Comment by Scoundreller
5 hours ago
I wonder how much of the power-efficiency is due to being much slower.
Don’t need to blast and beam-steer if you can deal with poor SNR by taking your time to differentiate the 0s and 1s?
Which is more power efficient per megabyte?
(But I get it: sometimes a few bits is all you need)
All of it. You can't really get around physics.
Iridium has historically targeted low-power, omnidirectional terminals (antennas can be larger at lower frequencies without requiring steering than at higher frequencies).
They recently had some forays into steered, high-bandwidth antennas with their Certus line and their second-generation satellites that now allow native packet switching (the first gen was circuit-switched at 2.4 kbps only), but that brings you into the bandwidth-limited regime, and is honestly just a waste of scarce L-band spectrum and much better served by all the Ku- and Ka-band LEO competitors.
It's going to be interesting to see if Rocketlab start also serving that market, like some of their main competitors already are.
> (antennas can be larger at lower frequencies without requiring steering than at higher frequencies).
No.
1. Iridium uses frequencies fairly close to GPS (~1.6GHz).
2. Iridium uses cylindrically-polarized transmissions (like GPS), which enable compact omnidirectional helical antennas
> They recently had some forays into steered, high-bandwidth antennas with their Certus line and their second-generation satellites that now allow native packet switching (the first gen was circuit-switched at 2.4 kbps only), but that brings you into the bandwidth-limited regime,
This is AI slop?
No, the point of using an electrically-steered beam antenna is that it improves SNR, so that you are not bandwidth limited.