Can WiFi And Cellphones Coexist On The Upper 6GHz Band
WiFi Already Uses It, But Will It Share?
If you have been to a large event recently, you were probably reminded what happens when a large amount of wireless devices congregate in one area. The frequency bands get overwhelmed and your internet connection becomes spotty, at best. To resolve this various bandwidths have been opened up for use, trying to spread the traffic across the spectrum. The best practice has been to separate WiFi traffic and cellphone traffic by assigning them different parts of the spectrum, but that could change.
Ofcom are proposing ways that the upper 6GHz band could be used by WiFi and cell signals simultaneously. One idea is to design a MAC database which specifies where and when access is allowed by devices; WiFi on the 6GHz band for short range WAPs for installation inside and cell signals when you are outside. They also propose enhancing channel sensing on WiFi devices to help avoid collisions and perhaps introducing the same ability to cellphones.
The FCC have already opened up the entire upper 6GHz band for low-power Wi-Fi for indoor use, as long as the device has an automated frequency coordination system to prevent collisions with other equipment. There are many legacy devices which use the same band, and they will definitely not be smart enough to sense traffic.
It’s a challenge, and one that needs to be solved now so that new devices will have somewhere to transmit over, instead of trying to squeeze into already crowded frequencies.
Brit telecoms regulator Ofcom has kicked off a consultation over proposals that would see both mobile networks and Wi-Fi users have access to frequencies in the upper 6GHz band, if appropriate mechanisms can be agreed to make it work.
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There’s no coexisting with cell. Cell will take over any spectra it has acces to and has enough political influence to get away with it. Don’t open that door as there’s no stopping them once they get a toe in.
Seems the FCC will further ruin the 6GHz band. One current issue with 6GHz APs, is that while for now there is very little interference, the experience in terms of performance is worse than the 5GHzband once you are no longer in the same room as the AP.
Furthermore, this is not due to the higher frequency since we are effectively going from about5.8GHz to to around 6.1GHz. The materials attenuation difference is negligible.
The main issue are the heavy FCC imposed restrictions on transmit power that essentially ensures a lower effective SNR at all times due to a low transmit power.
The max transmit power for the AP is much lower,and client devices are required to use a 6dBm lower transmit power than the AP, this means that where your client device will top out at 1000mW (depending on what the RF front end the WiFi adapter maker goes with), that same client will be capped to a max of 125mW assuming a 160MHz channel width.
If the noise floor seen by the AP is low, then it is required to further reduce its transmit power, which in turn, with the 6dB rule, forced the client device to use a lower transmit power as well. the end result is far less range and a larger throughput dropoff with distance.
As more services are allowed to use the 6GHz band, the noise floor will increase for those wanting to use it for WiFi, but the low transmit power limits will mean that there will be less headroom for the AP and client to overcome that noise floor, thus lower and lower SNR.
As it is now, to get a faster and smoother 6GHz experience, you need to be within 10 ft and line of site to have a worthwhile throughput boost over 5GHz.
6GHz had a lot of potential but as it is now, it is far too crippled via nonsensical regulation.