Difference between Atheros and MediaTek?

theoretically yes, in practice? write a driver for such operation!

is that so?

small scrape of FCC test report from mikrotik:

Model No.: RBSXTsqG-5acD
Serial No.: 7C3F04B03EF9/720
Equipment Secondary Function(s): None
Type of Technology: 802.11a/b/g/n
Installation type: Fixed
Construction/Location for Use: Outdoor
Software/Firmware Release: ROUTEROS v6.38.5
Hardware Release: r2
Transmit/Receive Operation: Transceiver - Full Duplex
Rated Input Voltage and Current: 100 – 240 VAC 0.4A MAX, 50-60 Hz, PoE: 24Vdc, 0.38mA
Operating Frequency: Rated: 50/60 Hz

Yeah, I think that just means it's not a receive only or transmit only device. it can both receive and transmit, but not simultaneously at least not on a single band.

That would be very strange, as such a device usually is called "half-duplex".

Full duplex operation out of a single antenna is basically cutting edge PhD level research: https://spectrum.ieee.org/tech-talk/telecom/wireless/new-full-duplex-radio-chip-transmits-and-receives-wireless-signals-at-once

Does there exist a wifi chip that can do this? I don't know, but it seems exceedingly unlikely that something supposedly first demonstrated in a research lab in 2016 was already available in a commercial wifi set up certified by the FCC in the same year.

Much much more likely that the RBSXTsqG-5acD has multiple radios and multiple antennas so that it can simultaneously transmit and receive on different bands or someone just plopped that text in there because they chose it off a pull-down menu without it actually meaning anything much.

seems to suggest that indeed there are two radios involved in this chipset.


You also need to consider that the wave bands are pretty much by definition a time shared resource, making this a 'hub' rather than a 'switch' - so yes, while the remote end is transmitting, you can only wait for your turn and not send at the same time.

Yes, there are tricky ideas imaginable (the easy way by using a second radio) like very advanced MIMO/ beam-forming and (concurrent) multi-channel wlan cards, but those haven't left the design paper yet.


Conclusion is, that the docs from mikrotik is incorrect, stating "Transceiver - Full Duplex".

I understand some of the building process, I suppose I have to add whats a green in the files changed , erase whats a red and build?

I didn't found the GPL drop for the EU version. Since the $ difference from US and EU variants are nice, does the US refurbished variant work our should work in EU?

Ok tri-band its the way to go :slightly_smiling_face:

For an overview of wireless driver issues in Linux, I recommend watching the presentation by OpenWRT and Linux kernel developer Felix Fietkau, which was given at the 2015 Chaos Computer Conference:

"Wireless Drivers: Freedom considered harmful?" - it can be found online. It's a bit out of date, but as far as I understand is mostly still relevant.

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