Bill - One of the primary uses I can think of for unused bandwidth is bulletins using a "flood and fill" protocol. The original one I remember was RadioMirror, but that code is very old (MS-DOS) and unmaintained and mostly unobtanium. FLAMP (FL digi suite Amateur Multicast Protocol) - http://www.w1hkj.com/files/manuals/US_English/FLAmp_2.2_Users_Manual.pdf. One really nice thing about FLAMP is that it doesn't require "acks" from receiving stations - it does Forward Error Correction and if there's an error received in a FLAMP transmission, the receiving station won't recreate the file until it receives a complete error-free transmission. There's an infinite source of bulletin info specific to Amateur Radio, including periodic APRS products, updated repeater lists, club bulletins, etc.
Good point Steve. I also remember reading about a service a few years ago that would broadcast information over a GEO satellite to a basic receiver. It numbered it's fragments and would repeat the message several times over the course of a few days so that the ground station could assemble what it had missed. That plus FEC could be fun for gathering data without having to leave your gear on 24x7...
Or from a multicast perspective, have a mechanism to request fills for any packets that fail at the end of the initial data dump... I'm not sure I have that much useful information to put on the air, but it would be fun to work out the project. I also BTW like the idea of a paging / message system being developed over, similar to APRS instant messaging, but with persistence and retries if you somehow miss the first transmission.
Bill - One of the primary uses I can think of for unused bandwidth is bulletins using a "flood and fill" protocol. The original one I remember was RadioMirror, but that code is very old (MS-DOS) and unmaintained and mostly unobtanium. FLAMP (FL digi suite Amateur Multicast Protocol) - http://www.w1hkj.com/files/manuals/US_English/FLAmp_2.2_Users_Manual.pdf. One really nice thing about FLAMP is that it doesn't require "acks" from receiving stations - it does Forward Error Correction and if there's an error received in a FLAMP transmission, the receiving station won't recreate the file until it receives a complete error-free transmission. There's an infinite source of bulletin info specific to Amateur Radio, including periodic APRS products, updated repeater lists, club bulletins, etc.
Good point Steve. I also remember reading about a service a few years ago that would broadcast information over a GEO satellite to a basic receiver. It numbered it's fragments and would repeat the message several times over the course of a few days so that the ground station could assemble what it had missed. That plus FEC could be fun for gathering data without having to leave your gear on 24x7...
Or from a multicast perspective, have a mechanism to request fills for any packets that fail at the end of the initial data dump... I'm not sure I have that much useful information to put on the air, but it would be fun to work out the project. I also BTW like the idea of a paging / message system being developed over, similar to APRS instant messaging, but with persistence and retries if you somehow miss the first transmission.