WiFi antenna recommendations?

Fixed. I was feeling guilty so I ran it through the optimizer in

4NEC2. I haven't built a 5 dipole AMOS yet using these dimensions.
Reply to
Jeff Liebermann
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I put one up I use with a WiFi repeater and I can see dozens of wirless routers in my neighborhood. The antena i mounted at about

20ft on my chimney. There are about 8 or 9 with no security. If I so chose I would never have to pay for internet service. There is another subdivsion behind my house I havent even looked at that one yet. Strange thing I know 3 of the people who have the open systems and they are farly savy about these things. I wonder if they are leaving them open on purpose.

Jimmie

Reply to
JIMMIE

my WAP is open - no WEP or WPA, and I have MAC filtering.....

yeah - if you REALLY wanted to get in, I guess you could, but in most cases... it's someone war driving, or ??

Reply to
ps56k

It would certainly be best to remove the interference. If you have 4 bars now, 5 bars might not do away with the problem. Moving the microwave just

5' more might be enough. You may have to bite the bullet and put in some wiring to move the router.

Some of these guys are prone to take a practical problem like yours and turn it into a full-blown engineering problem or a swap meet for their break through technology or even an opportunity to throw mud. One engineering problem we faced was how to contain UHF security and housekeeping repeaters to a high rise building and it's underground structure. The final result was 99% coverage in the building and the parking structure, but when security went off the property, the radios went away. Visits to other buildings showed no coverage there either. We had to do that for both security and so we could get co-ordinated for licensing in an urban area. But it was a multi-million dollar system. This is free.

Placing one of those in an upstairs room is an invitation to the neighbors. I run a combination of wired and wireless. Wired to the desktop and to a port replicator for the laptop and wireless to a print server with several printers in a shop area, and the AP is off unless I want to roam around or do print jobs. There are times I have printed from the laptop, wireless in the shop to baby-sit print jobs, but it keeps the office clear and quiet. One of these days I will have to run a cat5 out to the shop. It is simply faster and more secure. The end result is my router, 1 foot off the floor with the power set to 50% to do all I need to do.

Reply to
JB

If stealing internet service from the neighbors is your intended purpose, you selected the wrong type of antenna. A sector antenna may be a great idea for running a WISP or central access point, where you're never sure of the direction the client radios are coming from. It's a bad idea for use at the client end. The idea is to pickup as little interference as possible. You're reception of 9 stations is a problem as any one of these could provide sufficient interference to make your pirated internet connection useless. I suggest you look into a panel or dish antenna, which will provide a much narrower horizontal beamwidth, with the added bonus of more antenna gain.

I was running an open access point at my office for a while. However, I was also monitoring connection attempts and traffic. I figured that nobody would bother. Wrong. I had some bum in a pickup truck and camper, connect regularly to make VoIP phone calls. I had no problem with him using the system and we eventually came to an arrangement. However, he stupidly told all his friends, who immediately abused the system, so I locked it up with a WPA password.

In another incident, one of my customers was in a hotel that wanted real money to use their Wi-Fi. (This was about 6 years ago, before the widespread proliferation of free Wi-Fi service). So, he connected to a random open access point. The security on his laptop was more than a little lacking (writable shared folders), resulting in the installation of multiple trojan horses, spam bots, etc. I suspect the open access point was an intentional trap set for hotel visitors.

Reply to
Jeff Liebermann

My home system is "1540 Jackson Ave" which is my address. The assumption is that someone wanting to use my system can bang on the door and ask permission. My office SSID uses the company name.

I'll stand by my statement. Unless you're running a mesh network, an omni at the client end is a bad idea. The client knows the direction of the desired access point and should use a directional antenna to minimize interference. In my limited experience (I ran a small WISP and neighborhood LAN/WLAN for a few years) interference is the most serious impediment to reliable operation. The more you can do to NOT hear the undesired stations, the more reliable the connection.

Sorta. You can do route switching easily enough, but load balancing between multiple internet connections can't be done without IP bonding, which requires everyone's cooperation (including the ISP's). The problem is that you can't use multiple ISP's to improve the download speed from a single connection. For example, if you want to download a large file, it will only go as fast as the speed of the fastest ISP connection. The other WAN interfaces remain comatose because there's no way to bond the single destination IP to two different download streams and routes. You can download something else using the 2nd WAN interface, but you can't use it to increase the speed of the first. Uploading has a similar limitation, where you can't improve the speed to a single connection. Where such routers work best is if there is a LAN full of users sharing multiple WAN connections, not for a single user looking for "better throughput..."

I've used a few of these with moderate success:

(See load balancing and multi-homing routers near bottom of page).

Incidentally, multiple cient radios, run to a passive combiner in a single omni antenna is a total loser. The FCC specifically proscribes synchronizing wi-fi radios. Even if the isolation can be increased sufficiently to prevent receiver overload, it's highly probable that a receive packet will arrive exactly when some other client radio goes into transmit. Some relief can be obtained by using different non-overlapping channels (1, 6, 11), but only with expensive bandpass cavity filters. The spread spectrum spreads quite nicely into the spectrum of the adjacent radio.

Reply to
Jeff Liebermann

Great way to collect accounts and passwords, sit outside a coffee shop with some gear and you're set.

Reply to
Bill Kearney

Which raises the question, if someone uses your access point without permission are you within your rights to do whatever you please with the packets (and their contents) you detect?

Seems fair, steal my airwaves and I'll steal your data in return.

Reply to
Bill Kearney

As far as the FCC is concerned, I suspect that the usual "third party reception" rules would apply. If the communication is transmitted over the airwaves but is not intended for you, you're permitted to intercept the communication but *not* to make gainful personal use of what you overhear.

There was one company which tried to prosecute some local "wardrivers" who had publicized the fact that the company was running an open wireless network. The FCC not only refused to pursue their complaint (pointing out that the company had created the problem and failed to mitigate it by turning on WEP), but cited the company for running an illegal Part 15 network (they were using external high-power amplifiers on their APs).

I'm reasonably sure that any criminal actions you implement with the use of such data (e.g. making any unauthorized access to a protected computer system, etc.) would *NOT* seen as legitimate by The Powers That Be, even if you gained knowledge of that data by scarfing it off of your own access point during an unauthorized use thereof.

As I understand it, there isn't any standard interpretation (even in under U.S. laws) as to what rights-of-usage apply to an open access point, in the absence of a statement by the AP's owner as to what the rules are. The FCC doesn't appear to consider this aspect of the wireless problem to be part of their jurisdiction.

I believe that in some areas, using such an AP without having received some explicit form of permission is considered to be a tort (a civil wrong) and the owner could file suit against you. Using the AP to break into a computer network (e.g. accessing files, etc.) could easily qualify as a prosecutable "computer crime".

I've read that some municipalities have passed a rule which says that the act of setting up an insecure access point, and broadcasting beacons "to the wind", counts as something akin to an open invitation... enough so that the use of the AP without explicit permission isn't considered a crime, or (I think) even a tort. This might especially be true in the case of those APs/routers which come with a WEP password pre-installed (the 2Wire models are one example) and in which the owner must explicitly disable the security feature if s/he decides that this is appropriate.

Reply to
Dave Platt

LMAO! My SSID is the same as my front gate Password. That way I never have to worry about opening it when I get home from work and the party is always in full swing when I get there! It's a little bit bothersome when dead bodies turn up in the moat though!

Reply to
JB

Nope. Two wrongs don't make a right. You'll also find that "an eye for an eye" and retailiation are not actionable in the USA legal system. Simply having your rights violated, does not magically make it open season on the perpetrator. The courts are expected to deal out the necessary justice, not you. For example, catching a burglar in the act does not give you the right to pound him into the ground. You can and probably will be charged with battery for doing that.

I have some experience and opinions with Wi-Fi related crimes and enforcement, but I don't wanna start yet another political discussion.

Reply to
Jeff Liebermann

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I dont steal internet service but I do have an arrangement with a couple of my neighbors so we can use each other service. This has come in handy a couple of time now in just the last few months when my cable went out and another neighbors cable modem went out. Its also a ton of fun just to build the antennas and be able to do it.

I must confess I have tapped in to a few unsecure home APs to check my email while traveling. These are often easier to find than a hotspot.

Jimmie

Reply to
JIMMIE

Higher gain omni has flatter /narrower beam. So it has to be pointed more accurately, tilting as needed to connect with desired AP.

As Jeff says, there's no reason to use an omni for a client. Get a much cheaper directional antenna and you will get more gain with less interference. Pointing will be easier too.

Take a look at the pattern for this one:

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Or consider a combination weatherproof box with built in panel antenna like this:

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the version that has the pigtail you need)

That's the first thing you want to determine, by the way, how much gain is needed? Another thread....

Steve

Reply to
seaweedsl

Funny story... I work as a contractor and was in an office in Louisiana that supposedly had an internal wi-fi setup. Signal sure did seem weak for an internal connection. All the guys there said they didn't know what happened to it. "It used to work good".

Mr. Boss, the guy who installed it originally, was in town and said "hey, whats wrong with the wifi?". Turns out the little wireless router had fallen behind some other gear and become unplugged. All during this time the office traffic had been going thru the network of a nearby residence.

Reply to
exray

There are outfits that make Omni Antennas for the 2.4 Ghz Band, that have Down-tilt designed into them. This helps deal with the flattening of the Vertical Polarization for local connections. I have one located on a 60ft Tower that has multiple AP's at various Azimuths, with ranges out to 2 miles. Works well for a Central Distribution.

Reply to
Bruce in alaska

Agreed, for an AP, if 360 coverage is needed, an omni with downtilt is an appropriate option.

Not for clients.

Reply to
seaweedsl

Yep, for Clients, I use 12dbi Panel Antennas, which are very compact and provide the required F/B Ratio and gain, for each link.

Reply to
Bruce in alaska

On Fri, 21 Nov 2008 09:00:09 -0500, "Bill Kearney" wrote in :

"Alligator effect" normally refers to higher transmit power (not higher antenna gain) -- big mouth, small ears.

It actually usually makes sense, since higher gain means narrower receive pattern, which better rejects off-axis interference. Interference in exactly the same path is possible but unlikely.

Reply to
John Navas

This antenna works great wit my laptop and desktop:

D-Link ANT24-0700 Antenna, 7db gain

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Reply to
d_musicant

I have this Comet antenna mounted on my roof and it works super!

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Reply to
d_musicant

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