5 ms·
I'll let you all in on a little secret - for the last 15+ years there have been lots of cities with 902 Mhz FHSS networks covering every little inch of them. A
by ghshephard 6y ago
I'll let you all in on a little secret - for the last 15+ years there have been lots of cities with 902 Mhz FHSS networks covering every little inch of them. Any of the Utilities (predominantly electrical, but some water) - that have remote meter reading often use that part of the spectrum with enough duty cycle that they can trap nearby GFCI breakers. In the case of companies like the old Silver Spring Networks (itself, a descendent, technologically in many way from Richochet) - it's IPv6 for consumer distribution. 25 Million+ nodes when I left them in 2017. Since merged with Itron, so I'm sure it's doubled or tripled since then.
- VectorLock 6y agoI still have some Richochet modems. They were nice because you could use them as point-to-point radio modems after the Ricochet network became defunct. But with so many options for low cost and more compact radios in a such a huge plethora of spectrum options they're totally defunct now.
- Layke1123 6y agoOh boy do I love the free market!!!!
- dopidop 6y agoWe have the same where I grew up. Electricity is a national monopoly. Water was one under a national mandate of small provider until the early 2000.
- Layke1123 6y agoCurious to hear more about this if you don't mind sharing.
- dopidop 6y agoI was thinking of France, where the national Electricity provider is rolling out « linky », a 900Mhz capable meter. My understanding is that the 900Mhz range is already in production for french meter since a while as well.
- Layke1123 6y agoLol, downvote me all you want, all you do is reinforce the point that no one can actually articulate a rebuttal because you know it's true. I take it as a badge of honor every time I'm downvoted when it comes to questioning market dynamics.
- schoolornot 6y agoI had to Google what you mentioned about GFCI breakers. Found this: http://www.arrl.org/gfci-and-afci-devices http://www.arrl.org/gfci-and-afci-devices.
- drmpeg 6y agoWhat the 902 to 928 MHz spectrum looks like. All those blips in the waterfall are smart meters or some other IoT device. http://www.w6rz.net/33cm.png http://www.w6rz.net/33cm.png
- imglorp 6y agoIs everybody narrowband in this spectrum? Why would they do that instead of spread/hopping or some such? What's going to happen to all these narrow guys when the band starts getting busy?
- drmpeg 6y agoIt's a mix of wideband and narrowband, but everything is frequency hopped. In the waterfall, the strong wideband bursts have a red colored center frequency. The narrowband bursts are just vertical lines.
- teh_klev 6y ago> with enough duty cycle that they can trap nearby GFCI breakers. Do you mean "trip" rather than trap? If not could you explain what this means?
- MisterTea 6y agoAssume they mean trip. I have never heard of the term trap used for GFCI's.
- teh_klev 6y agoGFCIs go by a different name in the UK (RCD - Residual Current Device), so I wondered if this was a US specific electrical term I'd not heard of.
- ghshephard 6y agoSorry, yeah, trip. Park the Smart Meter too close the GFCI and it induces enough current to cause it to fail-safe, breaking the circuit.
- beams_of_light 6y agoI was surprised to learn that fire suppression systems use 900MHz networks for backup alerting as well. My whole city is enmeshed with it.