Your APRS idea is interesting and I only know it from the "positioning" side, not from passing any text, so you may want to continue looking into it. I do not know that APRS is currently passing any traffic other than positions, at least as used in the US. I also do not know whether it's used outside the US. Please do remember that APRS and most other amateur digital service are not designed to be "reliable" which means they may not "try again" to pass a message and the message may become garbled in transmission. Some do attempt to error-correct, but not most.
Some more observations on your criteria: Low-cost: maybe. Each operator has to have equipment which generally runs USD$500 to many thousands. Also Android is low cost if you have some kind of connection to the radio operator. So the "last mile" or "first mile" depending on how you look at it, is not expensive. But you said tribal areas, so I don't know what your challenges would be on that count. Reliable: amateur radio has varying reliability, and it is easily interfered with if someone wants to do that. In planning emergency operations we take into account that there may be malicious interference even during an emergency. Even most amateur radio digital protocols do not have very robust error-correction, so they're a bit iffy. Easiest to expand: maybe and maybe not. You have to have a stable of radio operators available both locally and remotely. (Presuming you want information to go from somewhere to somewhere.) Without a telco: Yes for the amateur portion at least. Without licensing: Although I encourage folks to become amateur radio operators, they do need to be licensed. The government that giveth it can taketh it away at the stroke of a pen. I will skip saying more right now. Also I note in your original statement that you are talking about "tribal areas" with poor connectivity. Your challenge is going to be getting your signal from the tribal area to a reliable amateur radio operator. That's unless the radio operator is already in the tribal area. If the cell phone can's connect, then amateur VHF and UHF probably wouldn't work either, so you'd have to rely upon HF with longer range but much greater variability in terms of signal propagation. > Keep in mind that amateur radio is a point-to-point service subject to the vagaries of radio propagation. In other words, there is no reliable path 24/7 from one point to another unless you're using prearranged VHF or UHF frequencies and line of sight propagation. Commonly for emergency ops we arrange all of this in advance and have emergency power and operators trained, and frequencies and modes chosen. For HF propagation there is no guarantee your message will get through because "the bands may be dead." We've been thinking here (San Francisco) of linking amateur packet radio with local mesh wi-fi (see Byzantium Project for example) to transfer some traffic in semi-automated ways during emergency, but this is a long way from actual implementation. The Byzantium folks are on this list and can comment. HF: high frequency (meaning roughly 1mHz to many gHz, which is reliant upon ionospheric conditions for signal propagation VHF: very high frequency (generally 100mHz to 150mHz) line of sight mostly, with repeaters being generally used UHF: ultra… (generally 200mHz and up) line of sight mostly, and repeaters APRS: Automatic Packet Reporting System (a digital position-reportig protocol used on certain amateur frequencies) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Sky (Jim Schuyler, PhD) -We work backstage so you can be the star Blog: http://blog.red7.com/ Phone: +1.415.759.7337 PGP Keys: http://web.red7.com/pgp On Mar 6, 2013, at 12:08 PM, Ali-Reza Anghaie <a...@packetknife.com> wrote: > I'm assuming privacy issues are of minimal concern given the other problems > at play here - I could be wrong but bear with me. > > Trying to think of lowest-cost, reliable, easiest to expand and re-deploy > without a telco or other licensing. > > I wonder is a low-bandwidth text HF APRS > (http://www.aprs.org/aprs-messaging.html) option with a laminated deck of > shorthand medical terms would be a reasonable remote field option? About as > rudimentary as you get but considering a worst case scenario - it might just > work. -Ali > > > > On Tue, Mar 5, 2013 at 9:15 PM, Sky (Jim Schuyler) <s...@red7.com> wrote: > Since "HAM" (amateur radio) is real radio, not phone, an Android app wouldn't > use it directly. The app might -control- an amateur radio remotely, and there > is software available to do this. However, I'm not sure what benefit it would > bring to this project. > > In the US, amateur radio operators must send all information in "clear text," > and encryption is illegal, thus you would not want to try to exchange medical > info because you'd need to encrypt it. In other countries it -should- be > illegal to transmit medical info in the clear, so I'd suggest avoiding this. > > Also, "high frequency" amateur radio doesn't have sufficient bandwidth to > transfer much digital information. VHF/UHF does in theory, but in general > amateur radio operators restrict their bandwidth and the maximum usable > transfer rate is under 9600 baud. i.e. very slow. > > -Sky AA6AX > > - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > Sky (Jim Schuyler, PhD) > -We work backstage so you can be the star > Blog: http://blog.red7.com/ > Phone: +1.415.759.7337 > PGP Keys: http://web.red7.com/pgp > > On Mar 5, 2013, at 5:47 PM, ITechGeek <i...@itechgeek.com> wrote: > >> Depends on what information you might be transmitting and the specific >> laws of the local country/countries involved. >> >> HAMs have to be licensed through the local countries licensing >> authority (in the case of the US would be the FCC). >> >> Under US you could probably get away with allowing them to coordinate >> if it is non-profit in nature, but you would not be able to discuss >> any medical information that would allow a third party to possibly >> identify the patient. >> >> And some countries are very restrictive on who can get HAM licenses >> due to the potential to get around their propaganda controls. Also >> rules can change based on frequencies being used cause lower >> frequencies can transmit further. >> >> Can you provide the country or countries involved? >> >> ----------------------------------------------------------------------------------------------- >> -ITG (ITechGeek) >> i...@itechgeek.com >> https://itg.nu/ >> GPG Keys: https://itg.nu/contact/gpg-key >> Preferred GPG Key: Fingerprint: AB46B7E363DA7E04ABFA57852AA9910A DCB1191A >> Google Voice: +1-703-493-0128 / Twitter: ITechGeek / Facebook: >> http://fb.me/Jbwa.Net >> >> >> On Tue, Mar 5, 2013 at 8:07 PM, Yosem Companys <compa...@stanford.edu> wrote: >>> From: Dr. Tusharkanti Dey <dr.tusharkanti...@gmail.com> >>> >>> Dear All, >>> >>> I am proposing to set up a ICT based health project in tribal areas with >>> poor infrastructural facilities with poor cell phone connectivity due to >>> unstable signal strengths. i have learnt that HAM radio software from >>> HamSphere is downloadable on android phones.I would like to know whether >>> these android phones with HAM radio software installed can be used for >>> communication used for voice communication between health workers >>> themselves and with head quarter staff. Will it be legally permissible and >>> what technical requirements will be needed to set up such system. The other >>> alternative of setting up of mobile signal boosters or long distance WiFi >>> hubs are currently not affordable to our limited resource organisation >>> >>> Thanks, >>> Dr.Tusharkanti Dey >>> -- >>> Too many emails? Unsubscribe, change to digest, or change password by >>> emailing moderator at compa...@stanford.edu or changing your settings at >>> https://mailman.stanford.edu/mailman/listinfo/liberationtech >> -- >> Too many emails? Unsubscribe, change to digest, or change password by >> emailing moderator at compa...@stanford.edu or changing your settings at >> https://mailman.stanford.edu/mailman/listinfo/liberationtech > > > -- > Too many emails? Unsubscribe, change to digest, or change password by > emailing moderator at compa...@stanford.edu or changing your settings at > https://mailman.stanford.edu/mailman/listinfo/liberationtech > > -- > Too many emails? 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