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Comment by matthewdgreen | Hacker News Reader

> Have the 2.4 GHz and 5.8 GHz unlicensed bands become unusable by device proliferation? What makes you fear the 900 MHz band will be meaningfully different?

We are both commenting on an article that describes how a massive corporation (Amazon) might be deploying large-scale mesh networks on this band, and using this to drive huge numbers of devices at near the maximum feasible bitrate. This is obviously a speculative article and maybe none of this will come to pass. But within the bounds of speculation, this seems qualitatively different than what's happened (as of today) on the 2.4 and 5.8 GHz bands.

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That's why I cite the other bands; this is what has happened already in the US and Europe on the other unlicensed bands.

Looking at my WiFi network right now, I have 2 APs and 25 clients connected (8 of which are amazon-). When I turn on my TVs, those power up a few additional clients (Chromecasts and FireTVs) on WiFi. I can see between 12 and 18 other networks depending on when I scan (plus who knows how many that aren’t broadcasting SSIDs).

Is Amazon likely to be able to put more devices on Lora than I have on WiFi now? More concentrated than NYC or Paris WiFi is today?

The maximum bitrate the article references is not a Shannon-Hartley bitrate limit, but rather a fairness-limited maximum transmission duty cycle to ensure other, also unlicensed users can access the spectrum.

Edited to rephrase as a question rather than an argument: How much is the "fair duty cycle" mandated by the law, and how much is politeness? My understanding is that multiple providers could be competing in this space and (if this system is popular) they may want larger and larger slices of that cycle. I don't know what the law requires here, so I don't know that there's any requirement that personal WiFi users need to get much if any spectrum once every corporate user has taken their piece.

Unlicensed spectrum doesn't mean unregulated. It just means individual users of devices don't need operator licenses. To facilitate that operations in unlicensed bands have regulatory operating limits. Devices are under the general rules covering harmful interference (don't cause it), accepting interference from licensed operations (you must accept it), and basic electronic device regulations.

But a corporate player or players can deploy a lot of devices that individually comply and eat up a lot of the available bandwidth, making personal applications like Wifi less functional. And moreover: once there’s a financial incentive to do this (which really resilient mesh networks will provide) the financial incentives to use this bandwidth may be much greater than they have been historically, and saying “well it hasn’t happened yet so it won’t be a problem” offers very little predictive value. This is my concern, and I am open to being convinced that the regulations in place will prevent this. So far none of the comments in this thread have given me a convincing reason not to worry, though it’s helpful that someone actually posted the (individual device) transmission limits.

https://www.law.cornell.edu/cfr/text/47/15.247

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