Actually, I was talking to another HAM on 2M (144MHz) the other day. He said that he has experienced interference all the way up into the 2M band from the BPL system that is being tested in Emmaus, PA (near Allentown, about 60 miles north of Philadelphia).
If his reports are true, that means this could also affect aircraft frequencies which are around the 118MHz range. Not very good.
I'm all for cheap broadband, and I wish I had an alternative to cable available in my area. But, the [BPL] system throws out interference by the truck loads, and affects all kinds of people, services, and businesses that use the radio spectrum.
I'm a member in good standing of the American Radio Relay League (ARRL), and the Radio Amateurs of Canada (RAC). And, I will contribute as many resources to this fight as I can afford.
I'm not sure what radio modems they are using. But, it actually sounds a little archaic if you ask me. I mean you have to work with what you have when you're on a budget (or worse... don't have one). But, it seems that this could be setup a lot better with some equipment donotions. HAMs (amatuer radio operators) are generally relatively generous people. And, all they would need is a couple HF radios since they have the computers already.
AX.25 is natively supported in Linux, and could easily be leveraged to make this whole thing a lot better. With some donated HF radios, they could have routable RF network up all the time in no time. They might even be able to use APRS instead of AX.25. But, AX.25 is a more proven protocol for this type of thing. See the AX.25 Linux HOWTO for details. Information about the protocol can be found at TAPR's website. They might even be able to get a little bit more speed, though not much, by using 10 Meter (28 MHz) FM. Though 10M can be probmatic sometimes, so I'm not sure I'd recommend that. 20M (14 MHz) and down are much better frequencies if you want something reliable. A DSP based noise filter would certainly help things in regards to speed, but they cost a bit of money.
As far as the modem goes... You can use a sound card and a small "control" box. All the box does is operate the PTT (push to talk) circuit. So, you might be able to do with out that if you wire things up just so. But, I have not played with that as of yet. You can also use a Terminal Node Controller (TNC) to get the signal to the radio. Some of the newer TNCs have a DSP filter built in, so that could be an advantage there. But, the best you can hope for on HF is about 2400 bps at half duplex, and 2400 is pushing it. There's just too much noise on Upper/Lower Side Band, and I'm not sure if you would want to use AM (though that might be an option).
There are a number of sites to check out if anyone is interested in digital commincations over amatuer radio. TAPR is a very good one, as is RATS. RATS works with a protocol known as ROSE. There is another one called NETROM, but I don't have a link readily available for that. TCP/IP is by far the best for this type of thing though. You can also check out the ARRL's site, and the FCC'samatuer radio page, for more information on amatuer radio in general here in the United States. BTW, you don't need to know morse code anymore to get on VHF/UHF. And, to get on HF you only need 5 wpm on the code, which is not all that hard.
Ok, I admit that last paragraph was a sales pitch. But, amatuer radio seems to be a dying hobby; at least here in the US. So, anything that can be done to increase interest is a good thing.:)
Ok, I didn't read all the replies... So, I apologize in advance if this is a repeat.
This solotion uses a combination of HAM and Commercial pieces. The commercial part of it is you'll need to license frequencies from the government. The HAM part of it is packet radio. There is a college in Italy that is using this. They have connection speeds ranging from 2Mb to 34Mb. Check out their web site here. The theoretical limit is 155Mb according to the site. If your interested in reading more about packet radio you can check out The Tucson Amateur Packet Radio Club. I'm not sure what is entailed in licensing frequencies from the government. But, it can't be that much trouble.
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Actually, I was talking to another HAM on 2M (144MHz) the other day. He said that he has experienced interference all the way up into the 2M band from the BPL system that is being tested in Emmaus, PA (near Allentown, about 60 miles north of Philadelphia).
If his reports are true, that means this could also affect aircraft frequencies which are around the 118MHz range. Not very good.
I'm all for cheap broadband, and I wish I had an alternative to cable available in my area. But, the [BPL] system throws out interference by the truck loads, and affects all kinds of people, services, and businesses that use the radio spectrum.
I'm a member in good standing of the American Radio Relay League (ARRL), and the Radio Amateurs of Canada (RAC). And, I will contribute as many resources to this fight as I can afford.
I'm not sure what radio modems they are using. But, it actually sounds a little archaic if you ask me. I mean you have to work with what you have when you're on a budget (or worse ... don't have one). But, it seems that this could be setup a lot better with some equipment donotions. HAMs (amatuer radio operators) are generally relatively generous people. And, all they would need is a couple HF radios since they have the computers already.
:)
AX.25 is natively supported in Linux, and could easily be leveraged to make this whole thing a lot better. With some donated HF radios, they could have routable RF network up all the time in no time. They might even be able to use APRS instead of AX.25. But, AX.25 is a more proven protocol for this type of thing. See the AX.25 Linux HOWTO for details. Information about the protocol can be found at TAPR's website. They might even be able to get a little bit more speed, though not much, by using 10 Meter (28 MHz) FM. Though 10M can be probmatic sometimes, so I'm not sure I'd recommend that. 20M (14 MHz) and down are much better frequencies if you want something reliable. A DSP based noise filter would certainly help things in regards to speed, but they cost a bit of money.
As far as the modem goes... You can use a sound card and a small "control" box. All the box does is operate the PTT (push to talk) circuit. So, you might be able to do with out that if you wire things up just so. But, I have not played with that as of yet. You can also use a Terminal Node Controller (TNC) to get the signal to the radio. Some of the newer TNCs have a DSP filter built in, so that could be an advantage there. But, the best you can hope for on HF is about 2400 bps at half duplex, and 2400 is pushing it. There's just too much noise on Upper/Lower Side Band, and I'm not sure if you would want to use AM (though that might be an option).
There are a number of sites to check out if anyone is interested in digital commincations over amatuer radio. TAPR is a very good one, as is RATS. RATS works with a protocol known as ROSE. There is another one called NETROM, but I don't have a link readily available for that. TCP/IP is by far the best for this type of thing though. You can also check out the ARRL's site, and the FCC's amatuer radio page, for more information on amatuer radio in general here in the United States. BTW, you don't need to know morse code anymore to get on VHF/UHF. And, to get on HF you only need 5 wpm on the code, which is not all that hard.
Ok, I admit that last paragraph was a sales pitch. But, amatuer radio seems to be a dying hobby; at least here in the US. So, anything that can be done to increase interest is a good thing.
I'll step down off my soap box now.
Ok, I didn't read all the replies... So, I apologize in advance if this is a repeat. This solotion uses a combination of HAM and Commercial pieces. The commercial part of it is you'll need to license frequencies from the government. The HAM part of it is packet radio. There is a college in Italy that is using this. They have connection speeds ranging from 2Mb to 34Mb. Check out their web site here. The theoretical limit is 155Mb according to the site. If your interested in reading more about packet radio you can check out The Tucson Amateur Packet Radio Club. I'm not sure what is entailed in licensing frequencies from the government. But, it can't be that much trouble.