[LINK] Wi-Fi 7

[David]

I apologise for this late response, but all the hoopla over WiFi-7 seems to lose touch with two issues: the composition of the target market, and Shannon's famous equation describing the maximum bandwith of a noisy channel.

No doubt there are specialised application environments where 40 Gbit/sec WiFi might be useful, but surely not many.  Is the average family whose members run their lives on their mobiles & laptops going to make a dent in that sort of bandwidth, especially when they're connected to a 0.1 Gbit/s NBN service?

And concerning Shannon's equation, which is basic engineering physics not a heuristic observation like Moore's Law, things aren't as straightforward as the press release implies.

For example, the 2.4 GHz band offers fourteen 20 MHz channels but at least some overlap, whereas the 5 GHz band is divided into 24 non-overlapping 20 MHz channels.  However 5 GHz is also absorbed more readily by brick or cement-block walls, which makes the signal noisier.  Of course WiFi is a contention medium too.

Also, if I remember correctly, 4096-QAM means that 12 bits are signalled with every state-change on the medium, so the potential for transmission errors with the WiFi-7 standard in a residential strata building is easy to imagine.  There's no free lunch here.

On 12/12/2023 18:20, Fernando Cassia wrote:
> I can count ~35 APs in 2.4 from my 12th floor apartment. Some from the same block, some from across the street, others from an intersection 150 meters away. Oh the joys of low frequencies with wide range...
Next time you're in a fully booked inter-city train service where people tend to while away the travel time on their devices, I suggest checking out the number of visible WiFi and Bluetooth connections...

I hope everybody has as relaxing break over the holiday season, or at least as relaxing as possible!

Cheers,
_David Lochrin_