Quote from: matthewh3 on July 24, 2014, 01:49:04 AM

You'd need about 2kbps to download seven 1MB blocks an hour. That's a lot of bandwidth 24/7/365 on a global HF network. I think the Bitsat project and the use of UHF and SHF for a lot more relative bandwidth is the best solution for a global wireless network - https://bitcointalk.org/index.php?topic=334701.0

6 blocks/hr * 1048576 * 8 = 50331648 bits/hr

50331648 bits/hr / 3600 seconds = 13981 bps = 13.981 kbps (with no additional overhead)

For 7 blocks/hr, 16.311 kbps (with no additional overhead)

These rates exceed conventionally available AX.25 packet radio / TNC throughputs for HF and VHF ham bands (generally 300 baud FSK for HF, and 1200 baud AFSK or 9600 baud AFSK for VHF/UHF). Either use of higher frequency bands or a custom modulation format that would tend to have a bandwidth exceeding amateur radio rules in most ITU countries on HF, VHF and UHF frequencies would be needed. At that point you might as well just set up a 900MHz, 2.4GHz or 5GHz 802.11 link.

Quote from: TheButterZone on July 28, 2014, 07:06:28 AM

Yes, anyone can tune in to listen to ham radio, but it's important that we have parts of the radio spectrum to ourselves, otherwise all frequencies from DC to daylight would be licensed for commercial and public safety (much of which isn't listenable without buying horrifically expensive gear, if it isn't completely encrypted for no reason other than to eliminate transparency) use.

$10 to $15 for a Realtek-based DVB-T USB receiver dongle used as an SDR (software defined radio), and you can receive whatever you want from 24 to 1766MHz (in the case of versions of the dongle using an R820T RF front end).
http://sdr.osmocom.org/trac/wiki/rtl-sdr