revisiting the 434 MHz band
werner at openmoko.org
Tue Jul 20 21:07:45 EDT 2010
Ron K. Jeffries wrote:
> I question whether is if feasible (legal) to ship
> a commercially available kit where the user selects between 868 and
> 915 MHz. We need solid info.
Agreed. By the way, differences also exist in the 2.4 GHz band.
Some countries allow a wider frequency range (and hence more
channels) than others.
> There are lots of interesting 2.4 GHz options including Zigbee and
> derivatives. Unlike the 868 and 915 MHz bands, it offers high
> bandwidth, and the hardware is very low cost.
Ah, this depends. E.g., all the protocols that are based on IEEE
802.15.4-2003, among them ZigBee, are not very fast, compared to
the 802.11 family.
According to Wikipedia, ZigBee has a licensing problem that would
preclude its use with Free Software, but the underlying
IEEE 802.15.4 seems to be unencumbered. One could then put, say,
6LoWPAN on top of it.
Cost should be quite low for IEEE 802.15.4. Something like a BOM
cost of USD 4 for RF chip and surroundings.
> If a future Nanonote were to support a wifi stack,
I guess for this to happen, someone would have to find a WLAN
module or chipset Wolfgang likes :)
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