Alternative Frequency Wireless Ethernet Devices?

rtgree01 asks: "Do Slashdot readers know of any wireless ethernet devices that are not 900 MHz, 2.4GHz, or 5GHz. This is for a project that will be in an extremely harsh EMI area (thousands of V/m at those frequencies). Also, to make things even more impossible, line of sight is not available, even though the range for this system should be 30 feet max. Some of you might suggest to stick with a standard wired solution, but that is not optimal at all. Any suggestions would be greatly appreciated."

Comments

Mirrors

[mfos.org]

I don't know the exact setup you have, but IR with mirrors might work

How much bandwith?

[thefatz]

How much data do you plan on sending? Data over ham might work. You might be able to find some 19.2kbps wireless modems that work together. Any Ideas?

Re:How much bandwith?

[Komodo]

I don't think it's actually illegal to transmit encrypted data , but you have to keep a copy of the transmitted data (in the clear) for inspection by certain parties, definitely including the FCC.

What makes it illegal is that it's abusing a part of the spectrum that's reserved and licensed for a particular type of operations (amateur radio). You need to be licensed, and the terms of the license prohibit commercial use - there's very specific rules about that.

Use the right frequencies

[anthony_dipierro]

You could use MURS along with a ham rig. Or even better if you have the time, use a licensed frequency.

GENRIP

[nesthigh]

Depending on the amount of data you need to transmit.. GENRIP, GENeric Radio IP, based on STRIP , may work for you. As discussed here before, it basically extends IP over any serialized radio. So, you can choose your own frequency and power.

next

Modulated light

[Futurepower(R)]

He's right. Modulated light avoids electromagnetic noise.

Re:900MHz

[Koos Baster]

Checked that. Europe uses 900, 1800 and 1900Mhz (a triband phone can use all of them).

Slightly off topic; the 900 Mhz appears to use more energy, so you're probably best off with higher frequencies. This may be a reason some telcos have already decided to ditch the older 900Mhz frequency in favour of the others.

Fiber?

[wowbagger]

It sounds like this guy needs to communicate to some device that is at a different potential than the rest of the system.

Have you considered using fiber? High bandwidth, pretty much immune to RF interference, high voltage isolation.

However, if the target is moving around (some sort of industrial machine, perhaps?) this might not work.

That's the problem with a lot of Ask Slashdots - the person asking really cannot give a lot of information about his needs, so we cannot weed out suggestions that won't work.

Re:Fiber?

[wik]

>That's the problem with a lot of Ask Slashdots - the person asking really cannot give a lot of information about his needs, so we cannot weed out suggestions that won't work.

Nor will s/he give information about which frequencies *are* good. If a clue isn't given, expect plenty of useless answers. In addition, there is no justification for why a wired connection isn't optimal (and how "optimal" is defined in this situation). It almost seems as if this person doesn't want an answer!