2 foot dipole on its roof, with my laptop just under a mile away.
 
i dont think i would want my buisness relying on some wireless link. i think a more reliable solution would be to maybe get broadband at each office and setup a vpn. most cable isp are faster then the T1
 
Eickst said:
Sure you can do that. It's called WiMax. Let me know how those prices hit you.
Click to expand...
More info?

r00k said:
Here is one suggestion:

***D-Link DWL-2100AP for all 5 buildings and the Main Building.
.....At the Main Building, specify the Mode to be WDS with AP
.....Set your SSID accordingly
.... Note that, for now, this mode will restrict you to WEP until a newer firmware comes out (which should)
.....You will manually enter the MAC addresses for each client AP into the table.
..... Set up a small (2 or 3 foot) all-weather dipole antenna, mounted on the roof.
...... Add one 1-watt antenna amplifier in between the root AP and the dipole.

****At each client building
.......Set each client AP to use WDS
.......you can use either a dipole or a small dish,
.......no need for an amplifier.

you will also need extension antenna cables for each ap to get them mounted.
however, this setup should be able to take care of you quite reasonably, provided you dont have a ton of stuff in the way of line of sight.

i have this set up at a forest preserve out in my area, and i could pick up signal from the root ap, with a 2 foot dipole on its roof, with my laptop just under a mile away.
Click to expand...

So no matter what- I am looking at extra equipment at each remote location (even if it is just an AP)? That's what I was afraid of.
How much are dipoles? I'm guessing the APs will be around $50 each and the dipoles would be .... (I understand I will have to spend money at the central AP.)
 
Well sure, you should expect to purchase at least some equipment. The following are just some samples, but tomorrow i could have model numbers of equipment needed if necessary.

http://www.hyperlinktech.com/web/hg2409u.php - dipole antenna 47.99 each

http://www.hyperlinktech.com/web/ha2401g_series.php?SKU=HA2401GXI-1000 - 1W amp, 199

http://www.hyperlinktech.com/web/cable_feed200.php - look at N-male to N-Female, 20ft = $34

Here is the direct link to their connector guide. It's the connections that confuse me most of the time. http://www.hyperlinktech.com/web/radio_to_connector_list.php
 
So I'm looking at about $100 per client building to get the signal there (assuming cabling isn't too bad).
And a few hundred for the building that is broadcasting...
 
marley1 said:
most cable isp are faster then the T1
Click to expand...
lol.. that is a breach of contract for pretty much every agreement I've seen with various ISP's. You can't run their cable internet in a business or even run any services out of it. Not only that, but reliability blows and the upload is super slow as well. Usually max connections are limited and their hardware blows that they provide you.
 
w1retap said:
lol.. that is a breach of contract for pretty much every agreement I've seen with various ISP's. You can't run their cable internet in a business or even run any services out of it. Not only that, but reliability blows and the upload is super slow as well. Usually max connections are limited and their hardware blows that they provide you.
Click to expand...

Business packages do exist. we are on T1 now but at our old shop Optimum Business gave us 1mb up and 8mb down. Only reason we are running T1 is thats all that is available. For what we pay now I can have cable and a dsl failover and still save money.
 
The problem with what you want to do is 802.11x was never meant to do this. You can only legally use 1W worth of transmitting power + at 2.4 ghz, that just isnt' enough to do what you want to do. You can use fancy antennas, but beware - antennas don't magically create more signal, they simply focus it to different areas.

Omnidirectional antennas:
A high gain Omni antenna takes signals that are spheracal (spelling? i.e. round like a ball) and squash the top and bottom parts of the signal so it looks more like a donut. Almost every standard router with rubber duck antennas is an omni antenna rated at something like 4-6db - if you'd get a 15db omni antenna, you'd be able to extend the range. See an omni antenna's signal pattern here: http://www.cisco.com/warp/public/102/omni-vs-direct3.gif

Directional antennas:
a directional antenna - yagi, grid, Parabolic, panel - takes that same sphere of signal and focuses it in a triangular pattern - usually 15-20 degrees. Here is a signal pattern map of a yagi antenna (they all look pretty much the same) - http://www.antennawarehouse.com/images/Wilson/Wil_301124_pattern.jpg

Another thing to consider is the 2.4ghz spectrum (what wifi uses) doesn't go through stuff very well - especially trees + hills. If you don't have a clear line of sight from building to building, you probably won't make this work. To get line of sight, you'll probably need to go to the roofs... which brings on the cost of antenna mounts, cabling to the roof, and waterproof containers for your equipment (you should keep your equipment as close as you can to the antenna as possible - you'll loose major portions of your signal if you don't use cabling that costs about $3 a foot or better)

My suggestions - get a high DB omni antenna for your main building (a central buiding - not necc where the internet connection comes in) - then get directional antenna for each of the other buildings. Buy high quality routers - cisco would be best, but engenious routers are also good as they have a high signal to noise ratio (can tune in wireless "stations" better) and transmit at 200mw (compared to 50mw in most consumer routers like linksys, buffalo, dlink, etc)

Be ready for some trial/error as this is fairly complex science involved. If you don't have 20-50 hours for research, buying, setting up + trial/error then I'd suggest hiring someone to do a wireless survey and proposal for equipment. Also, don't be surprized if you wind up having to try several diffrent types of routers and antennas.... you'll find something that works eventually... but you'll probably have several pieces that don't work for your situation.

You probably won't get this project done for less than $200 per building - Good luck
 
Good points. Something I didn't think about- each building isn't a whole half mile away. There are buildings inbetween each of them...

So would it be possible to connect everything in a daisy-chain fashion? Like the furthest away could be connected to the closest house that has connection, and then that house connects to the central building (or if it is still too far- to the next-closest?).

They are more or less in a straight line, with the central building at the end of the line...
 
teststrips said:
My suggestions - get a high DB omni antenna for your main building (a central buiding - not necc where the internet connection comes in) - then get directional antenna for each of the other buildings. Buy high quality routers - cisco would be best, but engenious routers are also good as they have a high signal to noise ratio (can tune in wireless "stations" better) and transmit at 200mw (compared to 50mw in most consumer routers like linksys, buffalo, dlink, etc)
Click to expand...

Everything that "teststrips" said are very valid points, and exactly how I would (and have) gone about doing it. I would add a few more points.

Increasing your mW on the access point itself , at a central location without doing it elsewhere will probably not work well. When you increase the power it is only transmit power, so your signal may get there, but if the other AP cant send it's reply back it will never work. You need to use the appropriate Antenna and power at each side. I usually try and utilize the largest antenna without having too much noise. It's a balance thing.


I have an install that utilizes a 12dB omni at the central location, and 14dB Backfires at the 3 remote sites utilizing off the shelf Buffalo routers. The longest shot I am making is nearly a 1/4 mile and I have exceptional signal.. I also have nearly perfect line of sight. Looking at it now It is probably a little over kill with the antennas, but I wanted to make sure that weather, and bandwidth were not issues.

Another thing to note is you are dealing with shared bandwidth. What you expect your bandwidth to be, needs to be divided up amongst the clients per channel. In my situation I could have had 3 directional (Or omni directional) antennas on channels 1, 6 and 11 at the main office and then had each other site on their own channel with it's own bandwidth.

As "marley1" mentions if this is an important link you may want to consider an internet connection with VPN, and utilizing the wireless as backup.
 
This *is* providing all connectivity- including internet.
The problem is that where these buildings are at is too far away for either cable or DSL, so T1 is the only option with enough speed... I obviously don't want to pay $4200/month when I can just share a $700/month connection.

Option 1
I'm thinking I could install a switch where the T1 comes in (or use the router- don't know what ATT provides... I know I need a firewall so I may just get a firewall with built-in switch or something), run one line of the switch to the central AP, the rest to the computers in the main building.
At this point I still need to know:
#1. What AP to get?
#2- What antenna to get?
Obviously I can install the AP inside the building, just run the antenna to the roof? It will need to be omni, for sure, as directional just won't cover enough width.
Then I can do similar setups (minus the routers/firewalls) in each remote building, using directional antennas pointed to the central?

Option 2
Similar to above, but I am thinking if the furthest building from the central (1/2 mile) cannot reach it, I can point it to a building mid-way, and bridge conenctions like a daisy-chain. The only thing with this is I would have to have an "in" and "out" antenna, correct?
 
zacdl said:
This *is* providing all connectivity- including internet.
The problem is that where these buildings are at is too far away for either cable or DSL, so T1 is the only option with enough speed... I obviously don't want to pay $4200/month when I can just share a $700/month connection.

Option 1
I'm thinking I could install a switch where the T1 comes in (or use the router- don't know what ATT provides... I know I need a firewall so I may just get a firewall with built-in switch or something), run one line of the switch to the central AP, the rest to the computers in the main building.
At this point I still need to know:
#1. What AP to get?
#2- What antenna to get?
Obviously I can install the AP inside the building, just run the antenna to the roof? It will need to be omni, for sure, as directional just won't cover enough width.
Then I can do similar setups (minus the routers/firewalls) in each remote building, using directional antennas pointed to the central?

Option 2
Similar to above, but I am thinking if the furthest building from the central (1/2 mile) cannot reach it, I can point it to a building mid-way, and bridge conenctions like a daisy-chain. The only thing with this is I would have to have an "in" and "out" antenna, correct?
Click to expand...

Option 1

#1 Choose an ap's that fits within your budget.. I did my 1/4 mile, 3 location (4 counting the central point) setup with $50 Buffalo equipment and those antennas I listed above. If I were to choose a AP now I would try and get one that I could adjust the power on (something like what teststrips mentioned "engenious routers" 200Mw.

#2 You wont know until you actually survey using the antennas and access points. Depending on line of sight there may be nothing that would work. I would suggest getting a variety (Maybe 4) directional’s and maybe 2 omni's for the central. They are pretty inexpensive, and having a few extras for future projects is always nice.

Option 2
- No you don’t need an in and out antenna. The traffic should be able to get from one place to the other without issue. Once your wds is set up every client on every side of the network should be able to talk. I would put the central AP in as close to the Physical center as possible, that way you are running it as short as possible. Think of it this way. let's call the central site, site A and 2 of the outlying areas site B and C. B and C will be able to talk to each other no matter where A is, unless the AP does some sort of network segregation, which is not really a default.

NOTE: whatever you do make sure you have UPS/surge protection on the equipment. as well as lightening arrestors for the antennas!


Are you located near Southeast Michigan?
 
Depending on the buildings in question and a site plan you may be best off doing multiple directional links between each building using something like a http://routerboard.com/rb100.html (the rb153 running nix with 2+ wifi cards) or http://routerboard.com/rb500.html (532 +564 == 6 wifi cards) and directional links out from there.

if possible stick the ap in a weatherproof box and keep your cable from the box to the antennas as short as possible <1M is good

also if you use the routerboard stuff you will be able to do POE for them

antennas are cheap directional is best

best way to start is to map it.
get some sat pics with topographic overlays so you can see what is between each building

draw a line from each rooftop to every other roof top. work out what might get through and what links will get interference etc.

then get up on top of each one and take many many pictures to look at.

optimally you want to be able to see at least 2 other tops from each building and 1 top from the outliers failing this you need to start looking into how big a mast you might need.

If you can grab the maps and trace out the buildings you need to link in their rough relative locations we might be able to help you work out what you may need.

oh forgot to ask although its not really relevant to the wireless side. are all the sites going to be on one big link or are you going to tunnel connections to the internet so that each site does not see the others (or at least won't read it)
 
Regardless, you are going to have to have clear line of sight and very little interference. With the budget you are on, I can still see you running into major issues, not only with connectivity, but also with reliablity.
 
The more I think- Option 2 won't work out well for future planning.

Everything needs to be in the "star" topology here- everything pointed to the central point.

I didn't think about tunneling here, but after you said it- it seems like it would be nice to be able to set it up to where each one just LOOKS like it has its own internet connection at least. But I was planning on one large network.

So let's say I have a decent AP on the main building that can go 1/2 mile... what is needed for the "clients"? Same setup? The clients, for all I care, can be directional, I just wish the main AP were to be omni. Will most any directional antenna work here, since it has more energy focused in one direction?

thanks.
 
Can't you give us a google earth imagery map of the places you need the network to cover?
 
Nope... not near enough detail to tell anything...
I can't even tell where the buildings are at- just way too blurry in that location.
 
So looking over all these posts again, tell me if this will work:

For the main building:
Access Point
12 dBi Omnidirectional Wireless LAN Antenna
1W Amp

For "Client" Buildings:
Access Point
14 dBi Backfire Wireless LAN Antenna

For Both:
Cabling to get to the roof (I might need more than this) N-Male to N-Female: 200-Series Cable 20'

Suggestions on model numbers for the APs? The only thing I forsee is them needing to be able to use the antennas with ease. The DWL-2100AP for all?

And this should work? Gives me plenty of range? I know it sounds like r00k is getting about a mile, which would be great once I account for any other obstructions that may exist.
 
zacdl said:
So looking over all these posts again, tell me if this will work
Click to expand...

Things look about right, but no one can really tell if it will work out or not until some testing is already done. There is a lot of stuff should work in theory that it doesn't - and again a lot of stuff that shouldn't work in theory but works fine.

I've never been one for d-link products - I'd go with something DD-WRT capable so you have the option to run alternate firmwares (sveasoft, tomato, Open-WRT, etc). But to each his own.. if you like + are familiar with the D-link stuff - stick with it.
 
zacdl said:
So looking over all these posts again, tell me if this will work:

For the main building:
Access Point
12 dBi Omnidirectional Wireless LAN Antenna
1W Amp

For "Client" Buildings:
Access Point
14 dBi Backfire Wireless LAN Antenna

For Both:
Cabling to get to the roof (I might need more than this) N-Male to N-Female: 200-Series Cable 20'

Suggestions on model numbers for the APs? The only thing I forsee is them needing to be able to use the antennas with ease. The DWL-2100AP for all?

And this should work? Gives me plenty of range? I know it sounds like r00k is getting about a mile, which would be great once I account for any other obstructions that may exist.
Click to expand...

LMR 200 @ 20 feet is about 3.3 dB loss
LMR 400 @ 20 feet is about 1.3 dB loss

Use LMR 400 if you can.

Wheres your lighting arrestors?

Every 3dB is about 2X the power. i.e. if you had your radio set to 100 mW and then changed it to 200 mW. It’s like saying you had a 6dB antenna and changed it to a 9dB antenna. Loss is your enemy I would go for better cable.

From a simple look you would be ILLEGAL with a 1 Watt AMP you can only have a 6db or less Omni directional antenna to fall within the FCC guidelines.

Keep in mind when you calculate the total you can use the loss in the cable, but you still would be to high. You can use this calculator to help.

You really need to survey and test with a variety of antennas. I have about 4 or 5 left over from the job I did. There are so many things that can go wrong and you can do wrong, you really need the equipment in hand to be able to test with. This doesn’t account for someone putting up a AP in between after you have put this in and effectively cutting your bandwidth in 1/2, or worse yet a microwave oven, 2.4 Ghz chordless phone, name your non 802.11 2.4 Ghz device that totaly kills your connection.

I guess what I’m trying to say, is what you have listed (with the exception of the amp pushing you above the legal limit) would be a good starting point, but be prepared to buy more, as well as not have this work at all.
 
are you legally allowed to setup your own wimax station?

like i know wimax covers a much longer range, are you able to throw one of those up on your house and broadcast what you need or do you have to go through the town/state?
 
zacdl said:
Thanks for the info, so do I need the 1 Watt Amp? Get rid of that and get the better dB antenna or go with more of an amp and less dB? Which is better?

As far as the lightning stuff- I put one of those in-line of the antenna cable I guess, but I just ground this to something?
Click to expand...


I prefer bigger antennas. You dont need to supply power to them, and it's 2 less connectors in the line. That being said I am going to go back to my you need to have a varity to put in place for surveying (testing) speach. Here is what I would START with.

3- 20' LMR 400
1 - 14dB backfire directional antenna
1 - 24db Grid Antenna
1- 8dB omni directional antenna. Rember you are going to have loss in the connectors anc cable so we can go higher than the 6dB
1 - 12dB Omni directional (Not for use with AMP)
1- 1 Watt Bidirectional AMP
2- Ap's

This gives you a minimal starting setup. Yes there are things in here you may never use, but those 14dB backfires may not make the 1/2 mile.

Yes you do need to ground the arrestors. I perfer to run my own ground.

NOTE: Make sure your ends are right (type/Gender) on the cables / antennas and lightning arrestors. It's easier than you think to screw that up.
 
Cool- what kind of connectors do I need to have on hand to hook the cable to the antennas and APs?
 
Wow, I never knew hyperlink took off. They used to be a back alley joint.
I'll be buying from them soon.

A friend of mine used to run Signull (signull.com) but he got picked up by a software company and is mainly working on software now, hasn't updated in a few years.
 
Shameless plug for my own ebay auction here - I tried to sell via the forums without any luck. This setup would give you a good idea of how your setup would preform - it includes:

- An EUB-362 USB wifi adapter - this transmits at 200mw + has an excelent recieve sensitivity - one of the best adapters for wifi available.
- A - 2.4 GHz 15 dBi Parabolic Grid Antenna - N-Female
- Wireless LAN Pigtail Reverse Polarity SMA to N-Male 2 foot

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=230166353942

You could see just how well things go with an unmodified router + just upgrading the client end - but for the 1/2 mile run, you may need to do more.

As I've said before, you'll likely have "extras" after you find things that don't work. This is the setup that helped me design 4 wifi setups for clients... I've since decided to sub-contract that work out because it just takes so much damn time.
 
As an eBay Associate, HardForum may earn from qualifying purchases.
I'm thinking that might work for the client end, sure. But the USB will def. not work being that specification is only 5m long ;) I most definately would need something longer.

Plus this would really only allow for a single computer use...
 
zacdl said:
I'm thinking that might work for the client end, sure. But the USB will def. not work being that specification is only 5m long ;) I most definately would need something longer.

Plus this would really only allow for a single computer use...
Click to expand...


I used these - http://www.monoprice.com/products/p...cs_id=1030304&p_id=2779&seq=1&format=2&style= - to get longer distances when needed. I've had 4 of them plugged togehter during some testing periods.

I don't think my auction would be great for a permanant solution - it simply gives you the ability to see how well things will work... to do your own "wireless survery" of sorts.
 
zacdl said:
Cool- what kind of connectors do I need to have on hand to hook the cable to the antennas and APs?
Click to expand...

Ahh yes I forgot to mention pigtails. RP-SMA is the connector those Dlink AP's use. This one, uses LMR 400, (most with smaller connectors use LMR 100,195,200) so your loss will be less using the LMR 400.

I usually try and get to LMR400 cable with N connectors as quickly as possible.

If you are ok with the lightning arrestor hanging out the back of the ap you could eliminate the pigtail all together.

Reverse-Polarity SMA-Plug to Reverse-Polarity SMA-Jack

20 foot N-Male to Reverse Polarity SMA Plug: 400-Series Cable. (CA4NMRSF020) (about 1/2 way down the page.

If I did this I would mount the AP and the Lightning arrestor as well as a few inches of the cable to something so you don’t snap the antenna connector off.

Also any connectors you have outside should be protected by something from the elements. They make this rubber tape stuff that is meant for waterproofing connections. You can pick it up at home depot. It's basically rubber tape. it has a paper separator to keep it from sticking to itself until you use it. Once you have a good layer of that on it you should tape over that with electrical tape. There is nothing worse than standing on a roof (or on a ladder) in the middle of winter trying to fix a bad connection, because water or whatever got into it!.
 
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