802.11n and 802.11ac compatibility.

GotNoRice

GotNoRice

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I'm a bit confused about the extent to which these two technologies are compatible.

I know that N operates on both 2.4Ghz and 5Ghz, whereas AC operates only on 5Ghz. Yet many AC routers advertise as operating on both 2.4Ghz and 5Ghz. So what happens when you connect to an AC access point on 2.4Ghz? Does that operate using 802.11n?

What happens when you try to connect to an 802.11ac access point using an 802.11n client on 5Ghz? Is this possible, or are legacy connections only possible at 2.4Ghz?

I have a Netgear WNDR4500 (802.11n, dual band) currently that I am very happy with. I figure I will eventually switch over to AC. I'm trying to determine if I would be better off simply replacing the N unit with an AC unit, or running both (perhaps WNDR4500 to handle 2.4Ghz clients, AC access point to handle 5Ghz clients, or similar).

Any thoughts/advice?
 
Your over thinking it.

Let me sort this out for you...

The 802.11n wireless protocol can operate on both 2.4Ghz and 5Ghz in 20Mhz and 40Mhz channel widths.

The 802.11ac wireless protocol is capable of being used on both 2.4Ghz and 5Ghz, but is currently only implemented on 5Ghz at channel widths of 20-60Mhz

On a dual radio unit, you can connect with 802.11n on 2.4Ghz and 802.11ac on 5Ghz at the same time with no problems.


If you choose to connect both a 802.11n and 802.11ac clients to a 5Ghz 802.11ac access point you will see performance impacts when your 802.11n device is connected. This is because the 5Ghz radio will be bouncing back and forth between two different protocols which have a different level efficiencies related to each.

If you have no 802.11ac clients the AP will just operate in 802.11n mode and you will have normal 802.11n type performance.
 
Each connection will be made at the highest rate. AC router to AC access point is AC. AC Router to N access point is N. AC Routers are 100% compatible with all other connections. I have had AC for a while and AC to AC is REALLY fast!!!!
 
I have the asus g75vx with the broadcom 802.11ac card. I also have a dlink dgl-4500 router set at 2.4ghz. I get a lot of disconnects and dropped packets. Is this because the router is set at 2.4? I am trying to figure out if the router is to blame or the laptop. I can use the laptop elsewhere just fine even on 2.4ghz. Also, other wireless devices work fine on the dgl-4500. all firmware/drivers are on latest version.
I forgot to mention that if I set the dgl-4500 to 5ghz then it works fine. However, if I do that I cannot use any of my other devices because they are 2.4ghz
 
Last edited:
jsimms2 said:
I have the asus g75vx with the broadcom 802.11ac card. I also have a dlink dgl-4500 router set at 2.4ghz. I get a lot of disconnects and dropped packets. Is this because the router is set at 2.4? I am trying to figure out if the router is to blame or the laptop. I can use the laptop elsewhere just fine even on 2.4ghz. Also, other wireless devices work fine on the dgl-4500. all firmware/drivers are on latest version.
I forgot to mention that if I set the dgl-4500 to 5ghz then it works fine. However, if I do that I cannot use any of my other devices because they are 2.4ghz
Click to expand...
Is it connecting with AC at 2.4ghz? Or is it using N?

In my experience N @ 2.4GHz on most consumer routers/APs is garbage. On a DAP-2553 I was testing I got less than 1mbit/s on [email protected], and full speed on [email protected] from the same laptop.
May have been a bug in the Intel drivers, not sure, just my story. The UniFi's at work seem to do N over 2.4GHz just fine.
 
jsimms2 said:
I have the asus g75vx with the broadcom 802.11ac card. I also have a dlink dgl-4500 router set at 2.4ghz. I get a lot of disconnects and dropped packets. Is this because the router is set at 2.4? I am trying to figure out if the router is to blame or the laptop. I can use the laptop elsewhere just fine even on 2.4ghz. Also, other wireless devices work fine on the dgl-4500. all firmware/drivers are on latest version.
I forgot to mention that if I set the dgl-4500 to 5ghz then it works fine. However, if I do that I cannot use any of my other devices because they are 2.4ghz
Click to expand...


Any response we could offer would be a wild guess...

Run inSSIDer on a laptop and post the output for all three views. Once we have that... we can start to offer you specific advice.
 
I just set the dgl-4500 to 5ghz mode and hooked up an older router to serve the 2.4ghz devices. Thanks for the tip on inSSIDer I downloaded it and it shows me connected at n for some reason instead of a.
 
UPDATE: I installed the drivers for Atheros on ASUS website and now the laptop works on the old router even in 2.4ghz mode.
 
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