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Since facebook and all the social media warfare, I have realized that the internet is awesome, but not very scalable to embedded devices: new generation network standards are still expensive to make work.

The internet is good for high bandwidth, but the installations are quite static, and I don't really believe that smartphones and tablets will really replace micro-computers in terms of network capabilities.

So my question: I'm thinking about a CB-radio-like protocol for P2P data transmission.

Do you think a low frequency, long distance, peer-to-peer radio network would be possible ?

If the protocol would provide unencrypted and encrypted mode, do you think people would use it knowing that somebody could try to sniff packets ? Would this kind of physical protocol be possible to integrated on simple phone (does lower frequencies consume more energy ?).

(Could you redirect me to somewhere I could ask this question if you don't have any idea ?)

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  • \$\begingroup\$ I'm not sure since I think in meshed networks, a node can forward a flow of packets to an other device. That's not what I want to do. I want to litteraly transpose the CB concept to the data concept. \$\endgroup\$ – jokoon Feb 24 '11 at 15:17
  • \$\begingroup\$ It's entirely possible technically, provided you're able to power the transmitters adequately, but it's effectively prohibited by the EU and US radio licensing regimes. You may be able to get permission to do this in the "whitespace" region abandoned by analog TV in Europe. \$\endgroup\$ – pjc50 Jun 30 '14 at 15:45
  • \$\begingroup\$ yeah, but if regulations would pop up, it would be interesting, that would mean much cheaper networking... Imagine chatting with people in the 10km area, like a radio tweeter... \$\endgroup\$ – jokoon Jun 30 '14 at 20:44
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I'm tempted to say this is a contentious issue for discussion, not something with a "right" answer. However, you could investigate the OLPC Mesh protocol. In general, lower carrier frequencies mean lower bandwidth for data on them. It's not so much that they consume more energy (in fact they have greater range for the same transmit power) but that the antenna gets larger or less efficient if size constrained.

If you are trying to do peer-peer networking on a simple phone, the transmit energy associated with the forwarding of packets could badly affect the battery life.

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  • \$\begingroup\$ In general, lower carrier frequencies mean lower bandwidth for data on them. No, this is a mathematical certainty: Read up on the Shannon-Hartley Theorems \$\endgroup\$ – Kevin Vermeer Feb 24 '11 at 14:18
  • \$\begingroup\$ Thanks, I did know about that. I suppose I meant "in principle" rather than "in general" to avoid the charge that protocol X uses a lower carrier frequency that protocol Y but is specified as a higher data rate, which can occur when the Shannon limit isn't being reached by protocol Y. In other words, you can send 1 bit per second using a 2.4GHz carrier and 9600 bps using a 433MHz carrier, so someone could argue the bandwidth of a given implementation is not higher, but of course the maximum possible bandwidth is higher even if it is not used. \$\endgroup\$ – Martin Feb 24 '11 at 15:14
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People use public none-ncrypted WiFi hotspots even if anyone can read their traffic.

CB indeed require much more power. 10mW for WiFi, 1-2-5W for CB to get few Km of range. On CB you can probably transmit some 50-100 kbit over 5km at 1-5W power level. This is deadly slow.

And the worst part: lower freq require much larger antennas.

It is possible to have WiFi working over some 1-2km on openspace provided that you are using directional antenna on 1 side. So you may have funny hotspots having some 20-50 directional antennas covering large area.

But this all is garbage in comparison to coming earth-wide satellite internet - modern satellites have hundreds of beams so there is plenty of bandwidth for everyone.

Anyway, these days you have 3G/4G network coverage everywhere, so it's not worth bothering.

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  • \$\begingroup\$ How many mW are required to get 5km of range out of your WiFi antenna? Martin was correct; low frequency gets you more range for an equivalent power if the antenna size is not constrained, but limits bandwidth. \$\endgroup\$ – Kevin Vermeer Feb 24 '11 at 14:13
  • \$\begingroup\$ With directional antenna - standard power (10mW) \$\endgroup\$ – BarsMonster Feb 24 '11 at 14:15
  • \$\begingroup\$ Well, we need then to talk the same bandwidth. How much range would we get with 25kHz band @ 2.4Ghz? :-) That's 800 times more power/bandwidth. If we would have same power per kHz difference would be much much smaller. \$\endgroup\$ – BarsMonster Feb 24 '11 at 14:17
  • \$\begingroup\$ I don't really about 3G 4G networks, because those networks are freaking expensive, and require subscription etc. I'm just just wondering if I can have P2P freely, knowing that a significantly slower bandwidth is acceptable, since I want to create my own protocol for data transport. By P2P I really mean NOT having an hotspot, I really mean cellphone TO cellphone, by radiowaves. Hotspots amplify signals and receives weak signals, but I'm interested in full P2P. \$\endgroup\$ – jokoon Feb 24 '11 at 15:09
  • \$\begingroup\$ @BarsMonster i don't agree that 50-100 kbps is dead slow. You can fit a VOiP session in there without struggle... Yes some people would rather die than watch a 1080p stream on that bandwidth but i know people who work and live on speeds like that... \$\endgroup\$ – Leonardo Sep 4 '14 at 16:26
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No, FCC limits WiFi and related protocols power. You won't get CB sorts of distance (miles).

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  • \$\begingroup\$ you can get several miles of range in the 900Mhz ISM band with appropriate antennas without exceeding FCC limits. \$\endgroup\$ – Mark May 19 '11 at 22:31
  • \$\begingroup\$ Or just get a ham radio license. \$\endgroup\$ – Connor Wolf May 20 '11 at 1:59
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CB will work with 1200 baud with a TNC2S modem, but highly restricted in the U.S. However I don't see an issue with sideband, but I am not a lawful expert either.

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  • \$\begingroup\$ Are you really sure that CB is allowed for uses such as carrying data? Also, just being able to transmit bits from one place to another doesn't make a "public network" that anyone can chime in on. Wifi has special protocols for making sure multiple nodes don't step on each other, and bandwidth goes down when the number of nodes gets high. With the large area CB would cover and the low data rate (if allowed at all), this just doesn't sound feasible. \$\endgroup\$ – Olin Lathrop Nov 21 '12 at 21:34

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