Wireless Network - 1 Mile !

[dbdezyne]

1. Need recommdendations on hardware for wireless capability of 1 mile.
2. Need to isolate wireless network from LAN.

Example: One pc "remote" will be about a mile away in another building. It needs to collect data and/or communicate with another pc a mile away in main facility. The pc in the main facilty will also need to be on the LAN in that facility, however, the remote pc should not be able to get on the LAN for security reasons. My understanding of this is that a wireless bridge can be used to connect the two pc together but keep the remote pc off of the LAN. The main pc will have to NIC cards, one for the LAN and the other for the wireless network.

Am I on the right track with this connectivity. I would appreciate a little insight into how this can be setup.

thanks

[cat5e]

Putting aside the Distance there are few forms of Wireless Bridging (see here, http://www.ezlan.net/bridging ), one of them would do want you need to do.

As for 1 mile briding with 2.4GHz Wireless, it can be done provided that there is a direct line of sight (No Building trees hills or other obstructions in between, the two Antenna, they have to look "eye to eye"

Example here, http://www.wirelessnetworkproducts.c...n=Custom&ID=21

There is a lot of Antenna's hardware that can be suitable, which one would be best for you depend on the specific environment and how physically the hardware can be installed. Examples: http://www.wirelessnetworkproducts.c...S&Category=223

[Sterling_Aug]

I hope you have lots of money and even more patience when try to constantly fix the wireless connection when it doesn't work.

One mile is an excessive distance to expect to work reliabely.

[r8500]

Wow, at one mile, if a bird flew past it would knock out the signal I would think.

[cat5e]

Wow, at one mile, if a bird flew past it would knock out the signal I would think.

The best I ever saw was a Guy that as part of is M.E.E graduate work, Bridged 5 Miles using Linksys WAP11.

[Servo888]

I hope you have lots of money and even more patience when try to constantly fix the wireless connection when it doesn't work.

One mile is an excessive distance to expect to work reliabely.

You don't need a lot of money... All it takes is about 150 bucks worth of amplification and antenna, and you have reliable wireless. One mile is NOTHING!

[millwork]

Hello dbdezyne,

I think Sterling is right – this could be pretty costly especially since it’s probably a “business” as indicated in the original post by the terms “main facility” etc.

Rather than post specifics (interpretation issues), recommend you review FCC Regulations and in particular Part 15 that has had some recent changes pertaining to digital mode of operation for transmitters in 2400 to 2483.5MHz. It’s better to be safe than sorry.

For “personal” or “experimental” use, there are fewer restrictions. But for “business” use, at least some interpretations indicate, “Part 15 business users must obtain (manufacture specific) Part 15 certified external components (antennas, coaxial cable, amplifiers etc.) or the system assembly must be performed by an FCC licensed technician who will issue, maintain or otherwise record a certification of compliance.”

It’s more costly just to get both antennae high and clear than the simple purchase of amplifiers.

Some of the amplifiers on the market are not certified for digital mode of operation (although they may work fine) and also may exceed the effective radiated power (ERP) limit for “business” use. Also, as cat5e mentioned, the antennae need to be directional and pointed directly at each other with no obstructions. However, the gain quotient of directional antennae may also allow the ensemble to exceed the ERP limit for businesses.

Of course, if you have a FCC licensed technician, currently certified for this equipment, on the payroll, costs would be a lot less.

Yet another concern would be unauthorized interception and use of the signal. But that, as they say, is another story.

John B.

[kwebb]

A mile isn't a really big deal if you know what your doing. You definitely do NOT need to amplify anything for a one mile shot. You simply need line of site, the right hardware and some working knowledge of how to setup a wireless WAN link. Even the panning is pretty elementary once you get the hang of it. Panning at 1 mile isn't too hard. As long as your within spec there is no need to get an fcc certified tech, whatever that is. lol If you don't amp then you really don't have anything to worry about. Your not going to exceed 1W to the radiator and 4W's out of it, which is the FCC reg for the 2.4 unlicensed band. For a one mile shot, two 100mW bridges and a 7-9dBi yagi would be plenty. Plenty. This assuming a very short transmission cable run however. Once you start adding copper/coax from antenna to bridge then you have to accomodate that signal loss somewhere else. You do not amp a 1mile shot though. If your coax run is long then you just get very low loss cable. LMR600 for a 60 foot run for example

[crusious31]

Wow, at one mile, if a bird flew past it would knock out the signal I would think.

That would be microwave antenna's. The birds get knocked dead in the process. Just like puting it in the microwave oven.

[millwork]

Hello dbdezyne,

It’s time to get more information from you. This will help the wireless experts address this query: “1. Need recommendations on hardware for wireless capability of 1 mile.” Then maybe someone will recommend specific equipment.

Is this for business use or personal use?

What is the lay-of-the-land between the two “facilities” and can you get the antennae high enough for clear line-of-sight?

What is the estimated distance from equipment to an antenna that is high and clear? One or the other antenna may not need to be mounted all that high.

Agree with kwebb that the length of cable needs to be as short as possible. TMS LMR and Andrews Heliax have the least loss for the physical size. LMR600 (about $2.50 - $3.00 per foot) and Andrews LDF4-50A (about $3.50 per foot) are good choices for longer runs. Although the Heliax has a less loss, it’s really stiff and harder to work with.

For anyone that’s interested, here's a handy line loss calculator for coaxial cable. Be sure to enter 2400 and not 2.4 for the frequency in MHz.

Although yagi antenna design is pretty efficient and they are very inexpensive to build or buy, for a few dollars more there are many 2.4GHz antennae with a parabolic reflector and no director elements. Yagis typically have a radiating pattern of 30 to 40 degrees and the parabolic ones are around 20 to 25 degrees. This concentrates the signal even more toward the target antenna.

Oh BTW, you’re not going to hurt any birds with this low power system. Even if they land on the antenna, it’ll be just a tingle. Since this is a continuous and not intermittent mode of transmission, they probably won’t land on the antenna anyway.

John B.

[dbdezyne]

Well, here is the solution. Corporate was very adamant about not opening up a hole in their firewall to allow wireless access even to a restricted ip. I completely understand their concern so I didn't push it. It was just an easy solution to my problem. The supplier had a 2.4Ghz broadband transmitter in our facility and a receiver in theirs which is about a mile away. I was able to send data to the transmitter and the transmitter converts the data to rs232 and sends it to the receiver. I installed a pc on their end to receive the rs232 and convert it back to the data that I needed. Problem solved. Thanks for all of the input on the wireless. Maybe I'll get another chance at it again.