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by ac29 1937 days ago
There are no duty cycle limitations for 900MHz in the US. Its regulated largely like 2.4GHz (see 47 CFR § 15.247). There are rules for frequency hopping systems that limit the amount of time you can dwell on any given channel, but there are less restrictions on non-hopping systems. High-ish bandwidth 900MHz radios are pretty common and can do multiple megabits per second (at least with enough signal-to-noise ratio, which isnt always practical over non-trivial distances).
2 comments
rmoriz 1937 days ago
The duty cycle limits by ETSI are in place because of the population/usage density. If FCC does not put in place a regulation there will no shared high bandwidth usage over a long distance in high density areas. Think of 2.4 GHz WiFi.
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jeffypoo 1937 days ago
Can you share some examples of high bandwidth 900 radios? In my experience, it’s difficult to get bitrates above ~100kbps on 900 over any meaningful distance.
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myself248 1937 days ago
The Ubiquiti Rocket M900 would be a good place to start.

Or if you have a couple old Ricochet E-radios and want to do some packet hacking, they'll do 1Mbaud at whatever modulation you ask.

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ac29 1937 days ago
I work with industrial grade 900MHz radios, and most can do over 1Mbps... with enough SNR, which as I mentioned can be difficult. I would say a typical ~city sized network I've worked on tend to operate in 100-1000kbps modes, with real world throughputs maxing out at more like 300-400 kbps on typically 1-10 mile links.

Manufacturers include FreeWave, GE MDS, XetaWave, 4RF, and others. These are typically ~$1000 radios, so not great for hobbyist use.

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jamiek88 1937 days ago
Yeah I’d be very happy to be pointed in the direction of a multiple megabit per second 900 radio. Take my money!
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KirillPanov 1937 days ago
I have the Ubiquiti M900 radios. With a (~5-foot) yagi they definitely deliver the advertized 100mbit/sec.
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jlgaddis 1936 days ago
In addition to Ubiquiti (already mentioned), Motorola (Cambium) also made some PTP and PTMP radios ("Canopy"?) that were quite popular in the WISP community years ago.

I'd be surprised if you can't easily find both on eBay.

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