XBee SX radios are very long-range (multiple miles/km) using small antennas and low power. They are typically faster than the similar LoRa technology, though sacrificing some distance.
My xbnet program provides a nice Unixy interface to XBee radios, including the ability to run TCP/IP atop them.
Unlike LoRa, XBee radios offer hardware Mesh Networking as well as better collision detection, automatic retransmit, and a “transparent mode” that makes them act as a serial null-modem cable with a radio.
Links to this note
This started out at a post on my blog. This edited version is intended to be kept more up-to-date.
This page gives you references to software by John Goerzen.
When things are difficult – maybe there’s been a disaster, or an invasion (this page is being written in 2022 just after Russia invaded Ukraine), or maybe you’re just backpacking off the grid – there are tools that can help you keep in touch, or move your data around. This page aims to survey some of them, roughly in order from easiest to more complex.
LoRa radios are very long-range (multiple miles/km) using small antennas and very low power. In exchange for this, they give up speed; the longest-range LoRa modes operate at only around 300bps.
I loaded up this title with buzzwords. The basic idea is that IM systems shouldn’t have to only use the Internet. Why not let them be carried across LoRa radios, USB sticks, local Wifi networks, and yes, the Internet? I’ll first discuss how, and then why.