Moto X, multiple AC access points, & link speed issues.

[djjsin]

I'm having some interesting issues with the AC WiFi on my moto x and I don't even know where to begin to fix this.

I got multiple Asus rt-ac66u/r access points all set with different channels and the same SSID. When I connect my Moto X to the 5.0 AC WiFi, it properly connects to the closest Access Point and shows me a link speed of 433mbps (as it should). If I then walk to another room, I can tell by the signal meter when it switches access points (which it does properly), but from this point on the link speed will not go above 86mbps. If I turn the WiFi off and on (no matter which access point), it then properly reconnects to the closest access point, and the link speed is again 433mpbs....until I move and the device automatically switches Access Points.

Anyone got any ideas on this? How to continue to get a 433mbps link speed (when distance permits), even after the device has automatically switched from one access points to another?

I don't have any other AC devices to test, so kind if hard to pin point router or moto x issue.......though I'm leaning towards moto x issue since turning off WiFi and back on fixes the issue.

 

[grenefroggie]

Make sure nothing else is connected to the AP ever!

Now let me explain:

802.11 is kind of a crappy protocol when you get to understand it. It serves its purpose in home routers, and the average Joe doesn't really care what his modulation rate is. You however, are not the average Joe.

First off, what is your channel size? 802.11AC can only get it's maximum advertised throughput with a 160Mhz channel. Being that your max data rate you are seeing is 433Mbps tells me it is running in an 80Mhz channel using only on antenna.

What is the Gaurd Level set to in the router? I don't have an ASUS router, so I can't compare. The best router I have right now does 802.11N but only has two antennas, not three to make optimal use of the total 450Mbps modulation rate. If you Guard Level is set to 800ns as opposed to 400ns on the AP in question, then that could be an issue too.

What other devices are connected to the AP? If there is an N or A device connected to the AP, transmitting data, then it is going to transmit at the current modulation rate of the device connected.

Assume you have an N device connected with a poor signal, or at the least, a signal that will not allow the best possible modulation rate for N would explain why you are not getting 433Mbps, but only 86Mbps. Which would also mean that the Guard Level is most likely set to 400ns on that AP (it would seem it is on the main AP as well).

Last but not least, you could also have a bad AP. A loose antenna, maybe a blown radio. Not impossible, but not likely.

Those are just some ideas. I am not an expert on the 802.11 protocol, and AC is still new to me, I do work with 802.11 equipment every day. With that being said, I haven't had a chance to play with many 802.11AC APs because I do not own an AC device.....YET!

 

[djjsin]

That's for the message, its really annoying. I got a total of three of these Asus devices, and this happens no matter if my device is switching from A to B, B to C, C to A....doesn't matter what combination which instantly tells me its probably not something with bad hardware. All three units experience the same issue.

Yes it is running at 80mhz. All have the identical same settings, though I'm not fully familiar with the "guard level" I don't remember seeing that one in the firmware.

I've tried different firmwares in the routers. Custom firmwares. Dd-wrt....same issues everywhere.

I'm not a WiFi expert either. And it definitely appears to happen when one device automatically move from one access point to the other.

Plus, the fact that it works once powered off and then back on...no matter which access point its connected at that time, leads me away from the "problem with access point".


BTW, even though its switching automatically, using the router logs and the signal level, I know for a face which AP its connecting to each time.

I'm almost thinking its AC issue. Like its only connecting over the 5.0 20 band or something when it switches.


And BTW, I got no other 5.0 devices while doing my tests. Only the router/APs and the Moto Xs

 

[grenefroggie]

If the routers are dual-band, unless you have your phone set to only connect to 5Ghz, it will prefer 2.4Ghz because the scan list it uses to see which networks are available is smaller. Meaning you have from 2412-2462 (11 channels) to scan before you phone stops looking for networks. With 5Ghz you have 18 channels total making scan times longer an taking longer to display wireless networks. Are you ASUS routers set to transmit only 5Ghz? This could also be an issue.

Guard Level might not be a changeable setting in the firmware. It should be, but I cannot attest to that being the case.

 

[djjsin]

Ya, I have different ssids for the 2.4 and 5 networks, so I know its connected to the 5......

 

[grenefroggie]

What is the channel separation on the APs? If they overlap that could also prove to be an issue.

Do you have any friends with AC devices to try and replicate the issue? Try using one router and see if the problem still occurs. Try each AP to see what it does.

It very well could be the phone, I just hate to think the first issue is the phone.

 

[djjsin]

What is the channel separation on the APs? If they overlap that could also prove to be an issue.

Do you have any friends with AC devices to try and replicate the issue? Try using one router and see if the problem still occurs. Try each AP to see what it does.

It very well could be the phone, I just hate to think the first issue is the phone.

I've cut the number of access points down to 2. They are set at channels 36 and 149. There should be no overlapping. I've tested with other 5.0 devices, some N and some AC and here's what I found.

Laptops work great when roaming from one access point to the other. I see no problems what so ever. (I confirm the handoff when they roam by looking at Mac addresses connected via WiFi in the router logs)

When android devices roam, after the handoff, the connection is then stuck in 20mhz bandwidth until I power off the WiFi and power it back on.

I've confirmed this to happen on the Moto X connected via 5.0 AC WiFi, and the Nexus 7 connected via 5.0 N WiFi...

 

[grenefroggie]

That is super weird. With laptops you have no issues, but were they running N or AC? Looks like it could be an Android issue indeed. Any chance you might be able to try a Windows phone or an iPhone? Quite peculiar.