[ninjaef]

So my wifey bought me this new router. I've been moaning about the ISP provided crap for some time.

By the way, I am no expert!

So this router has three bands. Looking at the webGUI I see that it has a 2.4(GHz) band, a 5 band and a mixed 2.4/5 band. The 5 band has selectable 160MHZ and QAM support. The mixed band has upto 80Mhz and no QAM. Then there are settings for Tx/Rx (1-1, 2-2 and so on) and something i read online about Spatial Streams, and 2x2 and 3x3 and so on??

Please can someone explain in laymen terms , the following.
1. What do the frequency and QAM do?
2. What are spatial streams
3. What are theTx/Rx numbers
4. Is 160Mhz better than 80 and better than 40. some settings are mixed (dynamic, full, etc)
5. And how can i tell if my devices (Laptop, iPhone 8+ and iPad) can use fetaures in 1-4 above, and what settings do I need to apply for each band (radio)?


I have googled but the information is piecemeal, I havent been able to link it together to a point I understand, and I'm going round in circles. So I'm kinda hoping some nice chap will come on here and impart their wisdom by providing a considered response I can understand.

[ninjaef]

I found this, which explains perfectly.

https://www.intel.co.uk/content/www/uk/en/support/articles/000005725/network-and-i-o/wireless-networking.html

So in summary (for this router)
* The router will operate a number of WiFi bands.
* Each band can be configred for combinations of 40Mhz, 80Mhz or 160Mhz data channels.
* Each channel is further split into Multiple Input/Multipe Ouput or MIMO spatial streams
* It is advertised as 3200Mpbs (600 on the n band, 2600 on the ac band)
* So on the 802.11n band, the router must be 4x4 (4x150mpbs) = 600mpbs
* And on the 802.11ac band 160Mhz channel it must have a 2x2 on 160Mhz (2x866mbps) = 1732mbps
* And on the 802.11ac band 80Mhz channel it must be a 2x2 (2x433mpbs) = 866mbps

so taking those speeds together, that is 600 + 1732 + 866 = 3198mbps , or "3200"

* In order to use these combinations the CLIENT MUST be capable of using all streams and at the appropriate frequency?
* So my iPhone 6 Plus uses the Murata 339S0228 wifi chipset. This is based on a Broadcom BCM4339 which supports a lot of nice technologies, like LDPC, STBC, TurboQAM, but it is only 1 spatial stream (1x1, no MIMO) module. Which means on the ac band , it can only go as high as 80Mhz which means at 1x1 this is 433Mbps. Crap!
* I checked the chipsets of all my other clients....
* None of my clients can use the 160Mhz channel !
* Further, the most streams any of my clients have, is 2x2
* So in summary, the highest speed I will see on my ac band (theoretical) is 2x2 on the 80Mhz channel which is 866mbps

* And, so is the 160Mhz channel is completely useless for me, nothing will work on that channel?



Have I got it about correct?

[zakaron]

It sounds like you are on the right track. Just don't confuse channels with the MHz bandwidth. Channels are made up of frequency ranges which are in turn measure in MHz (or GHz). In the 2.4GHz user space, there are 3 non-overlapping channels: 1, 6, 11. If you are in a crowded area, all devices are trying to compete for space between these channels. That's why you should only use one of these 3 so you do not overlap and cause interference unnecessarily. being that each channel is divided into 5MHz bandwidth ranges, you can see that the base setting for the 2.4 radio is 20MHz (or 4 channels). So if you assign channel 6 with 20MHz, you will use channels 4-8 for your bandwidth range. If your neighbor uses channel 11 at 20MHz, he will use 9-13. This causes no overlap and a clean signal for both parties. If you are a "bad neighbor" and use 40MHz on channel 6, you have now added additional channels to increase your bandwidth, so you now are in the usable space of both channel 1 and 11. That's also why your performance may drop with 40MHz, because your devices now have to contend with additional interference. If you are out in the country with no one for miles, then you'll be fine to use 40MHz and enjoy the added bandwidth.
Now the 5GHz user space is much more spread out with a lot more frequency ranges and therefore channels. This is why you can more easily get away with using 80MHz width channel ranges and not cause interference, because it is so much more spread out.
Here's a good reference on the channel breakdown and visualization to understand the overlap better: https://en.wikipedia.org/wiki/List_of_WLAN_channels

Now as far as MIMO goes, that is just the ability to send or receive multiple signals at the same time over 1 channel. By adding more antennas to the router, it can cover more streams and therefore can communicate with multiple devices at the same time. By nature, radio transmission is half duplex. The antenna will either transmit or receive. By adding multiple transmit & receive antenna to these new routers, you can get a lot of clients connected and at fast speeds.
And yes, in order to take advantage of full AC at 160MHz, the client device needs to support the additional streams.

Oh, and this is what the Rx and Tx values you asked about earlier are - it just stands for receive (rx) and transmit (tx). You might find these listed as bytes or packets.

[aairon]

@ninjaef

VHT160 is not practical at this time.

Mu-mimo does not work with any third party firm/software builds at this time.

You need to read a lot, avoid soliciting answers, you may get a lot of confused answers from equally uninformed users.

I think you're far better off googling and piecing things together yourself.

Study it or your taking a big chance on random answers from complete strangers who may actually know nothing and just copy and paste answers.

[myersw]

[ninjaef]

I worked it out in the end.
But thanks for your considered replies

[myersw]

@=ninjaef