June 2, 2008 at 6:06 pm #2868
Heath, caching sites such as wikipedia is probably not the best way to go. Its simply too unlikely most of it will ever be used. Though caching its top few thousand pages may be a fair idea. Bastidge is right on using a caching proxy. My own suggestion on such a proxy would be to extend the cached websites TTL and also let the servers query cached sites for updates during hours that average the lowest bandwidth usage. This way the most commonly accessed sites are kept nice and up to date, DNS poisoning is less likely to happen(I’m paranoid, sue me ), and the updates will have the lowest perceivable impact on the network.
It may also be worth using(as an auxillary not replacement) a large lan or even man network(depending on community size) to create an “internet” by and for that community to host information relevant to the community. A plus is that it’d work faster, a downside is it would be limited in access. So I think a combination of the two would be useful. But that’s just me.June 2, 2008 at 7:15 pm #2872
This sure is interesting… FX.25
It’s an extension to AX.25 adding forward error correction at layer 1
15% of the AX.25 packets [9/61] were decodable without the FEC capability
46% of the AX.25 packets [(9+19)/61] were decodable with the FEC capabilityJune 2, 2008 at 7:29 pm #2873
Given that they were deliberately using a low-quality signal, that is a hell of an imrpovement(many thanks for the link). I think 62-67% should be our goal for absolute worst(oh in a perfect world) but 46% is not horrible by any means. Many many thanks for the links.
Bastidge, in your opinion would using the AX.25 of FX.25 for something such as gopher and/or usenet be an avenue worth pursuing? It would help save precious bandwidth over other connections while allowing for steady sources of news and communication between spars(in addition to its already mentioned qualities such as weather and gps)June 2, 2008 at 8:23 pm #2875
On a boat on the ocean, the horizon is about 5km away. Cell phones transmit and receive about up to about 40 km. Cell phones are not a long distance technology. Most cell sites are connected via landlines, that’s where their bandwidth comes from.
However, it is a mature technology that would work in a multiple-seastead environment. It’s quite a bit moe expensive than plain old radios though.June 2, 2008 at 8:27 pm #2877
Look for surplus HF modems. Check DRMS and HAM radio sites. You don’t need the radio to test it, the modems can be connected with hand-built cross-over cables. Eventually, to be useful, you need at least a pair of radios, or one radion and a buddy with all the gear. You’ll also need to get HAM radio license, which I understand is much easier since they removed the Morse code requirement.June 2, 2008 at 8:33 pm #2879
I would think RSS perhaps. Gopher and Usenet seem to have been passed by, largely. Some things on a seastead are likely to seem like a step backward for a while tho, so maybe it would be worthwhile. I’d say that it depends a lot on the usage characteristics of that SS owners. This is definitely not a technology for large downloads. The smaller the discrete chunks of data, the better.June 2, 2008 at 8:37 pm #2880
I’m not sure what you’re getting at. You’re not getting processing power on a satellite, you’re getting a channel. Those channels are expensive. If you’re using a tiny bit of the channel (a download in the midst of a stream of downloads) it’s not so bad, this is how dish network and diret PC work. There are FAR fewer upload channels whoever, and using them is very expensive if they are dedicated to you. By using a landline to make your web requests (small amount of info) and the satellite to deliver content (large amount of info) it is using the satellite’s bandwidth very effectivily. Anything that doesn’t need to go through a satellite should not.June 2, 2008 at 8:40 pm #2881
Agreed on many things seeming like a step backwards. The reason I brought it up is that to my thinking(at least during this small arbitrary chunk of time) it could be used to fill several needs. Primarily dissemination of data(though i have to concede rss is a better means for that) and mass communication(though perhaps something akin to a bbs would work better than usenet). It would use a more stable technology and also give some motivation for bettering internet connections for seabased use.
Another thought brought on by the mention of gps is to include it as a general navigation tool for SS’s in general. It would allow SS to be able to network coordinates with other SS allowing groups to keep a good bit of space between one another, if they so desire. Just random tickings of the clockwork in my head at the moment. Maybe with some sleep it’ll develop into a cohesive thought.June 2, 2008 at 10:15 pm #2886
ok, that’s clever as hell how they did that.
it’s a ax.25 postprocessor on both ends. the receiving ax.25 algorithm doesn’t get confused by the fx.25 frame
this means it should be really easy to hackJune 2, 2008 at 10:26 pm #2888
I was thinking more of the radio beam links that connect cell stations wirelessly, where landlines are impractical: they provide speeds up to 155 Mbps over kilometers. I’m not sure whether tropospheric scatter can be used with them, apparently the french army uses (or used, it’s 70s tech) one such system (Ariane Tropo) so it should be possible, it allows extending the range to 400 km with a 1 KW emitter – but then, it most likely does not use microwaves, since these are absorbed too steeply by the atmosphere. The advantage of the ocean is that there’s no obstacle (Fresnel ellipsoid is always empty) and the radiospecter is unencumbered for the most part. The disadvantage is humidity, which absorbs some frequencies.
It requires a receiving pair of antennas being deployed on land and interconnected, though. For early seasteads sat access will be preferred.June 3, 2008 at 6:53 am #2892
Microwaves are line of sight. Your horizon on the ocean is very close. You would need a very high mast to transmit microwave very far- that’s why military units site their microwave transceivers high on mountain tops when they can.June 4, 2008 at 9:18 am #2918June 4, 2008 at 1:52 pm #2932
Good job! Whenever I manage to get home again, I’ll sneak a peak at the code and see if there is anything I can think of to do to it. I’m with you in being a bit distressed about the long. Maybe it’ll be something as easy as a fudged long long, but life never is easy.
Should we work on a list of potential uses it’d have aboard a seastead?June 4, 2008 at 1:59 pm #2934
i’m not even gonna say itJune 4, 2008 at 2:05 pm #2937
I’m guessing I missed something obvious, if so my appologies. Too much to do this morning to give things the attention I ought to. Feel free to pummel me with a trout.
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